(ISSN 0892-1016) 


The 

Journal 

of 

Raptor Research 


March 1998 


Volume 32 


Number 1 


Contents 

Preface: Conservation and Ecology of Raptors in the Tropics. Richard t. 

Watson 1 

Conservation Status of Tropical Raptors. Keith l. Biidstein, Wendy Scheisky, jorje 

Zalles and Susie Ellis 3 

Conservation Status of Birds of Prey in the South American Tropics. 

Richard O. Bierregaard, Jr. 19 

Raptors in the East African Tropics and Western Indian Ocean Islands: 

State of Ecological Knowledge and Conservation Status. Munir virani and 
Richard T. Watson 28 

Current Status and Conservation of Falconiformes in Tropical Asia, jean- 

Marc Thiollay 40 

Tropical Forest Raptors in Indonesia: Recent Information on 

Distribution, Status, and Conservation, s. (Bas) van Baien 56 

Status and Conservation of Raptors in Australia’s Tropics. Nick Mooney 64 

BOOK Review. Edited by Jeffrey S. Marks 74 

Manuscript Referees 76 


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© This paper meets the requirements of ANSI/NISO Z39.48-1992 (Permanence of Paper). 


THE JOURNAL OF RAPTOR RESEARCH 

A QUARTERLY PUBLICATION OF THE RAPTOR RESEARCH FOUNDATION, INC. 
Vol. 32 March 1998 No. 1 

J. Raptor Res. 32(l):l-2 

© 1998 The Raptor Research Foundation, Inc. 

PREFACE 

CONSERVATION AND ECOLOGY OF RAPTORS IN THE TROPICS 

Richard T. Watson 

The Peregrine Fund, Inc., 566 W. Flying Hawk Lane, Boise, ID 83709 U.S.A. 


Tropical ecosystems contain the most biological- 
ly diverse habitats on earth (Wilson 1988). Over 
75% of the world’s endemic species occur in trop- 
ical regions (Bibby et al. 1992) and over 25% of 
the world’s ecoregions are in the tropics (Bailey 
1996). One such ecoregion, tropical rainforest, 
covers less than 10% of the earth’s land surface yet 
contains more than half of the species on earth. 
This is alarming because tropical ecosystems are 
disappearing faster than all other habitats around 
the world (Whitmore 1997). Their loss has pro- 
found implications for the conservation of the 
world’s biological diversity (Wilson 1988) . The loss 
of tropical forests is the most conspicuous threat, 
but the conversion of savanna areas to intensive 
agriculture is also a threat by reducing available 
habitat to nonforest species. 

With an estimated 90% of all species of raptors 
occurring, wholly or in part, in the tropics (Ken- 
nedy 1986), and 45% of all raptor species found 
in tropical rainforests (Thiollay 1994), the loss of 
tropical ecosystems is especially alarming for these 
birds. As top-order predators with low population 
densities, raptors are particularly sensitive to habi- 
tat loss. In addition to this sensitivity, their high 
visibility and general allure, make them ideal spe- 
cies for conserving critically-endangered habitats. 
Nevertheless, the distribution and status of many 
raptors are poorly known because many are secre- 
tive, forest-dwelling species (Meyburg and van Bal- 
en 1994, Thiollay 1994, van Balen 1994). 

Because of the need for more information on 
the current status of tropical raptors and threats 
that jeopardize their future survival, I organized 
this symposium as part of the 1996 joint meeting 
of the Raptor Research Foundation and American 


Ornithologists’ Union held in Boise, Idaho. Its pur- 
pose was to bring together currently active re- 
searchers from each of the tropical biogeograph- 
ical regions of the world to give first-hand accounts 
of the status of raptors in their region. Together, 
these papers represent a complete synthesis of the 
current state of knowledge and conservation status 
of the world’s raptors in the tropics. They provide 
information on distributions and population den- 
sities, taxonomy, breeding behavior, habitat re- 
quirements, and sensitivity to habitat modification 
that can be used to influence the future of raptor 
research and conservation in many of the world’s 
tropical areas. 

Acknowledgments 

This symposium was supported by the Peregrine Fund, 
Inc. Publication of this issue was funded in part by the 
Peregrine Find, Inc. and the Raptor Research Founda- 
tion, Inc. 

Literature Cited 

BAILEY, R.G. 1996. Ecosystem geography. Springer, New 
York, NY U.S.A. 

Bibby, C.J., N.J. Collar, M.J. Crosby, M.F. Heath, Ch. 
Imboden, T.H. Johnson, A.J. Long, A.J. Statters- 
field and S.J. Thirgood. 1992. Putting biodiversity 
on the map: priority areas for global conservation 
I.C.B.P., Cambridge, U.K. 

Kennedy, R.S. 1986. Raptors in the tropics — the next 50 
years. Raptor Res. Rep. 5:17-25. 

Meyburg, B.-U. and S. van Balen. 1994. Raptors on Su- 
lawesi (Indonesia): the influence of rainforest de- 
struction and human density on their populations. 
Pages 269-276 in B.-U. Meyburg and R.D. Chancellor 
[Eds.], Raptor conservation today. World Working 
Group for Birds of Prey and Owls, London, U.K. 


1 


2 


Watson 


Vol. 32, No. 1 


Thiollay, J.-M. 1994. A world review of tropical forest 
raptors: current trends, research objectives and con- 
servation strategy. Pages 231-239 in B.-U. Meyburg 
and R.D. Chancellor [Eds.], Raptor conservation to- 
day. World Working Group for Birds of Prey and Owls, 
London, U.K. 

van Balen, S. 1994. The status and conservation of birds 
of prey in the Sondaic and Wallacean regions of In- 
donesia. Pages 245-254 in B.-U. Meyburg and R.D. 
Chancellor [Eds.], Raptor conservation today. World 


Working Group for Birds of Prey and Owls, London, 
U.K. 

Whitmore, T.C. 1997. Tropical forest disturbance, dis- 
appearance, and species loss. In W.F. Laurence and 
R.O. Bierregaard, Jr. [Eds.], Tropical forest remnants: 
ecology, management, and conservation of fragment- 
ed communities. Univ. Chicago Press, Chicago, IL 
U.S.A. 

Wilson, E.O. 1988. Biodiversity. National Academy 
Press, Washington, DC U.S.A. 


J. Raptor Res. 32(1):3-18 

© 1998 The Raptor Research Foundation, Inc. 


CONSERVATION STATUS OF TROPICAL RAPTORS 1 

Keith L. Bildstein, Wendy Schelsky and Jorje Zalles 

Hawk Mountain Sanctuary, 1700 Hawk Mountain Road, Kempton, PA 19529 U.S.A. 

Susie Ellis 

IUCN Conservation Breeding Study Group, Minneapolis Zoo, Minneapolis, MN U.S.A. 


Abstract. — Seventy-six percent (222) of the world’s 292 species of diurnal raptors are found mainly or 
completely in the tropics. Forty-six percent of all tropical raptors are threatened by habitat loss, 11% by 
environmental contaminants, and 19% by direct persecution. Seventeen percent are threatened by two 
of these factors, 2% by all three factors. Regionally, 42% of all Neotropical, 60% of all Afrotropical, 60% 
of all Indomalayan, and 77% of all Australotropical raptors are threatened by one of more of these 
factors. IUCN classifies 27% of all tropical raptors (59 species) as Near Threatened, Vulnerable, Endan- 
gered, or Critically Endangered. Similar statistics are 23% (17 of 73 species), 14% (11 of 80 species), 
33% (21 of 63), and 34% (12 of 35), for the Neotropical, Afrotropical, Indomalayan, and Australotrop- 
ical regions, respectively. Thirty percent of all tropical raptors are endemics. Fifty-seven percent of all 
tropical raptors are complete, partial, or irruptive migrants. The degree of endemism and migration 
behavior varies among the four regions. Although some of the regional differences in conservation 
status reflect regional differences in knowledge, many appear to reflect ecological differences among 
the four regions. 

Key WORDS: Conservation status ; tropics ; tropical raptors', endemics', migration. 


Estado de conservacion de las aves rapaces tropicales 

Resumen. — Setenta y seis por ciento (222) de las especies de aves rapaces diurnas del mundo (292) se 
encuentran en los tropicos. Cuarenta y seis por ciento de todas las aves rapaces tropicales estan amen- 
azadas por la perdida de habitat, 11% por contaminantes ambientales y 19% por persecution directa. 
Diez y siete por ciento estan amenazadas por dos de estos factores, 2% por los tres factores. Regional- 
mente, 42% de todas las aves rapaces neotropicales, 60% de todas las afrotropicales, 60% de todas las 
indomalayas y 77% de todas las especies tropicales de Australia estan amenazadas por uno o mas de 
estos factores. La IUCN clasifica el 27% de todas las aves rapaces tropicales (59 especies) como Cercan- 
amente Amenazadas, Vulnerables, Amenazadas, o Crfticamente Amenazadas. Estadisticas similares in- 
dican 23% (17 de 73 especies), 14% (11 de 80 especies), 33% (21 de 63) y 34% (12 de 35), para las 
regiones neotropical, afrotropical, indomalayay australiana respectivamente. Treinta por ciento de todas 
las aves rapaces tropicales son endemicas. Cincuenta y siete por ciento de todas las aves rapaces tropi- 
cales son migratorias totalmente, parcialmente o en forma irruptiva. El grado de endemismo y com- 
portamiento migratorio varia entre las cuatro regiones. Aunque las diferencias regionales en el estado 
de conservacion reflejan las diferencias regionales de conocimiento, parece que tambien son el reflejo 
de las diferencias ecologicas entre las cuatro regiones. 

[Traduction de Cesar Marquez] 


Tropical ecosystems are some of the most bio- 
logically diverse habitats on earth (Wilson 1988). 
Seventy-six percent of all centers of avian endem- 
ism (e.g., “endemic bird areas,” Bibby et al. 1992) 
occur in tropical regions, and the same is true for 
many plant and animal taxa (Gentry 1986, Mc- 


1 This paper is dedicated to the memory of Hawk Moun- 
tain Sanctuary’s longtime friend, Roger Tory Peterson. 


Neely et al. 1988, Myers 1988, Thirgood and Heath 
1994). Biogeographically, 27% (8 of 30) of the 
world’s ecoregions are represented in the tropics 
(Bailey 1996). Tropical rainforests, which cover 
only 7% of the earth’s land surface, are estimated 
to contain more than half of the world’s species 
(Wilson 1988). 

Previous studies suggest that 90% of all species 
of raptors occur, wholly or in part, in the tropics 


3 


4 


Bildstein et al. 


Vol. 32, No. 1 


(Kennedy 1986) , and that 45% of all species of rap 
tors occur in tropical rainforests (Thiollay 1985a, 
1994). Half of all tropical countries have at least 
50 species of raptors (Table 1). 

Many tropical raptors, especially forest dwellers, 
are secretive and difficult to study. The distribution 
and status of many species are poorly known (Mey- 
burg and van Balen 1994, Thiollay 1994, van Balen 
1994; but see Thiollay 1985b, Kennedy 1986, Burn- 
ham et al. 1994, Watson and Lewis 1994). Even so, 
several patterns are apparent. The major threat to 
tropical raptors is habitat destruction (Thiollay 
1989a, 1992, 1994), followed by environmental 
contamination and shooting (Thiollay 1985a). 
Overall, endemic species are more likely to be 
threatened, as are nonmigratory and Old World 
species. 

Previous studies of tropical raptors have focused 
on individual species, countries, regions, or habitat 
types (e.g., Meyburg and Chancellor 1989, 1994, 
Baker-Gabb 1994, Thiollay 1994, van Balen 1994, 
and references therein). We use these and other 
published sources, including del Hoyo et al. (1994), 
together with the unpublished IUCN Raptor Con- 
servation Assessment and Management Plan and 
Hawk Mountain Sanctuary Hawks Aloft Worldwide 
databases, to proride an overview of raptor diver- 
sity and conservation status in the tropics. 

Specifically, we assess regional differences and 
the influence of ecological circumstances on the 
conservation status of tropical species. We detail 
the distribution of the world’s tropical raptors re- 
gionally, assess regional differences in diversity and 
conservation status, and determine the extent to 
which endemism and migratory behavior are as- 
sociated with conservation status. We also discuss 
how conservationists can better protect tropical 
raptors. Because our focus is global and regional, 
individual species are mentioned in the text only 
as examples of general patterns. A list of the con- 
servation status of individual species appears in Ap- 
pendix 1. 

Study Area and Methods 

The Tropics Defined. Geographically, the tropics in- 
clude regions on both sides of the Equator extending to 
23.5°N and S (the Tropics of Cancer and Capricorn, re- 
spectively). Terrestrial ecosystems within the region are 
characterized by near constant day lengths, relatively 
high solar radiation, and, when adjusted for altitude, rel- 
atively high diurnal and nocturnal temperatures (Desh- 
mukh 1986). Although the tropics have a somewhat more 
complex ecological definition that takes climate, as well 
as geography, into account (Deshmukh 1986, Bailey 


1996), the regions defined both ways are largely coinci- 
dent. We define the earth’s four tropical regions, the 
Neotropics, Afrotropics, Indomalayan Region, and Aus- 
tralotropics, geographically as the land masses between 
the Tropics of Cancer and Capricorn in each of these 
four regions. 

Approximately 85% of the Neotropics is in the Humid 
Tropical Domain ecoregion (Bailey 1996), of which 
slightly more than half is savanna; the remainder is trop- 
ical rainforest. Dry Domain ecoregions in the Neotropics 
include both steppe and desert. Overall, approximately 
40% of the Neotropics is in the Tropical Rainforest ecore- 
gion. 

The Afrotropics include the southern half of the Ara- 
bian Peninsula and most of Africa and Madagascar. Ap- 
proximately 55% of the region is in the Humid Tropical 
Domain ecoregion (Bailey 1996). Dry Domain ecore- 
gions in the Afrotropics are mainly deserts, including the 
southern Sahara and the Namib, with some steppe. Ap- 
proximately 10% of the Afrotropics is in the Tropical 
Rainforest ecoregion. 

The Indomalayan tropics cover much of southeast Asia 
and neighboring islands. More than 95% of the region 
is in the Humid Tropical Domain ecoregion (Bailey 
1996) , of which half is savanna, and half is rainforest. Dry 
Domain ecoregions are limited to eastern India. Overall, 
approximately 50% of the Indomalayan region is in the 
Tropical Rainforest ecoregion. 

The Australotropics include the Moluccas, parts of Aus- 
tralia, and all of New Guinea. Approximately 60% of the 
region is part of the Humid Tropical Domain (Bailey 
1996), slightly more than half of which is savanna. Dry 
Domain areas of the Australotropics include tropical por- 
tions of the Great Sandy Desert of interior Australia, and 
its associated steppes. Approximately 30% of the Austral- 
otropics is in the Tropical Rainforest ecoregion. 

Tropical Raptors Defined. We consider raptors to be 
members of the avian families Accipitridae, Sagittariidae, 
and Falconidae; and the avian subfamily Cathartinae 
(Sibley and Monroe 1990), the birds that most authori- 
ties call diurnal raptors (Brown and Amadon 1968, Ama- 
don and Bull 1988, del Hoyo et al. 1994, Griffiths 1994). 
For our purposes, tropical raptors include the subset of 
these 292 species (Amadon and Bull 1988) whose com- 
bined breeding and nonbreeding distributions, as de- 
tailed in del Hoyo et al. (1994), occur wholly or mainly 
(>50%) within the tropics. Species (e.g., Swainson’s 
Hawk [Buleo swainsoni\) , whose migratory routes include 
the tropics, but whose breeding and nonbreeding ranges 
lie wholly or mainly outside of the tropics, are not in- 
cluded as tropical raptors. 

Endemic Raptors Defined. As a group, raptors are rel- 
atively large, frequently migratory birds that occur at low 
densities across large areas. Few can be characterized as 
restricted-range, or endemic species (e.g., species with 
breeding ranges below 50 000 km 2 , Bibby et al. 1992). 
Even so, some species have relatively small ranges com- 
pared with others. Such species often are used as “um- 
brella” or “flagship” species for local and regional con- 
servation efforts (e.g., Philippine Eagle [Pithecophaga jef- 
feryi, Kennedy 1983], Barred Forest-falcon [Micrastur ruf- 
icollis, C. Marquez, pers. comm.], Mauritius Kestrel [Falco 
punctatus, Jones 1981]). Here, we consider endemic spe- 


March 1998 


Status of Tropical Raptors 


5 


Table 1. Wholly and mainly tropical countries with at least 50 species of raptors; together with the migration, 
distribution, and conservation status ( sensu Collar et al. 1994) of those raptors. 


Number of Species 


Near 

Critically 

Country 

Total (Migrants) 

Endemics 

Vulnerable Threatened Endangered Endangered 

Neotropics 


Argentina 

61 (39) 


1 

10 


Bolivia 

68 (40) 


1 

7 


Brazil 

66 (39) 

1 

2 

7 


Colombia 

75 (43) 

1 


10 

1 

Costa Rica 

53 (34) 


6 


Ecuador 

72 (37) 

4 

1 

9 

2 

French Guiana 

55 (31) 


5 


Guyana 

50 (30) 


6 


Mexico 

54 (41) 


4 


Panama 

57 (34) 


7 


Paraguay 

51 (37) 


1 

6 


Peru 

57 (38) 

2 


9 

1 

Venezuela 

75 (38) 


8 


Afro tropics 


Angola 

58 (47) 


1 

1 


Botswana 

54 (47) 


2 

1 


Burundi 

54 (34) 


1 

1 


Cameroon 

59 (47) 


1 

1 


Central African 


Republic 

55 (43) 


1 

1 


Chad 

52 (47) 


1 

1 


Djibouti 

50 (47) 


2 

1 


Ethiopia 

71 (61) 


4 

1 


Ivory Coast 

50 (38) 


1 

1 


Kenya 

72 (62) 


3 

2 


Madagascar 

16 (4) 

11 


3 

2 

Malawi 

56 (46) 


2 

1 


Mozambique 

60 (50) 


3 

2 


Namibia 

56 (47) 


2 

2 


Nigeria 

59 (47) 


1 

1 


Senegal 

51 (44) 


1 

1 


Sudan 

74 (64) 


3 

1 


Tanzania 

69 (58) 


2 

2 


Uganda 

71 (59) 


1 

1 


Zaire 

65 (52) 


1 


Zambia 

58 (49) 


2 

1 

Zimbabwe 

56 (47) 


2 

2 

Indomalayan 


India 

63 (59) 

3 

4 

14 


Indonesia 

62 (51) (39 [39] ) a 

16 (8) 

2 (1) 

8 (6) 

1 (1) 

Myanmar 

52 (47) 


4 

10 


Australotropical 


Indonesia 

62 (33) (39 [22] ) a 

16 (9) 

2 (1) 

8 (2) 

1 (0) 


a Indonesia, which spans the Indomalayan and the Australotropical regions, appears twice in the table. The data presented above 
represent country- and (tropical-region) totals. 


6 


Bildstein et al. 


Vol. 32, No. 1 


Table 2. Distribution of the world’s diurnal raptors as a function of tropical distribution. Taxonomy based on 
Amadon and Bull (1988); distribution based on del Hoyo et al. (1994). 


Number of Species (%) a 

Extent of Range in Tropics 

Worldwide 

Neotropics 

Afrotropics 

Indomalayan 

Australotropics 

All of range 

78 (27%) 

20 (22%) 

17 (15%) 

22 (26%) 

20 (41%) 

More than half of range 

144 (49%) 

53 (58%) 

63 (56%) 

41 (49%) 

15 (31%) 

Less than half of range 

60 (21%) 

19 (21%) 

32 (29%) 

21 (25%) 

14 (29%) 

None of range 

10 (3%) 


Total 

292 

92 

112 

84 

49 


a Worldwide percentages represent proportions of all species, including those that occur only outside of the tropics. Regional per- 
centages represent proportions of species of raptors from that region. 


cies to be raptors whose overall ranges are limited to one 
or two countries. We consider endemic genera to be gen- 
era that occur in only one tropical region. 

Threats to Tropical Raptors. Human threats to tropical 
raptors include habitat destruction and fragmentation, 
pollution and pesticide use, and direct human persecu- 
tion (Newton and Chancellor 1985, Diamond and Love- 
joy 1985, Meyburg and Chancellor 1989, 1994, and ref- 
erences therein). 

Statistical Tests. We used log-likelihood ratio (G) tests 
with Yates correction in tests where df = 1 (Zar 1984), 
to assess regional differences in the endemic, migration 
and conservation status of tropical raptors, as well as to 
determine the extent to which endemism and migration 
were associated with differences in the conservation sta- 
tus of the birds. In all analyses, differences were consid- 
ered significant if P < 0.05. 

Results 

Distribution, Endemism, and Migratory Status. 

Seventy-eight species of raptors (27%) occur whol- 
ly within the tropics. An additional 144 species 
(49%) occur mainly within the tropics. Overall, 
282 species (97%) of the world’s raptors have 


breeding or wintering distributions that occur, at 
least in part, within one or more tropical regions 
(Table 2). Seven countries have 70 or more species 
of tropical raptors (Table 1). The distribution and 
status of the world’s 222 wholly or mainly tropical 
raptors appear in Appendix 1. 

Raptor faunas differ considerably among the 
four regions. Eighty-nine percent of tropical rap- 
tors occur in a single tropical region, and except 
for the contiguous Indomalayan and Australotrop- 
ical regions, there is little species overlap among 
regions (Table 3). Regional faunal specificity is 
greatest in the Neotropics, where 72 of 73 species 
have tropical distributions restricted to that region; 
the single exception being the nearly cosmopolitan 
Osprey ( Pandion haliaetus) (Table 3). Twenty-six 
Neotropical genera (50 species) occur only in that 
tropical region, compared with 12 (19), 5 (10), 
and 4 (5), genera (species), respectively, in the Af- 
rotropics, Indomalayan Region, and Australotrop- 
ics (Table 4). 


Table 3. Regional distribution of tropical raptors. Species with region-restricted ranges are those that occur in only 
one tropical region. Widespread species occur in more than one tropical region. 


Number of Species 

(%) 


Extent of Range 

Worldwide 

Neotropics 

Afrotropics 

Indomalayan 

Australotropics 

Wholly tropical raptors 

Region-restricted 

77 (99%) 

20 (100%) 

17 (100%) 

21 (95%) 

19 (95%) 

Widespread 

1 (1%) 

0 

0 

1 (5%) 

1 (5%) 

Mainly tropical raptors 

Region-restricted 

121 (84%) 

52 (98%) 

48 (76%) 

18 (44%) 

3 (20%) 

Widespread 

23 (16%) 

1 (2%) 

15 (24%) 

23 (56%) 

12 (80%) 

Wholly and mainly tropical raptors 
Region-restricted 198 (89%) 

72 (99%) 

65 (81%) 

39 (62%) 

22 (63%) 

Widespread 

24 (11%) 

1 (1%) 

15 (19%) 

24 (38%) 

13 (37%) 


March 1998 


Status of Tropical Raptors 


7 


Table 4. Distribution of tropical endemics. Endemic 
species are species whose range is restricted to one, or at 
most, two countries; endemic genera are genera restrict- 
ed to one tropical region. 


Region 

Number (%) 
Endemic Species 

Number (%) 
Endemic Genera 

Neotropics 

7 (10%) (a)* 

26 (76%) (a) 

Afrotropics 

12 (15%) (a) 

12 (38%) (b) 

Indomalayan 

18 (29%) (b) 

5 (21%) (b) 

Australotropics 

22 (63%) (c) 

4 (25%) (b) 

All regions 

67 (30%) 

47 (70%) 


a Regions with the same letters are not significantly different 
from one another (log-likelihood ratio [G] test; species: df = 1; 
P < 0.05; genera: df = 1; P < 0.05). 


Endemism is high in tropical raptors. Fifty-six 
percent of all wholly tropical raptors (44 of 78 spe- 
cies) occur in only one or two countries, compared 
with only 12% of all other raptors (log-likelihood 
ratio test: G — 54.3, df — 1, P < 0.001). The Aus- 
tralotropics have more endemic species than any 
other tropical region (vs. Neotropics: log-likeli- 
hood ratio test: G = 30.7, df = 1, P < 0.001; vs. 
Afrotropics: G = 23.6, df = 1 , P < 0.001; vs. In- 
domalayan: G — 9.6, df = 1, P < 0.005; Table 4). 

Ninety-one percent of all endemic tropical rap- 
tors (51 of 58 species) occur on islands, mainly in 
the Indian and South Pacific oceans. Three coun- 
tries, Indonesia (16), Papua New Guinea (14), and 
Madagascar (11), together have 41 species of en- 
demic raptors. 

Nine percent of all wholly, and 32% of all mainly 
tropical raptors, are complete or partial migrants 
(Kerlinger 1989). An additional 6% and 24%, re- 
spectively, are local or irruptive migrants (Table 5) . 
There are significantly more migratory raptors (lo- 
cal-irruptive species included) in the Afrotropics 
than in any other tropical region (vs. Neotropics: 
log-likelihood ratio test: G = 17.4, df = 1, P < 


0.001; vs. Indomalayan: G = 4.8, df = 1, P < 0.05; 
vs. Australotropics: G = 11.5, df = 1, P < 0.001; 
Table 5). 

Conservation Status. More than half of all trop- 
ical raptors are threatened by habitat loss, environ- 
mental contaminants, direct persecution, or com- 
binations of these factors (Table 6). Habitat loss 
appears to be the greatest threat (habitat loss vs. 
environmental contaminants: log-likelihood ratio 
test: G = 69.3, df = 1, P < 0.001; habitat loss vs. 
direct persecution: G = 35.2, df = 1, P < 0.001; 
Table 6). Neotropical raptors appear to be less 
threatened than those from other tropical regions 
(Table 6) . Direct persecution, especially, appears to 
occur less in the Neotropics than in other tropical 
regions (Table 6). Environmental contaminants, 
including pesticides, appear to be particularly im- 
portant threats in the Australotropics (Table 6) . 

Thirty-seven species of wholly or mainly tropical 
raptors (17% of the world’s tropical raptors) are 
listed as Critically Endangered, Endangered, or 
Vulnerable (Collar et al. 1994; Table 7). An addi- 
tional 22 species (10%) are listed as Near Threat- 
ened. Two species are listed as data deficient (Ta- 
ble 7) . Wholly tropical raptors appear be at greater 
risk than are mainly tropical raptors (log-likeli- 
hood ratio test: G = 17.1, df = 1 , P< 0.001; Table 
7). Nonmigratory species appear to be at greater 
risk than migratory ones (log-likelihood ratio test: 
G = 19.3, df = 1, P< 0.001; Table 8). Forty (68%) 
of all Threatened and Near Threatened species are 
forest-dependent (Appendix 1). Twenty-eight at- 
risk species (47%) are restricted to islands. Twenty- 
one at-risk species (36%) are both forest-depen- 
dent and island-restricted. 

Countries with Endangered or Critically Endan- 
gered tropical raptors include Colombia (1 Endan- 
gered, 0 Critically Endangered), Cuba (1,0), Do- 
minican Republic (1,0), Ecuador (2,0), Haiti (1,0), 
Peru (1,0), Madagascar (0,2), Mauritius (1,0), In- 


Table 5. Migratory status of wholly and mainly tropical raptors. Status is based primarily on Kerlinger (1989) , as 
modified by del Hoyo et al. (1994) and Hawks Aloft Worldtvide. 


Migratory Status 

Worldwide 

Neotropics 

Afrotropics 

Indomalayan 

Australotropics 

Complete 

11 (5%) 

2 (3%) 

7 (9%) 

7 (11%) 

3 (9%) 

Partial 

61 (27%) 

16 (22%) 

33 (41%) 

21 (33%) 

7 (20%) 

Local-irruptive 

54 (24%) 

16 (22%) 

24 (30%) 

11 (17%) 

6 (17%) 

Total migratory 

126 (57%) 

34 (47%) (a) a 

64 (80%) (b) 

39 (62%) (a) 

16 (46%) (a) 

Nonmigratory 

96 (43%) 

39 (53%) 

16 (20%) 

24 (38%) 

19 (54%) 


a Regions with the same letters are not significantly different from one another (log-likelihood ratio [G] test; df = 1; P < 0.05). 


8 


Bildstein et al. 


Vol. 32, No. 1 


Table 6. Threats to tropical raptors. Threats are based, principally, on information in del Hoyo et al. (1994). 


Number of Species Affected (%) 

Threat 

Worldwide 

Neotropics 

Afrotropics 

Indomalayan 

Australotropics 

Wholly tropical raptors 


Habitat loss 

Environmental contami- 

38 (49%) 

7 (35%) 

10 (59%) 

8 (36%) 

14 

(70%) 


nants 

6 (8%) 

0 

2 (12%) 

0 

4 

(20%) 


Direct persecution 
Total number of species 

10 (13%) 

1 (5%) 

2 (12%) 

2 (9%) 

5 

(25%) 


affected 

40 (51%) 

7 (35%) 

11 (65%) 

8 (36%) 

15 

(75%) 


Number of species affected by: 


two threats 

12 (15%) 

1 (5%) 

3 (18%) 

2 (9%) 

6 

(30%) 


three threats 

1 (1%) 

0 

0 

0 

1 

(5%) 


Mainly tropical raptors 


Habitat loss 

Environmental contami- 

64 (44%) 

20 (38%) 

25 (40%) 

26 (63%) 

8 

(53%) 


nants 

18 (13%) 

6 (11%) 

10 (16%) 

7 (17%) 

5 

(33%) 


Direct persecution 
Total number of species 

33 (23%) 

5 (9%) 

22 (35%) 

13 (32%) 

8 

(53%) 


affected 

81 (56%) 

24 (45%) 

37 (59%) 

30 (73%) 

12 

(80%) 


Number of species affected by: 


two threats 

26 (18%) 

6 (11%) 

16 (25%) 

10 (24%) 

4 

(27%) 


three threats 

4 (3%) 

0 

2 (3%) 

3 (7%) 

2 

(13%) 


Wholly and mainly tropical raptors 


Habitat loss 

Environmental contami- 

102 (46%) 

27 (37%) (a) a 

35 (44%) (a, b) 

l 34 (54%) (a, b) 

22 

(63%) 

(b) 

nants 

24 (11%) 

6 (8%) (a) 

12 (15%) (a, b) 

l 7 (11%) (a) 

9 

(26%) 

(b) 

Direct persecution 
Total number of species 

43 (19%) 

6 (8%) (a) 

24 (30%) (b) 

15 (24%) (b) 

13 

(37%) 

(b) 

affected 

121 (55%) 

31 (42%) (a) 

48 (60%) (b) 

38 (60%) (b) 

27 

(77%) 

(b) 

Number of species affected by: 


two threats 

38 (17%) 

7 (10%) 

19 (24%) 

12 (19%) 

10 

(29%) 


three threats 

5 (2%) 

0 

2 (3%) 

3 (5%) 

3 

(9%) 


a Regions with the same letters are not significantly different from one another (log-likelihood ratio [G] test; df = l ;P< 0.05). 


donesia (1,0), the Philippines (0,1), Papua New 
Guinea (1,0), and the Solomon Islands (1,0) (Col- 
lar et al. 1994). 

Discussion 

Our analyses demonstrate several patterns that 
should be of use to conservationists. They show 
that there are high levels of within-country diver- 
sity and endemism in all tropical regions, there is 
high congruence of raptor species diversity and en- 
demism with those of other taxa, there is an indi- 
cation that habitat loss (as opposed to environ- 
mental contaminants and direct persecution) pos- 
es the greatest threat, there are associations be- 


tween at-risk conservation status and endemism, 
sedentary behavior, forest-dependence and island- 
dwelling, and there are significant regional differ- 
ences in the extent of migration behavior, endem- 
ism, and conservation status. 

Diversity and Endemism in Tropical Raptors. 
More than three-quarters of the world’s diurnal 
birds of prey occur wholly or mainly within the 
tropics, and more than one-third of these occur 
only within this region. Three “megadiversity” 
countries ( sensu Mittermeier 1988) in the Neotrop- 
ics (Colombia, Ecuador, and Venezuela) and four 
in the Afrotropics (Ethiopia, Kenya, Sudan, and 
Uganda) each contain 70 or more species of rap- 


March 1998 


Status of Tropical Raptors 


9 


Table 7. Conservation status of tropical raptors based on Collar et al. (1994). 


Conservation Status 

Worldwide 

Neotropics 

Afrotropics 

Indomalayan 

Australo- 

TROPICS 

Wholly tropical raptors 

Critically endangered 

3 (4%) 

0 

2 (12%) 

1 (5%) 

0 

Endangered 

6 (8%) 

3 (15%) 

1 (6%) 

1 (5%) 

1 (5%) 

Vulnerable 

7 (9%) 

1 (5%) 

0 

3 (14%) 

3 (15%) 

Total Threatened 

16 (21%) 

4 (20%) 

3 (18%) 

5 (23%) 

4 (20%) 

Near Threatened 

18 (23%) 

3 (15%) 

1 (6%) 

8 (36%) 

6 (30%) 

Not Threatened 

42 (53%) 

13 (65%) 

13 (76%) 

8 (36%) 

9 (45%) 

Insufficient data 

2 (3%) 

0 

0 

1 (5%) 

1 (5%) 

Mainly tropical raptors 

Critically Endangered 

0 

0 

0 

0 

0 

Endangered 

1 (1%) 

0 

0 

0 

1 (7%) 

Vulnerable 

5 (3%) 

2 (4%) 

2 (3%) 

0 

1 (7%) 

Total Threatened 

6 (4%) 

2 (4%) 

2 (3%) 

0 

2 (13%) 

Near Threatened 

19 (13%) 

8 (15%) 

5 (8%) 

8 (20%) 

0 

Not Threatened 

119 (83%) 

43 (81%) 

56 (89%) 

33 (80%) 

13 (87%) 

Insufficient data 

0 

0 

0 

0 

0 

Wholly and mainly tropical raptors 
Critically Endangered 3(1%) 

0 

2 (3%) 

1 (2%) 

0 

Endangered 

7 (3%) 

3 (4%) 

1 (1%) 

1 (2%) 

2 (6%) 

Vulnerable 

12 (5%) 

3 (4%) 

2 (3%) 

3 (5%) 

4 (11%) 

Total Threatened 

22 (10%) 

6 (8%) 

5 (6%) 

5 (8%) 

6 (17%) 

Near Threatened 

37 (17%) 

11 (15%) 

6 (8%) 

16 (25%) 

6 (17%) 

Not Threatened 

161 (73%) 

56 (77%) 

69 (86%) 

41 (65%) 

22 (63%) 

Insufficient data 

2 (1%) 

0 

0 

1 (2%) 

1 (3%) 


tors and have at least one-quarter of the world’s 
raptor species each. Fourteen rainforest “hot 
spots” (Myers 1988) which together comprise less 
than 1 % of the earth’s land surface contain more 
than 30% of the world’s raptor species (Thiollay 
1994). 

Tropical islands, many of whose natural habitats 
have been or are being destroyed (Green and Suss- 


Table 8. Conservation status of nonmigratory and mi- 
gratory wholly and mainly tropical raptors compared 
(conservation status based on Collar et al. [1994]). 


Conservation Status 

Non- 

migratory 

Migratory 

Critically endangered 

3 (3%) 

0 

Endangered 

6 (6%) 

1 (1%) 

Vulnerable 

7 (7%) 

5 (4%) 

Total threatened 

16 (17%) 

6 (5%) 

Near threatened 

24 (25%) 

13 (10%) 

Not threatened 

54 (56%) 

107 (85%) 

Insufficient data 

2 (2%) 

0 


man 1990, Hannah et al. 1994), host 24% (18 spe- 
cies) of all Threatened and Near Threatened spe- 
cies of raptors. 

The tropics are home to most of the world’s en- 
demic raptors, as well as to most of its endangered 
species. Indonesia, alone, has 24% (16 of 67 spe- 
cies) of all endemic birds of prey. Indeed, one rea- 
son for the high species diversity of tropical raptors 
is high regional endemism. For example, while the 
Nearctic and Western Palearctic share 11% (8 spe- 
cies) of their combined raptor faunas, their tropi- 
cal counterparts (e.g., the Neotropics and Afro- 
tropics) share less than 1% (1 of 152) of their com- 
bined faunas. Although overlap among the Afro- 
tropics, Indomalayan Region, and Australo tropics 
is higher than that between these regions and the 
Neotropics (Table 3), differences in faunal com- 
position among tropical regions is extensive, over- 
all. Seventy percent of all tropical genera (47 of 
67) occur in a single tropical region. 

Congruence of Raptor Diversity with Biodiver- 
sity in Other Groups of Plants and Animals . Geo- 


10 


Bildsteim et al. 


Vol. 32, No. 1 


graphic centers of raptor diversity and species en- 
demism are highly congruent with those for many 
groups of plants and animals (Gentry 1986, Mc- 
Neely et al. 1988, Myers 1988, Bibby et al. 1992, 
Thirgood and Heath 1994). Countries with ex- 
tremely high raptor diversity, as well as centers of 
raptor endemism, are important conservation sites 
for plants and other animals, too. 

Principal Threats to Raptors. Habitat loss re- 
mains the principal threat to tropical raptors. Many 
natural ecosystems in the region are being con- 
verted to human-dominated landscapes (Myers 
1984). A recent global analysis of human habitat 
disturbance (Hannah et al. 1994), for example, 
suggests that the Indomalayan and Afrotropical 
realms are the two most disturbed biogeographical 
realms ( sensu Udvardy 1975) on earth. Many bio- 
geographical provinces, including the Cuban and 
Greater Antillean provinces in the Neotropics, the 
Malagasy woodland-savanna province in the Afro- 
tropics, and the Java and Philippines province in 
the Indomalayan Realm, are overwhelmingly dom- 
inated by human landscapes (Hannah et al. 1994) . 
Many disturbed provinces harbor endemic and at- 
risk species of raptors. Because many tropical hab- 
itats are only now being threatened by human dis- 
turbance (Hannah et al. 1994), habitat loss will re- 
main a principal concern for some time. 

Overall, 68% of all Threatened and Near Threat- 
ened tropical raptors are forest-dependent species. 
Many of these species require enormous tracts of 
contiguous forest (Thiollay 1989a, 1993), and are 
thus particularly vulnerable to habitat loss (Dia- 
mond and Lovejoy 1985, Meyburg and Chancellor 
1989, 1994, and references therein). All but one of 
Australia’s 15 Threatened raptors are forest dwell- 
ers (Baker-Gabb 1994). 

Almost half (28 of 59 species) of all Threatened 
and Near Threatened tropical raptors are restrict- 
ed to islands. Current levels of habitat degradation 
on tropical islands (Hannah et al. 1994), together 
with the recent history of human-induced avian ex- 
tinctions at such sites (Moors 1985, Temple 1986, 
Wotzkow 1994), suggests that these species, too, are 
at high risk. 

Gregarious and nomadic, open-habitat species, 
including those that depend upon superabundant 
prey associated with seasonally fluctuating wetlands 
(e.g., Snail Kites [Rostrhavnus sociabilis]) , and upon 
swarming locusts (e.g., Montagu’s [Circus py gar gus\ 
and Pallid Harriers [C. macrourus], Swainson’s 
Hawks, Western [Falco vespertinus ] and Eastern 


Red-footed Falcons [F amurensis ], and Lesser Kes- 
trels [F. naumanni ] ) , also appear to be particularly 
vulnerable to habitat loss and degradation. Be- 
cause members of these species operate over enor- 
mous ecological neighborhoods, local habitat loss 
can significantly affect regional, and even conti- 
nental populations of these raptors (Bucher 1992) . 
The social nature of these species, together with 
the fact that they frequently feed on prey that are 
considered agricultural pests, means that large 
numbers can be poisoned by a single pesticide ap- 
plication (Thiollay 1989b, del Hoyo et al. 1994, 
Woodbridge et al. 1995). Even when individuals 
are not poisoned, large-scale efforts to remove in- 
sect pests, including swarming locusts from tropical 
regions, can threaten these species by significandy 
reducing prey availability (Thiollay 1989b). 

Overall, the increasing use of agricultural pesti- 
cides in many tropical countries (Goulston 1996) 
suggests that this threat, which has long been a 
concern in temperate agriculturalized countries 
(Hickey 1969, Cooke et al. 1982), is likely to in- 
crease. Tropical raptors also are threatened by the 
use of pesticides to control insect vectors of human 
diseases (Thiollay 1989b). 

Although direct persecution as a threat to trop- 
ical raptors appears to be decreasing overall 
(Thiollay 1994), shooting remains a threat in cer- 
tain countries (van Balen 1994, Bildstein et al. 
1995). Social species such as vultures, and species 
that flock on migration or that roost communally, 
as well as those that are considered to be agricul- 
tural or aquacultural pests, are especially vulnera- 
ble (Thiollay 1989b). Given the region’s increasing 
dependence upon aquaculture as a source of hu- 
man protein (World Resources Institute 1996), 
persecution of piscivorous raptors is likely to in- 
crease (FAO 1989 and references therein). 

Regional Differences. The current geographic 
distribution of tropical raptors is the result of com- 
plex interactions among climatic, geomorphologic, 
and ecological processes operating across numer- 
ous temporal and spatial scales (Sankovski and 
Pridnia 1995). In the Indomalayan and Australo- 
tropical regions, for example, raptor diversity is en- 
hanced because of numerous island endemics in 
Indonesia (16 species) and New Guinea (14 spe- 
cies), respectively (Table 4). In the Afrotropics, on 
the other hand, where species diversity is bolstered 
in part by island endemics from Madagascar, much 
of the region’s diversity results from the high num- 
ber of migrants from the Western and Eastern Pa- 


March 1998 


Status of Tropical Raptors 


11 


learctic (Newton 1995) (Table 5) . In the Neotrop- 
ics, diversity appears to result from geographic fea- 
tures and evolutionary processes particular to the 
region (e.g., forest refugia and centers of endem- 
ism, Haffer 1974 and Cracraft 1985). As a result, 
while the Neotropics have fewer endemic species 
(7) than any other region, they have significantly 
more endemic genera (26) (Table 4) . 

The Neotropics, and to a lesser extent the Af- 
rotropics (particularly when only continental Afri- 
ca is considered), have proportionately fewer at- 
risk species than do the Indomalayan and Austral- 
otropics. This difference appears to be attribut- 
able, mainly, to two factors: the greater number of 
island species in the Indomalayan Region and the 
greater incidence of disturbed ecosystems there 
(Hannah et al. 1994). 

Final Thoughts and Suggestions. Many conser- 
vation biologists have suggested focusing conser- 
vation efforts on megadiversity countries (Mitter- 
rneier 1988), biodiversity “hot spots” (Myers 
1988), specific habitats types (Wilson 1988 and ref- 
erences therein) , or endemic bird areas (Ribby et 
al. 1992). Thiollay (1994), for example, uses this 
approach in identifying four priority areas of trop- 
ical forest raptor diversity, which together contain 
40% of all tropical forest raptor species. All four 
areas, however, occur in only two tropical regions 
(the Indomalayan and Australotropical) , and fo- 
cusing on these sites will do little to protect the 
very different raptor communities of other 
regions. 

Recently, several conservation biologists have 
suggested that when choices need to be made on 
which species to protect, efforts should focus on 
species with the greatest “phylogenetic diversity” 
(e.g., those most distantly related to other existing 
taxa, Forey et al. 1994) . Eleven tropical raptors be- 
long to genera in which all members of the genus 
are Threatened or Near Threatened. The Neotrop- 
ics have five such species ( Harpyhaliaetus solitarius, 
H. coronatus, Morphnus guianensis, Harpia harpyja, 
and Spizastur melanoleucus) , the Afrotropics have 
one ( Eutriorchis astur) , the Indomalayan Region has 
three ( Ichthyophaga humilis, /. icMhyaetus, and Pithe- 
cophaga jefferyt ) , and the Australotropics have two 
( Lophoictinia isura and Harpyopsis novaeguineae) . 
Ten of these species are largely or entirely seden- 
tary, eight are large eagles (>1500 g), six are for- 
est-dependent species, and three are island forms. 
These species, especially, deserve focused conser- 
vation efforts. 


One of the greatest challenges facing conserva- 
tionists interested in protecting tropical raptors is 
our ignorance of the biology of many of these spe- 
cies. This is true not only of secretive forest-dwell- 
ing, range-restricted endemics (Meyburg and 
Chancellor 1994, and references therein), but also 
for wide-ranging migratory species whose ecology 
outside of the tropics is relatively well studied (Sen- 
ner and Fuller 1989, Newton 1995). Indeed, while 
we appear to have good information on species dis- 
tributions, we lack reasonable population estimates 
for many species of tropical raptors (del Hoyo et 
al. 1994), as well as information on factors limiting 
their distribution and abundance. We also know 
relatively litde about the extent to which tropical 
residents interact with migrants overwintering in 
the region (but see Kirk and Gosler 1994). 

We strongly recommend the expansion of field- 
work in tropical areas. Initiatives to gather infor- 
mation on species’ ecology, distributions, and 
abundances (Burnham et al. 1994) and Hawk 
Mountain Sanctuary’s Hawks Aloft Worldwide, which 
uses the spectacle of long-distance migration to 
strengthen local conservation activities along ma- 
jor migratory corridors in the tropics (Bildstein et 
al. 1995), together with meetings and publications 
that focus on tropical raptors (Meyburg and Chan- 
cellor 1989, 1994), should be continued and ex- 
panded. 

Because the fate of tropical raptors ultimately 
rests in the hands of the human inhabitants of 
these areas, individuals and organizations interest- 
ed in protecting tropical raptors need to encour- 
age and support training opportunities for conser- 
vationists and biologists living in the region. 

Acknowledgments 

We thank the hundreds of raptor biologists, conserva- 
tionists, and field-workers who contributed data essential 
to this manuscript. We especially thank the contributors 
and compilers of del Hoyo et al. (1994), including RO. 
Bierregaard, W.S. Clark, S.J.S. Debus, A. Elliot, D.C. 
Elouston, J. del Hoyo, A.C. Kemp, L.F. Riff, B.-U. Mey- 
burg, P.D. Olsen, J. Orta, A.F. Poole, J. Sargatal, J.-M. 
Thiollay, and C.M. White. We also thank the dozens of 
participants of IUCN raptor CAMP workshops in Bada- 
joz, Spain, Asuncion, Paraguay, and Duluth, MN U.S.A , 
the taxon and geographic editors associated with that ef- 
fort, and the 10 conservation organizations working to- 
gether on the project (BirdLife International, Fonds 
d’lntervention pour les Rapaces, The Hawk and Owl 
Trust, Hawk Mountain Sanctuary, The National Birds of 
Prey Centre, The Peregrine Fund, The Raptor Conser- 
vation Group, The Raptor Research Foundation, The 
World Working Group for Birds of Prey and Owls, IUCN- 


12 


Bildstein et al. 


Vol. 32, No. 1 


SSC Conservation Breeding Specialist Group). Also, we 
thank the more than 400 individuals who have contrib- 
uted data to Hawk Mountain Sanctuary’s Hawks Aloft 
Worldwide initiative. 

We thank Rick Watson for inviting us to participate in 
the symposium on tropical raptors, and Rick Watson, 
Marc Bechard, and two anonymous referees, for editing 
and improving our ms. Eric Atkinson provided statistical 
advice and analyses. This is Hawk Mountain Sanctuary 
contribution number 54. 

Literature Cited 

Amadon, D. and J. Bull. 1988. Hawks and owls of the 
world: a distributional and taxonomic list. Proc. West. 
Found. Vertebr. Zool. 3:295-357. 

Bailey, R.G. 1996. Ecosystem geography. Springer, New 
York, NY U.S.A. 

Baker-Gabb, D.J. 1994. Threatened raptors of Australia’s 
tropical forests. Pages 241-244 in B.-U. Meyburg and 
R.D. Chancellor [Eds.], Raptor conservation today. 
World Working Group for Birds of Prey and Owls, 
London, U.K. 

Bibby, C.J., N.J. Collar, M.J. Crosby, M.F. Heath, Ch. 
Imboden, T.H. Johnson, A.J. Long, A.J. Sattersfield 
and S.J. Thirgood. 1992. Putting biodiversity on the 
map: priority areas for global conservation. ICBP, 
Cambridge, U.K. 

Bildstein, K.L., J.J. Brett, L.J. Goodrich and C. Viver- 
ette. 1995. Hawks Aloft Worldwide: a network to pro- 
tect the world’s migrating birds of prey and the hab- 
itats essential to their migrations. Pages 504—16 in 
D.A. Saunders, J.L. Craig and E.M. Mattishe [Eds.], 
Nature conservation. Surrey Beaty 8c Sons, Chipping 
Norton, N.S.W., Australia. 

Brown, L. and D. Amadon. 1968. Eagles, hawks and fal- 
cons of the world. McGraw-Hill, New York, NYU.S.A. 
Bucher, E.H. 1992. The causes of extinction of the Pas- 
senger Pigeon. Curr. Ornithol. 9:1-36. 

Burnham, W.A., D.F. Whitacre and J.P. Jenny [Eds.]. 
1994. The Maya Project: use of raptors as tools for 
conservation and ecological monitoring of biological 
diversity. Pages 257-264 in B.-U. Meyburg and R.D. 
Chancellor [Eds.], Raptor conservation today. World 
Working Group for Birds of Prey and Owls, London, 
U.K. 

Collar, N.J., M.J. Crosby and A.J. Sattersfield. 1994. 
Birds to watch 2: the world list of threatened birds. 
BirdLife International, Cambridge, U.K. 

Cooke, A.S., A.A. Bell and M.B. Haas. 1982. Predatory 
birds, pesticides, and pollution. Institute of Terrestrial 
Ecology, Huntingdon, U.K. 

Cracraft,J. 1985. Historical biogeography and patterns 
of differentiation within the South American avifau- 
na: areas of endemism. Ornithol. Monogr. 36:49-84. 
del Hoyo, J., A. Elliot and J. Sargatal [Eds.]. 1994. 
Handbook of the birds of the world, Vol. 2. Lynx Ed- 
icions, Barcelona, Spain. 


Deshmukh, I. 1986. Ecology and tropical biology. Black- 
well Scientific, Palo Alto, CA U.S.A. 

Diamond, A.W. and T.E. Lovejoy [Eds.]. 1985. Conser- 
vation of tropical forest birds. ICBP, Tech. Publ. No. 
4, Cambridge, U.K. 

FAO. 1989. Report of the EIFAC working party on pre- 
vention and control of bird predation in aquaculture 
and fisheries operations. Food and Agriculture Or- 
ganization of the United Nations, Rome, Italy, 

Forey, P.L., C.J. Humphries and R.I. Vane-Wright [Eds.]. 
1994. Systematics and conservation evaluation. Clar- 
endon Press, Oxford, U.K. 

Gentry, A.H. 1986. Endemism in tropical vs. temperate 
plant communities. Pages 153—181 in M.E. Soule 
[Ed.], Conservation biology. Sinauer, Sunderland, MA 
U.S.A. 

Goulston, G. 1996. Crop protection in Latin America. 
PJB Publications, Ltd., London, U.K. 

Green, G.M. and R.W. Sussman. 1990. Deforestation his- 
tory of the eastern rainforests of Madagascar from sat- 
ellite images. Science 248:212-215. 

Griffiths, C.S. 1994. Monophyly of the Falconiformes 
based on syringeal morphology. Auk 111:787-805. 

Haffer, J. 1974. Avian speciation in tropical South 
America. Publ. Nuttall Ornithol. Club, No. 14. Nuttall 
Ornithological Club, Cambridge, MA U.S.A. 

Hannah, L., D. Lohse, C. Hutchinson, J.L. Carr and A. 
Lankerani. 1994. A preliminary inventory of human 
disturbance of world ecosystems. Ambio 23:246-250. 

Hickey, J.J. [Ed.] 1969. Peregrine Falcon populations: 
their biology and decline. Univ. of Wisconsin, Madi- 
son, WI U.S.A. 

Jones, C.G. 1981. The Mauritius Kestrel. Its biology and 
conservation. Hawk Trust Annu. Rep. 10:18-20. 

Kennedy, R.S. 1983. Can Filipinos learn to love this bird? 
Int. Wildl. 13(4):26-33. 

. 1986. Raptors in the tropics — the next 50 years. 

Raptor Res. Rep. 5:17-25. 

Kerlinger, P. 1989. Flight strategies of migrating hawks. 
Univ. Chicago Press, Chicago, IL U.S.A, 

Kirk, D.A. and A.G. Gosler. 1994. Body condition varies 
with migration and competition in migrant and resi- 
dent South American vultures. Auk 111:933-944. 

McNeely, J.A., K.R. Miller, W.V. Reid, R.A. Mittermeier 
and T.B. Werner. 1988. Conserving the world’s bio- 
logical diversity. IUCN, Gland, Switzerland. 

Meyburg, B.-U. and R.D. Chancellor. 1989. Raptors in 
the modern world. World Working Group for Birds 
of Prey and Owls, London, U.K. 

and . 1994. Raptor conservation today. 

World Working Group for Birds of Prey and Owls, 
London, U.K. 

and S. VAN Balen. 1994. Raptors on Sulawesi (In- 
donesia): the influence of rainforest destruction and 
human density on their populations. Pages 269-276 
in B.-U. Meyburg and R.D. Chancellor [Eds.], Raptor 


March 1998 


Status of Tropical Raptors 


13 


conservation today. World Working Group for Birds 
of Prey and Owls, London, U.K. 

Mittermeier, R.A. 1988. Primate diversity and the trop- 
ical forest: case studies from Brazil and Madagascar 
and the importance of megadiversity countries. Pages 
145-154 in E.O. Wilson [Ed.], Biodiversity. National 
Academy, Washington, DC U.S.A. 

Moors, PJ- 1985. Conservation of island birds. I.C.B.P., 
Tech. Publ. No. 3, Cambridge, U.K. 

Myers, N. 1984. The primary source. Norton, New York, 
NYU.S.A. 

. 1988. Threatened biotas: hot spots in tropical 

forests. The Environmentalist 10:243-256. 

Newton, I. 1995. Relationships between breeding and 
wintering ranges in Palaearctic-African migrants. Ibis 
137:241-249. 

and R.D. Chancellor. 1985. Conservation stud- 
ies on raptors. ICBP, Tech. Publ. No. 5, Cambridge, 
U.K. 

Sankovski, A. and M. Pridnia. 1995. A comparison of 
the southern Appalachian (U.S.A.) and southwestern 
Caucasus (Russia) forests: influences of historical 
events and present environment./. Biogeogr. 22:1073— 
1081. 

Senner, S.E. and M.R. Fuller. 1989. Status and conser- 
vation of North American raptors migrating in the 
Neotropics. Pages 53-58 in B.-U. Meyburg and R.D. 
Chancellor [Eds.], Raptors in the modern world. 
World Working Group for Birds of Prey and Owls, 
London, U.K. 

Sibley, C.G. and B.L. Monroe, Jr. 1990. Distribution 
and taxonomy of birds of the world. Yale Univ. Press, 
New Haven, CT U.S.A. 

Temple, S.A. [Ed.]. 1986. Endangered birds. Univ. Wis- 
consin Press, Madison, WI U.S.A. 

Thiollay, J.-M. 1985a. Falconiformes of tropical rain- 
forests: a review. Pages 155-165 in I. Newton and R.D. 
Chancellor [Eds.], Conservation studies on raptors. 
ICBP, Cambridge, U.K. 

. 1985b. The West African forest avifauna: a re- 
view. Pages 171-186 in I. Newton and R.D. Chancellor 
[Eds.], Conservation studies on raptors. ICBP, Cam- 
bridge, U.K. 

. 1989a. Area requirements for the conservation 

of rainforest raptors and game birds in French Guia- 
na. Conserv. Biol. 3:128-137. 

. 1989b. Distribution and ecology of Palearctic 

birds of prey wintering in West and Central Africa. 
Pages 99-107 in B.-U. Meyburg and R.D. Chancellor 


[Eds.], Raptors in the modern world. World Working 
Group for Birds of Prey and Owls, London, U.K. 

. 1992. Influence of selective logging on bird spe- 
cies diversity in a Guianan rainforest. Conserv. Biol 6 - 
47-63. 

. 1993. Response of a raptor community to 

shrinking area and degradation of tropical rainforest 
in the south west Ghats (India). Ecogeography 16:97- 
110 . 

. 1994. A world review of tropical forest raptors. 

current trends, research objectives and conservation 
strategy. Pages 231-239 in B.-U. Meyburg and R D 
Chancellor [Eds.], Raptor conservation today. World 
Working Group for Birds of Prey and Owls, London, 
U.K. 

Thirgood, S.J. and M.F. Heath. 1994. Global patterns 
of endemism and the conservation of biodiversity. 
Pages 207-227 in P.L. Forey, C.J. Humphries and R.I. 
Vane-Wright [Eds.], Systematics and conservation 
evaluation, Clarendon Press, Oxford, U.K. 

Udvardy, M.D.F, 1975. A classification of the biogeo- 
graphical provinces of the world. IUCN, Morges, Swit- 
zerland. 

van Balen, S. 1994. The status and conservation of birds 
of prey in the Sondaic and Wallacean regions of In- 
donesia. Pages 245-254 in B.-U. Meyburg and R.D. 
Chancellor [Eds.], Raptor conservation today. World 
Working Group for Birds of Prey and Owls, London, 
U.K. 

Watson, R.T. and R. Lewis. 1994. Raptor studies in Mad- 
agascar’s rainforest. Pages 283-290 in B.-U. Meyburg 
and R.D. Chancellor [Eds.], Raptor conservation to- 
day. World Working Group for Birds of Prey and Owls, 
London, U.K. 

Wilson, E.O. [Ed.]. 1988. Biodiversity. National Acade- 
my Press, Washington, DC U.S.A. 

Woodbridge, B., K.K. Finley and S.T. Seager. 1995. An 
investigation of the Swainson’s Hawk in Argentina./ 
Raptor Res. 29:202-204. 

World Resources Institute. 1996. World resources, 
1996-97. World Resources Institute, New York, NY 
U.S.A. 

Wotzkow, C. 1994. Status, distribution, current research 
and conservation of forest birds of prey in Cuba. 
Pages 291-299 in B.-U. Meyburg and R.D. Chancellor 
[Eds.], Raptor conservation today. World Working 
Group for Birds of Prey and Owls, London, U.K. 

Zar, J.H. 1984. Biostatistical analysis. Second Ed. Pren- 
tice Hall, Englewood Cliffs, NJ U.S.A. 

Received 16 October 1996; accepted 10 November 1997 


14 


Bildstein et al. 


Vol. 32, No. 1 


Appendix 1. Conservation and distribution status of the world’s tropical raptors. 


Species 

IUCN Conservation 
Status 

Endemic 

Forest 

Dependent 

Island 

Dependent 

Tropical 

Distribution 

Neotropics 


Coragyps atratus 

Nt a 

No 

No 

No 

Mainly 

Cathartes aura 

Nt 

No 

No 

No 

Mainly 

Cathartes burrovianus 

Nt 

No 

No 

No 

Mainly 

Cathartes melambrotus 

Nt 

No 

Yes 

No 

Wholly 

Sarcoramphus papa 

Nt 

No 

No 

No 

Mainly 

Pandion haliaetud 0 ’ 

Nt 

No 

No 

No 

Mainly 

Leptodon cayanensis 

Nt 

No 

Yes 

No 

Mainly 

Chondrohierax undnatus 

Nt 

No 

Yes 

No 

Mainly 

Elanoides forficatus 

Nt 

No 

Yes 

No 

Mainly 

Gampsonyx swainsonii 

Nt 

No 

No 

No 

Mainly 

Elanus leucurus 

Nt 

No 

No 

No 

Mainly 

Rostrhamus sodabilis 

Nt 

No 

No 

No 

Mainly 

Rostrhamus hamatus 

Nt 

No 

Yes 

No 

Wholly 

Harpagus bidentatus 

Nt 

No 

No 

No 

Mainly 

Harpagus diodon 

Nt 

No 

Yes 

No 

Mainly 

Ictinia plumbea 

Nt 

No 

No 

No 

Mainly 

Circus buffoni 

Nt 

No 

No 

No 

Mainly 

Acdpiter poliogaster 

Near tThreatened 

No 

Yes 

No 

Mainly 

Acdpiter superdliosus 

Nt 

No 

Yes 

No 

Mainly 

Acdpiter collaris 

Near threatened 

No 

Yes 

No 

Wholly 

Acdpiter gundlachi 

Endangered 

Yes 

No 

Yes 

Wholly 

Acdpiter bicolor 

Nt 

No 

No 

No 

Mainly 

Geranospiza caerulescens 

Nt 

No 

No 

No 

Mainly 

Leucopternis schistacea 

Nt 

No 

Yes 

No 

Wholly 

Leucopternis plumbea 

Near threatened 

No 

Yes 

No 

Wholly 

Leucopternis princeps 

Nt 

No 

Yes 

No 

Wholly 

Leucopternis melanops 

Nt 

No 

Yes 

No 

Wholly 

Leucopternis kuhli 

Nt 

No 

Yes 

No 

Wholly 

Leucopternis lacernulata 

Vulnerable 

Yes 

Yes 

No 

Mainly 

Leucopternis semiplumbea 

Near threatened 

No 

Yes 

No 

Wholly 

Leucopternis albicollis 

Nt 

No 

Yes 

No 

Wholly 

Leucopternis ocddentalis 

Endangered 

Yes 

Yes 

No 

Wholly 

Leucopternis polionota 

Near threatened 

No 

Yes 

No 

Mainly 

Asturina nitida 

Nt 

No 

No 

No 

Mainly 

Buteogallus aequinoctialis 

Nt 

No 

Yes 

No 

Mainly 

Buteogallus subtilis 

Nt 

No 

Yes 

No 

Wholly 

Buteogallus anthracinus 

Nt 

No 

Yes 

No 

Mainly 

Buteogallus urubitinga 

Nt 

No 

No 

No 

Mainly 

Buteogallus meridionalis 

Nt 

No 

No 

No 

Mainly 

Parabuteo unidnctus 

Nt 

No 

No 

No 

Mainly 

Busarellus nigricollis 

Nt 

No 

No 

No 

Mainly 

Geranoaetus melanoleucus 

Nt 

No 

No 

No 

Mainly 

Harpyhaliaetus solitarius 

Near threatened 

No 

Yes 

No 

Mainly 

Harpyhaliaetus coronatus 

Vulnerable 

No 

No 

No 

Mainly 

Buteo magnirostris 

Nt 

No 

No 

No 

Mainly 

Buteo leucorrhous 

Nt 

No 

Yes 

No 

Mainly 

Buteo ridgivayi 

Endangered 

Yes 

No 

Yes 

Wholly 

Buteo platypterus 

Nt 

No 

Yes 

No 

Mainly 

Buteo brachyurus 

Nt 

No 

No 

No 

Mainly 

Buteo galapagoensis 

Vulnerable 

Yes 

No 

Yes 

Wholly 

Buteo albicaudatus 

Nt 

No 

No 

No 

Mainly 


March 1998 


Status of Tropical Raptors 


15 


Appendix 1. Continued. 


Species 

IUCN Conservation 
Status 

Endemic 

Forest 

Dependent 

Island 

Dependent 

Tropical 

Distribution 

Buteo poecilochrous 

Nt 

No 

No 

No 

Mainly 

Buteo albonotatus 

Nt 

No 

No 

No 

Mainly 

Morphnus guianensis 

Near threatened 

No 

Yes 

No 

Mainly 

Harpia harpyja 

Near threatened 

No 

Yes 

No 

Mainly 

Spizastur melanoleucus 

Near threatened 

No 

No 

No 

Mainly 

Spizaetus ornatus 

Nt 

No 

Yes 

No 

Mainly 

Spizaetus tyrannus 

Nt 

No 

Yes 

No 

Mainly 

Spizaetus isidori 

Near threatened 

No 

Yes 

No 

Mainly 

Daptrius ater 

Nt 

No 

Yes 

No 

Wholly 

Daptrius americanus 

Nt 

No 

Yes 

No 

Mainly 

Phalcoboenus carunculatus 

Nt 

Yes 

No 

No 

Wholly 

Polyborus plancus 

Nt 

No 

No 

No 

Mainly 

Milvago chimachima 

Nt 

No 

No 

No 

Mainly 

Herpetotheres cachinnans 

Nt 

No 

No 

No 

Mainly 

Micrastur ruficollis 

Nt 

No 

Yes 

No 

Mainly 

Micrastur gilvicollis 

Nt 

No 

Yes 

No 

Wholly 

Micrastur mirandollei 

Nt 

No 

Yes 

No 

Wholly 

Micrastur semitorquatus 

Nt 

No 

Yes 

No 

Mainly 

Micrastur buckleyi 

Nt 

Yes 

Yes 

No 

Wholly 

Falco femoralis 

Nt 

No 

No 

No 

Mainly 

Falco rufigularis 

Nt 

No 

Yes 

No 

Mainly 

Falco deiroleucus 

Near threatened 

No 

Yes 

No 

Mainly 

Afro tropics 

Pandion haliaetu.P 

Nt 

No 

No 

No 

Mainly 

Aviceda cuculoides 

Nt 

No 

Yes 

No 

Mainly 

Aviceda madagascariensis 

Nt 

Yes 

Yes 

Yes 

Mainly 

Pernis apivorus 

Nt 

No 

No 

No 

Mainly 

Macheiramphus alcinuP 

Nt 

No 

Yes 

No 

Mainly 

Elanus caeruleufi 

Nt 

No 

No 

No 

Mainly 

Chelictinia riocourii 

Nt 

No 

No 

No 

Wholly 

Milvus migrant 

Nt 

No 

No 

No 

Mainly 

Haliaeetus vocifer 

Nt 

No 

No 

No 

Mainly 

Haliaeetus vociferoides 

Critically endangered 

Yes 

No 

Yes 

Wholly 

Aegypius tracheliotus 

Nt 

No 

No 

No 

Mainly 

Aegypius occipitalis 

Nt 

No 

No 

No 

Mainly 

Necrosyrtes monachus 

Nt 

No 

No 

No 

Mainly 

Gyps rueppellii 

Nt 

No 

No 

No 

Wholly 

Gyps africanus 

Nt 

No 

No 

No 

Mainly 

Neophron percnopterus h 

Nt 

No 

No 

No 

Mainly 

Gypohierax angolensis 

Nt 

No 

Yes 

No 

Mainly 

Circaetus gallicus h 

Nt 

No 

No 

No 

Mainly 

Circaetus cinereus 

Nt 

No 

No 

No 

Mainly 

Circaetus fasdolatus 

Near threatened 

No 

Yes 

No 

Mainly 

Circaetus cinerascens 

Nt 

No 

Yes 

No 

Wholly 

Terathopius ecaudatus 

Nt 

No 

No 

No 

Mainly 

Dryotriorchis spectabilis 

Nt 

No 

Yes 

No 

Wholly 

Eutriorchis astur 

Critically endangered 

Yes 

Yes 

Yes 

Wholly 

Polyboroides typus 

Nt 

No 

No 

No 

Mainly 

Polyboroides radiatus 

Nt 

Yes 

Yes 

Yes 

Mainly 

Melierax poliopterus 

Nt 

No 

No 

No 

Wholly 

Melierax metabates 

Nt 

No 

Yes 

No 

Mainly 


16 


Bildstein et al. 


Vol. 32, No. 1 


Appendix 1. Continued. 


Species 

IUCN Conservation 
Status 

Endemic 

Forest 

Dependent 

Island 

Dependent 

Tropical 

Distribution 

Melierax canorus 

Nt 

No 

No 

No 

Mainly 

Melierax gabar 

Nt 

No 

No 

No 

Mainly 

Kaupifalco monogrammicus 

Nt 

No 

Yes 

No 

Mainly 

Butastur ruftpennis 

Nt 

No 

No 

No 

Wholly 

Circus macrourud 

Near threatened 

No 

No 

No 

Mainly 

Circus pygargu d 

Nt 

No 

No 

No 

Mainly 

Circus aeruginosud 

Nt 

No 

No 

No 

Mainly 

Circus ranivorus 

Nt 

No 

No 

No 

Mainly 

Circus maillardi 

Near threatened 

Yes 

No 

Yes 

Mainly 

Accipiter tachiro 

Nt 

No 

Yes 

No 

Mainly 

Accipiter castanilius 

Nt 

No 

Yes 

No 

Wholly 

Accipiter brevipes 

Nt 

No 

No 

No 

Mainly 

Accipiter badiud 

Nt 

No 

No 

No 

Mainly 

Accipiter francesii 

Nt 

Yes 

Yes 

Yes 

Mainly 

Accipiter erythropus 

Nt 

No 

Yes 

No 

Wholly 

Accipiter minullus 

Nt 

No 

No 

No 

Mainly 

Accipiter madagascariensis 

Near threatened 

Yes 

Yes 

Yes 

Mainly 

Accipiter ovampensis 

Nt 

No 

Yes 

No 

Mainly 

Accipiter rufiventris 

Nt 

No 

No 

No 

Mainly 

Accipiter melanoleucus 

Nt 

No 

Yes 

No 

Mainly 

Accipiter henstii 

Near threatened 

Yes 

No 

Yes 

Wholly 

Urotriorchis macrourus 

Nt 

No 

No 

No 

Wholly 

Buteo oreophilus 

Nt 

No 

Yes 

No 

Mainly 

Buteo brachypterus 

Nt 

Yes 

Yes 

Yes 

Mainly 

Buteo auguralis 

Nt 

No 

Yes 

No 

Wholly 

Buteo augur 

Nt 

No 

No 

No 

Mainly 

Aquila pomarind 

Nt 

No 

No 

No 

Mainly 

Aquila rapad 

Nt 

No 

No 

No 

Mainly 

Aquila verreauxii 

Nt 

No 

No 

No 

Mainly 

Hieraaetus wahlbergi 

Nt 

No 

No 

No 

Mainly 

Hieraaetus fasciatud 

Nt 

No 

No 

No 

Mainly 

Hieraaetus spilogaster 

Nt 

No 

No 

No 

Mainly 

Hieraaetus pennatud 

Nt 

No 

No 

No 

Mainly 

Hieraaetus ayresii 

Nt 

No 

No 

No 

Mainly 

Hieraaetus bellicosus 

Nt 

No 

No 

No 

Mainly 

Spizaetus occipitalis 

Nt 

No 

No 

No 

Mainly 

Spizaetus africanus 

Nt 

No 

Yes 

No 

Wholly 

Spizaetus coronatus 

Nt 

No 

Yes 

No 

Mainly 

Sagittarius serpentarius 

Nt 

No 

No 

No 

Mainly 

Polihierax semitorquatus 

Nt 

No 

No 

No 

Mainly 

Falco naumannd 

Vulnerable 

No 

No 

No 

Mainly 

Falco newtoni 

Nt 

Yes 

No 

Yes 

Mainly 

Falco punctatus 

Endangered 

Yes 

Yes 

Yes 

Wholly 

Falco alopex 

Nt 

No 

No 

No 

Wholly 

Falco ardosiaceus 

Nt 

No 

No 

No 

Wholly 

Falco dickinsoni 

Nt 

No 

No 

No 

Mainly 

Falco zoniventris 

Nt 

Yes 

No 

Yes 

Mainly 

Falco chicquerd 

Near threatened 

No 

No 

No 

Mainly 

Falco concolor 

Nt 

No 

No 

No 

Mainly 

Falco cuvieri 

Nt 

No 

No 

No 

Mainly 

Falco biarmicus 

Nt 

No 

No 

No 

Mainly 

Falco fasciinucha 

Vulnerable 

No 

No 

No 

Mainly 


March 1998 


Status of Tropical Raptors 


17 


Appendix 1 . Continued. 


Species 

IUCN Conservation 
Status 

Endemic 

Forest 

Dependent 

Island 

Dependent 

Tropical 

Distribution 

Indomalayan 
Pandion haliaetuP 

Nt 

No 

No 

No 

Mainly 

Aviceda jerdoni 

Near threatened 

No 

Yes 

No 

Mainly 

Aviceda subcristatcP 

Nt 

No 

No 

Yes 

Mainly 

Aviceda leuphotes 

Nt 

No 

Yes 

No 

Mainly 

Pernis ptilorhynchus 

Nt 

No 

No 

No 

Mainly 

Pernis celebensis 

Nt 

Yes 

Yes 

Yes 

Wholly 

Macheirhamphus aldnus h 

Nt 

No 

Yes 

No 

Mainly 

Elanus caeruleu 

Nt 

No 

No 

No 

Mainly 

Milvus migrant 

Nt 

No 

No 

No 

Mainly 

Haliastur induP* 

Nt 

No 

No 

No 

Mainly 

Haliaeetus leucogasteP 

Nt 

No 

No 

No 

Mainly 

Ichthyophaga humilis 

Near threatened 

No 

No 

No 

Mainly 

Ichthyophaga ichthyaetus 

Near threatened 

No 

Yes 

No 

Mainly 

Aegypius calvus 

Near threatened 

No 

No 

No 

Mainly 

Gyps indicus 

Near threatened 

No 

No 

No 

Mainly 

Gyps bengalensis 

Near threatened 

No 

No 

No 

Mainly 

Neophron percnopterus h 

Nt 

No 

No 

No 

Mainly 

Circaetus gallicup 

Nt 

No 

No 

No 

Mainly 

Spibmis cheela 

Nt 

No 

No 

No 

Mainly 

Spibmis kinabaluensis 

Data deficient 

Yes 

Yes 

Yes 

Wholly 

Spilomis minimus 

Near threatened 

Yes 

Yes 

Yes 

Wholly 

Spilornis elgini 

Near threatened 

Yes 

No 

Yes 

Wholly 

Butastur teesa 

Nt 

No 

No 

No 

Mainly 

Butastur liventer 

Near threatened 

No 

No 

No 

Wholly 

Butastur indicuP 

Nt 

No 

Yes 

No 

Mainly 

Circus macrouruP 

Near threatened 

No 

No 

No 

Mainly 

Circus melanoleucos 

Nt 

No 

No 

No 

Mainly 

Circus pygarguP 

Nt 

No 

No 

No 

Mainly 

Circus aeruginosus h 

Nt 

No 

No 

No 

Mainly 

Accipiter trivirgatus 

Nt 

No 

Yes 

No 

Mainly 

Accipiter griseiceps 

Nt 

Yes 

Yes 

Yes 

Wholly 

Accipiter badiuP 

Nt 

No 

No 

No 

Mainly 

Accipiter butleri 

Near threatened 

Yes 

Yes 

Yes 

Wholly 

Accipiter sobensiP 

Nt 

No 

Yes 

No 

Mainly 

Accipiter trinotatus 

Nt 

Yes 

Yes 

Yes 

Wholly 

Accipiter JasciatuP 

Nt 

No 

No 

No 

Mainly 

Accipiter novaeholbndiaP 

Nt 

No 

Yes 

No 

Mainly 

Accipiter virgatus 

Nt 

No 

Yes 

No 

Mainly 

Accipiter nanus 

Near threatened 

Yes 

Yes 

Yes 

Wholly 

Accipiter erythraucherP 

Nt 

Yes 

Yes 

Yes 

Wholly 

Accipiter rhodogaster 

Nt 

Yes 

Yes 

Yes 

Wholly 

Pithecophaga jefferyi 

Critically endangered 

Yes 

Yes 

Yes 

Wholly 

Ictinaetus malayensis 

Nt 

No 

Yes 

No 

Mainly 

Aquila pomarincP 

Nt 

No 

No 

No 

Mainly 

Aquila rapaP 

Nt 

No 

No 

No 

Mainly 

Hieraaetus JasciatuP 

Nt 

No 

No 

No 

Mainly 

Hieraaetus pennatuP 

Nt 

No 

No 

No 

Mainly 

Hieraaetus kienerii 

Nt 

No 

Yes 

No 

Mainly 

Spizaetus cirrhatus 

Nt 

No 

No 

No 

Mainly 

Spizaetus bartelsi 

Endangered 

Yes 

Yes 

Yes 

Wholly 

Spizaetus lanceolatus 

Near threatened 

Yes 

Yes 

Yes 

Wholly 


18 


Bildstein et al. 


Vol. 32, No. 1 


Appendix 1. Continued. 


Species 

IUCN Conservation 
Status 

Endemic 

Forest 

Dependent 

Island 

Dependent 

Tropical 

Distribution 

Spizaetus philippensis 

Vulnerable 

Yes 

Yes 

Yes 

Wholly 

Spizaetus alboniger 

Nt 

No 

Yes 

No 

Wholly 

Spizaetus nanus 

Vulnerable 

No 

Yes 

No 

Wholly 

Polihierax insignis 

Near threatened 

No 

No 

No 

Wholly 

Microhierax caerulescens 

Nt 

No 

No 

No 

Mainly 

Microhierax latifrons 

Near threatened 

Yes 

No 

Yes 

Wholly 

Microhierax erythrogenys 

Nt 

Yes 

No 

Yes 

Wholly 

Falco naumannP 

Vulnerable 

No 

No 

No 

Mainly 

Falco araea 

Vulnerable 

Yes 

No 

Yes 

Wholly 

Falco moluccensis 

Nt 

Yes 

No 

Yes 

Wholly 

Falco chicquercP 

Near threatened 

No 

No 

No 

Mainly 

Falco severuA 

Nt 

No 

Yes 

No 

Mainly 

Falco jugger 

Nt 

No 

No 

No 

Mainly 

Australotropical 

Pandion haliaetuF 

Nt 

No 

No 

No 

Mainly 

Aviceda subcristatah 

Nt 

No 

No 

Yes 

Mainly 

Henicopernis longicauda 

Nt 

Yes 

Yes 

Yes 

Wholly 

Henicopernis infuscatus 

Near threatened 

Yes 

Yes 

Yes 

Wholly 

Macheirhamphus alcinu.P 

Nt 

No 

Yes 

No 

Mainly 

Elanus caeruleu.P 

Nt 

No 

No 

No 

Mainly 

Lophoictinia isura 

Vulnerable 

Yes 

No 

No 

Mainly 

Hamirostra melanosternon 

Nt 

Yes 

No 

No 

Mainly 

Milvus migrant 0 

Nt 

No 

No 

No 

Mainly 

Haliastur indus h 

Nt 

No 

No 

No 

Mainly 

Haliaeetus leucogasteft 

Nt 

No 

No 

No 

Mainly 

Haliaeetus sanfordi 

Vulnerable 

Yes 

Yes 

Yes 

Wholly 

Butastur vndicuA' 

Nt 

No 

Yes 

No 

Mainly 

Accipiter soloensi.P 

Nt 

No 

Yes 

No 

Mainly 

Accipiter fasciatuP 

Nt 

No 

No 

No 

Mainly 

Accipiter mwaehollandiaA 

Nt 

No 

Yes 

No 

Mainly 

Accipiter melanochlamys 

Nt 

Yes 

Yes 

Yes 

Wholly 

Accipiter albogularis 

Nt 

Yes 

Yes 

Yes 

Wfiiolly 

Accipiter rufitorques 

Nt 

Yes 

No 

Yes 

Wholly 

Accipiter haplochrous 

Nt 

Yes 

Yes 

Yes 

WTiolly 

Accipiter henicogrammus 

Nt 

Yes 

Yes 

Yes 

Wfiiolly 

Accipiter luteoschistaceus 

Near threatened 

Yes 

Yes 

Yes 

Wholly 

Accipiter imitator 

Endangered 

Yes 

Yes 

Yes 

Wholly 

Accipiter poliocephalus 

Nt 

Yes 

No 

Yes 

Wholly 

Accipiter princeps 

Near threatened 

Yes 

Yes 

Yes 

Wholly 

Accipiter brachyurus 

Vulnerable 

Yes 

Yes 

Yes 

Wholly 

Accipiter erythraucherP 

Nt 

Yes 

Yes 

Yes 

Wholly 

Accipiter meyerianus 

Nt 

No 

Yes 

Yes 

Wholly 

Accipiter buergersi 

Data deficient 

Yes 

Yes 

Yes 

Wholly 

Accipiter radiatus 

Endangered 

Yes 

No 

No 

Mainly 

Accipiter doriae 

Near threatened 

Yes 

Yes 

Yes 

WTiolly 

Buteo solitarius 

Near threatened 

Yes 

No 

Yes 

Wholly 

Harpyopsis novaeguineae 

Vulnerable 

Yes 

Yes 

Yes 

Wholly 

Aquila gurneyi 

Near threatened 

Yes 

Yes 

Yes 

Wfiiolly 

Falco several 

Nt 

No 

Yes 

No 

Mainly 


a Not threatened. 

b Occurs in more than one tropical region. 


f. Raptor Res. 32(l):19-27 
© 1998 The Raptor Research Foundation, Inc. 

CONSERVATION STATUS OF BIRDS OF PREY IN THE 

SOUTH AMERICAN TROPICS 

Richard O. Bierregaard, Jr. 

Department of Biology, University of North Carolina at Charlotte, 9201 University City Blvd., 

Charlotte, NC 28223-9201 U.S.A. 

Abstract. — The ICBP/IUCN Red Data Book lists as Threatened or Endangered five of the 82 species 
of Falconiformes and one of the 32 Strigiformes that breed in tropical South America. The White- 
collared Kite ( Leucopternis farbesi), an endemic of the Atlantic coastal forests of Brazil, can be added to 
this list. Because vast areas of South America, most notably its tropical forests, have been inadequately 
surveyed and few studies have been carried out on raptor species or assemblages, our knowledge of the 
distribution and natural history of many raptor species, especially owls and forest-dwelling Falconifor- 
mes, is rudimentary at best. Most needed for conservation purposes is information on population den- 
sities, distribution, and reproductive biology that will tell us how large populations are and how fast 
they can reproduce. For most species, these data are anecdotal or nonexistent. Although the majority 
of South America’s tropical raptors appear not to be globally threatened at present, more information 
is needed to confirm current assessments, recognize when species become threatened, and to move 
quickly and efficiently to address such threats. 

Key WORDS: Falconiformes ; Strigiformes ; endangered species ; habitat loss ; South America ; tropical forest, conser- 
vation. 


Estado de conservacion de las aves rapaces en los tropicos de America del Sur 

Resumen. — El Libro Rojo de la ICBP/IUCN incluye como amenazadas o en peligro a cinco de las 82 
especies de Falconiformes y una de las 32 Strigiformes que se reproducen en los tropicos de America 
del Sur. Leucopternis farbesi, endemica de los bosques costeros del Atlantico en Brasil puede ser adicionada 
a esta lista. Vastas areas de Suramerica, mas especificamente los bosques tropicales han sido inadecu- 
adamente investigados y pocos estudios han sido realizados sobre las especies de aves rapaces o sobre 
sus ensamblajes, nuestro conocimiento de la distribucion e historia natural de muchas especies de aves 
rapaces, especialmente buhos y Falconiformes de bosque, es rudimentario. Para propositos de conser- 
vacion se requiere de informacion relacionada con densidades poblacionales, distribucion, biologia 
reproductiva, que pueda decirnos de que tamano son las poblaciones y que tan rapido se pueden 
reproducir. Para la mayoria de las especies estos datos son anecdoticos e inexistentes. A pesar de que 
la mayoria de las aves rapaces de America del Sur no estan globalmente amenazadas en el presente, se 
requiere de mas informacion para confirmar las evaluaciones actuales y poder reconocer cuando una 
especie se encuentra en peligro y poder actuar rapidamente para en forma eficiente abordar las amen- 
azas. 

[Traduccion de Cesar Marquez] 


The South American continent is renowned for 
its avian diversity; roughly 32% (3100 species) of 
the world’s avifauna is found there, on only 12% 
of the world’s land surface. Birds of prey are no 
exception. Eighty-four Falconiformes and 32 Stri- 
giformes are resident in South America (following 
the taxonomy in Hume [1991] and del Hoyo et al. 
[1994]). These totals represent 28% and 21%, re- 
spectively, of the world’s species in these two or- 
ders. Most (82) of the Falconiformes (Appendix 1) 
and all of the owls (Appendix 2) are tropical or 


are found primarily south of the tropics but have 
ranges that extend into the tropics (north of 30°S) . 

Not coincidentally, South America is also re- 
nowned for its Amazonian rainforests, home to 
many of the continent’s remarkable avifauna. 
Among the raptors, 52 Falconiformes and 25 owls 
are associated with some sort of tropical forest, 
from the lowlands to high-altitude cloud forests. 

Tropical forests around the world are being 
cleared at alarming rates (Whitmore 1997) , with an 
inevitable loss of primary habitat and fragmenta- 


19 


20 


Bierregaard 


Vol. 32, No. 1 


tion of what remains. These landscape-wide 
changes have profound implications for the con- 
servation of biological diversity and have piqued 
the attention of biologists from the conservation 
community (e.g., Laurance and Bierregaard 1997). 
Although the loss of tropical forests is the most 
conspicuous threat to tropical species, the conver- 
sion of wooded or open savanna to intensive agri- 
culture is also taking its toll by reducing available 
habitat. 

Birds of prey, as top-order predators with large 
home ranges and generally low population densi- 
ties, may be especially sensitive to such habitat loss 
and fragmentation. Due to this, certain taxa may 
be important indicators of habitat integrity. Along 
with their high visibility and general allure, they 
are ideal “flagship species” for the conservation of 
critically endangered habitats. 

In this paper, I review the aspects of the biology 
of tropical species that I feel need to be better un- 
derstood if we are to assess accurately their conser- 
vation status, and then I briefly summarize the ar- 
eas where our knowledge is weakest. Within this 
framework, I discuss the principal threats to raptor 
species in the South American tropics, review 1 the 
general trends that are apparent, discuss the status 
of eight species that seem to merit special atten- 
tion, and make recommendations for future re- 
search. 

Data Needed 

Effective conservation must be based on a sound 
understanding of a number of biological factors, 
principally but not exclusively: distribution and 
population density, taxonomy, breeding behavior 
and reproductive rates, and habitat requirements, 
or, conversely, sensitivity to habitat modification. 
Information on migratory habits and prey special- 
ization is important as well. Distribution and pop- 
ulation density together provide an estimate of 
population size, which is crucial in monitoring the 
vulnerability of a species. 

Although it is not often considered in conser- 
vation discussions, our understanding of taxonomy 
at the specific and subspecific level is indeed im- 
portant. In fact, we face many problems in defining 
biological and phylogenetic species and in decid- 
ing how to deal with distinct populations (Zink and 
McKitrick 1995). These questions have conserva- 
tion implications because conservation laws focus 
at only the species level. 

Among Falconiformes, subspecific differentia- 


tion has hardly been studied in the South Ameri- 
can tropics. Including subspecies, the 82 Falconi- 
form species in South America represent only 128 
strictly South American taxa. Most species are 
monotypic and four species alone account for 22 
of these taxa (Appendix 1). The constraint of only 
considering South American forms is clearly arti- 
ficial since many of the species occur in Central 
America, Mexico, and the Caribbean, where many 
are represented by various distinct populations. In- 
cluding Central American, Mexican, and Caribbe- 
an populations, the number of taxa represented by 
the 82 species climbs from 128 (1.6 taxa/species) 
to 170 (2.1 taxa/species) (Appendix 1). Hence, the 
much smaller Central American region contains a 
great deal of biological diversity and is of great con- 
servation concern, particularly given the greater 
annual rate of deforestation there when compared 
to tropical South America (Whitmore 1997) . 

Data on reproductive biology such as behavior, 
clutch size, frequency of nesting attempts, survi- 
vorship of nestlings, and recruitment into the adult 
population can provide an estimate of a species’ 
potential rate of population growth. Combined 
with estimates of population size or density, these 
data are important in assessing the potential resil- 
ience of a population. 

Finally, information on each species’ habitat re- 
quirements will also help us to assess threats to its 
persistence. Not all species that are typically found 
in any given habitat are behaviorally or ecologically 
restricted to it. A number of North American rap- 
tors have shown great behavioral plasticity and are 
nesting in suburban (e.g., Merlins [Falco columbar- 
ium, Sodhi et al. 1991], Swainson’s Hawks [Buteo 
swainsoni ; England et al. 1995], Cooper’s Hawks 
[Accipiter cooperii; Rosenfield et al. 1995]) or urban 
(Peregrine Falcon [Falco peregrinus\) settings. In 
Central America, a number of raptors nest in both 
primary forest as well as more disturbed landscape 
mosaics of agriculture, second growth, and pri- 
mary forest (Whitacre pers. comm.). 

Data in Hand 

A recent review (Bierregaard 1995) highlighted 
the gaps in our knowledge of the natural history 
of the Falconiformes in Meso- and South America. 
Overall, the species we know the least about are 
the small residents of primary forest, especially 
those in the genera Accipiter, Leucopternis, and Mi- 
crastur. Nests have not been described for 16 spe- 
cies (Table 1 ) , and fewer than five nests have been 


March 1998 


Raptors in South American Tropics 


21 


Table 1. South American Falconiformes with very poorly known natural histories. 


Nest Undescribed 

Unknown Breeding 
Biology 

Scant or No Prey 
DATA a 

Leptodon forbesi 

X 

X 

0 

Harpagus diodon 


X 

+ 

Circus buffoni 


+ 

Accipiter poliogaster 

X 

X 

0 

Accipiter superciliosus 


+ 

Accipiter collaris 

X 

X 

0 

Accipiter ventralis 

X 


+ 

Accipiter erythronemius 

X 

X 

0 

Leucopternis schistacea 

X 

X 

+ 

Leucopternis plumbea 

X 

X 

+ 

Leucopternis princeps 

X 

X 

+ 

Leucopternis melanops 

X 

X 

~h 

Leucopternis kuhli 

X 

X 

+ 

Leucopternis lacernulata 

X 

X 

+ 

Leucopternis polionota 

X 

X 

+ 

Buteogallus subtilis 


+ 

Harpyhaliaetus solitarius 


+ 

Harpyhaliaetus coronatus 


+ 

Buteo albigula 


X 

+ 

Buteo ventralis 


X 

+ 

Phalcoboenus carunculatus 


X 


Phalcoboenus megalopterus 


X 


Phalocoboenus albogularis 


X 

+ 

Milvago chimachima 


X 


Micrastur plumbeus 

X 

X 

+ 

Micrastur gilvicollis 

X 


+ 

Micrastur mirandollei 

X 

X 

+ 

Micrastur buckleyi 

X 


0 

Spiziapteryx circumcinctus 


+ 


a 0 = no prey data available, + = anecdotal data only. 


described for an additional 12 species. Breeding 
behavior is unknown for 20 species and is only 
anecdotally known for an additional 18 species (Ta- 
ble 1). No prey data have been reported for five 
species and only anecdotal data are available for 
an additional 21 species (Table 1). 

Why do we know so little about so many species? 
Most of the poorly-known species are small, secre- 
tive inhabitants of dense, continuous forest, where 
observation is extremely difficult. Many, such as 
the forest falcons of the genus Micrastur, are cavity 
nesters and rarely seen, and field identification of 
many species is not always easy (Howell and Whit- 
taker 1995). 

Given all these difficulties, it is not surprising 
that with the notable exception of Thiollay’s work 
in French Guiana (e.g., Thiollay 1989b) there have 
been no intensive studies of more than a handful 


of raptor species in tropical South American for- 
ests. The majority of what we know about most rap- 
tors is derived from data that were collected inci- 
dentally during other studies. The discovery of 38 
nests of the Barred Forest-falcon ( Micrastur ruficol- 
lis; Thorstrom et al. 1991) stands out as one of the 
more remarkable studies. 

Threatening Factors 

The loss of primary, native habitats is the most 
serious threat to the flora and fauna of the world, 
and raptors in the tropics are no exception. The 
clearing of tropical rainforests occurred globally at 
an average rate of 0.81% per annum over the 1980s 
and shows no sign of abating (FAO 1993, cited by 
Whitmore 1997). Annual deforestation in Central 
America and the Caribbean (0.97%) was substan- 
tially above, while that in tropical South America 


22 


Bierregaard 


Vol. 32, No. 1 


(0.71%) was slightly below the global decade av- 
erage (FAO 1993, cited by Whitmore 1997). 

The tropical forests of South America can be 
coarsely divided into four regions: the lowlands 
and foothills west of the Andes, which are biogeo- 
graphically an extension of the Central American 
forests (or vice versa; Gentry 1990); the higher el- 
evation forests of the Andean Cordillera; the Am- 
azon basin; and the Atlantic forests of Brazil, which 
extend south through parts of Paraguay and Uru- 
guay into northern Argentina (Misiones) . 

Deforestation occurs across these four regions 
with variable causes, rates, and extents. It is occur- 
ring most rapidly in northwestern Ecuador and Co- 
lombia, across a broad front along the northern 
and southern fringes of the Amazon basin, and 
throughout the Atlantic coastal forests of Brazil ap- 
proximately 500 km southeast of Amazonia. Cur- 
rently, the extent of deforestation runs from 
roughly 90% in the Atlantic forests (where defor- 
estation began over 300 yr ago) and Ecuador’s Pa- 
cific lowlands and foothill forests below 900 m 
(Dodson and Gentry 1991) to roughly 6% in Ama- 
zonia as of 1988, with 15% of the region affected 
by deforestation, isolation, and edge effects (Skole 
and Tucker 1993). 

While the conservation of tropical forest is cru- 
cial, the conversion of open country such as the 
llanos and cerrado to cattle grazing and intensive 
agriculture is also vital due to the detrimental ef- 
fects on a broad range of different raptors. Partic- 
ularly egregious are the large-scale soybean and 
sugar cane plantations of eastern and southern 
Brazil. Compounding the problems associated with 
implanting vast expanses of monoculture crops is 
the indiscriminant use of pesticides. 

Alvarez-Lopez and Rattan (1995) reviewed the 
status of 14 species of resident, diurnal birds of 
prey in the Cauca Valley of Colombia. Several spe- 
cies have declined as expected due to reduction in 
forest or wetland habitats, but three open-country 
species unexpectedly declined as well. This may 
have been due to the effects of heavy' cattle grazing 
and/or pesticide use. 

Hunting by humans is certainly a problem for 
larger species of raptors. The frequency with which 
radio-tagged Harpy Eagles ( Harpia harpyja ) have 
been shot is an indication of this (E. Alvarez pers, 
comm.). Thiollay (1989a) has suggested that many 
forest species may be sensitive to what would be 
considered mild hunting pressure, and already re- 
duced in the large tracts of unsurveyed rainforest 


where they have been hunted by gold miners, 
rubber tappers, and indigenous peoples for hun- 
dreds of years (Redford 1992). 

Overall Trends 

Because so little of lowland Amazonia has been 
clearcut and most raptor species are broadly dis- 
tributed across the region, there are no species in 
great peril in this area. In contrast, some species 
inhabiting the slopes of the Andean Cordillera and 
Brazil’s Atlantic coastal forests are more vulnerable 
because they have more limited ranges and these 
ecosystems have been extensively clearcut. 

Throughout tropical South America, we can be 
fairly confident that 53 species are not globally 
threatened at present. Some species are even in- 
creasing their range as forests are felled and con- 
verted to a mosaic of forest fragments, agricultural 
land and second growth. For example, the Black- 
chested Buzzard-eagle ( Geranoaetus melonoleucus ; 
Teixeira et al. 1988) and White-tailed Hawk ( Buteo 
albicaudatus ; Pacheco and Whitney 1995) are mov- 
ing northeast into the decimated Atlantic forests of 
Brazil. 

Del Hoyo et al. (1994) considered 11 species to 
be Near Threatened (Appendix 1). Three of these 
are far too poorly known to make an assessment of 
their status, and the remaining eight are included 
primarily because they are large (eg., Harpy and 
Crested Eagles [Morphnus guianensis ] ) , rare (Black 
Solitary Eagle [ Harpyhaliaelus solitarius] ) , or have 
restricted ranges (Mantled Hawk [ Leucopternis po- 
lionota ] ) . 

There are insufficient data to adequately assess 
the status of at least 14 species. Of these, three are 
considered Near Threatened by del Hoyo et al. 
(1994) and 11 are probably Not Threatened (Ap- 
pendix 1). 

As a group, owls are probably less vulnerable 
than diurnal birds of prey because there are no 
very large species with large home ranges, and 
their nocturnal habits make them much less vul- 
nerable to hunting. As with the Falconiformes, 
however, special attention should be paid to spe- 
cies of owls in the Andes and Pacific slope where 
endemic species with very restricted ranges occur, 
as well as those in the Atlantic coastal forests. 

Three species of owls (Black-capped Screech 
Owl [Otus atricapillus] , Rusty-barred Owl [Strix hy- 
lophila ] and Tawny-b r owe d Owl [ Pulsatrix koeniswal- 
diana ] ) , which are endemic to southern Brazil and 
portions of its Atlantic coastal forest, should be 


March 1998 


Raptors in South American Tropics 


23 


watched simply because of the scale of habitat loss 
in this region. We can presume the Black-capped 
Screech Owl has small enough home range re- 
quirements that it should be able to hold out in 
relatively small remnant forest reserves, while the 
other two species are too poorly known to specu- 
late on their situation. 

Species Of Special Concern 

The Andean Condor ( Vultur gryphus) is Threat- 
ened over most of its range (Collar et al. 1992). 
Although it is still common in some areas, it is very 
rare in the northern Andes, where reintroduction 
programs are underway. The species is very poorly 
known biologically, but apparently has very low re- 
productive rates and consequently is very suscep- 
tible to persecution. 

The recently rediscovered White-collared Kite 
{Leucopternis forbesi; Teixeira et al. 1987), consid- 
ered a valid species by del Hoyo et al. (1994), may 
be the most endangered raptor in South America. 
While it is not uncommon in its range, the species 
is restricted to the extreme northeast of the Atlan- 
tic coastal forests of Brazil, an area undergoing 
devastating deforestation. 

The White-necked Hawk ( Leucopternis lacernula- 
ta) , another endemic to Atlantic forests of eastern 
Brazil, is also considered vulnerable/rare, with its 
population only partly protected. A recent report, 
however, provided interesting observations on 
hunting behavior, confirming that the species is an 
insect specialist that follows monkeys, army ants, 
and even lawn mowers to capture flushed insects 
(Martuscelli 1996). Such adaptability to the pres- 
ence of humans in the environment suggests that 
the species might persist as long as some habitat 
remains. 

The Gray-backed Hawk ( Leucopternis occidentalis ) 
is considered seriously endangered and in need of 
urgent action. It is endemic west of the Andes in 
Ecuador and adjacent northwest Peru, where de- 
forestation is proceeding rapidly, and it maintains 
sizeable populations at only two sites. Recent stud- 
ies by Vargas (1995) have substantially increased 
our knowledge and provided specific recommen- 
dations for protecting habitats for the species. 

The Crowned Solitary Eagle ( Harpy haliaetus co- 
ronatus) is mostly a bird of subtropical to temperate 
regions of South America, but it does extend into 
tropical zones in Brazil and Bolivia. Although it has 
been recorded over a broad geographic range, it 
apparently occurs at extremely low densities. Be- 


cause so little is known about possible threats to 
the species, it is considered only to be Vulnerable 
and is largely unprotected. It is in need of study. 

The Lesser Collared Forest-falcon ( Micrastur 
buckleyi ) is a very poorly known species recorded 
only from a small area in western Amazonia. It is 
considered rare, but its secretive habits and simi- 
larity to the sympatric Collared Forest-falcon ( M 
semitorquatus ) suggest that the bird may be more 
widespread. Collar et al. (1992) listed the species 
as insufficiently known and in need of further pro- 
tection, concluding, however, that it will probably 
prove relatively widespread and secure. I feel that 
it is a species for which we have insufficient data 
but which is probably not threatened. A western 
Brazilian record for the species has been retracted; 
the specimens on which this range extension was 
based are under study and may represent a new 
taxon (A. Whittaker pers. comm.). 

The Plumbeous Forest-falcon ( Micrastur plum- 
beus), endemic to the western slope of the Andes 
in Colombia and Ecuador, is Vulnerable, largely 
unprotected, and is in need of study. The species’ 
biology is practically unknown, but a study is un- 
derway in the Rio Nambi Nature Reserve in south- 
western Colombia with encouraging preliminary 
results (P. Salaman pers. comm.). 

The Long-whiskered Owl ( Xenoglaux loweryi) was 
recently discovered and described at only two lo- 
calities on the east slope of the Andean Cordillera. 
It is considered insufficiendy known and in need 
of further protection (Collar et al. 1992). 

Restricted Taxa 

A number of subspecies that are obligate forest 
dwellers with ranges occurring in areas undergoing 
rapid deforestation are worthy of careful attention. 
In Central America and the western slope of the 
Andes in Colombia and Ecuador, they are the Or- 
nate Hawk-eagle ( Spizaetus ornatus vicarius), Barred 
Forest-falcon ( Micrastur ruficollis interstes) , and Col- 
lared Forest-falcon ( Micrastur semitorquatus naso). 
In the forests of eastern Brazil and into northern 
Argentina, there is also a race of the Black Hawk- 
eagle ( Spizaetus tyrannus tyrannus ). A race of the 
Barred Forest-falcon (M r. olrogi) occurs only in 
the dry forests of northwest Argentina. 

New Research 

Since my earlier review (Bierregaard 1995), stud- 
ies have documented range expansions of several 
species. Black Hawk-eagles and Ornate Hawk-ea- 


24 


Bierregaard 


Vol. 32, No. 1 


gles, for example, have been recorded in new parts 
of Paraguay (Williams 1995) and in the third larg- 
est tract of forest in Brazil’s Atlantic forest in Santa 
Catarina (Serra do Tabuleiro) where Harpy Eagles 
were also reported as recently as 1989 (Albuquer- 
que 1995). The Crested Eagle has been reported 
in Beni, Bolivia (Pearman 1994) and the Black- 
and-white Hawk-eagle ( Spizastur melanoleucus) was 
reported in a new area in Paraguay (Lowen et al. 
1995). The Near Threatened Mantled Hawk has 
been discovered in an important tract of forest in 
southeastern Brazil (Forrester 1993, cited by Gon- 
zaga et al. 1995). 

In Venezuela, 30 breeding pairs of Harpy Eagles 
have been located (Anonymous 1996, and E. Al- 
varez pers. comm.). Preliminary results indicate 
that nests are much closer than would have been 
predicted by previous estimates of density and 
home range (Thiollay 1989a). Important data are 
being collected on local movement of juveniles in- 
strumented with satellite radiotransmitters. Two 
important studies on the Gray-backed Hawk and 
Plumbeous Forest-falcon (Vargas 1995, and P. Sal- 
aman pers. comm.), species whose biology was pre- 
viously virtually unknown (Bierregaard 1995), are 
providing data needed to monitor tropical raptors 
and design effective conservation action plans. 

Future Directions 

Almost any information about any Neotropical 
raptor, especially forest species, is useful. Studies of 
endemic species or subspecies in the Atlantic for- 
ests of Brazil are certainly of a very high priority. 
Similarly, raptor research in the Andes or Choco 
region of Colombia and adjacent Ecuador could 
provide a significant amount of information. In the 
central Amazonian lowlands, studies of any species 
in the genera Leucopternis, Acdpiter, or Micrastur are 
important. 

Literature Cited 

Albuquerque, J.L.B. 1995. Observations of rare raptors 
in southern Atlantic rainforest of Brazil. J. Field Orni- 
thol. 66:363-369. 

Alvarez-Lopez, H. and G.H. Kattan. 1995. Notes on the 
conservation status of resident diurnal raptors of the 
middle Cauca Valley, Colombia. Bird Conserv. Int. 5: 
341-348. 

Anonymous. 1996. Harpy Eagle conservation program. 
The Peregrine Fund 1995 Annual Report. The Pere- 
grine Fund, Inc., Boise, ID U.S.A. 

Bierregaard, R.O., Jr. 1995. The biology and conser- 
vation status of Central and South American Falcon- 


iformes: a survey of current knowledge. Bird Conserv. 
Int. 5:325-340. 

Collar, N.J., L.P. Gonzaga, N. Krabbe, A. Madrono Nie- 
to, L.G. Naranjo, T.A. Parker III, and D.C. Wege. 
1992. Threatened birds of the Americas. Smithsonian 
Inst. Press and International Council for Bird Pres- 
ervation, Cambridge, U.K. and Washington, DC 
U.S.A. 

del Hoyo, J., A. Elliot, and A. Sargatal [Eds.]. 1994. 
Handbook of birds of the world. Vol. II. New world 
vultures to guineafowl. Lynx Edicions, Barcelona, 
Spain. 

Dodson, C.H. and A.H. Gentry. 1991. Biological extinc- 
tions in western Ecuador. Ann. MO Bot. Gard. 78:273- 
295. 

England, A.S., J.A. Estep and W.R. Holt. 1995. Nest- 
site selection and reproductive performance of urban- 
nesting Swainson’s Hawks in the Central Valley of Cal- 
ifornia. J. Raptor Res. 29:179-186. 

FAO. 1993. Forest resources assessment 1990. Tropical 
countries. FAO Forestry Paper 112. 

Forrester, B.C. 1993. Birding Brazil: a check-list and 
site guide. John Geddes, Irvine, CA U.S.A. 

Gentry, A.H. [Ed.]. 1990. Four neotropical rainforests. 
Yale Univ. Press, New Haven, CT U.S.A, 

Gonzaga, L.P, J.F. Pacheco, C. Bauer and G.D.A. Cas- 
TIGLIONI. 1995. An avifaunal survey of the vanishing 
montane Adantic forest of southern Bahia, Brazil. Bird 
Conserv. Int. 5:279-290. 

Howell, S.N.G. and A. Whittaker. 1995. Field identi- 
fication of Orange-breasted and Bat Falcons. Cotinga 
4:36-43. 

Hume, R. 1991. Owls of the world. Running Press, Phil- 
adelphia, PA U.S.A. 

Laurance, W.F. and R.O. Bierregaard, Jr. [Eds.]. 1997 
Tropical forest remnants: the ecology, management, 
and conservation of fragmented communities. Univ. 
Chicago Press, Chicago, IL U.S.A. 

Lowen, J.C., R.P. Clay, T.M. Brooks, E.Z. Esquivel, L. 
Bartrina, R. Barnes, S.H.M. Butchart and N.I. 
Etcheverry. 1995. Bird conservation in the Para- 
guayan Atlantic forest. Cotinga 4:58-64. 

Martuscelli, P. 1996. Hunting behaviour of the Man- 
tied Hawk Leucopternis polionota and the White-necked 
Hawk L. lacernulata in southeastern Brazil. Bull. Brit 
Ornithol. Club 116:114-1 16. 

Pacheco, J.F. and B.M. Whitney. 1995. Range exten- 
sions for some birds in northeastern Brazil. Bull. Brit. 
Ornithol. Club 1 15:157-163. 

Pearman, M. 1994. Neotropical notebook. Cotinga 1:26- 
29. 

Redford, K. 1992. The empty forest. BioScience 42:412- 
422. 

Rosenfield, R.N., J. Bielefeldt, J.L. Affeldt and D.J. 
Beckman. 1995. Nesting density, nest area reoccupan- 
cy, and monitoring implications for Cooper’s Hawks 
in Wisconsin./. Raptor Res. 29:1-4. 


March 1998 


Raptors in South American Tropics 


25 


Skole, D.L. and C.J. Tucker. 1993. Tropical deforesta- 
tion and habitat fragmentation in the Amazon: satel- 
lite data from 1978 to 1988. Science 260:1905-1910. 

Sodhi, N.S., I.G. Warkentin and L.W. Oliphant. 1991. 
Hunting techniques and success rates of urban Mer- 
lins ( Falco columbarius) . J. Raptor Res. 25:127-131. 

Teixeira, D.M., J.B. Nacinovic and F.B. Pontual. 1987. 
Sobre a redescoberta de Leptodon forbesi (Swann, 1922) 
no nordeste do Brasil. Abstracts XIV Congresso Brasileiro 
de Zoologia in Jutz de Fora, Brasil 148. 

, J.B. Nacinovic and G. Luigi. 1988. Notes on 

some birds of northeastern Brazil (3). Bull. Brit. Or- 
nithol. Club 108:75—79. 

Thiollay, J.-M. 1989a. Area requirements for the con- 
servation of rainforest raptors and game birds in 
French Guiana. Conserv. Biol. 3:128-137. 

. 1989b. Censusing of diurnal raptors in a pri- 
mary rainforest: comparative methods and species de- 
tectability. J. Raptor Res. 23:72-84. 

Thorstrom, R.K., A.M. QuixchAn and G.M. Morales. 
1991. Breeding biology of the Barred Forest Falcon 
(Micrastur ruficollis) . 1991. Pages 121-126 in D.F. Whi- 


tacre, W.A. Burnham and J.P. Jenny [Eds.], Maya Pro- 
ject: using raptors and other fauna as environmental 
indicators for design and management of protected 
areas and for building local capacity for conservation 
in Latin America. The Peregrine Fund, Inc., Boise, ID 
U.S.A. 

Vargas, H. 1995. Food habits, breeding biology, and sta- 
tus of the Gray-backed Hawk ( Leucopternis occidentahs ) 
in western Ecuador. M.S. thesis, Boise State Univ., Boi- 
se, ID U.S.A. 

Whitmore, T.C. 1997. Tropical forest disturbance, dis- 
appearance, and species loss. In W.F. Laurance and 
R.O. Bierregaard, Jr. [Eds.], Tropical forest remnants, 
ecology, management, and conservation of fragment- 
ed communities. Univ. Chicago Press, Chicago, IL 
U.S.A. 

Williams, R. 1995. Neotropical notebook. Cotinga 4:65— 

68 . 

Zink, R.M. and M.C. McKitrick. 1995. The debate over 
species concepts and its implications for ornithology. 
Auk 112:701-719. 

Received 16 October 1996; accepted 8 October 1997 


26 


Bierregaard 


Vol. 32, No. 1 


Appendix 1. Number of Falconiform taxa in Meso- Appendix 1. Continued. 
America and Tropical South America. 


Meso- 

Trop- 


Meso- 

Trop- 


World- 

Amer- 

ICAL 


World- 

Amer- 

ICAL 


wide 

ICAN 

S.A. 


wide 

ICAN 

S.A. 

Species 

Taxa 

Taxa 

Taxa 

Species 

Taxa 

Taxa 

Taxa 


Buteo nitidus 

4 

1 

3 

CATHARTIDAE 


Buteo magnirostris 

12 

6 

6 

Cathartes aura 

4 

1 

2 

Buteo leucorrhous 

1 


1 

Cathartes burrovianus 

2 

2 

2 

Buteo brachyurus 

2 

1 

1 

Cathartes melambrotus 

1 


1 

Buteo albigula 

1 


1 

Coragyps atratus 

3 

1 

2 

Buteo albicaudatus 

3 


3 

Sarcoramphus papa 

1 


1 

Buteo galapagoensis 

1 


1 

Vultur gryphus 

1 


1 

Buteo polyosoma 

2 


1 

ACCIPITRIDAE 


Buteo poedlochrous 

1 ' 


1 


Buteo albonotatus 

1 


1 

Leptodon cayanensis 

2 


2 

Morphnus guianensis 

1 


1 

Leptodon forbesi 

1 


1 

Harpia harpyja 

1 


1 

Chondrohierax uncinatus 

3 

2 

1 

Spizastur melanoleucus 

1 


1 

Elanoides forficatus 

2 

1 

1 

Spizaetus tyrannus 

2 


2 

Gampsonyx swainsonii 

3 


3 

Spizaetus ornatus 

2 


2 

Elanus leucurus 

2 

1 

1 

Oroaetus isidori 

1 


1 

Rostrhamus sociabilis 

3 

2 

1 


Rostrhamus hamatus 

1 


1 

FALCONIDAE 


Harpagus bidentatus 

2 


2 

Daptrius ater 

1 


1 

Harpagus diodon 

1 


1 

Daptrius americanus 

1 


1 

Ictinia plumbea 

1 


1 

Phalcoboenus carunculatus 

1 


1 

Circus buffoni 

1 


1 

Phalcoboenus megalopterus 

1 


1 

Circus cinereus 

1 


1 

Caracara ( Polyborus ) plancus 

4 

2 

2 

Accipiter poliogaster 

1 


1 

Milvago chimachima 

2 


2 

Accipiter superciliosus 

2 


2 

Milvago chimango 

2 


1 

Accipiter collaris 

1 


1 

Herpetotheres cachinnans 

3 

1 

2 

Accipiter ventralis 

1 


1 

Micrastur ruficollis 

6 

1 

5 

Accipiter erythronemius 

1 


1 

Micrastur plumbeus 

1 


1 

Accipiter bicolor 

4 

1 

3 

Micrastur gilvicollis 

1 


1 

Geranospiza caerulescens 

6 

2 

4 

Micrastur mirandollei 

1 


1 

Leucopternis plumbea 

1 


1 

Micrastur semitorquatus 

2 


2 

Leucopternis schistacea 

1 


1 

Micrastur buckleyi 

1 


1 

Leucopternis princeps 

1 


1 

Spiziapteryx circumcinctus 

1 


1 

Leucopternis melanops 

1 


1 

Falco sparverius 

17 

8 

7 

Leucopternis kuhli 

1 


1 

Falco femoralis 

3 

1 

2 

Leucopternis lacernulata 

1 


1 

Falco rufigularis 

3 


3 

Leucopternis semiplumbea 

1 


1 

Falco deiroleucus 

1 


1 

Leucopternis albicollis 

4 

1 

3 

Falco peregrinus 

19 

1 

1 

Leucopternis occidentalis 

1 


1 

82 species, total taxa: 

190 

42 

128 

Leucopternis polionota 

1 


1 

Taxa/ species 


Buteogallus aequinoctialis 

1 


1 

(tropical S.A. only) 


1.6 

Buteogallus anthracinus 

3 

2 

1 

Taxa/ species 


Buteogallus subtilis 

3 

2 

1 

(tropical M-A. & S.A.) 


2.1 

Buteogallus urubitinga 

2 

1 

1 


Buteogallus meridionalis 

1 


1 


Parabuteo unicinctus 

2 


2 


Busarellus nigricollis 

2 


2 


Geranoaetus melanoleucus 

2 


2 


Harpyhaliaetus solitarius 

2 

1 

1 


Harpyhaliaetus coronatus 

1 


1 


March 1998 


Raptors in South American Tropics 


Appendix 2. Number of Strigiformes in Meso-America 
and Tropical South America. 


Meso- 

Trop- 


World- 

Amer- 

ICAL 


wide 

I CAN 

S.A. 

Species 

Tax a 

Taxa 

Taxa 


TYTONIDAE 

Tyto alba 

35 

9 

5 

STRIGIDAE 

Otus albogularis 

3 


3 

Otus atricapillus 

3 


3 

Otus choliba 

17 


16 

Otus colombianus 

1 


1 

Otus guatemalae 

17 

10 

7 

Otus ingens 

3 


3 

Otus koepckeae 

1 


1 

Otus marshalli 

1 


1 

Otus petersoni 

1 


1 

Otus roboratus 

1 


1 

Otus watsonii 

6 


6 

Lophostrix cristata 

3 

2 

1 

Bubo virginianus 

17 

3 

6 

Pulsatrix koeniswaldiana 

1 


1 

Pulsatrix melanota 

2 


2 

Pulsatrix perspicillata 

6 

2 

4 

Glaucidium brasilianum 

12 

2 

9 

Glaucidium hardyi 

1 


1 

Glaucidium jardinii 

2 

1 

1 

Glaucidium minutissimum 

8 

7 

1 

Glaucidium peruanum 

1 


1 

Xenoglaux louteryi 

1 


1 

Speotyto cunicularia 

19 

5 

12 

Ciccaba albitarsus 

2 


2 

Ciccaba huhula 

1 


1 

Ciccaba nigrolineata 

1 


1 

Ciccaba virgata 

8 

3 

5 

Strix hylophila 

1 


1 

Strix rufipes 

3 


1 

Rhinopteryx clamator 

3 


3 

Asio flammeus 

10 

2 

4 

Asio stygius 

6 

4 

2 

Aegolius harrisii 

3 

3 


34 species, total taxa: 

200 

53 

108 

Taxa/ species 

(tropical S.A. only) 


3.2 

Taxa/ species 

(tropical M-A. and S.A.) 


4.7 


J. Raptor Res. 32(l):28-39 
© 1998 The Raptor Research Foundation, Inc. 


RAPTORS IN THE EAST AFRICAN TROPICS AND WESTERN 
INDIAN OCEAN ISLANDS: STATE OF ECOLOGICAL 
KNOWLEDGE AND CONSERVATION STATUS 

Munir Virani 1 and Richard T. Watson 

The Peregrine Fund, Inc., 566 West Flying Hawk Lane, Boise, ID 83709 U.S.A. 

Abstract. — From our review of articles published on diurnal and nocturnal birds of prey occurring in 
Africa and the western Indian Ocean islands, we found most of the information on their breeding 
biology comes from subtropical southern Africa. The number of published papers from the east African 
tropics declined after 1980 while those from subtropical southern Africa increased. Based on our Knowl- 
edge Rating Scale (KRS), only 6.3% of breeding raptors in the east African tropics and 13.6% of the 
raptors of the Indian Ocean islands can be considered Well Known, while the majority, 60.8% in main- 
land east Africa and 72.7% in the Indian Ocean islands, are rated Unknown. Human-caused habitat 
alteration resulting from overgrazing by livestock and impacts of cultivation are the main threats facing 
raptors in the east African tropics, while clearing of forests through slash-and-burn methods is most 
important in the Indian Ocean islands. We describe conservation recommendations, list priority species 
for study, and list areas of ecological understanding that need to be improved. 

Key Words: Conservation ; east Africa ; ecology, western Indian Ocean ; islands', priorities', raptors; research. 


Aves rapaces en los tropicos del este de Africa y en islas al oeste del Oceano Indico: estado del cono- 
cimiento ecologico y de su conservacion 

Resumen. — De nuestra recopilacion de articulos publicados sobre aves rapaces diurnas y nocturnas que 
se encuentran en Africa y en las islas al oeste del Oceano Indico, encontramos que la mayoria de la 
informacion sobre aves rapaces residentes se origina en la region subtropical del sur de Africa. El 
numero de publicaciones provenientes de los tropicos del este de Africa, declino despues de 1980, 
mientras que aquellos del subtropico del sur del continente aumentaron. Con base en nuestra escala 
de valoracion del conocimiento solo el 6.3% de las especies residentes en los tropicos del este del Africa 
y el 13.6% de las aves rapaces de islas del Oceano Indico pueden ser consideradas como Bien Conocidas, 
mientras que la mayoria 60.8% del este de Africa y 72.2% de las islas al oeste del Oceano Indico fueron 
clasificadas como Desconocidas. La alteracion de habitats de origen antropico como resultado del so- 
brepastoreo y los impactos de la agricultura son las principales amenazas para las aves rapaces de los 
tropicos del este de Africa, mientras que la deforestation a partir de la quema y tala de bosques es la 
amenaza mas importante en las islas del Oceano Indico. Describimos recomendaciones de conservacion, 
identificamos las especies prioritarias para estudiar e identificamos las areas de entendimiento ecologico 
que deben ser mejoradas. 

[Traduction de Cesar Marquez] 


Raptors are an important tool to focus conser- 
vation strategies locally, regionally, and globally 
(Watson 1991). They can be used as “umbrella spe- 
cies” because their large home ranges and low 
nesting densities necessitate that any protected ar- 
eas encompassing viable populations or complete 
communities protect sufficient habitat and popu- 
lations of most, if not all, other species in the food 


1 Also National Museums of Kenya, Nairobi and Leicester 
University, U.K. 


web below them (Thiollay 1992). Because of their 
top positions in terrestrial and aquatic food webs, 
raptors can be used as indicators of worldwide pol- 
lution by pesticides (Newton 1979). Changes in 
raptor distribution or abundance can serve as a 
measure of our impact on landscapes, even in re- 
mote areas (Reichholf 1974). Finally, raptors are 
popular and charismatic and several species have 
become significant “flagships” for increasing pub- 
lic interest and support of conservation programs 
(Burnham et al. 1992, Thiollay 1992). 

This paper combines our collective knowledge 


28 


March 1998 


East African and Western Indian Ocean Raptors 


29 


of raptors in the east African tropics and western 
Indian Ocean islands as part of a worldwide review 
of their conservation and ecology. We chose to 
combine these two regions in one paper to facili- 
tate comparison of island with continental situa- 
tions in adjacent geographic areas. The east Afri- 
can tropics (including all countries between the 
Tropics of Cancer and Capricorn and east of about 
20°E, Zanzibar and Pemba islands) and the western 
Indian Ocean islands (comprising Madagascar, 
Mauritius, Seychelles, Reunion, and Comores) sup- 
port roughly 23% of the world’s avifauna accord- 
ing to species listed in Martin (1987), Langrand 
(1990), Perlo (1995), and Zimmerman et al. 
(1996). These areas contain a broad spectrum of 
habitats, from montane through lowland, dry, 
moist, and riparian forests, to open woodland, sa- 
vanna, scrubland, desert, marsh, mangroves, and 
others. The east African tropics support 82 species 
of diurnal birds of prey and 23 nocturnal owls 
(Britton 1980, Brown et al. 1982, Fry et al. 1988). 
Three-quarters of these raptors, or roughly 20% of 
the world’s raptor species, breed within this area 
while the rest use the region as a migratory path- 
way. The Indian Ocean islands support 22 endemic 
raptor species (15 diurnal birds of prey and seven 
nocturnal owls), five other breeding species, and 
two Palearctic migrants. Although both these areas 
boast a tremendous diversity of birds that attracts 
the attention of bird watchers worldwide, their rap- 
tors are still poorly understood in many respects, 
ranging from basic biology to the factors affecting 
distribution and abundance. Conserving raptors, 
or using them as a tool to achieve broader conser- 
vation goals, is impossible without a sound under- 
standing of their ecological requirements. 

In this paper, we first give an overview of the 
state of ecological knowledge and conservation sta- 
tus of breeding raptors in the east African tropics 
and the western Indian Ocean islands, based on 
546 published papers and recent lists of species in 
jeopardy. Second, we outline the main conserva- 
tion issues, contrast threats to raptors on the main- 
land with those on islands, summarize information 
on causes of threats, and cite particular examples 
of problems. Lastly, we discuss priorities for further 
studies and focus of conservation efforts. 

Methods 

We reviewed the literature in peer-reviewed journals on 
105 species in Africa, 79 of which breed in tropical east 
Africa, and 22 that are endemic to the Indian Ocean 
islands. The review was divided into pre-1980 and post- 


1980 material. Pre-1980 titles were obtained from the bib- 
liography of Brown et al. (1982) and Fry et al. (1988). 
Post-1980 titles were obtained from a keyword search 
from 1980 through the first quarter of 1996 on the RIOS- 
IS (Biological Abstracts Inc.) and RRTAC (Raptor Re- 
search and Technical Assistance Center, Boise, ID U.S.A ) 
computer databases. We assumed that the material ob- 
tained represented a significant proportion of all articles 
published in peer-reviewed journals, and that these 
sources accurately reflect ecological knowledge based on 
scientific studies. Ad-hoc accounts published in newslet- 
ters or magazines can provide additional knowledge but 
they were not included in this review as they are difficult 
to find and their significance to the understanding of a 
species’ ecology is difficult to assess. 

Based on a similar review of the status and knowledge 
of Central and South American raptors (Bierregaard 
1995), we assigned scores to each species from 1 to 5 
from our Knowledge Rating Scale (KRS) where 1 = an- 
ecdotal, speculative or unstudied; 2=1 nest or 1 year 
low sample size studies; 3 = multi-year, local area studies, 
<5 pairs; 4 = multi-year, >5 pairs; and 5 = >10 pairs, 
>10 years, or regional studies. This was repeated for four 
subject areas, factors affecting distribution and abun- 
dance, population trends, breeding biology, and feeding 
ecology. Scores for each subject were summed for each 
species (min. 4, max. 20), and species ranked by score. 
Species were then grouped into four categories of knowl- 
edge based on their scores: Unknown (score 4—6), Little 
Known (score 7-10), Known (score 11-13), and Well 
Known (score 14 and above). Although these categories 
were subjective, they simplified our review by separating 
species into roughly common levels of knowledge. To 
compare between subject areas, we calculated a “study 
index” (first line of Tables 1 and 2) by summing the KRS 
for all species within each subject, and converting the 
total to a percentage of the maximum possible if all spe- 
cies had KRS of 5. Species’ total scores were calculated 
by summing KRS for all species in all subject areas and 
expressed as a percentage of the maximum possible if all 
species had KRS of 5. The conservation status of each 
species was compiled from two sources (Collar et al 
1994, Bennun and Njoroge 1996). 

Results and Discussion 

State of Ecological Knowledge and Conservation 
Status. We found 251 and 295 articles in our pre- 
1980 and post-1980 literature searches, respective- 
ly. During the pre-1980 era, raptor research origi- 
nated almost equally from countries in the east Af- 
rican tropics (36%) and subtropical southern Af- 
rica (39%), with 14% originating from tropical 
west Africa and 12% from north and central Africa. 
From 1980 through the first quarter of 1996, the 
proportion of publications originating from sub- 
tropical southern Africa increased to 55% and de- 
creased to 25% from countries in the east African 
tropics, while they increased from the western In- 
dian Ocean islands (10%) and decreased from 
tropical west and north Africa (each 5%). The 


30 


Virani and Watson 


Vol. 32, No. 1 


Table 1. Knowledge rating scores (KRS) for distribution and abundance, population biology, breeding biology, and 
feeding ecology of 79 raptor species breeding in the east African tropics. Species are listed in order of increasing 
KRS. KRS scores: 1 = anecdotal, speculative or unstudied; 2 = single nest and single year low sample size studies; 3 
= multi-year local area studies; 4 = multi-year and >10 pairs; 5 = >10 pairs, >10 years or regional studies. Conser- 
vation status for species in the east African region (Bennun and Njoroge 1996): EN = Endangered, NT = Near 
Threatened, VU = Vulnerable, RR = Regional Responsibility. Global conservation status categories (Collar et al. 
1994): EN = Endangered, NT = Near Threatened, VU = Vulnerable. 


Common Name 

Scientific Name 

Dis- 

TRIB. 

AND 

Abund. 

Pop- Breed- Feed- 

ULAT. INC ING 

Bio- Biol- Ecol- 

LOGY OGY OGY 

Proportion of Studies 
in Each Subject Area 

Species 

Total 

Conservation 

Status 

11% 

9% 

26% 

20% 

13% 

Regional Global 

Buzzard, Mountain 

Buteo oreophilus 

1 

1 

1 

1 

4 

NT 


Buzzard, Red-necked 

Buteo augur alis 

1 

1 

1 

1 

4 


Eagle, Congo Serpent 

Dryotriorchis spectabilis 

1 

1 

1 

1 

4 


Snake-eagle, Southern 

Circaetus fasciolatus 

1 

1 

1 

1 

4 

NT 

NT 

Banded 


Falcon, Pygmy 

Polihierax semitorquatus 

1 

1 

1 

1 

4 


Hawk-eagle, Ayre’s 

Hieraaetus ayresii 

1 

1 

1 

1 

4 

VU 


Hawk-eagle, Cassin’s 

Spizaetus africanus 

1 

1 

1 

1 

4 


Hawk, Long-tailed 

Urotriorchis macrourus 

1 

1 

1 

1 

4 


Kestrel, Fox 

Falco alopex 

1 

1 

1 

1 

4 


Kestrel, Grey 

Falco ardosiaceus 

1 

1 

1 

1 

4 


Kite, African Swallow- 

Elanus ( Chelictinia ) riocourii 

1 

1 

1 

1 

4 


tailed 


Kite, Black 

Milvus migrans 

1 

1 

1 

1 

4 


Owlet, Albertine 

Glaucidium albertinum 

1 

1 

1 

1 

4 

VU-RR 

VU 

Owlet, Chestnut Barred 

Glaucidium capense caste- 

1 

1 

1 

1 

4 


neum 


Owlet, Etchecopar’s 

Glaucidium capense etcheco- 

1 

1 

1 

1 

4 


pari 


Owlet, Red-chested 

Glaucidium tephronotum 

1 

1 

1 

1 

4 

VU 


Owl, Fraser’s Eagle 

Bubo poensis 

1 

1 

1 

1 

4 


Owl, Congo-bay 

Phodilus prigoginei 

1 

1 

1 

1 

4 


VU 

Owl, Pemba Scops- 

Otus pembaensis 

1 

1 

1 

1 

4 

VU-RR 

NT 

Owl, Usambara 

Bubo vosseleri 

1 

1 

1 

1 

4 

VU-RR 

VU 

Secretary-bird 

Sagittarius serpentarius 

1 

1 

1 

1 

4 


Sparrowhawk, Black 

Accipiter melanoleucus 

1 

1 

1 

1 

4 


Buzzard, Augur 

Buteo augur 

2 

1 

1 

1 

5 


Buzzard, Lizard 

Kaupifalco monogrammicus 

1 

1 

2 

1 

5 


Snake-eagle, Brown 

Circaetus cinereus 

1 

1 

2 

1 

5 

NT 


Eagle, Western Banded 

Circaetus cinerascens 

1 

1 

2 

1 

5 

VU 


Hawk, African Cuckoo 

Aviceda cuculoides 

1 

1 

2 

1 

5 

NT 


Falcon, Taita 

Falco fasciinucha 

1 

1 

2 

1 

5 

VU 

VU 

Goshawk, Gabar 

Micronisus ( Melierax ) gabar 

1 

1 

2 

1 

5 


Goshawk, Little Banded 

Accipiter badius 

1 

1 

2 

1 

5 


(Shikra) 


Kestrel, Dickinson’s 

Falco dickinsoni 

1 

1 

2 

1 

5 


Owl, Abyssinian Long- 

Asio abyssinicus 

1 

1 

1 

2 

5 


eared 


Owl, Pearl-spotted 

Glaucidium perlatum 

1 

1 

1 

2 

5 


Owl, Pel’s Fishing 

Scotopelia peli 

1 

1 

2 

1 

5 

VU 


March 1998 


East African and Western Indian Ocean Raptors 


31 


Table 1. Continued. 


Dis- 

TRIB. 

AND 

Abund. 

Pop- Breed- Feed- 

ULAT. ING ING 

Bio- Biol- Ecol- 

LOGY OGY OGY 

Proportion of Studies 
in Each Subject Area 

Species 

Total 

Conservation 

Status 

Common Name 

Scientific Name 

11% 

9% 

26% 

20% 

13% 

Regional Global 

Owl, Sokoke Scops- 

Otus ireneae 

1 

2 

1 

1 

5 

VU-RR VU 

Owl, Spotted Eagle- 

Bubo africanus 

1 

1 

1 

2 

5 


Owl, African Wood- 

Ciccaba woodfordii 

1 

1 

2 

1 

5 


Sparrowhawk, Little 

Accipiter minullus 

1 

1 

2 

1 

5 


Vulture, Palm-nut 

Gypohierax angolensis 

1 

1 

1 

2 

5 


Vulture, White-headed 

Trigonoceps occipitalis 

1 

1 

2 

1 

5 

VU 

Snake-eagle, Black- 

Circaetus pectoralis 

2 

1 

2 

1 

6 


chested 

Hobby, African 

Falco cuvieri 

1 

1 

2 

2 

6 


Hawk, Bat 

Macheiramphus alcinus 

1 

1 

2 

2 

6 

NT 

Owl, Cape Eagle- 

Bubo capensis 

2 

1 

1 

2 

6 

VU 

Owl, White-faced Scops- 

Otus leucotis 

1 

1 

2 

2 

6 


Sparrowhawk, Ovambo 

Accipiter ovampensis 

1 

1 

3 

1 

6 

NT 

Vulture, Egyptian 

Neophron percnopterus 

2 

2 

1 

1 

6 

NT 

Vulture, African White- 

Gyps africanus 

1 

1 

2 

2 

6 

NT 

backed 

Hawk-eagle, African 

Hieraaetus spilogaster 

1 

1 

4 

1 

7 


Eagle, Long-crested 

Lophaetus occipitalis 

2 

1 

2 

2 

7 


Owl, Barred 

Glaucidium capense 

4 

1 

1 

1 

7 


Vulture, Hooded 

Necrosyrtes monachus 

1 

1 

4 

1 

7 


Vulture, Ruppell’s Griffon 

Gyps rueppellii 

4 

1 

1 

1 

7 

NT 

Falcon, Peregrine 

Falco peregrinus 

1 

1 

3 

3 

8 


Goshawk, Dark Chanting- 

Melierax metabates 

1 

1 

3 

3 

8 


Goshawk, Pale Chanting- 

Melierax canorus 

1 

1 

3 

3 

8 


Harrier-hawk, African 

Polyboroides typus 

1 

1 

3 

3 

8 


Falcon, Lanner 

Falco biarmicus 

1 

2 

3 

3 

9 


Owl, Giant Eagle 

Bubo lacteus 

4 

1 

2 

2 

9 


Falcon, Red-necked 

Falco chicquera 

1 

3 

3 

3 

10 

NT 

Goshawk, African 

Accipiter tachiro 

1 

3 

3 

3 

10 


Kestrel, Rock (Common) 

Falco tinnunculus 

2 

2 

3 

3 

10 


Kite, Black-winged 

Elanus caeruleus 

1 

1 

4 

4 

10 


Owl, Barn 

Tyto alba affinus 

1 

1 

4 

4 

10 


Owl, African Grass 

Tyto capensis 

1 

1 

4 

4 

10 

VU 

Owl, Scops Eurasian- 

Otus scops 

1 

1 

4 

4 

10 


Eagle, African Crowned 

Stephanoaetus coronatus 

3 

3 

3 

3 

12 

VU 

Eagle, Tawny 

Aquila rapax 

3 

3 

3 

3 

12 


Eagle, Wahlberg’s 

Aquila wahlbergi 

2 

2 

4 

4 

12 


Harrier, African Marsh 

Circus ranivorus 

1 

3 

4 

4 

12 

NT 

Sparrowhawk, Red- 

Accipiter rufiventris 

3 

3 

3 

3 

12 

NT 

breasted 

Eagle, Martial 

Polemaetus bellicosus 

3 

3 

3 

4 

13 

VU 

Kestrel, Greater 

Falco rupicoloides 

3 

3 

4 

3 

13 

NT 

Owl, African Marsh 

Asio capensis 

4 

1 

4 

4 

13 

NT 

Vulture, Lappet-faced 

Torgos tracheliotus 

4 

4 

3 

3 

14 

NT 

Bateleur 

Terathopius ecaudatus 

4 

4 

4 

4 

16 


Vulture, Bearded 

Gypaetus barbatus 

4 

4 

4 

4 

16 

EN 


32 


Virani and Watson 


Vol. 32, No. 1 


Table 1. Continued. 


Dis- 

Pop- 

Breed- 

Feed- 


TRIB. 

ULAT. 

ING 

ING 


AND 

Bio- 

Biol- 

Ecol- 

Species 

Abund. 

LOGY 

OGY 

OGY 

Total 


Proportion of Studies Conservation 

in Each Subject Area Status 


Common Name 

Scientific Name 

11% 

9% 

26% 

20% 

13% Regional Global 

Eagle, African Fish- 

Haliaeetus vocifer 

4 

4 

5 

4 

17 

Eagle, Black (Verreaux’s) 

Aquila verreauxii 

4 

4 

5 

5 

18 


Table 2. Knowledge rating scores (KRS) for distribution and abundance, population biology, breeding biology and 
feeding ecology of 22 endemic raptors of the western Indian Ocean islands. Species are listed in order of increasing 
KRS. KRS scores: 1 = anecdotal, speculative or unstudied; 2 = single nest and single year low sample size studies; 3 
= multi-year local area studies; 4 = multi-year and >10 pairs; 5 = >10 pairs, >10 years or regional studies. Global 
conservation status (Collar et al. 1994): CR = Critical; EN = Endangered; VU = Vulnerable; NT = Near-threatened 


Distrib. 

AND POPULAT. BREEDING FEEDING SPECIES 

Abund. Biology Biology Biology Total 

Proportion of Studies in Each Subject Area 

CONSER- 
. VATION 

Status 

Common Name 

Scientific Name 

18% 

10% 

16% 

6% 

15% 

Global 

Falcon, Madagascar Cuck- 
oo- 

Aviceda madagascariensis 

1 

1 

1 

1 

4 


Goshawk, Henst’s 

Accipiter henstii 

1 

1 

1 

1 

4 

NT 

Harrier-hawk, Madagascar 

Polyboroides radiatus 

1 

1 

1 

1 

4 


Harrier, Reunion 

Circus maillardi 

1 

1 

1 

1 

4 

NT 

Kestrel, Aldabra 

Falco newtoni aldabranus 

1 

1 

1 

1 

4 


Kestrel, Madagascar 

Falco newtoni 

1 

1 

1 

1 

4 


Owl, Grand Comoro Scops- 

Otus pauliani 

1 

1 

1 

1 

4 

CR 

Owl, Malagasy Scops- 

Otus rutilus 

1 

1 

1 

1 

4 


Owl, Seychelles Scops- 

Otus insularis 

1 

1 

1 

1 

4 

CR 

Owl, White-browed 

Ninox superciliaris 

1 

1 

1 

1 

4 


Sparrowhawk, Anjouan 

Accipiter francesii pusillus 

1 

1 

1 

1 

4 


Sparrowhawk, Frances’s 

Accipiter francesii 

1 

1 

1 

1 

4 


Sparrowhawk, Madagascar 

Accipiter madagascariensis 

1 

1 

1 

1 

4 

NT 

Serpent-eagle, Madagascar 

Eutriorchis astur 

2 

1 

1 

1 

5 

CR 

Owl, Anjouan Scops 

Otus rutilus capnodes 

2 

1 

1 

1 

5 

CR 

Owl, Madagascar Long- 
eared 

Asia madagascariensis 

1 

1 

1 

2 

5 


Kestrel, Banded 

Falco zoniiientris 

2 

1 

2 

2 

7 


Owl, Madagascar Red 

Tyto soumagnei 

2 

1 

2 

2 

7 

EN 

Buzzard, Madagascar 

Buteo brachypterus 

3 

1 

4 

4 

12 


Kestrel, Seychelles 

Falco araea 

4 

4 

4 

4 

16 

VU 

Fish-eagle, Madagascar 

Haliaeetus vociferoides 

5 

4 

4 

4 

17 

CR 

Kestrel, Mauritius 

Falco punctatus 

5 

5 

5 

4 

19 

EN 


March 1998 


East African and Western Indian Ocean Raptors 


33 


post-1980 shift in the proportion of studies from 
east Africa to southern Africa may be partly due to 
the death in 1980 of Leslie Brown who contributed 
almost a quarter of all pre-1980 articles from east 
Africa. 

Of the four subject areas reviewed, breeding bi- 
ology (26%) was best studied in the African rap- 
tors, followed in descending order by feeding ecol- 
ogy, factors affecting distribution and abundance, 
and population biology (Table 1). Indian Ocean 
island species were mostly less well-studied than 
continental species, but scored higher in factors 
affecting distribution and abundance (18%), fol- 
lowed in descending order by breeding biology, 
population biology, and feeding ecology (Table 2). 
There was little difference in species’ total scores 
between continental species (13%, Table 1) and 
Indian Ocean island species (15%, Table 2), both 
of which indicate our knowledge is substantially in- 
complete. Breeding biology may be the most often 
studied aspect of raptor ecology on mainland Af- 
rica because there are many large species, often 
inhabiting open landscapes, that build large con- 
spicuous nests which are used year after year, thus 
facilitating observations on nesting behavior. The 
relatively small sizes of the Indian Ocean islands 
perhaps enable a better and more accurate survey 
of distribution and abundance of island raptors. 
The fact that many Indian Ocean island species are 
Threatened may also have contributed to an inter- 
est in distribution and abundance studies. Popu- 
lation trends and demographic parameters were 
least studied in both regions (Tables 1 and 2) pos- 
sibly being the most difficult kind of studies to 
complete. Monitoring and understanding popula- 
tion changes is probably the most important kind 
of knowledge needed for species that are in jeop- 
ardy. 

Of 79 species that breed in the east African trop- 
ics, five (6.3%) scored a total KRS >14 and could 
be said to be Well Known, eight (10.1%) scored 
from 11-13 and might be considered Known, 18 
(22.8%) were rated Unknown in at least two sub- 
ject areas, and may be considered Little Known, 
while the majority' 48 (60.8%) were rated Un- 
known in all four subject areas (Table 1). Well 
Known species were large and charismatic, or lo- 
cally threatened such as the Lappet-faced Vulture 
( Tm'gos tracheliotus), Bearded Vulture ( Gypaetus bar - 
batus ), Bateleur ( Terathopius ecaudatus ), African 
Fish-eagle ( Haliaeetus vocifer ) , and Black Eagle (Aq- 
uila verreauxit) (Table 1). 


Almost 40% of all the breeding raptors in Africa 
have been placed in a recently compiled east Af- 
rican list of birds in jeopardy (Table 1, Bennun and 
Njoroge 1996). This regional list, comprising spe- 
cies found in Kenya, Uganda, Tanzania, Rwanda, 
and Burundi, was compiled to give more detailed 
resolution of conservation priorities in these coun- 
tries and to set a regional agenda for research, 
monitoring, and conservation. Of the 30 breeding 
raptors listed in jeopardy in the east African re- 
gion, one species is listed as Endangered, 14 as Vul- 
nerable, and 15 as Near Threatened (Table 1). In 
contrast, only seven of the 79 breeding African spe- 
cies were listed as globally Threatened (Table 1, 
Collar et al. 1994). This substantial difference is 
because many raptors have continental ranges 
which make their global (but not necessarily re- 
gional) status more secure. There may also be a 
regional awareness that raptor populations are de- 
clining because once-common species are not seen 
as frequently as they were within memory, but data 
are lacking. It may also reflect an inherent prob- 
lem of categorizing a species’ status based on stan- 
dard criteria for which data are almost invariably 
lacking, especially on a global scale. 

Species considered globally Vulnerable or Near 
Threatened that rated as Unknown in our KRS 
and, therefore, should be targeted for study in- 
cluded Southern Banded Snake-eagle ( Circaetus fas- 
ciolatus ), Albertine Owlet ( Glaucidium albertinum), 
Congo Bay-owl ( Phodilus prigoginei ) , Pemba Scops- 
owl ( Otus pembaensis), Usambara Eagle-owl ( Bubo 
vosseleri ) , and Taita Falcon ( Falco fasciinucha ) (Ta- 
ble 1). The Sokoke Scops-owl ( Otus ireneae), previ- 
ously listed as Endangered (Collar and Stuart 
1985) but now listed as Vulnerable (Collar et al. 
1994, Bennun and Njoroge 1996), was rated Un- 
known, but a recent study has increased our knowl- 
edge of this bird to at least Known in all four sub- 
jects (Virani 1995a). 

Of 22 endemic Indian Ocean island species, only 
three (14%) rated as Well Known (Table 2). The 
majority of species (83.6%) were rated Little 
Known or Unknown (Species Total <10, Table 2). 
The Endangered Mauritius Kestrel ( Falco puncta- 
tus ) and the Vulnerable Seychelles Kestrel ( Falco 
araea) were considered Well Known. The Endan- 
gered Madagascar Fish-eagle ( Haliaeetus vocifero- 
ides ) was rated Known but recent studies have 
raised our knowledge level to Well Known (Watson 
et al. 1996, Rafanomezantsoa 1997, Watson 1997, 
Watson et al. 1997). Half of the endemic raptors 


34 


Vi RANT AND WATSON 


Vol, 32, No. 1 


of the Indian Ocean islands were listed at some 
level of global jeopardy (Collar et al. 1994). Of 
these, five were listed as Critically Endangered, two 
as Endangered, one as Vulnerable, and three as 
Near Threatened (Table 2). 

Among the Unknown species that should be tar- 
geted for study were the Endangered Grand Com- 
oro Scops-owl ( Otus pauliani ) , Seychelles Scops-owl 
( Otus insularis) , Anjouan Scops-owl ( Otus capnodes ) , 
and Anjouan Sparrowhawk ( Accipiter francesii pusil- 
lus ) (Table 2). Two notable recent rediscoveries, 
the Madagascar Serpent-eagle ( Eutriorchis astur) 
and Madagascar Red Owl (Tyto soumagnei ), have 
changed the species’ status from possibly extinct to 
extant (Halleax and Goodman 1994, Thorstrom et 
al. 1995); they were listed as Critically Endangered 
and Endangered, respectively (Collar et al. 1994). 
Studies on the Madagascar Red Owl in 1994-95 
provided first data on breeding and diet (Thor- 
strom et al. 1997, Thorstrom and Rene de Roland 
1997) so that the species could be rated as Known 
m two subject areas. 

Threats to Raptors. The main threats facing rap- 
tors in the east African tropics can be summarized 
as rapidly changing land-use patterns resulting 
from an increase in human population size (Sorley 
and Andersen 1994). The precise impacts of 
changing land uses on breeding and migrant rap- 
tors are species specific. In general, anthropogenic 
habitat alteration can influence raptor distribution 
and abundance through direct changes in habitat 
characteristics, such as availability of suitable nest- 
ing and perching sites (Enderson 1964, Marion 
and Ryder 1975, Stahlecker 1978, Janes 1984), or 
indirectly through changes in prey abundance and 
availability (Baker and Brooks 1981). In east Africa, 
we believe that four main factors affect raptor den- 
sity and diversity as a result of changes in habitat 
that accompany human land-use pressures: (1) 
overgrazing by domestic livestock resulting in the 
alteration of original vegetative cover that affects 
prey abundance and distribution (Sorley and An- 
derson 1994); (2) impact of cultivation that com- 
pletely replaces native vegetation and involves the 
use of pesticides and fertilizers potentially toxic to 
raptors and other vertebrates (Sorley and Ander- 
son 1994); (3) human hunting pressure that di- 
minishes prey populations (Sorley and Anderson 
1994); and (4) direct human persecution (Reran 
1981) with resulting changes in behavior (Knight 
et al. 1989), species abundance and diversity 
(Craighead and Mindell 1981), and indirect per- 


secution through secondary poisoning as in Kenya 
(Thomsett pers. comm.). 

Threats to raptors on the Indian Ocean islands 
are similarly related to increasing human popula- 
tions but they tend to be more extreme because of 
the limited area of islands, limited potential for dis- 
persion of both humans and raptors, and high de- 
gree of endemism among island raptor species. 
Threats to raptors depend on the human coloni- 
zation history, the faunal community, and the set 
of conservation problems that are unique to each 
island. For these reasons we will describe the con- 
servation issues in some detail for each island sep- 
arately. 

Madagascar, the largest of the Indian Ocean is- 
lands (587 000 km 2 ), supports 22 species of diurnal 
and nocturnal birds of prey. All except two of these 
breed on Madagascar. Eleven species, 10 of which 
are found in forest habitats and one in wetlands 
and coastal areas, are endemic to the island. Sub- 
fossil remains indicate that two Aquila species ex- 
isted on Madagascar during the Quaternary 
(Goodman and Rakotozafy 1995) and a Stephan- 
oaetus species has been identified from the Holo- 
cene (Goodman 1994), but neither genus now sur- 
vives on Madagascar. The island was relatively re- 
cently colonized by humans who are known to 
have been present since 1890 ± 90 B.R (MacPhee 
and Burney 1991). With a current human popu- 
lation of about 14 million, a population growth 
rate of 3.1% per year and per capita income 
around $230 per year (World Bank 1992), the ma- 
jor threats to raptors, their habitats, and most oth- 
er biota are driven by the subsistence needs of the 
human population. The greatest single threat to 
extant endemic raptors is from human induced 
habitat modification that renders forest or wetland 
habitat unsuitable for them. Clearing of eastern 
rainforest by slash-and-burn agriculture was esti- 
mated to occur at an average rate of 1 1 1 000 ha/ 
year from 1950-85 when 3.8 million ha (34% of 
original forest cover) remained (Green and Suss- 
man 1990). Most of the western dry deciduous for- 
ests have been replaced by relatively sterile savan- 
na, but deforestation continues in the west when 
deliberate grassland fires escape into forest areas. 
Loss of wetlands due to drainage and modification 
for production of rice continues and protection of 
remaining wetlands is unpopular because of the 
need to put new areas into production. Only one 
significant wetland exists within a protected area 


March 1998 


East African and Western Indian Ocean Raptors 


35 


(Lake Tsimanampetsotsa, Langrand and Goodman 
1995). 

Habitat conservation is the single most impor- 
tant priority in Madagascar, with greater emphasis 
on wetlands than has been achieved to date. Man- 
agement of wild populations of certain species, like 
the Madagascar Fish-eagle (Watson 1997), may also 
be needed in the near future, and captive breeding 
may be required not long after that. In the long 
term, however, sustainable agriculture and agro- 
forestry to provide local inhabitants with needed 
food, fuel and fiber, accompanied by a reduction 
of population growth, are among the prerequisites 
for effective conservation. Addressing social and 
economic needs of local peoples are needed if con- 
servation is to succeed. For example, ways to en- 
hance local traditional rules and taboos are being 
explored to achieve conservation of habitats in the 
absence of protected areas (Razandrizanakanirina 
and Watson 1997). 

Besides habitat loss, raptors are persecuted, es- 
pecially in the west where we know nestlings of 
Madagascar Fish-eagle have been taken for food or 
as pets and adults have been killed. Given the low 
population size and low productivity of this species 
(Watson et al. 1997), the loss of just a few nestlings 
and adults each year has a significant impact on 
the species’ survival (Watson 1997). Much perse- 
cution occurs out of ignorance about the value and 
rarity of species so increased public awareness is 
urgent. 

The Seychelles comprise three large islands, the 
largest of which is Mahe (145 km^) , and numerous 
others. It supports two endemic raptors, the forest 
dwelling Seychelles Kestrel with a world population 
of about 420 pairs on Mahe, Silhouette and 
through reintroduction on Praslin, as well as some 
satellite islands (Watson 1989), and Seychelles 
Scops-owl with a population of perhaps 80 pairs all 
in highland forests on Mahe. Threats to the kestrel 
were loss of suitable habitat on Praslin in the 19th 
and early 20th centuries, and human persecution. 
Public awareness, enforcement of bird protection 
laws, and banning of private ownership of firearms 
has inhibited illegal shooting (Watson 1981), while 
habitat recovery on Praslin has allowed the reintro- 
duction of the species to this island. Much of the 
present day highland forest habitat (secondary 
growth) of the Seychelles Scops-owl is incorporated 
in the Morne Seychellois National Park. A better 
understanding of the species’ food and nesting re- 
quirements is needed to assess the effects of log- 


ging outside the protected area. Monitoring of 
small island populations is clearly desirable be- 
cause of their susceptibility to extinction from ran- 
dom catastrophic events as well as human induced 
change. 

Four volcanic islands form the Comoro archi- 
pelago (Ngazidja or Grand Comoro, Ndzuani or 
Anjouan, Mwali or Moheli, and Maore or Mayotte) . 
Each island supports its own, mainly forest dwell- 
ing avifauna (Louette and Stevens 1992). Humans 
arrived perhaps 1000 years ago and deforestation 
on lowland coastal areas is complete. Most endem- 
ic species remain only in higher altitude forest and 
tree-heath on top of Mt. Karthala on Ngazidja and 
on Mwali. Little to no forest remains, even at high 
altitudes, on Ndzuani and Maore. The only re- 
maining endemic raptor species are the Grand Co- 
mores Scops-owl (Karthala Scops-owl) and An- 
jouan Scops-owl. The latter was rediscovered on 
Ndzuani in 1992 having not been recorded with 
certainty since about 1886 (Safford 1993). It is 
found only in a few remaining patches of upland 
forest (above 800 m) where the population is es- 
timated as probably 100-200 pairs. The species is 
endangered by forest clearance and capture for 
food by people. Safford (1993) recommended an 
investigation of the feasibility and consequences of 
the species’ introduction to neighboring island of 
Mwali, as this may be the species’ only hope for 
survival. The Grand Comores Scops-owl is con- 
fined to forest (virgin through degraded and small 
patches) between 1000-1900 m on Mt. Karthala on 
Ngazidja (Herremans et al. 1991). A 1989 study es- 
timated that there was perhaps more than 1000 
pairs on the island assuming 10 000 ha of suitable 
habitat and a territory size of about 5 ha for each 
owl pair. Although encouraging, the data are ten- 
uous and there remains the long-term threat of 
habitat loss through forest fragmentation from 
fires, logging, and clearing for pasture. The spread 
of the introduced Indian Myna ( Acridotheres tristis ) 
as forest is opened is also a threat to endemic spe- 
cies from competition and other interspecific in- 
teractions. 

Various subspecies of Frances’s Sparrowhawk (A. 
francesii) are found on the Mascarene islands. A. 
francesii francesii occurs on Madagascar, but on Co- 
mores it is represented by three subspecies, none 
of which are present on Mwali. A. francesii griveaudi 
is found on Ngazidja but is not common (del Hoyo 
et al. 1994), A. francesii pusillus on Ndzuani was 
once common but is now probably close to extinc- 


36 


Virani and Watson 


Vol. 32, No. 1 


tion due to hunting (Louette and Stevens 1992), 
and A. francesii brutus on Maore is common on the 
moist west side (del Hoyo et al. 1994). Rainforest 
protection wherever it occurs is the highest con- 
servation priority on the Comores. Remaining for- 
est is modified by firewood collecting, timber ex- 
traction, understory clearing for vegetables and 
crops, and cattle grazing. The creation of a forest 
reserve on Mt. Karthala would protect habitat for 
four endemic birds (Louette and Stevens 1992) 
and similar habitat protection may be feasible on 
Mwali where the human population is still low. 
There is little hope for establishing a reserve on 
Ndzuani due to population pressure. Control of 
hunting which may affect raptors, control of ani- 
mal introduction, and public education are also 
high priorities (Louette and Stevens 1992), as are 
investigations into introduction of the Anjouan 
Scops-owl to Moheli and protection of specific nest 
sites on Ndzuani. 

The island of Mauritius (1843 km 2 ) was covered 
with native forest when Europeans first began to 
settle on it near the end of the 17th century 
(Vaughan and Wiehe 1937), but destruction for 
lumber, firewood, and agricultural land was mas- 
sive. Habitat loss, hunting, and introduced species 
probably contributed to the demise of the Mauri- 
tian Owl ( Scops commersoni) along with the Dodo 
(Rap has cucullatus) and other fauna during the 
18th century (Diamond 1987). Today only small, 
highly degraded vestiges of forest remain on rug- 
ged uplands, principally Black River Gorges 
(Cheke 1987, Jones and Owadally 1988). Loss of 
native forest, use of organochlorine pesticides, and 
predation by introduced species undoubtedly con- 
tributed to the decline of the Mauritius Kestrel 
which, in 1974, was reduced to just four wild birds 
confined to about 4000 ha of native forest (Cade 
and Jones 1993). Captive breeding and manage- 
ment in the wild has returned the population size 
to 56-68 breeding pairs and 222-286 individuals 
(end of 1993-94 breeding season) and there is rea- 
son to hope that the population may rise to 200- 
250 pairs occupying degraded or even exotic for- 
est-like habitats (Jones et al. 1994). 

Reunion is a volcanic island of 2510 km 2 that lies 
800 km east of Madagascar and 200 km west of 
Mauritius. Colonized and still run as a Department 
by the French, some endemic fauna are known to 
have become extinct from hunting and the effects 
of introduced species. The history of human de- 
struction of native vegetation parallels that of Mau- 


ritius, but was somewhat constrained by the very 
rugged topography. A proportionately larger area 
of native forest remains uncut, but nearly all of it 
is over 500 m and most over 1000 m elevation (Di- 
amond 1987), Currently 35% of the land surface 
is forest and woodland, 26% agricultural, and the 
remaining is listed as “other.” The only raptor 
known to breed is the Reunion Harrier ( Circus 
maillardi ) that is also found on Madagascar and Co- 
mores. Today, the species persists in exotic vege- 
tation. It suffered a severe post-war decline but has 
increased since banning DDT. Introduction of spe- 
cial protection in 1966 to reduce persecution 
seems ineffective (Thiollay pers. comm.). There is 
compelling evidence of a yet undescribed Scops 
Owl in the forests (Bretagnolle and Attie 1996) 
that needs investigation. 

Conservation and Study Recommendations. 
Conservation needs of island fauna and flora are 
generally more urgent than continental species, 
except where limited distributions on continents 
mimic the island situation (e.g., Sokoke Scops-owl, 
Virani 1995a, 1995b). Conservation needs for rap- 
tors on the Indian Ocean islands are variable de- 
pending on the island, but they have the following 
priorities in common: conservation of native hab- 
itats, prevention of exotic species introduction and 
control of existing introduced exotics, and preven- 
tion of direct exploitation, persecution, and inter- 
ference. Conservation needs for raptors in the east 
African tropics include protection of habitat es- 
pecially where species’ distributions are limited to 
small habitat patches, such as the Sokoke Scops- 
owl, control of environmental contaminants, and 
control of persecution through public education 
and awareness. In particular, because raptors typi- 
cally need very large ranges in which to forage and 
survive, current national parks may not be suffi- 
cient to maintain viable raptor populations. It is 
important, therefore, to develop a “living with 
wildlife” ethic among people that will allow coex- 
istence of raptors on land shared with people. 
Where conservation organizations and individual 
expertise are absent or poorly developed, such as 
in Madagascar and Comores, we recommend de- 
velopment of local capacity through training at 
technician through doctoral level, technical advis- 
ing, and provision of material and financial re- 
sources (Watson and Lewis 1994). 

For raptors rated as Little Known and at least 
Threatened (Tables 1 and 2), priority should be 
given to studies that collect the information need- 


March 1998 


East African and Western Indian Ocean Raptors 


37 


ed to determine the best coarse of action to re- 
duce the probability of the species’ extinction. 
Such studies include, but are not limited to, the 
following: (1) measuring the species’ population 
size and distribution (e.g., Sokoke Scops-owl [Vir- 
ani 1995a, 1995b]) to include genetic distribution 
if subpopulations exist that are small and disjunct; 
(2) understanding the species’ nesting and forag- 
ing habitat needs (e.g., Madagascar Fish-eagle 
[Berkelman 1997] and Madagascar Red Owl); (3) 
monitoring population trends, productivity, surviv- 
al to maturity and adult survival (e.g., Madagascar 
Fish-eagle [Watson et al. 1997]); (4) understanding 
breeding and other behaviors that may affect the 
species’ ability to recover from low population size 
(e.g., Madagascar Fish-eagle [Watson et al. 1997]); 
(5) understanding movements including migration 
and natal dispersal (e.g., Madagascar Fish-eagle 
[Rafanomezantsoa 1997]); and (6) understanding 
the effects of human persecution and other an- 
thropogenic effects (e.g., Madagascar Fish-eagle 
[Watson 1997]. In addition to study of Little 
Known Threatened species, in a few cases that are 
Known, such as the Madagascar Fish-eagle, Grand 
Comores Scops-owl, or Anjouan Scops-owl, we en- 
dorse urgent protection of key breeding sites, and, 
as needed, preliminary use of wild population 
management to increase the population size and 
reduce the risk of extinction (Louette and Stevens 
1992, Safford 1993, Watson et al. 1996, Watson 
1997). Wetlands and the water-forest ecotone in 
Madagascar need focused conservation efforts if 
they are to survive (Watson 1997). Efforts to pro- 
tect significant blocks of remaining rainforest in 
Madagascar (e.g., Projet Masoala 1995, which used 
the area estimated for a viable population of Mad- 
agascar Serpent-eagles to help justify the size of 
protected area) are important for the survival of 
the Madagascar Serpent-eagle, Madagascar Red 
Owl, and other forest species and should be en- 
couraged and duplicated wherever possible. 

Acknowledgments 

We thank Alan Kemp, Leon Bennun and Andrew Jen- 
kins for their constructive review of this paper. 

Literature Cited 

Baker, J.A. and R.J. Brooks. 1981. Distribution patterns 
of raptors in relation to density of meadow voles. Con- 
dor 83:42-47. 

Bennun, L.A. and P. Njoroge. 1996. Birds to watch in 
east Africa: a preliminary Red Data list. Research Rep. 


23, Centre for Biodiversity, National Museums of Ke- 
nya, Nairobi, Kenya. 

Berkelman, J. 1997. Habitat requirements and foraging 
ecology of the Madagascar Fish-eagle. Ph.D. disserta- 
tion, Virginia Polytechnic Institute and State Univ , 
Blacksburg, VA U.S.A. 

Bierregaard, R.O., Jr. 1995. The biology and conser- 
vation status of Central and South American Falcon- 
iformes: a survey of current knowledge. Bird Conserv 
Int. 5:325-340. 

Britton, P.L. [Ed.]. 1980. Birds of east Africa, their hab- 
itat, status and distribution. East Africa Natural His- 
tory Society, Nairobi, Kenya. 

Bretagnolle, V. and C. Attie. 1996. Comments on a 
possible new species of Scops Owl Otus sp. on Reun- 
ion. Bull. A.B.C. 3(1) :36. 

Brown, L.H., E.K. Urban and K. Newman. 1982. The 
birds of Africa. Vol. I. Academic Press, London, U K 

Burnham, W.A., D.F. Whitacre and J.P. Jenny. 1992. 
The Maya Project: use of raptors as tools for conser- 
vation and ecological monitoring of biological diver- 
sity. Pages 257-264 in B.-U. Meyburg and R.D. Chan- 
cellor [Eds.], Raptor conservation today. World Work- 
ing Group on Birds of Prey, Berlin, Germany. 

Cade, TJ- and C.J. Jones. 1993. Progress in restoration 
of the Mauritius Kestrel. Conserv. Biol. 7:169-175. 

Cheke, A.S. 1987. An ecological history of the Mascare- 
ne Islands, with particular reference to extinctions 
and introductions of land vertebrates. Pages 5-89 m 
A.W. Diamond [Ed.], Studies of Mascarene Island 
birds. Cambridge Univ. Press, Cambridge, U.K. 

Collar, N.J. and S.N. Stuart. 1985. Threatened birds 
of Africa and related islands: the ICBP/IUCN Red 
Data Book. International Council for Bird Preserva- 
tion and International Union for Conservation of Na- 
ture and Natural Resources, Cambridge, U.K. 

Collar, N.J., M.J. Crosby and A.J. Stattersfield. 1994. 
Birds to Watch 2. The world list of threatened birds 
Birdlife Conserv. Ser. No. 4. BirdLife International, 
Cambridge, U.K. 

Craighead, F.C., JR- and D.P. Mindell. 1981. Nesting 
raptors in western Wyoming, 1947 and 1975./. Wildl. 
Manage. 45:865-872. 

del Hoyo, J., A. Elliot and J. Sargatal [Eds.]. 1994. 
Handbook of birds of the world. Vol. 2. New World 
vultures to guineafowl. Lynx Edicions, Barcelona, 
Spain. 

Diamond, A. W. [Ed.]. 1987. Studies of Mascarene Island 
birds. Cambridge Univ. Press, Cambridge, U.K. 

Endersqn, J.H. 1964. A study of the Prairie Falcon in 
the central Rocky Mountain Region. Auk 81:332-352 

Fry, C.H., S. Keith and E.K. Urban [Eds.]. 1988. The 
birds of Africa. Vol. III. Academic Press, London, U K. 

Green, G.M. and R.W. Sussman. 1990. Deforestation his- 
tory of the eastern rainforests of Madagascar from sat- 
ellite images. Science 248:212-215. 

Goodman, S.M. 1994. Description of a new species of 


38 


Virani and Watson 


Vol. 32, No. 1 


subfossil eagle from Madagascar: Stephanoaetus (Aves: 
Falconiformes) from the deposits of Ampasambazim- 
ba. Proc. Biol. Soc. Wash. 107:421-428. 

and L.M.A. Rakotozafy. 1995. Evidence for the 

existence of two species of Aquila on Madagascar dur- 
ing the Quaternary. Geobios 28:241-246. 

Halleax, D. and S. Goodman. 1994. Rediscovery of the 
Madagascar Red Owl Tyto soumagnei (Grandidier 
1878). Bird Conserv. Int. 4:305-311. 

Herremans, M., M. Louette and J. Stevens. 1991. Con- 
servation status and vocal and morphological descrip- 
tion of the Grand Comoro Scops Owl Otus pauliani 
Benson 1960. Bird Conserv. Int. 1:123-133. 

Janes, S.W. 1984. Influences of territory composition 
and interspecific competition on Red-tailed Hawk re- 
productive success. Ecology 65:862-870. 

Jones, C.G. and A.W. Owad al ly. 1988. The life histories 
and conservation of the Mauritius Kestrel Falco punc- 
tatus (Temminck 1823), Pink Pigeon Columba mayeri 
(Prevost 1843) and Echo Parakeet Psittacula eques 
(Boddart 1783). Proc. R. Soc. Arts Sci. Mauritius 5:79- 
130. 

, W. Heck, R.E. Lewis, Y. Mungroo, G. Slade and 

T. Cade. 1994. The restoration of the Mauritius Kes- 
trel Falco punctatus population. Ibis 137:S173— S180. 

Keran, D. 1981. The incidence of man-caused and nat- 
ural mortalities to raptors. Raptor Res. 15:108-112. 

Knight, R.L., D.E. Anderson, M.J. Bechard and N.V. 
Marr. 1989. Geographic variation in nest-defence be- 
haviour of the Red-tailed Hawk Buteo jamaicensis. Ibis 
131:22-26. 

Langrand, O. 1990. Guide to the birds of Madagascar. 
Yale Univ. Press, New Haven, CT U.S.A. 

and S. Goodman. 1995. Monitoring Madagas- 
car’s ecosystems: a look at the past, present, and fu- 
ture of its wetlands. Pages 203-214 in T.B. Herman, 
S. Bondrup-Nielson, J.H. Willison and N. Munro 
[Eds.], Ecosystem monitoring and protected areas. 
Science and Management of Protected Areas Associ- 
ation, Nova Scotia, Canada. 

Louette, M. and J. Stevens. 1992. Conserving the en- 
demic birds on the Comoro Islands, I: general consid- 
erations on survival prospects. Bird Conserv. Int. 2:61— 
80. 

MacPhee, R.D.E. and D.A. Burney. 1991. Dating of 
modified femora of extinct dwarf hippopotamus from 
southern Madagascar: implications for constraining 
human colonization and vertebrate extinction events. 
J. Arch. Sci. 18:695-706. 

Marion, W.R. and R.A. Ryder. 1975. Perch-site prefer- 
ence of four diurnal raptors in northeastern Colora- 
do. Condor 77:350-352. 

Martin, B.P. 1987. World birds. Guinness Superlatives, 
Enfield, U.K. 

Newton, I. 1979. Population ecology of raptors. T. & 
A.D. Poyser, London, U.K. 


Perlo, B.V. 1995. Birds of eastern Africa. Harper Col- 
lins, London, U.K. 

Projet Masoala. 1995. Proposition des limites du Parc 
National Masoala. CARE International Madagascar, 
Wildlife Conservation Society, The Peregrine Fund, 
Antananarivo, Madagascar. 

Rafanomezantsoa, S. 1997. Behavior and natal dispersal 
of fledgling Madagascar Fish-eagles. Pages 403-412 in 
R.T. Watson [Ed.], Madagascar wetlands conservation 
project. Progress report III, 1995-1996. The Pere- 
grine Fund, Boise, ID U.S.A. 

Razandrizanakanirina, D. and R.T. Watson. 1997. The 
process of developing the wetland community-based 
conservation project: 1997-1998. Pages 33-44 in R.T. 
Watson [Ed.], Madagascar wetlands conservation proj- 
ect. Progress report III, 1995-1996. The Peregrine 
Fund, Boise, ID U.S.A, 

Reichholf, J. 1974. Artenreichtum, Haufigkeit und Div- 
ersitat derGreifvogel in einigen Gebieten yon Suda- 
merika. J. Ornithol. 115:381-397. 

Safford, R.J. 1993. Rediscovery, taxonomy and conser- 
vation of the Anjouan Scops Owl Otus capnodes (Gur- 
ney 1889). Bird Conserv. Int. 3:57-74. 

Sorley, C.S. and D.E. Andersen. 1994. Raptor abun- 
dance in southcentral Kenya in relation to land-use 
patterns. Afr. J. Ecol. 32:30-38. 

Stahlecker, D.W. 1978. Effect of a new transmission 
line on wintering birds of prey. Condor 80:444-446. 

Thiollay, J-M. 1992. A world review of tropical forest 
raptors. Current trends, research objectives and con- 
servation strategy. Pages 231-239 in B.-U. Meyburg 
and R.D. Chancellor [Eds.], Raptor conservation to- 
day. World Working Group on Birds of Prey, Berlin, 
Germany. 

Thorstrom, R., R.T. Watson, B. Damary, F. Toto, M. 
Baba and V. Baba. 1995. Repeated sightings and first 
capture of a live Madagascar Serpent-eagle Eutriorchis 
astur. Bull. B.O.C. 115:40—45. 

Thorstrom, R. and L. A. Rene de Roland. 1997. First 
nest record and nesting behaviour of the Madagascar 
Red Owl ( Tyto soumagnei). Ostrich 68:42-43. 

Thorstrom, R., J. Hart and R.T. Watson. 1997. New 
record, ranging behaviour, vocalization and food of 
the Madagascar Red Owl (Tyto soumagnei). Ibis 139: 
477-481. 

Vaughan, R.E. and P.O. Wiehe, 1937. Studies on the 
vegetation of Mauritius, I. A preliminary survey of 
plant communities./. Ecol. 25:289-343. 

Virani, M.Z.A. 1995a. The ecology of the endangered 
Sokoke Scops Owl Otus ireneae. M.S. thesis, Univ. 
Leicester, U.K, 

. 1995b. Sokoke Scops Owl in Tanzania. Swara: 

May-June. 

Watson, J. 1981. Population ecology, food and conser- 
vation of the Seychelles Kestrel ( Falco araea) on Mahe. 
Ph.D. dissertation, Univ. Aberdeen, U.K. 

. 1989. Successful translocation of the endemic 


March 1998 


East African and Western Indian Ocean Raptors 


39 


Seychelles Kestrel Falco araea to Praslin. Pages 363- 
367 in Meyburg B.-U. and R.D. Chancellor, [Eds.], 
Raptors in the modern world. World Working Group 
on Birds of Prey, Berlin, Germany. 

Watson, R.T. 1991. Using birds of prey as an environ- 
mental conservation tool: The Peregrine Fund’s 
World Programme. Environ . Conserv. 18:269-270. 

, 1997. Madagascar Fish-eagle conservation. Pages 

45-49 in R.T. Watson [Ed.], Madagascar wetlands con- 
servation project. Progress report III, 1995-1996. The 
Peregrine Fund, Boise, ID U.S.A. 

and R. Lewis. 1994. Raptor studies in Madagas- 
car’s rainforest. Pages 283—290 in B.-U. Meyburg and 
R.D. Chancellor [Eds.], Raptor conservation today. 
World Working Group on Birds of Prey, Berlin, Ger- 
many. 

, S. Thomsett, D. O’Daniel and R. Lewis. 1996. 


Breeding, growth, development, and management of 
the Madagascar Fish-eagle ( Haliaeetus vodferoides) J 
Raptor Res. 30:21-27. 

, S. Razafindramanana, R. Thorstrom and S. Ra- 

fanomezantsoa. 1997. Breeding biology, productivi- 
ty, siblicide and conservation of the Madagascar Fish- 
eagle. Pages 289-306 in R.T. Watson [Ed.], Madagas- 
car wetlands conservation project. Progress report III, 
1995-1996. The Peregrine Fund, Boise, ID U.S.A. 

World Bank. 1992. World development report 1992: de- 
velopment and the environment. Oxford Univ. Press, 
New York, NY U.S.A. 

Zimmerman, D.A., D.A. Turner and D-J. Pearsin. 1996. 
Birds of Kenya and northern Tanzania. Princeton 
Univ. Press, Princeton, NJ U.S.A. 

Received 16 October 1996; accepted 12 November 1997 


J. Raptor Res. 32(1) :40-55 
© 1998 The Raptor Research Foundation, Inc. 


CURRENT STATUS AND CONSERVATION OF FALCONIFORMES IN 

TROPICAL ASIA 

Jean-Marc Thiollay 

Laboratoire d Ecologie, E.N.S., 46, rue d’Ulm 75230 Paris Cedex 05, France 

Abstract. — I reviewed the distribution, abundance, habitat selection, and population trends of 69 di- 
urnal raptors found in 13 subregions from India to Indochina, Sumatra, and Java. At least four species 
are Endangered or Vulnerable and 19 are at lower risk or have insufficient data to determine their 
status. Among 49 breeding species, 33 have a world range mostly within South Asia, half with high 
conservation value scores. Others have small (six species) or substantial (10 species) populations but a 
much wider distribution. Of all 69 taxa, eight are mature forest-interior species, six are associated with 
gaps or disturbance, 14 are woodland, edge, or upper canopy dwellers, 14 are associated with grasslands 
or cultivation, and seven are river or wedand species. Most wintering migrants (20) are nonforest species. 

There is evidence of largescale population declines on the continent of Asia, as well as insular syndrome 
involving increased density and wider habitat breadth on islands. The most important threats to diurnal 
raptors are (1) habitat loss, especially of lowland rainforest to cultivation, (2) habitat degradation, mainly 
from logging, and (3) forest fragmentation. Few species are successfully adapting to new man-made 
habitats and none are from the forest-interior guild. Main conservation priorities include surveys and 
ecological studies, extension and enforcement of protected areas, and sustainable logging practices. 

Key Words: raptor populations:, South Asia; distribution; conservation. 


Estado actual y conservation de falconiformes en el Asia tropical 

Resumen. — Resumi la distribution, abundancia, selection de habitat, y tendencias poblacionales de 69 
aves rapaces diurnas de 13 subregiones desde India hasta Indochina, Sumatra, yjava. Por lo menos 4 
especies estan amenazadas o son vulnerables, 19 estan en menos riesgo o no existe information sufi- 
ciente para determinar su estado. Entre las 49 especies, 33 tienen un area de distribution dentro del 
Sur de Asia, la mitad de estas tienen un valor de conservation alto. Otras tienen poblaciones reducidas 
(6 especies) o substanciales (10 especies) con distribuciones mas amplias. De todos los 69 taxones, 8 
son especies del interior de bosques maduros, 6 estan asociados a zonas abiertas o disturbadas, 14 son 
especies de bosque, borde o dosel, 14 estan asociados a pastizales o cultivos, y 7 son especies de rfos o 
humedales. Casi todas las migratorias (20) no son especies de bosque. Existen evidencias sobre la di- 
minution poblacional de las especies a gran escala en el continente Asiatico, como tambien sobre el 
sindrome insular que incluye el aumento de densidades y espacios entre habitats en islas. Las amenazas 
mas importantes para las aves rapaces diurnas son: (1) Perdida de habitat, especialmente de los bosques 
de lluvia de tierras bajas convertidas a cultivos, (2) degradation del habitat a partir de actividades 
forestales, y (3) fragmentation del bosque. Pocas especies se estan adaptando exitosamente a los nuevos 
habitats creados por el hombre. Las prioridades de conservation, incluyen investigation es y estudios 
ecologicos, apoyo y extension de areas protegidas y practicas forestales sostenibles. 

[Traduction de Cesar Marquez] 


Several Asian countries have the densest and fas- 
test growing human populations in the world, as 
well as the fastest growing economies and stan- 
dards of living. As a result, there is dramatic pres- 
sure on natural habitats, resources, and biodiver- 
sity of this area. 

Raptors are good indicators of environmental 
changes because they are top predators, they in- 
clude species with a variety of specific habitat re- 


quirements, prey selection and degrees of toler- 
ance to disturbance, and their species numbers, at 
least in some areas, are correlated with the total 
bird species richness (Thiollay 1997). My aim here 
is to review the composition, distribution, popula- 
tion levels, and conservation priorities of diurnal 
raptors in Southeast Asia in the early 1990s. Most 
information about the geographical distribution of 
raptor species is scattered in the literature and 


40 


March 1998 


Status of Raptors in Tropical Asia 


41 


much less is known about their habitat selection 
and their actual abundances. These last critical 
components of their status are rapidly changing 
and may be different today than they were report- 
ed in regional syntheses based on information that 
is decades old. To update and complement pub- 
lished data, I shall rely primarily on the results of 
numerous personal raptor surveys and field studies 
carried out in 27 states or provinces in eight coun- 
tries during the last 20 yr. 

Study Area 

The area under consideration extends from India to 
Indochina, south of the Himalayas and China, and down 
to the Greater Sundas, west of the Wallace Line (Fig. 1). 
This is a faunistically homogeneous, 7 million-km 2 re- 
gion, that now has a human population of >1.4 billion 
people. It is divided into three broad biogeographic 
zones: Indian (India to Burma), Indochinese (Thailand 


to Vietnam), and Sundan (Malaysia to Java). In terms of 
its raptors, the area can be divided more precisely into 
13 subregions (Table 1). 

The main vegetation type is a rich, closed-canopy, 
moist forest with trees approximately 50 m in height 
(Whitmore 1985). At best, only 42% of the original forest 
remains (global estimate from Collins et al. [1991], as- 
suming a constant deforestation rate since the 1980s). 
This estimate includes evergreen to semi-deciduous, low- 
land and montane forests that have often already been 
logged or degraded, where annual rainfall is 2-4 m or 
more and no month receives under 60 mm of precipi- 
tation. At higher latitudes, marked dry seasons (^3 
months with <60 mm of rainfall) result in drier, more 
deciduous monsoon forests grading into lower wood- 
lands or even subdesert scrubland in north western In- 
dia. Lowland swamp forests are locally extensive in Bor- 
neo and Sumatra. Mangroves ( Avicennia , Rhizophora) are 
widespread along low coastlines and estuaries and cover 
over 4000 km 2 in the Sundarbans of Bangladesh alone 
Former coastal forests have been replaced by coconut 


42 


Thiollay 


Vol. 32, No. 1 


Table 1. Total size of study areas, remaining forested areas (1980-88), and existing protected areas in 1000s of km 2 
(from Collins et al. 1991). 


Subregions 

Land 

Area 

Rain 

Forest 

Monsoon 

Forest 1 

Mangrove 
and Swamp 
Forest 

Protected 

Areas 2 

Northern India a 

1805.9 

0.9 

98.1 

1.2 

106.0 

Peninsular India 

944.6 

20.0 

18.4 

0.1 

16.6 

Northeastern India b 

640.4 

46.7 

38.8 

4.5 

9.3 

Sri Lanka 

64.7 

1.4 

10.8 


7.2 

Andamans-Nicobars 

6.3 

2.6 

3.6 

0.6 

0.6 

Burma (Myanmar) 

657.7 

220.3 

88.4 

3.0 

7.0 

Thailand + Cambodia 

688.3 

127.4 

79.2 

13.4 

66.9 

Laos + Vietnam 

556.1 

134.3 

45.3 

1.6 

8.2 

Peninsular Malaysia 0 

330.3 

64.5 


5.2 

6.2 

Northern Borneo 

203.9 

113.5 


21.7 

8.1 

Kalimantan 

532.1 

323.6 


73.7 

29.7 

Sumatra d 

472.6 

155.3 


75.3 

45.0 

Java + Bali 

138.6 

12.8 


9.2 

3.7 

Total 

7041 

1223 

382 

209 

314 


1 Includes both lowland and montane forest, and from intact to highly degraded stands. 

2 Includes also nonforest areas and low protection status areas such as protection forests or hunting reserves. 
a North of 20°N, excluding Himalayan and Tibetan ranges. 

b Includes Bangladesh. 

' Includes Peninsular Thailand, Tenasserim and Singapore. 
d Includes outlying islands. 


plantations. Upper montane areas above tree line are in- 
significant in size. 

Wetlands are mostly associated with rivers and to a less- 
er extent with marshes, peat swamps, coastal lagoons, 
many artificial lakes, and vast areas of temporarily inun- 
dated ricefields. Permanent agriculture is often intensive 
over huge, densely-inhabited areas. Nevertheless, a sub- 
stantial density of trees, patches of grassland for catde 
grazing, and fallow areas with low second growth are re- 
tained. In more remote and forested areas on slopes, 
shifting cultivation has resulted in various successional 
stages of secondary growth. Tree plantations are often 
extensive. They range from the diversified, forest-like 
agroforests of Indonesia to the vast and uniform indus- 
trial plantations of fast growing exotic trees grown for 
fuel or pulpwood ( Eucalyptus , Gmelina, and Acacia) , lum- 
ber ( Tectona , Pinus , and Dipterocarpaceae) , fruit (Mango), 
and especially rubber ( Hevea ) and oil ( Elaeis ). Together 
with open cultivated woodlands and home gardens, they 
currently cover much larger areas than natural forests. 
Urban, industrial, and recreational areas are increasing 
everywhere with the increasing human population and 
economic development. 

Methods 

Only resident and regular wintering migrant diurnal 
raptors were considered, while vagrants and transient mi- 
grants were ignored. I surveyed raptor populations over 
extensive areas from 1975-95, mostly in Nepal, northern 
and southern India, Andamans, Sri Lanka, Malaysia, Bor- 
neo, Sumatra, Java, Laos, and Vietnam. In each region, 


two sets of methods were used to assess the relative abun- 
dance and habitat selection of raptors. First, extensive 
transect counts were made along roads, tracks, and forest 
trails, either by car with numerous stops or on foot. The 
second method was an adaptation of the point count 
method (Thiollay 1989, 1995) where 1-km 2 sample quad- 
rats, predominantly covered by a single habitat type, were 
censused for 4 hr from vantage lookouts during morning 
periods (0900-1200 H) when most raptors were active 
The results were expressed in mean number of individ- 
uals, respectively, per km of transect or per 1-km 2 sample 
plot. Differences between these abundance indices (with- 
in, but not between species, because of unequal detect- 
abilities) were tested among habitats and study areas us- 
ing Kruskal-Wallis one-way AN OVA, followed by a non- 
parametric multiple pair-wise comparison procedure 
based on two-tailed Mann-Whitney 6-tests (Sokal and 
Rohlf 1981). 

Habitat types, where each individual raptor was record- 
ed in cumulative random samples, were used to assess 
specific habitat selection compared to habitat availability 
using the method of Neu et al. (1974). Thus, species 
were classified into broad categories of habitat prefer- 
ence, illustrating their distributional trend along the hab- 
itat gradient from primary forest to deforested habitats 
and their ability to withstand increasing deforestation. 
Random records were also used to measure specific hab- 
itat niche breadth, (3 = S(p ; 2 ) -1 , where p ; was the pro- 
portion of birds sighted in the i th habitat category. Two- 
tailed sign tests were used for interspecifc comparisons 
of habitat niches. 


March 1998 


Status of Raptors in Tropical Asia 


43 


Table 2. Component scores of the conservation index attributed to tropical Asian raptors. The total index was the 
sum of the species rank value in each of three parameters. 


Conservation Parameters 

Rank 

Range Area 

Main Habitat 

Population Trend 

0 

>75% of S. Asia 

Open and cultivated habitats 

Stable or increasing 

1 

50-75% of S. Asia 

Forest edges or woodlands 

Probable but undocumented decline 

2 

25-49% of S. Asia 

Disturbed or secondary forests 

Moderate or locally documented decline 

3 

<25% of S. Asia 

Primary forest interior 

Significant and widespread decrease 


The following habitat categories were defined: WET, 
all wetlands from marshes, lakes and rivers to swamp for- 
ests and mangroves; CULT, grasslands and cultivated ar- 
eas; TREE, open woodlands, orchards, isolated woodlots, 
and edges; FOR 1, highly degraded forest with dense sec- 
ond growth and open canopy, as well as tree plantations; 
FOR 2, secondary forest heavily logged or disturbed and 
agroforests; FOR 3, high, submature but logged forest 
with almost continuous canopy; and FOR 4, large tracts 
of dense, mostly evergreen, undisturbed, primary forest. 

Most accounts are based on personal observations ei- 
ther unpublished or in Thiollay (1978, 1983, 1993, 1995, 
1996, 1997) and Thiollay and Meyburg (1988), and sup- 
plemented by information provided by numerous orni- 
thologists. The following references were used to sum- 
marize data available for each country not personally sur- 
veyed and to estimate population trends by comparison 
with past status: Baker 1928, Delacour andjabouille 1931, 
Whistler 1941, Deignan 1963, Smythies 1953, 1981, Wil- 
dash 1968, Henry 1971, King et al. 1975, Medway and 
Wells 1976, Ali and Ripley 1978, Morris 1986, van Marie 
and Voous 1988, Lekagul and Round 1991, MacKinnon 
and Philipps 1993, del Hoyo et al. 1994. 

A numerical conservation index was assigned to each 
species whose breeding population was mostly within the 
study region according to Usher (1986). It was the sum 
of three 0-3 scores, such that the species with the most 
limited geographic range and habitat preference, the 
highest forest use, and the most declining populations 
(e.g., the most Vulnerable or Threatened species) got the 
highest ranking (Table 2). All values were conservative 
estimates to avoid an overemphasis of the threat level. 

Results 

Raptor Community Composition and Distribu- 
tion. In South Asia, 20 species of Falconiformes are 
nonbreeding migrants and are found only in win- 
ter. They include 12 widespread species (5 harriers 
( Circus spp., Chinese Goshawk [Accipiter soloensis], 
Japanese Sparrowhawk [A. gularis ] , Grey-faced Buz- 
zard [ Butastur indicus ], Common Buzzard [Buteo 
buteo ], Steppe Eagle [ Aquila nipalensis ], Booted Ea- 
gle [Hieraaetus pennatus ] , and Eurasian Hobby [Fal- 
co suhbuteo ] ) . Eight species (Eurasian Black Vulture 
\Aegypius monachus ] , Eurasian Sparrowhawk [Accip- 
iter nisus\, Long-legged Buzzard [ Buteo rufinus ] , 


Greater Spotted Eagle [ Aquila clanga] , Eurasian 
Imperial Eagle [A. heliaca ], Lesser Kestrel [Falco 
naumanni\ , Merlin [F. columbarius ] , and Saker Fal- 
con [F. cherrug]) are rare or local in their occur- 
rence. 

Among the 49 breeding species, 15 are spread 
over the three geographical zones, eight are in two 
zones, 20 are in only one zone, and six are restrict- 
ed to Andamans or Java (Table 3). The number of 
resident species steadily decreases from large con- 
tinental areas (north and northeast India, 35 taxa), 
the large southern peninsulas (south India to In- 
dochina, 23-28 taxa), narrow peninsulas and the 
largest islands (Malaysia and Borneo, 19-20 taxa), 
to more outlying islands (Sri Lanka to Java, 17-18 
taxa) and oceanic archipelagoes (4—6 taxa). The 
reduction in species richness is related to both 
land area, degree of isolation, and historical fac- 
tors. 

Habitat Selection and Implications. Eight species 
associated with interior primary moist forests, ex- 
cept the island endemics Andaman Serpent-eagle 
( Spilornis elgini ) and Nicobar Serpent-eagle ( S. klos- 
si) , are intolerant of logging or forest fragmenta- 
tion, These species may have no viable populations 
outside the current extent of undisturbed forest. 
Crested Goshawk ( Accipiter trivirgatus) and Wal- 
lace’s Hawk-eagle ( Spizaetus nanus ) are almost ex- 
clusively found in lowland forest while Jerdon’s 
Baza (Aviceda jerdoni) and Javan Hawk-eagle ( Spi- 
zaetus bartelsi ) are found at elevations as high as 
submontane forest. Blyth’s Hawk-eagle ( Spizaetus 
alboniger ) and Mountain Hawk-eagle ( S. nipalensis) 
are restricted to hill and montane forests and they 
withdraw in winter from upper altitudes to lowland 
India and Malaysia. 

Six forest species actually use forest gaps, upper 
canopy, and edges for hunting and are more tol- 
erant to disturbance, fragmentation, and logging. 
They may actually benefit from partial opening of 


44 


Thiollay 


Vol. 32, No. 1 


Table 3. Distribution of 49 raptor breeding species within South Asia. 


Distributed in 


Number 

of 

Species 

S to NE 
Indta 

Andamans 

AND 

Nicobars 

Thailand 
to Vietnam 

Malaysia 

Borneo 

Sumatra 

Java 

Examples 

4 

+ 

+ 

+ 

+ 

+ 

Spilornis cheela, Accipiter virga- 


tus 

7 

+ 


+ 

+ 

+ 

Pernis ptilorhynchus, Accipiter tri- 


virgatus 

1 

+ 

+ 


Aviceda leuphotes 

4 

+ 


+ 

+ 


Aviceda jerdoni, Ichthyophaga 


humilis 

1 

+ 


+ 


+ 

Falco severus 

1 

+ 


+ 

+ 

Falco peregrinus 

6 

+ 


+ 


Accipiter badius, Milvus migrans 

11 

+ 


Butastur teesa, Falco chicquera 

3 


+ 


Spilornis elgini , S. klossi 

1 


+ 


Polihierax insignis 

1 


+ 


+ 

Butastur liventer 

5 


-I- 


Spizaetus alboniger, S. nanus 

1 


+ 

+ 

Michrohierax fringillarius 

3 


+ 

Spizaetus bartelsi, Falco moluccen- 


sis 

Total 

35 

8 

24 

22 

18 


Andamans-Nicobars (oceanic archipelago) and Java (landbridge island), because of their endemic taxa, have been separated from 
the larger Indian, Indochinese and Sundan subregions. 


the forest. Five species (Black Baza [Aviceda leupho- 
tes ] , Oriental Honey-buzzard [Pernis ptilorhynchus ] , 
Besra [Accipiter virgatus ], Indian Black Eagle [Icti- 
naetus malayensis ], and Rufous-bellied Eagle [Hi- 
eraaetus kieneni] ) have a wide altitudinal range, 
while one species (Kinabalu Serpent-eagle [Spilor- 
nis kinabaluensis ]) is restricted to montane forest. 
Populations of honey-buzzards and bazas are aug- 
mented in winter when the northern subspecies 
migrates south. All six species easily fly between 
separate forest patches. 

Nineteen species are associated with woodlands, 
edges, and open or degraded secondary forests. 
They are not true forest species and tolerate a 
moderate level of deforestation and readily accept 
tree plantations. Crested Serpent-eagle ( Spilornis 
cheela), Shikra ( Accipiter badius), Nicobar Sparrow- 
hawk (A. butleri), Changeable Hawk-eagle ( Spizaetus 
cirrhatus), White-rumped Pygmy Falcon ( Polihierax 
msignis), and Red-necked Falcon ( Falco chicquera ) 
forage in forests from mid-level to the ground. All 
species of falconets ( Microhierax spp.) take prey in 
flight from exposed perches, including emergent 
trees of closed canopies. Bat Hawks ( Macheiram - 


phus alcinus) , Oriental Hobbies ( Falco severus) , and 
Peregrine Falcons ( F. peregrinus) hunt above or 
around the forest and are more sensitive to prey 
abundance than to vegetation structure. Wintering 
migrants (Chinese Goshawk, Japanese Sparrow- 
hawk, Eurasian Sparrowhawk, Common Buzzard, 
Booted Eagle \Hieraaetus pennatus ] , and Eurasian 
Hobby) share the least wooded habitat types. 

Ten migrant and 14 resident species use open 
grasslands and cultivated and suburban areas. They 
are mostly distributed in the drier, less forested 
northern tropics. They appear to avoid dense for- 
ests, but only the smaller species (Black-winged 
Kite [ Elanus caeruleus ], two species of buzzards [Bu- 
tastur spp.], and three species of falcons), migrants 
(Grey-faced Buzzard [Butastur indicus ], Long-leg- 
ged Buzzard, two species of harriers and three spe- 
cies of falcons), and scavengers (Black Kites [Mil- 
vus migrans], and six species of vultures) may ac- 
tually benefit from extensive deforestation, culti- 
vation, and overgrazing. Eagles (Short-toed 
Snake-eagle [ Circaetus gallicus\ and three species of 
Aquila ) usually remain associated with more natu- 
ral habitats. 


March 1998 


Status of Raptors in Tropical Asia 


45 


Eleven wetland species use marshes and rice- 
fields, freshwater lakes, coastal lagoons, rivers and 
forest streams, or sea coasts. Residents are Brah- 
miny Kite ( Haliastur indus) , White-bellied Sea-eagle 
( Haliaeetus leucogaster ) , Pallas’s Sea-eagle (H. leuco- 
ryphus), Grey-headed Fish-eagle ( Ichthyophaga ich- 
thyaetus), Lesser Fish-eagle (/. humilis ) , and Lesser 
Spotted Eagle ( Aquila pomarina ) . Migrants include 
Western Marsh-harrier ( Circus aeruginosus ) , Eastern 
Marsh-harrier (C. spilonotus ), Pied Harrier (C. me- 
lanoleucos), and Greater Spotted Eagle. The Osprey 
(Pandion haliaetus) has a small coastal breeding 
population in Java but is overall a widespread win- 
tering species. The response of wetland raptors to 
habitat changes differs among species. Large pi- 
scivorous birds such as sea and fishing eagles are 
often adversely affected because of decreasing fish 
stocks and suitable trees for hunting perches along 
banks. More terrestrial eagles (e.g., Aquila) may be 
affected by a lack of undisturbed shallow 7 marshes 
and humid grasslands, whereas more versatile spe- 
cies (e.g., species of Haliastur and Circus) may be 
benefitted because they are much more adaptable 
to heavy human disturbance of wetlands. 

Northern migrants, except locally the Booted 
Eagle (Hieraaetus pennatus), are virtually absent 
from forests. They make up 32-42% of all raptor 
species in the other three habitat categories. 

Conservation Status. The number of Threat- 
ened or Near Threatened species is alarming. 
Among the 49 breeding taxa, 22 have a high con- 
servation index (5-9) and/or are in one of the 
categories of threat in the IUCN World Red List 
(Table 4, Collar et al. 1994). There is no extinct 
species nor is any raptor population currently de- 
pendent on a captive-breeding program. However, 
two subspecies of the Lesser Spotted Eagle ( Aquila : 
pomarina hastata) from India, and Wallace’s Hawk- 
eagle ( Spizaetus nanus stresemanni) from Nias Is- 
land, W. Sumatra, seem to be Critically Endan- 
gered (Thiollay 1996). 

All eight forest interior species, nearly half of the 
more tolerant forest or wedand species, and 25% 
of woodland and open habitat species are consid- 
ered Rare, Threatened or of Special Concern be- 
cause of their high conservation index (Table 5). 
Only two wintering migrants are globally Vulnera- 
ble (Greater Spotted Eagle) or Near Threatened 
(Eurasian Black Vulture, Aegypius monachus). Sev- 
eral other migrants have small and local popula- 
tions in South Asia, but they are widespread else- 
where. 


Population Trends. There are very few accurate 
data on raptor population dynamics in South Asia 
or trends in recent decades, yet many species con- 
sidered common or widespread 50 yr ago in re- 
gional accounts are now obviously rarer and more 
local. This is especially true for eagles, both from 
rainforests (hawk-eagles) and wetlands (fishing ea- 
gles), but also for many usually abundant species 
in genera such as Milvus , Haliastur, Elanus, Accipiter, 
Butastur, and Falco, which are now rare, if not al- 
most extirpated from large, intensively cultivated 
areas in Thailand, Vietnam, Malaysia, and Java. 
The decline is especially striking for vultures ( Gyps 
spp. and Sarcogyps calvus ) w 7 hich have apparendy 
disappeared, at least as breeders, from vast regions 
in Peninsular Malaysia, Thailand, and Indochina 
where they were once considered common. Even 
in India, their main stronghold, my roadside 
counts over a 20-yr period show significant de- 
clines in some areas. Finally, at least the forest in- 
terior species which cannot adapt to degraded 
woodlands or even to fragmented secondary forest, 
may be decreasing in parallel with deforestation. 

Specific Regional and Distribution Patterns. An 
increased density and a wider habitat niche of 
some species may result from competitive release 
when fewer competitors coexist, especially on is- 
lands (Wright 1980, Blondel 1990). Field measure- 
ments showed such striking examples of habitat 
shifts and density compensations. For example, 
Crested Serpent-eagles are widespread everywhere 
in secondary forests and woodlands in the absence 
of any congeners. However, on the Andaman ar- 
chipelago, it is associated only with mangroves, for- 
est edges or gaps, and deforested areas, whereas 
the endemic Andaman Serpent-eagle occupies all 
types of forest interior (Fig. 2), In another exam- 
ple, Changeable Hawk-eagle is restricted to open 
woodlands and degraded forests in India at upper 
elevations, in Malaysia, Borneo, and Sumatra be- 
cause another Spizaetus always replaces it in dense 
forests. In Vietnam, lowland India, and the Anda- 
mans, where there is no forest Spizaetus, Changea- 
ble Hawk-eagles, are found throughout primary 
forests and more open secondary stands (Fig. 3). 
Altitudinal segregation occurs between Wallace’s 
Hawk-eagle (in the lowlands) and Blyth’s Hawk-ea- 
gle (at upper elevations) throughout their sympat- 
ric distribution. The Besra is a common forest rap- 
tor at any elevation from southwest India to Viet- 
nam and Java, in sympatry with the larger Crested 
Goshawk. Conversely, in northern India, Nepal, 


46 


Thiollay 


Vol. 32, No. 1 


Table 4. Conservation status of breeding raptors in tropical Asia, west of the Wallace Line. The conservation index 
(see Methods) is given for mostly South Asian species, and not for taxa with extra world range. The IUCN status 
(criteria in Mace and Stuart 1994) involves only Threatened (= Endangered or Vulnerable) or Near Threatened (low 
risk) species. 


Species 

Conservation Status 

Species whose world range is mostly within South Asia 


Jerdon’s Baza (Aviceda jerdoni) 

7, low risk 

Black Baza ( Aviceda leuphotes) 

5 

Oriental Honey-buzzard ( Pernis ptilorhynchus) 

3 

Brahminy Kite ( Haliastur indus) 

2 

White-bellied Sea-eagle ( Haliaeetus leucogaster) 

3 

Lesser Fish-eagle ( Ichthyophaga humilis ) 

6, low risk 

Grey-headed Fish-eagle ( Ichthyophaga ichthyaetus) 

6, low risk 

Indian White-backed Vulture ( Gyps bengalensis) 

4, low risk 

Long-billed Vulture ( Gyps indicus) 

4, low risk 

Red-headed Vulture ( Sarcogyps calvus ) 

7, low risk 

Crested Serpent-eagle ( Spilornis cheela) 

2 

Nicobar Serpent-eagle ( Spilornis klossi ) 

6, low risk 

Kinabalu Serpent-eagle ( Spilornis kinabaluensis) 

7, data deficient 

Andaman Serpent-eagle ( Spilornis elgini) 

6, low risk 

Crested Goshawk ( Accipiter trivirgatus) 

5 

Nicobar Sparrowhawk ( Accipiter butleri ) 

7, low risk 

Besra (Accipiter virgatus) 

4 

White-eyed Buzzard ( Butastur teesa) 

4 

Rufous-winged Buzzard ( Butastur liventer ) 

6, low risk 

Indian Black Eagle ( Ictinaetus malayensis ) 

4 

Rufous-bellied Eagle ( Hieraaetus kienerii) 

6, low risk 

Changeable Hawk-eagle ( Spizaetus cirrhatus) 

2 

Mountain Hawk-eagle ( Spizaetus nipalensis) 

7, low risk 

Blyth’s Hawk-eagle ( Spizaetus alboniger) 

7 

Javan Hawk-eagle ( Spizaetus bartelsi ) 

9, Endangered 

Wallace’s Hawk-eagle ( Spizaetus nanus) 

9, Endangered 

White-rumped Pygmy Falcon ( Polihierax insignis) 

5, low risk 

Collared Falconet ( Microhierax caerulescens ) 

4 

Black-tighted Falconet ( Microhierax fringillarius ) 

4 

White-fronted Falconet ( Microhierax latifrons ) 

5, data deficient 

Pied Falconet ( Microhierax melanoleucus ) 

5, low risk 

Oriental Hobby (Falco severus ) 

4 

Laggar Falcon (Falco jugger) 

3 

Species with small and marginal breeding population in South Asia, ranging mo 
Osprey (Pandion haliaetus ) 

stly outside the region 

Pallas’s Sea Eagle (Haliaeetus leucoryphus) 
Eurasian Griffon (Gyps fulvus) 

Short-toed Snake-eagle ( Circaetus gallicus) 

Vulnerable 

Lesser-spotted Eagle (Aquila pomarina) 
Spotted Kestrel (Falco moluccensis ) 

Endangered 

Species with a substantial population in South Asia, but with a larger population 
Bat Hawk (Macheiramphus alcinus) 

Black-winged Kite (Elanus caeruleus) 

Black Kite (Milvus migrans) 

Egyptian Vulture (Neophron percnopterus) 

Shikra (Accipiter badius ) 

Tawny Eagle (Aquila rapax) 

elsewhere (Asia to Africa) 


March 1998 


Status of Raptors in Tropical Asia 


47 


Table 4. Continued. 


Species 

Conservation Status 

Bonelli’s Eagle ( Hieraaetus fasciatus) 
Common Kestrel ( Falco tinnunculus) 


Red-necked Falcon ( Falco chicquera) 
Peregrine Falcon ( Falco peregrinus) 

low risk 


Borneo, Sumatra, and maybe Malaysia, it is con- 
fined to upper elevations (1000-2000 m) separated 
from the Crested Goshawk which occurs alone in 
the lowlands. 

When all species were pooled, the density index 
of raptors in mature forests (but not in deforested 
habitats) was similar in the study areas of southwest 
India, southern Vietnam and western Sumatra, but 
it increased significantly in Sri Lanka and the An- 
daman Islands (+45%, P < 0.001, Table 6). Most 
taxa exhibited a significant density increase in un- 
disturbed forests both between small and large is- 
lands and between islands and continental areas. 
The two Serpent-eagles in the Andamans reached 
extremely high densities in their preferred habitat: 
2.78 birds/km 2 sample plot for Andaman Serpent- 
eagles in primary forests and 2.25 birds/km 2 for 
Crested Serpent-eagles in mangroves vs. 0.71-0.98 
birds/km 2 for the latter in continental woodlands. 
The abundance of Black Bazas ( Aviceda leuphotes) 
was three times higher in the Andamans than in 
Vietnam. However, the density of the one species 
of goshawk and hawk-eagle in Andamans was 
equaled and even surpassed by the cumulative 
abundance of all goshawks or hawk-eagles and ea- 
gle species ( Hieraaetus spp.) in the forests of the 
four other study areas. High population densities 
enable birds on relatively small islands to minimize 
their extinction risk. A higher tolerance to habitat 
change or disturbance may also allow them to bet- 


ter withstand human-made habitat degradation 
and fragmentation which tend to be especially se- 
vere on islands. 

Main Threats and Conservation Issues 

Habitat Loss. Most natural habitats in tropical 
Asia are decreasing primarily because of defores- 
tation. Most areas with fertile, deep soils have long 
histories of cultivation. The few remaining forests 
are on infertile soils, peat swamps, and steep slopes 
that support poorer forest types and less complex 
animal communities (Collins et al. 1991). Lowland 
rainforests, the richest of them all, are most at risk 
and are the target of most new setdements. Moist 
forests were disappearing during the early 1980s at 
an estimated rate of 1 7 000 km 2 /yr within our study 
area alone (FAO 1988, Collins et al. 1991) and 
there is no evidence that this trend has decreased 
since then. Clearcutting for either shifting or per- 
manent industrial cultivation is the main cause of 
deforestation. In monsoon forests, heavy collection 
of fuel wood is an additional pressure. Montane 
forests are more secure because of their poor ac- 
cessibility and suitability for agriculture but they 
have also lower raptor species richness. In north- 
ern Borneo and western Sumatra, I recorded 10- 
11 species in all primary forests surveyed below 
1200 m while at 1200-2200 m, there were only 4— 
6 species. 

The destruction of swamp and riverine forests 


Table 5. Status, habitat selection and conservation of raptors in South Asia. Number of species in each category 
among the 69 regular species. 


Resident 

Wintering 

Rare 3 

Threatened 15 

Mature forest interior species 

8 


4 

8 

Gap tolerant forest species 

6 


2 

3 

Woodland or forest edge species 

14 

6 

5 

5 

Dry open habitat species 

14 

10 

8 

6 

Wetland species 

7 

4 

5 

5 


3 Rare = low density and/ or patchy distribution in suitable habitats. 
b Threatened = Endangered to low risk, data deficient and/or conservation value 5-9. 


48 


Thiollay 


Vol. 32, No. 1 


Figure 2. Comparative distribution of the widespread Crested Serpent-eagle ( Spilornis cheela ) in India, Sumatra, and 
Andamans and the endemic Andaman Serpent-eagle (S. elgini) in the Andamans. Percentages of random records in 
each habitat category (see text for definition). B = habitat niche breadth. Values on bars are the selection indices 
from relative habitat availability. * = statistically significant positive or negative selection (Neu et al. 1974). 


affects eagles and the drainage of wetlands is det- 
rimental to harriers and other wintering migrants. 
Ricefields that replace marshes are much poorer 
in vertebrate prey, and mangroves are heavily used 
for timber and shrimp farming. Large mangrove 
forests in estuaries, such as the Sundarbans (Sarker 
1986), harbor dense populations of several raptors 
that have already been lost from similar areas in 
southern Vietnam (Morris 1986). 

Habitat Degradation. Habitat degradation is an 
insidious, widespread phenomenon that diminish- 


es the quality of natural habitats. Raptor commu- 
nities become less complex in these areas and their 
overall density may also decline. From open wood- 
lands to undisturbed rainforests in all five study 
areas, the overall mean species richness per sample 
plot increased by 162% and the mean abundance 
index by 176% (Table 4). 

The main causes of forest degradation are log- 
ging and shifting cultivation. Both lead to second- 
ary stands whose general characteristics include 
lower and more open canopies, a reduced number 


March 1998 


Status of Raptors in Tropical Asia 


49 


Habitats 


Figure 3. Comparative distribution of Changeable 
Hawk-eagle ( Spizaetus cirrhatus ) with a forest congener in 
India and Sumatra and without competitor in the An- 
daman Islands. Symbols as in Fig. 2. 


and diversity of large trees, a denser undergrowth, 
and a higher frequency of gaps and dense vine tan- 
gles than primary forest. Effects of logging are se- 
vere (Burgess 1971). During the first years after 
logging, the density, diversity, and accessibility of 
many prey species decrease markedly (Wilson and 
Johns 1982, Johns 1985, 1986, 1987, Bennett and 
Dahaban 1995, Hill et al. 1995), although a partial 
recovery occurs after 10 yr and suitable manage- 
ment practices may minimize losses (Johns 1989, 
1992). The ultimate stages of forest degradation 
are dense stands of bamboo ( Bambusacae ) or patch- 
es of high coarse grass ( Imperata cylindrica), both of 
which prevent forest regeneration and are unsuit- 
able for most raptors. 

Road building through forests brings distur- 
bance, hunting, gaps, and dense edges. Sylviculture 
leads to decreasing biodiversity and permanently 
submature stands because some fast-growing spe- 
cies are favored over hardwoods (Panayotou and 
Ashton 1992). The widespread exploitation of mi- 
nor forest products, especially resins and rattans 
( Calamus sp.) is an additional cause of disturbance 
and hunting. 

Raptor species adapting to man-made habitats 
naturally occur in open grasslands, woodlands, for- 
est edges, and gaps. They are generalists and have 
a wide distribution. Most artificial landscapes are 
unsuitable for dense forest specialists with indus- 
trial tree plantations being the poorest. Even the 
diversified traditional agroforests of Indonesia do 
not conserve more than half the forest raptor spe- 
cies and only as long as natural forest remains 


Table 6. Mean number of raptor/ species and adult birds on sample plots surveyed in five areas of South Asia. 


SW Ghats 

South 

Western 

Sri Lanka 


(India) 

Vietnam 

Sumatra 

SW 

Andamans 

Total Number of 1-km 2 Sample Plots 

156 

56 


103 

18 

130 

Open habitats 

Species richness/ 

1.71 ± 

1.14 

1.21 ± 

1.05 

0.47 ± 0.15 

1.00 ± 0.63 

0.79 ± 0.17 

(CULT + TREE) 

plot (x ± SD) 
Individuals/plot 

2.37 ± 

1.74 

2.00 ± 

1.46 

0.77 ± 1.09 

1.17 ± 0.75 

1.04 ± 1.12 


(x ± SD) 


Degraded forests, 

Species richness/ 

2.11 ± 

0.77 

1.77 ± 

1.36 

1.29 ± 0.77 

2.50 ± 0.54 

1.77 ± 0.82 

agroforests 

plot (x ± SD) 


and mangroves 

Individuals/plot 

3.06 ± 

1.24 

2.77 ± 

2.04 

1.83 ± 0.15 

4.17 ± 1.16 

2.77 ± 1.45 

(FOR 1 + FOR 2) 

(x ± SD) 


Primary or 

Species richness/ 

2.55 ± 

0.97 

2.45 ± 

1.08 

2.64 ± 0.87 

3.33 ± 1.63 

2.60 ± 0.65 

litde disturbed 

plot (x ± SD) 


forests 

Individuals/plot 

3.65 ± 

1.47 

3.67 ± 

1.68 

3.43 ± 1.16 

4.33 ± 1.36 

5.20 ± 1.51 

(FOR 3 + FOR 4) 

(x ± SD) 


50 


Thiollay 


Vol. 32, No. 1 


nearby (Thiollay 1995). Many dams, built in agri- 
cultural areas, are favored by Black and Brahminy 
Kites, Grey-headed Fish-eagle, and wintering har- 
riers which also benefit from irrigated and more 
wooded surroundings. 

Forest Fragmentation and Insularization. Be- 
cause of their necessarily large foraging range, low 
density, and sensitivity to disturbance, forest rap- 
tors may be severely affected by forest fragmenta- 
tion, especially forest interior species that are re- 
luctant to cross large open areas. In lowland forest 
study areas of India, Sri Lanka, Vietnam, and Su- 
matra, there were 0.16-0.34 bazas, hawk-eagles, ea- 
gles ( Hieraaetus spp.) or Besras per km 2 . Assuming 
that there was at least an extra bird for each ter- 
ritorial pair, these figures represented an average 
density of about one pair of each species/ 1000— 
1500 ha of primary forest. 

Two examples illustrate the magnitude of the 
fragmentation process. In the 1600-km long west- 
ern Ghats of Peninsular India, only 20 000 km 2 of 
humid evergreen forest remain, but the largest un- 
disturbed continuous fragment is the 90 km 2 Silent 
Valley National Park (Daniels 1996). In Cochinchi- 
na (23 500 km 2 ), a single 280 km 2 patch of semi- 
evergreen forest remains (approximately 1% of the 
province) within the 350 km 2 Nam Cat Tien Na- 
tional Park. The Indian Black Eagle, formerly re- 
corded, has not been found there during recent 
intensive surveys. 

In the Andaman archipelago, the most extinc- 
tion-prone raptors on small islands were the rarest 
and most specialized species, but unexpectedly 
they were also the smallest ones. Serpent-eagles 
and hawk-eagles were found on all islands smaller 
than 1 km 2 . Some pairs range over two or three 
small islands showing a high tolerance to naturally 
fragmented forest (Thiollay 1997). 

Persecution and Pollution. Raptor shooting is 
common, as well as trapping and nest robbing for 
pets, trophies, and sales to restaurants. Trade is es- 
pecially prominent in Indonesia, Thailand, and In- 
dochina. The lack of hunting in large parts of In- 
dia results in an obviously higher frequency of rap- 
tors in densely inhabited areas than anywhere else. 
Hunting and trapping pressure, however, may have 
even more severe effects through reduction of prey 
species, notably for eagles. In large parts of Indo- 
china, wildlife has been reduced to extremely low 
levels. Overfishing in streams, lakes, and marshes 
may also be a limiting factor for piscivorous eagles. 

There is no monitoring of pesticide levels in 


Asian raptors nor definite evidence of their effects. 
However, pesticides are heavily used in most coun- 
tries (except Laos) , especially Indonesia and Thai- 
land. Ricefields are routinely sprayed even in re- 
mote areas. This trend is probably increasing be- 
cause of the intensification of agriculture and the 
use of more productive but pest-sensitive new va- 
rieties. The dramatic disappearance of raptors 
from several cultivated regions (e.g., Java [van Bal- 
en et al. 1993], Thailand [Lekagul and Round 
1991], and Vietnam [Thiollay pers. obs.]) suggests 
that pesticides have had a negative effect on rap- 
tors over the last 20 yr. No comparable declines 
have been recorded in forested or little-cultivated 
areas. 

The disappearance of the once common vul- 
tures and kites in populated areas, especially Thai- 
land, Indochina, and Malaysia, can be explained 
by a lower food availability due to increased sani- 
tation. This may have also begun to occur in India. 

Conclusions and Recommendations 

In summary, tropical Asian raptors may be divid- 
ed into three broad groups from a conservation 
point of view. First, true forest species mostly sen- 
sitive to habitat loss, degradation, and fragmenta- 
tion, need protected areas of undisturbed forests. 
The second group includes forest edge or gap and 
woodland species that are more tolerant to forest 
disturbance and opening. Their conservation re- 
quires habitat management, measures to minimize 
the effects of habitat changes, and provision of 
their minimum needs in terms of tree cover and 
prey availability. Most wetland species are also de- 
pendent on habitat management actions. The last 
group includes the grassland species which are 
more adaptable to human activity and are now 
largely found in cultivated and deforested areas. 
Their highest management priority is the direct 
protection from persecution and pollution. Most 
migrants also fall in this category. 

Basic knowledge necessary to design appropriate 
conservation strategies is often lacking. Specific 
ecological requirements are little known, popula- 
tion levels and trends are not quantitatively docu- 
mented, and threats and causes of declines are 
poorly understood. Also, demographic parameters, 
minimum viable population sizes, and dispersal 
abilities have never been investigated in most Asian 
raptor species. An intensive survey and conserva- 
tion action plan are currently in progress only for 
the Javan Hawk-eagle (estimated population 100 


March 1998 


Status of Raptors in Tropical Asia 


51 


pairs, van Balen 1995). Assessing the distribution, 
size, and viability of remaining populations of 
threatened forest and wetland eagles such as hawk- 
eagles and fishing eagles is an urgent priority. Only 
immediate measures could save the Critically En- 
dangered subspecies of the Wallace’s Hawk-eagle 
( Spizaetus nanus stresemanni) from Nias Island or 
the Lesser Spotted Eagle ( Aquila pomarina hastata ) 
from Indo-gangetic plains. 

The extension and enforcement of the current 
network of protected areas is a high priority. Pro- 
tected areas cover only 4.5% of Southeast Asia 
(IUCN 1990) and many of them are heavily dis- 
turbed and increasingly encroached by people. 
The highest conservation priority is the lowland 
rainforest which is fast disappearing everywhere. 
Forest management policies must promote biodi- 
versity conservation in production forests, reduce 
logging damages, maintain a network of unlogged 
patches, and avoid large plantations of exotic trees. 
Tree cash crops could be made more hospitable to 
raptors by increasing their structural and floristic 
diversity, and traditional agroforests must be en- 
couraged (Thiollay 1995). Finally, cultivated areas 
become the most widespread habitat and the main 
wintering ground for migrants. Therefore, their 
sound management is a priority for the conserva- 
tion of raptors in Asia, with an emphasis on the 
maintenance of trees and fallow patches, and a 
drastic reduction of hunting pressure and pesticide 
use. 

Literature Cited 

Ali, S. and S.D. Ripley. 1978. Handbook of the birds of 
India and Pakistan. Vol. 1. Oxford Univ. Press, Delhi, 
India. 

Baker, E.C.S. 1928. The fauna of British India birds. Vol. 

V. Taylor and Francis, London, U.K. 

Bennett, E.L. and Z. Dahaban. 1995. Wildlife response 
to disturbances in Sarawak and their implications for 
forest management. Pages 66-86 in R.B. Primack and 
E. Lovejoy [Eds.], Ecology, conservation and manage- 
ment of Southeast Asian rainforests. Yale Univ. Press, 
New Haven, CT U.S.A. 

Blondel, J. 1990. Long-term studies on bird communi- 
ties and populations in mainland and island Mediter- 
ranean forests. Pages 167-182 in A. Keast [Ed.], Bio- 
geography and ecology of forest bird communities. 
S.P.B. Academic Publ., The Hague, Netherlands. 
Burgess, P.F. 1971. The effect of logging on hill dipter- 
ocarp forests. Malay. Nat. J. 24:231-237. 

Collar, N.J., M.J. Crosby and A.J. Stattersfield. 1994. 
Birds to watch. The world list of threatened birds. 
Birdlife International, Cambridge, U.K. 


Collins, N.M., J.A. Sayer and T.C. Whitmore [Eds]. 
1991. The conservation atlas of tropical forests, Asia 
and the Pacific. IUCN and MacMillan Press, London 
U.K. 

Daniels, R.J.R. 1996. Landscape ecology and conserva- 
tion in the western Ghats, south India. Ibis 138:64—69. 

Deignan, H.G. 1963. Checklist of the birds of Thailand 
Bull. U.S. Natl. Mus. 226, Smithsonian Inst., Washing- 
ton DC U.S.A. 

del Hoyo, J., A. Elliott and J. Sargatal. 1994. Hand- 
book of the birds of the world. Vol. 2. Lynx Edicions, 
Barcelona, Spain. 

Delacour, J. and P. Jabouille. 1931. Les oiseaux de 
l’lndochine Fran^aise. Exposition coloniale interna- 
tionale, Paris, France. 

FAO. 1988. An interim report on the state of forest re- 
sources in the developing countries. FAO, Rome, It- 
aly. 

Henry, G.M. 1971. A guide to the birds of Ceylon. Ox- 
ford Univ. Press, London U.K. 

Hill, J.K., K.C. Hamer, L.A. Lace and W.M. Banham. 
1995. Effects of selective logging on tropical forest 
butterflies on Burn, Indonesia./. Applied Ecol. 32:754— 
760. 

IUCN. 1990. IUCN directory of South Asian protected 
areas. IUCN, Gland and Cambridge, U.K. 

Johns, A.D. 1985. Selective logging and wildlife conser- 
vation in tropical rainforest: problems and recom- 
mendations. Biol. Conserv. 31:355-375. 

. 1986. Effects of selective logging on the ecolog- 
ical organization of a peninsular Malaysian rainforest 
avifauna. Forktail 1:65-79. 

. 1987. The use of primary and selectively logged 

rainforest by Malaysian Hornbills ( Bucerotidae ) and im- 
plications for their conservation. Biol Conserv. 40:179- 
190. 

. 1989. Recovery of a peninsular Malaysian rain- 
forest avifauna following selective timber logging: the 
first twelve years. Forktail 4:89—105. 

. 1992. Species conservation in managed tropical 

forests. Pages 15-53 in T.C. Whitmore and J.A. Sayer 
[Eds.], Tropical deforestation and species extinction. 
Chapman and Hall and IUCN, London, U.K. 

King, B., M. Woodcock and E.C. Dickinson. 1975. A 
field guide to the birds of Southeast Asia. Collins, 
London, U.K. 

Lekagul, B. and P.D. Round. 1991. A guide to the birds 
of Thailand. Saha Karn Bhaet Co., Bangkok, Thai- 
land. 

Mace, G. and S. Stuart. 1994. Draft IUCN Red List Cat- 
egories. Species 21—22:13—24. 

MacKinnon, J. and K. Philipps. 1993. A field guide to 
the birds of Borneo, Sumatra, Java, and Bali. Oxford 
Univ. Press, Oxford, U.K. 

Medway, L. and D.R. Wells. 1976. The birds of the Ma- 
lay peninsula. Witherby, London U.K. 


52 


Thiollay 


Vol. 32, No. 1 


Morris, G.E. 1986. Birds of prey in Vietnam. Birds of Prey 
Bull 3:163-169. 

Neu, L.W., C.R. Byers and J.M. Peek. 1974. A technique 
for analysis of utilization-availability data. J, Wildl. 
Manage. 38:541-545. 

Panayotou, T. and P.S. Ashton. 1992. Not by timber 
alone. Economics and ecology for sustaining tropical 
forests. Island Press, Washington, DC U.S.A. 

Sarker, S.U. 1986. Population dynamics of raptors in the 
Sundarban forests of Bangladesh. Birds of Prey Bull. 3: 
157-162. 

Smythies, B.E. 1953. The birds of Burma, 2nd Ed. Oliver 
and Boyd, Edinburgh U.K. 

. 1981. The birds of Borneo. The Sabah Society, 

Kota Kinabalu. 

Sokal, R.R. AND F.J. Rohlf. 1981. Biometry. Freeman 
and Co., San Francisco, CA U.S.A. 

Thiollay, J.M. 1978. Distribution des Falconiformes ni- 
cheurs autour du massif de l’Annapurna (Himalaya 
central). Oiseau Rev. Fr. Omithol. 48:291-310. 

. 1983. Evolution actuelle du peuplement de ra- 

paces diurnes dans le nord de Borneo. Alauda 51: 
109-123. 

. 1989. Censusing of diurnal raptors in a primary 

rainforest: comparative methods and species detect- 
ability. J. Raptor Res. 23:72—84. 

. 1993. Response of a raptor community to 

shrinking area and degradation of tropical rainforest 
in the southwestern Ghats (India). Ecography 16:97- 
110 . 

. 1995. Rainforest raptor communities in Suma- 
tra: the conservation value of traditional agroforests. 
In D.M. Bird, D.E. Varland andJ.J. Negro [Eds.], Rap- 
tor adaptations to human influenced environments. 
Academic Press, London U.K. 


. 1996. The raptor community of Nias Island, Su- 
matra: survey and conservation. Rukila 8:113-116. 

. 1997. Distribution and abundance patterns of 

bird community and raptor populations in the An- 
daman Archipelago. Ecography 20:67-82. 

and B.-U. Meyburg. 1988. Forest fragmentation 

and the conservation of raptors: a survey of the island 
of Java. Biol. Conserv. 44:229-250. 

Usher, M.B. 1986. Wildlife conservation evaluation: at- 
tributes, criteria and values. Pages 3-44 in M.B. Usher 
[Ed.], Wildlife conservation evaluation. Chapman 
and Hall, London, U.K. 

van Balen, B. 1995. Red data bird: Javan Hawk-eagle. 
World Birdwatch 17:20-21. 

, I.S. Suwelo, D.S. Hadi, D. Soepomo, R. Marlon 

and Mutiarina. 1993. The decline of the Brahminy 
Kite, Haliastur indus, on Java. Forktail 8:83-88. 

van Marle, J.G. and K.H. Voous. 1988. The birds of 
Sumatra. B.O.U. Checklist No. 10. British Ornitholo- 
gists’ Union, Tring, U.K. 

Whistler, H. 1941. Popular handbook of Indian birds. 
Gurney and Jackson, London U.K. 

Whitmore, T.C. 1985. Tropical rainforests of the Far 
East, 2nd Ed. Clarendon Press, Oxford U.K. 

Wildash, P. 1968. Birds of south Vietnam. Charles Tutde 
Publ., Tokyo, Japan. 

Wilson, W.L. and A.D. Johns. 1982. Diversity and abun- 
dance of selected animal species in undisturbed for- 
est, selectively logged forest, and plantations in East 
Kalimantan, Indonesia. Biol. Conserv. 24:205-218. 

Wright, S.J. 1980. Density conservation in island avifau- 
nas. Oecologia 45:385—389. 

Received 16 October 1996; accepted 9 October 1997 


March 1998 


Status of Raptors in Tropical Asia 


53 


Appendix 1. Status and distribution of raptors in South Asia. B = breeding but may include additional, wintering 
nonresident populations; W = only wintering migrants, usually from Eastern Palearctic zone. Number of subspecies 
in parentheses after species names. 


N 

Pen. 

Sri 

NE 

Anda- 

Bur- 

Thai- 

Viet- 

Malay Sara- 

S Bor- Suma- 


India 

India Lanka India 

mans 

MA 

land 

NAM 

Pen. 

WAK 

neo 

IRA 

Java 

Osprey 

Pandion haliaetus (2) 
Jerdon’s Baza 

W 

W 

W 

W 


w 

W 

W 

W 

w 

W 

w 

B 

Aviceda jerdoni (3) 
Black Baza 


B 

B 

B 


B 

B 

B 

W 

B 

B 

B 


Aviceda leuphotes (3) 
Oriental Honey-buzzard 


B 

W 

B 

B 

B 

W 

W 

W 


W 


Pernis ptilorhynchus (4) 
Bat Hawk 

B 

B 

B 

B 

W 

B 

B 

B 

B 

B 

B 

B 

B 

Macheiramphus alcinus (1) 
Black-winged Kite 


B 

B 

B 

B 


Elanus caeruleus (2) 
Black Kite 

B 

B 

B 

B 


B 

B 

B 

B 

B 

B 

B 

B 

Milvus migrans (2) 
Brahminy Kite 

B 

B 

B 

B 


B 

B 

B 

W 


Haliastur Indus (2) 

B 

B 

B 

B 


B 

B 

B 

B 

B 

B 

B 


White-bellied Sea-eagle 
Haliaeetus leucogaster (1) 
Pallas’s Sea-eagle 

B 

B 

B 

B 

B 

B 

B 

B 

B 

B 

B 

B 

B 

Haliaeetus leucoryphus (1) 

B 


B 


B 


Lesser Fish-eagle 
Ichthyophaga humilis (1) 
Grey-headed Fish-eagle 

B 


B 


B 

B 


B 

B 

B 

B 


Ichthyophaga ichthyaetus (2) 
Egyptian Vulture 

B 

B 

B 

B 


B 

B 

B 

B 

B 

B 

B 

B 

Neophron percnopterus ( 1 ) 
Indian Black-backed Vulture 

B 

B 


Gyps bengalensis (1) 
Long-billed Vulture 

B 

B 


B 


B 

B 

B 

B 


Gyps indicus (2) 
Eurasian Griffon 

B 

B 


B 


B 

B 

B 


Gyps fulvus (1) 
Eurasian Black Vulture 

B 


B 


Aegypius monachus (1) 
Red-headed Vulture 

W 


Sarcogyps calvus (1) 
Short-toed Snake-eagle 

B 

B 


B 


B 

B 

B 

B 


Circaetus gallicus (1) 
Crested Serpent-eagle 

B 

B 


W 

W 

W 

W 


Spilomis cheela (16) 

B 

B 

B 

B 

B 

B 

B 

B 

B 

B 

B 

B 

B 

Nicobar Serpent-eagle 
Spilomis klossi (2) 
Kinabalu Serpent-eagle 
Spilomis kinabaluensis (1) 
Andaman Serpent-eagle 


B 


B 


Spilomis elgini (1) 


B 


Pallid Harrier 

Circus macrourus (1) 
Pied Harrier 

W 

W 

W 

W 

W 

W 


Circus melanoleucos (1) 

W 

W 

W 

W 


54 


Thiollay 


Vol. 32, No. 1 


Appendix 1. Continued. 


N 

Pen. 

Sri 

NE 

Anda- 

Bur- 

Thai- 

Viet- 

Malay Sara- 

S Bor- 

SUMA- 


India 

India Lanka India 

MANS 

MA 

land 

NAM 

Pen. 

WAK 

NEO 

TRA 

Java 

Montagu’s Harrier 
Circus pygargus (1) 
Western Marsh Harrier 

W 

W 

W 

W 


Circus aeruginosus (1) 
Eastern Marsh Harrier 

W 

W 

w 

W 


Circus spilonotus (1) 
Crested Goshawk 


w 

W 

w 

W 

w 


w 


Accipiter trivirgatus (7) 
Shikra 

B 

B 

B 

B 


B 

B 

B 

B 

B 

B 

B 

B 

Accipiter badius (4) 
Nicobar Sparrowhawk 
Accipiter butleri (2) 
Chinese Goshawk 

B 

B 

B 

B 

B 

B 

B 

B 


Accipiter soloensis (1) 
Japanese Sparrowhawk 


W 

W 

W 

W 

W 

W 

W 

W 

W 

Accipiter gularis (2) 
Besra 


W 

w 

w 

w 

W 

W 

W 

W 

W 

Accipiter virgatus (7) 
Eurasian Sparrowhawk 

B 

B 

B 

B 

B 

B 

B 

B 

B 

B 

B 

B 

B 

Accipiter nisus (1) 
White-eyed Buzzard 

W 

W 

W 

W 


W 

W 

W 


Butastur teesa ( 1 ) 

B 

B 


B 


B 


Rufous-winged Buzzard 
Butastur liventer (1) 
Grey-faced Buzzard 


B 

B 

B 


Butastur indicus ( 1 ) 
Common Buzzard 


W 

W 

W 

W 

W 

W 

W 

Buteo buteo (2) 
Long-legged Buzzard 

W 

W 

W 

W 


W 

W 

W 


W 

Buteo rufinus (1) 

w 


Indian Black Eagle 
Ictinaetus malayensis (2) 
Lesser Spotted Eagle 

B 

B 

B 

B 


B 

B 

B 

B 

B 

B 

B 

B 

Aquila pomarina (1) 
Greater Spotted Eagle 

B 


B 


Aquila clanga (1) 

W 


W 


W 

W 

W 


Tawny Eagle 
Aquila rapax (1) 
Steppe Eagle 

B 

B 


B 


B 

W 


Aquila nipalensis (1) 
Eurasian Imperial Eagle 

W 

W 


W 


W 


Aquila heliaca (1) 
Bonelli’s Eagle 

W 


w 


W 


Hieraaetus fasciatus (I) 
Booted Eagle 

B 

B 


B 


B 

B 

B 


Hieraaetus pennatus ( 1 ) 
Rufous-bellied Eagle 

W 

W 


W 


W 


W 


Hieraaetus kienerii (2) 


B 

B 

B 


B 

B 

B 

B 

B 

B 

B 

B 

Changeable Hawk-eagle 
Spizaetus cirrhatus (5) 
Mountain Hawk-eagle 

B 

B 

B 

B 

B 

B 

B 

B 

B 

B 

B 

B 

B 

Spizaetus nipalensis (2) 

B 

B 

B 

B 


B 

W 

W 


March 1998 


Status of Raptors in Tropical Asia 


55 


Appendix 1. Continued. 


N 

Pen. 

Sri 

NE 

Anda- 

Bur- 

Thai- 

Viet- 

Malay Sara- 

S Bor- 

SUMA- 


India 

India Lanka India 

MANS 

ma 

land 

NAM 

Pen. 

WAK 

neo 

IRA 

JAVA 

Blyth’s Hawk-eagle 
Spizaetus alboniger (1) 
Javan Hawk-eagle 
Spizaetus bartelsi (1) 
Wallace’s Hawk-eagle 


B 

B 

b 

B 

B 

Spizaetus nanus 
White-rumped Pygmy Falcon 


B 

B 

B 

B 


Polihierax insignis (3) 


B 

B 

B 


Collared Falconet 
Microhierax caerulescens (2) 
Black-thighed Falconet 
Microhierax fringillarius (1) 
White-fronted Falconet 

B 


B 


B 

B 

B 

B 

B 

B 

B 

B 

Microhierax latifrons (1) 
Pied Falconet 


B 


Microhierax melanoleucus (1) 


B 


B 


B 


Lesser Kestrel 
Falco naumanni (1) 
Common Kestrel 

W 

W 


W 


Falco tinnunculus (2) 
Spotted Kestrel 
Falco moluccensis (1) 
Red-necked Falcon 

W 

B 

B 

W 


W 

W 

W 


B 

Falco chicquera (1) 

B 

B 


Merlin 

Falco columbarius (2) 
Eurasian Hobby 

W 


w 


Falco subbuteo (2) 

W 

W 


W 


W 

W 

w 


Oriental Hobby 
Falco severus (1) 
Laggar Falcon 

B 

W 

W 

B 


B 

B 

B 


B 

Falco jugger ( 1 ) 
Saker Falcon 

B 

B 


B 


B 


Falco cherrug (1) 
Peregrine Falcon 

W 


W 


Falco peregrinus (5) 

B 

B 

B 

B 

w 

B 

W 

W 

B 

B 

B 

B 

B 

Total breeding 

31 

28 

17 

31 

8 

31 

23 

23 

19 

20 

18 

18 

18 

Total wintering 

16 

11 

9 

14 

5 

13 

15 

15 

10 

6 

5 

6 

4 


Pen = Peninsular, Andamans = + Nicobars, Thailand = +Cambodia, Vietnam = +Laos, Sarawak — + Sabah. 


f. Raptor Res. 32(l):56-63 
© 1998 The Raptor Research Foundation, Inc. 


TROPICAL FOREST RAPTORS IN INDONESIA: RECENT 
INFORMATION ON DISTRIBUTION, STATUS, AND 

CONSERVATION 

S. (Bas) van Balen 

BirdLife International— Indonesia Programme, P. O. Box 31 0, BOGOR 1 6003, Indonesia; and 
Department of Terrestrial Ecology and Nature Conservation, Wageningen Agricultural University, 

Bornsesteeg 69, 6708 PD Wageningen, The Netherlands 

Abstract. — In Indonesia (subregions Sumatra, Kalimantan, Java/Bali, Sulawesi, Lesser Sundas, Moluc- 
cas, and Irian Jaya) , 68 species of diurnal birds of prey, nine of which are endemic to the region, are 
known to occur. Ever-growing pressure on natural habitats, in particular the timber-rich, tropical rain- 
forests, as well as hunting and the use of pesticides, is believed to have major impacts on the numbers 
and distribution of these species. The status of 20 species is a matter of concern since three species are 
considered globally Threatened and eleven others are Near Threatened. The status of yet another five 
species is of local concern as they are widespread and relatively common elsewhere. 

Key Words: status diurnal birds of prey; conservation ; distribution', Indonesia. 


Aves rapaces de bosques tropicales en Indonesia: informacion reciente sobre su distribucion, estado, y 
conservacion 

Resumen. — En Indonesia (subregiones de: Sumatra, Kalimantan, Java/Bali, Sulawesi, Lesser Sundas, 
Moluccas, y Irian Jaya), existen 68 especies de aves rapaces diurnas, nueve de las cuales son endemicas 
a la region. La presion constante sobre los habitats, en particular sobre los bosques de lluvia ricos en 
madera, como tambien la caza y el uso de pesticidas han tenido un impacto importante en la poblacion 
y distribucion de estas especies. El estado de 20 especies es un aspecto alarmante debido a que tres 
especies son consideradas como globalmente amenazadas y otras once como cercanamente amenazadas. 
El estado de las otras cinco especies es preocupante a nivel local unicamente debido a que tienen una 
distribucion amplia y son relativamente comunes en otras areas. 

[Traduccion de Cesar Marquez] 


Straddling the equator over a distance of 4500 
km, the republic of Indonesia has about 1539 bird 
species. Of these, 381 are endemic (Andrew 1992, 
1993) and the country ranks among the five bird- 
richest in the world (Groombridge 1994). There 
are 68 species of birds of prey, and many are forest 
dwellers, occupying many niches, with ^30 species 
on the largest islands, and at least two or three 
species on even the smallest oceanic islands (Ap- 
pendix 1). Many of Indonesia’s species are among 
the world’s least known (Meyburg 1986) because 
they are restricted to remote, little known places. 
Most research on these species has been taxonom- 
ic and was carried out in the decades before or 
around the turn of this century. Our knowledge 
on the biology and ecology on Indonesian raptors 
has been and is still fragmentary. In this paper, I 
try to summarize work done so far on raptors in 
Indonesia and identify gaps in our knowledge, as- 


sess the status of a number of selected species, eval- 
uate the current protection system, and give rec- 
ommendations for future research and protection 
measures. Although only part of the Indonesian 
raptor fauna is presumed to be dependent on for- 
ests, none can survive without some kind of wood- 
land. Therefore, I have considered both forest and 
nonforest raptors. 

Studies, Past and Present 

The first written scientific report of raptors in 
Indonesia was made by a merchant, Baron Von 
Wurmb (1779-82) who described a hawk and the 
Brahminy Kite ( Haliastur indus). In subsequent 
centuries, most studies of birds in Indonesia fo- 
cused on collecting specimens; nevertheless, they 
produced a relatively accurate distribution map for 
raptors across the archipelago, with standard an- 
notated checklists developed for Sulawesi, Lesser 


56 


March 1998 


Raptors in Indonesia 


57 


Table 1. Recent raptor studies conducted in Indonesia. 


References 

Research Subject 

Taxa 

1. Ash 1984, 1993 

Autumn migration in NW Bali 

Migratory raptors 

2. Thiollay and Meyburg 1988 

Forest fragmentation and raptor conservation on Java 

Falconiformes 

3. van Balen et al. 1993 

Conservation status on Java 

Haliastur indus 

4. Meyburg and van Balen 1994 

5. van Balen and Meyburg 1994; 

Conservation on Sulawesi 

Falconiformes 

Sozer and Nijman 1995 

Conservation, ecology and distribution 

Spizaetus bartelsi 

6. Thiollay 1996a, b 

Conservation, ecology and distribution on Sumatra 

Falconiformes 


Sundas and Moluccas (White and Bruce 1986), 
and Sumatra (van Marie and Voous 1988). Similar 
checklists are currently being written for Java, Bali, 
and Borneo, but locations such as Irian Jaya (e.g., 
western New Guinea) still need to be studied. Dur- 
ing the past decade, the study of raptors in Indo- 
nesia has experienced considerable growth and 
studies are currently being undertaken on the Gur- 
ney’s Eagle ( Aquila gurneyi) and Javan Hawk-eagle 
( Spizaetus bartelsi ) (N. R0v and J.O. Gjershaug pers. 
comm.; T. Yamazaki pers. comm.). 

National Overview 

Indonesia’s 17 000 islands show a great variety in 
habitats, influenced by climate, edaphic factors, to- 
pography, and human interference. On Java and 
most of the Lesser Sundas, high human population 
pressure, dating back from ancient times, has had 
far-reaching effects on natural ecosystems. In the 
past few decades, high technology and extensive 
exploitation of natural resources have increased 
this pressure from people at an alarming rate (Ta- 
ble 2). 

Java and Bali. Largely deforested, Java and Bali 
are essentially a mosaic of paddy fields, cities, and 
villages in the low lands, with most forest fragments 
covering the numerous volcanoes on the two is- 


lands. The most developed forest reserve system in 
Indonesia is located on these islands. However, due 
to extreme population pressure, many reserves es- 
tablished in the first half of this century are small 
and have probably lost most of their species diver- 
sity. Because of extreme habitat fragmentation, the 
endemic Javan Hawk-eagle is considered to be En- 
dangered (Collar et al. 1994). Development has 
been most concentrated in open woodland areas, 
where five raptor species, the Brahminy Kite, Ru- 
fous-winged Buzzard ( Butastur liventer), Black- 
winged Kite ( Elanus caeruleus), Changeable Hawk- 
eagle ( Spizaetus cirrhatus), and Spotted Kestrel (Fal- 
co moluccensis) , are disappearing (Thiollay and Mey- 
burg 1988, van Balen et al. 1993, Holmes 1995). 

Lesser Sundas. Burning, wood collection, and 
inefficient subsistence agriculture have long been 
destructive forces to the forests of these islands. 
The coundess islands of the Lesser Sundas are cov- 
ered in a parklike landscape of extensive grass- 
lands, thickets, and wooded river valleys. The most 
extensive forests are on Sumbawa and north Flores 
where there are few people. The conservation area 
network in the Lesser Sundas is insufficient (Sujat- 
nika et al. 1995), but the typical park landscapes 
seem to favor a relatively diverse raptor fauna in- 


Table 2. Land use and the human population in Indonesia (after Sujatnika et al. 1995). 


Total Area 
(X10 6 HA) 

Forest 

(%) 

Development 
Area (%) 

Population 

(X10 6 ) 

Density 
(per km 2 ) 

Growth 
Rate (%) 

Kalimantan 

53.95 

74 

23 

9.10 

17 

3.5 

Irian Jaya 

42.20 

85 

28 

1.65 

4 

3.5 

Sulawesi 

18.92 

59 

40 

12.52 

66 

2.0 

Sumatra 

47.34 

49 

45 

36.51 

77 

3.0 

Java/Bali 

13.77 

10 

72 

110.36 

801 

1.8 

Lesser Sundas 

8.29 

18 

49 

7.39 

89 

2.3 

Moluccas 

7.45 

74 

38 

1.86 

24 

2.8 


58 


VAN BALEN 


Vol. 32, No. 1 


eluding Short-toed Eagles ( Circaetus gallicus), Bo- 
nelli’s Eagles ( Hieraaetus fascialus). Changeable 
Hawk-eagles, Variable Goshawks ( Accipiter novaehol- 
landiae), and Brown Goshawks {A. fasciatus) . 

Sumatra. The larger part of the Sumatran low- 
land rainforest has been logged or is under a pro- 
duction regime. Mountain forests are relatively se- 
cure, though degradation and encroachment on 
lower slopes is widely reported (Sujatnika et al. 
1995). Small islands with distinct races of raptors 
are found off west Sumatra, notably Nias Island 
(e.g,, Thiollay 1996b). Separated by mainland Ma- 
laysia by only a narrow sea strait, Sumatra is an 
important passage and wintering area for southern 
bound migratory raptors from northern temperate 
regions. 

Kalimantan (Former Dutch Borneo). Until re- 
cently, extensive rainforest covered most of the is- 
land, but conversion into plantations, wasteland 
(notably alang-alang [ Impel ata cylindrica\ grass- 
fields) , and secondary growth is beginning to dom- 
inate the landscape. The island’s endemic raptors, 
the Mountain Serpent-eagle ( Spilornis kinabaluen- 
sis ) and White-fronted Falconet ( Microhierax lato- 
frons) are restricted to the northern, non-Indone- 
sian part of the island. 

Sulawesi (Former Celebes). Extensive lowland 
rainforest still covers Sulawesi, although mainly at 
moderate altitudes. In southwest Sulawesi, the 
sparse forest is only on high mountain tops, where- 
as extensive lowlands and hill forests still cover cen- 
tral Sulawesi. Agriculture, transmigration, and log- 
ging continue to absorb large areas of lowland for- 
est. Montane forest is relatively untouched, al- 
though some encroachment occurs on the lower 
slopes (Sujatnika et al. 1995). Despite harsh cli- 
matic conditions and deforestation, Coomans de 
Ruiter (1947) reported more raptors in southwest 
Sulawesi than anywhere else. Nevertheless, the for- 
merly common Black Kite ( Milvus migrans) has de- 
creased in numbers (Meyburg and van Balen 
1994). The status of the three endemic Accipiters is 
largely unknown, partly because of identification 
problems. 

Moluccas, Originally, the numerous islands of 
Moluccas were covered in tropical rainforest. High 
quality timber, and local climatic and edaphic con- 
ditions attracted loggers and led to the develop- 
ment of plantations of nutmeg and cloves. As a 
result, lowland forests have rapidly disappeared, 
and little virgin forest remains. The largest stretch- 
es of remaining original forest are found on Ser- 


am, Buru, and Halmahera (Poulsen pers. comm.). 
These areas support Rufous-necked Sparrowhawks 
(Accipiter erythrauchen) , Moluccan Goshawks (A. 
henicogrammus) , and a number of endemic races. 

Irian Jay a (Former Dutch New Guinea). Irian 
Jaya comprises the second largest and most pristine 
region in Indonesia. However, development from 
mining, logging, resettlement schemes, and infra- 
structure improvement is proceeding rapidly. Two 
large forest eagles in this area, the New Guinea 
Harpy Eagle ( Harpyopsis novaeguineae ) and Gur- 
ney’s Eagle { Aquila gurneyi ), are presumably still 
safe, but monitoring is needed to ensure that they 
continue to do well. 

Conservation of Indonesian Raptors 

There are 20 species of raptors that are globally 
Threatened and Near Threatened with extinction 
(Collar et al. 1994), or may be classified as such, 
pending further field research. The number of 
open woodland and forest edge species that are 
listed is striking. 

One of the greatest threats to these raptors is the 
loss of habitat. Large trees for perches, roosts, and 
nests are important components of raptor habitat 
(Janes 1985). Huge islands like Kalimantan and 
Irian Jaya seem well-forested and secure (Table 2), 
but present human population growth and habitat 
conversion may soon alter this. Therefore, man- 
agement of the existing forest reserve systems 
needs to be improved without delay. 

Hunting also poses a serious threat to raptors on 
Java and most other regions in Indonesia. With the 
immensely increased number of air rifles accom- 
panying the nation’s overall improved standard of 
life, raptors, like many other birds, have been dec- 
imated, especially near settlements. 

With more people that can afford the high price 
and care of pet eagles and hawks, the demand for 
wild birds is high, despite legal protection of all 
diurnal raptors. 

It is not clear if pesticides have played a major 
role in the decline of Brahminy Kites on Java. Nev- 
ertheless, a recent decline in the species reported 
from Laos indicates that the species may be un- 
dergoing a widespread decline in Southeast Asia 
(Thewlis et al. 1995). A coincident increase in use 
of pesticides on Java and Bali in the 1970s (van 
Balen et al. 1993) and the overall decline of Pond 
Herons ( Ardeola speciosa ) and egrets ( Egretta spp., 
van Helvoort 1981) is striking. The ban on 57 va- 
rieties of organophosphate chemicals since 1986 


March 1998 


Raptors in Indonesia 


59 


Table 3. Indonesian raptors of conservation concern, threats to their survival, and research needs. 


Species 

Threats 1 

Trend 

RDB 

Status 

Research 

Needs 

End- 

emic 

Taxa 

Refs. 

Aviceda jerdoni 

L2 

?< 

?NT 

monitoring 

2 

2 

Pernis ptilorhynchus 

1,2,3 

?= 

- 

taxonomy 

1 

3 

Macheiramphus aldnus 

1,4,7 

?<(B) 

- 

monitoring 

- 

4 

Elanus caerulaeus 

4,5 

«(J,S) 

- 

monitoring 

1 

4, 5 

Haliastur Indus 

?1, ?4, 5, 6 

«(J) 

- 

monitoring 

- 

1 

Ichthyophaga humilis 

1, 2 

< 

?NT 

monitoring 

- 

2 

Ichthyophaga ichthyaetus 

1, ?4, ?5 

?< 

?NT 

monitoring 

- 

2 

Accipiter henicogrammus 

1, ?3 

< 

p 

ecology 

1 

6 

Accipiter erythrauchen 

1, 2, 3 

?< 

p 

ecology 

2 

6 

Accipiter nanus 

?3 

?< 

NT 

ecology 

1 

2 

Accipiter buergersi 

7 

?= 

DD 

ecology 

- 

2 

Accipiter doriae 

1, 2, 3 

?= 

NT 

ecology 

- 

2 

Butastur liventer 

1, ?3, ?4 

<(J) 

NT 

monitoring 

- 

2 

Harpyopsis novaeguineae 

?3, 4, 7 

? = 

V 

ecology 

- 

2 

Aquila gurneyi 

1 

?= 

NT 

ecology 

- 

2 

Spizaetus cirrhatus 

1, 4, ?5 

<(J) 

- 

monitoring 

2 

4 

Spizaetus bartehi 

1, 3, 4, 7 

?« 

E 

ecology 

1 

2 

Spizaetus nanus 

1,3 

?< 

V 

ecology 

1 

2 

Spizaetus lanceolatus 

1,2 

? = 

NT 

ecology 

1 

2 

Falco moluccensis 

4, ?5 

<(J,S) 

- 

monitoring 

2 

5 


1 Threats: 1 — habitat loss; 2 — habitat degradation; 3 — forest fragmentation; 4 — hunting; 5 — pesticides; 6 — improved sanitation; 7 — 
low density/ small population. Trend: < — decrease; << — dramatic decrease; = — (presumably) stable; J — Java; S — Sulawesi; B — 
Borneo. RDB Status or Global Conservation Status (after Collar et al. 1994): E — Endangered; V — Vulnerable; DD — data-deficient; 
NT — Near Threatened; ? — possible candidate. Refs.: 1 — Van Balen et al. 1993; 2 — Collar et al. 1994; 3 — del Hoyo et al. 1994; 4 — van 
Balen 1994; 5 — Holmes 1995; 6 — M. Poulsen and D. Permiasa pers. comm. 


(Whitten et al. 1996) has not yet resulted in an 
increase in either of these species. 

Decreased food availability associated with the 
growing human population and increased sanita- 
tion have perhaps affected only a few, scavenging 
raptors (e.g., Brahminy Kite in large cities on Java 
[van Balen et al. 1993]). 

Research 

There are several specific areas where further re- 
search is necessary on Indonesian raptors (Table 
3) . It is not yet known what the long-term impact 
of logging will be on raptor populations in Indo- 
nesia. Selective logging leaves a relative high forest 
cover which supports widespread populations of 
raptors. Several species of raptors in Indonesia are 
so poorly studied that their taxonomic status may 
change as information on them increases (Sujat- 
nika et al. 1995) . A number of island races, some 
vulnerable to extinction, may prove to be full spe- 
cies, such as Accipiter griseogularis comprising A. no- 
vaehollandiae obiensis of Obi Island, A. n. griseogularis 


of Bacan and Halmahera Islands, and A. n. mortyi 
of Morotai Island (White and Bruce 1986); Spizae- 
tus cirrhatus floris of Sumbawa and Flores Islands, 
Spizaetus nanus stresemanni of Nias Island, and Per- 
nis p. ptilorhynchus of Java and P. p. torquatus of Su- 
matra, Borneo, and peninsular Malaysia (del Hoyo 
et al. 1994) . Only fragmentary information is avail- 
able on migration routes of northern migratory 
raptors. Bali Strait (Ash 1984, 1993), the eastern 
part of the Java Sea (J.H. Becking pers. comm.), 
and the Puncak pass in west Java are known as pas- 
sage points, but huge stretches in between and be- 
yond need to be investigated. 

Recommendations and Conclusions 

Future raptor studies in Indonesia should focus 
on the causes of declines of formerly common 
open woodland species, habitat use and measure- 
ment of home ranges of raptors, effects of habitat 
degradation and forest fragmentation, and migra- 
tion routes of raptors over Indonesia. 

Large areas of Sulawesi, the Moluccas, Kaliman- 


60 


VAN BALEN 


Vol. 32, No. 1 


tan, and other areas virtually are unexplored. The 
possible addition of additional natural areas that 
might be added to the current network is urgent. 

Raptors are either persecuted because they are 
suspected of killing domestic fowl or because they 
are sought as pets, especially the rarer ones. Public 
education needs to be undertaken at all levels 
through the use of posters, television spots, and 
newspaper articles to increase awareness of the im- 
portance of raptors. Local bird-watching clubs 
should be supported in monitoring the passage of 
migratory raptors as well resident raptors. 

Captive breeding has become a popular issue, 
and often too quickly considered the most impor- 
tant solution to preserve a particular rare species. 
The Javan Hawk-eagle has recently been indicated 
as a candidate for such a program. Before steps are 
taken towards establishing a captive population, 
further consideration should be given to the con- 
tribution of such a program to conservation of the 
species, its effect on the wild population, and the 
availability of secure habitat for reintroduced birds. 

A steering committee of local and international 
experts in the field of raptor ecology and conser- 
vation should supervise any future conservation ac- 
tion. Major steps have already been made by the 
adoption of an Action Plan by the “Focus Group 
for Javan Hawk-eagle Conservation” and the estab- 
lishment by the State Minister of Environment in 
January 1997 of the “Working Group for Manage- 
ment of Indonesian Raptor Areas.” Both initiatives 
are cooperative activities of the State Ministry of 
Environment, the Directorate General of Forest 
Protection and Nature Conservation (PHPA) and 
the Indonesian Institute of Sciences (LIPI) involv- 
ing various national and international organiza- 
tions, including BirdLife International-Indonesian 
Programme. 

The commitment of Indonesia’s Government to 
preserve its local wildlife is attested to by the adop- 
tion of two of its birds of prey as the mascot of 
Jakarta (Brahminy Kite) and as a national symbol 
(Javan Hawk-eagle) . The former is Indonesia’s 
most ubiquitous raptor and the second is one of 
its rarest birds of prey. 

Acknowledgments 

I would like to thank the Peregrine Fund and Dr. Rick 
Watson in particular for financial support to attend the 
symposium. Paul Jepson, Michael Poulsen, Prof. C.M. 
White and an anonymous reviewer gave useful comments 
on drafts of the paper, for which I am very grateful. 


Literature Cited 

Andrew, P. 1992. The birds of Indonesia. A checklist 
(Peters’ Sequence). Indonesian Ornithological Soci- 
ety, Jakarta, Indonesia. 

. 1993. The birds of Indonesia, Kukila checklist 

No. 1. Additions, corrections and notes — 1. Kukila 6: 
47-52. 

Ash, J.S. 1984. Bird observations on Bali. Bull. Br. Orni - 
thol. Club 104:24-35. 

. 1993. Raptor migration on Bali. Forktaii 9:3-11. 

Collar, N.J., M.J. Crosby and A.J. Stattersfield. 1994. 
Birds to watch: the world list of threatened birds. 
BirdLife International, Cambridge, U.K. 

Coomans de Ruiter, L. 1947. Roofvogelwaarnemingen 
in Zuid-Celebes. Limosa 20:213-229. 

del Hoyo, J., A. F. i.i. iott and J. Sargatal. 1994. Hand- 
book of the birds of the world. Vol. 2. Lynx Edicions, 
Barcelona, Spain. 

Groombridge, B. [Ed.]. 1994. Biodiversity data source- 
book. World Conservation Monitoring Centre, World 
Conservation Press, Cambridge, U.K. 

Holmes, D.A. 1995. Editorial. Kukila 7:85-90. 

Janes, S.W. 1985. Habitat selection in raptorial birds. 
Pages 159-188 in M.L. Cody [Ed.], Habitat selection 
in birds. Academic Press, Orlando, FL U.S.A. 

MacKinnon, J. and J. Wind. 1980. Birds of Indonesia. 
FAO, Bogor, Indonesia. 

Meyburg, B.-U. 1986. Threatened and near-threatened 
diurnal birds of prey of the world. Birds of Prey Bull 
3:1-12. 

and S. van Ba i.f. n. 1994. Raptors on Sulawesi (In- 
donesia) : the influence of rainforest destruction and 
human density on their populations. Pages 269-276 
in B.-U. Meyburg and R.D. Chancellor [Eds.], Raptor 
conservation today. World Working Group for Birds 
of Prey and Owls, London, U.K. 

Sozer, R. and V. NlJMAN. 1995. Behavioral ecology, dis- 
tribution and conservation of the Javan Hawk-eagle 
Spizaetus bartelsi Stresemann, 1924. Verslagen en 
Technische Gegevens No. 20. Institute of Systematics 
and Population Biology, Univ. Amsterdam, The Neth- 
erlands. 

Sujatnika, P., P.R. Jepson, T. Soehartono, M.J. Crosby 
and A. Mardiastuti. 1995. Conserving Indonesian 
biodiversity: the endemic bird area approach. PHPA 
and BirdLife International-Indonesia Programme, Ja- 
karta, Indonesia. 

Thewlis, R.M., J.W. Duckworth and G.Q.A. Anderson. 
1995. Ornithological records from Laos. Forktaii 11: 
47-100. 

Thiollay, J.-M. 1996a. Rainforest raptor communities in 
Sumatra: the conservation value of traditional agro- 
forests. Pages 245-260 in D.M. Bird, D.E. Varland and 
J.J. Negro [Eds.], Raptor adaptations to human influ- 
enced environments. Academic Press, London, U.K. 


March 1998 


Raptors in Indonesia 


61 


. 1996b. The raptor community of Nias Island, 

Sumatra: survey and conservation. Kukila 8:113-116. 

and B.-U. Meyburg. 1988. Forest fragmentation 

and the conservation of raptors: a survey on the is- 
land of Java. Biol. Conse rv. 44:229—250. 
van Balen, S. 1994. The status and conservation of birds 
of prey in the Sondaic and Wallacean regions of In- 
donesia. Pages 245-254 in B.-U. Meyburg and R.D. 
Chancellor [Eds.], Raptor conservation today. World 
Working Group for Birds of Prey and Owls, London, 
U.K. 

and B.-U. Meyburg. 1994. The Java Hawk-eagle 

Spizaetus bartelsv. results of recent research on distri- 
bution status and ecology. Pages 89-92 in B.-U. Mey- 
burg and R.D. Chancellor [Eds.], Raptor conserva- 
tion today. World Working Group for Birds of Prey 
and Owls, London, U.K. 

, I.S. Suwelo and D.S. Hadi. 1993. The decline 

of the Brahminy Kite Haliastur indus on Java. Forktail 
8:83-88. 


van Helvoort, B. 1981. Bird populations in the rural 
ecosystems of West Java. Student Report No. 560. Ag- 
ricultural Univ., Wageningen, The Netherlands. 

VAN Marle, J.G. and K.H. Voous. 1988. The birds of 
Sumatra. B.O.U. Check-list 10. British Ornithologists’ 
Union, London, U.K. 

VON WuRMB, F. 1779-1782. Verhandelingen van het Ba- 
taviaasche Genootschap van Kunsten en Wetenschap- 
pen. Vol. 1-4. 

White, C.M.N. and M.D. Bruce. 1986. The birds of Wal- 
lacea (Sulawesi, the Moluccas and Lesser Sunda Is- 
lands, Indonesia): an annotated check-list. B.O.U 
Check-list 7. British Ornithologists’ Union, London, 
U.K. 

Whitten, T., R.E. Soeriaatmadja and S.A. Afiff. 1996 
The ecology of Java and Bali. Periplus, Singapore. 

Received 16 October 1996; accepted 11 November 1997 


62 


VAN BALEN 


Vol. 32, No. 1 


Appendix 1. Distribution of raptors in Indonesia. Sequence, nomenclature, and subregional boundaries follow 
Andrew (1992). 


R 1 S Distribution Habitat 


Osprey ( Pandion haliaetus) <> 

Jerdorfs Baza (Aviceda jerdoni) < 

Pacific Baza ( Aviceda subcristata) > 

Black Baza ( Aviceda leuphotes) < 

Long-tailed Buzzard ( Henicopernis longicauda) P 

Oriental Honey-buzzard ( Pernis ptilorhynchus ) < 

Barred Honey-buzzard ( Pernis celebensis) < 

Bat Hawk ( Macheiramphus alcinus) <P 

Black-winged Kite ( Elanus caeruleus) <P 

Black Kite ( Milvus migrans) <> 

Whistling Kite ( Haliastur sphenurus ) > 

Brahminy Kite (Haliastur indus) <> 

White-bellied Sea-eagle ( Haliaeetus leucogaster) <> 

Lesser Fish-eagle ( Ichthyophaga humilis) < 

Grey-headed Fish-eagle ( Ichthyophaga ichthyaetus ) < 

Short-toed Eagle ( Circaetus gallicus ) < 

Crested Serpent-eagle ( Spilomis cheela) < 

Sulawesi Serpent-eagle ( Spilomis rufipectus ) E 

Spotted Harrier ( Circus assimilis ) > 

Pied Harrier ( Circus melanoleucos) < 

Western Marsh-harrier ( Circus aeruginosus) < 

Eastern Marsh-harrier (Circus spilonotus) <P 

Swamp Harrier ( Circus approximans) > 

Crested Goshawk ( Accipiter tiivirgatus) < 

Sulawesi Goshawk ( Accipiter griseiceps ) E 

Shikra (Accipiter badius) < 

Chinese Goshawk (Accipiter soloensis) < 

Spot-tailed Goshawk (Accipiter trinotatus) E 

Brown Goshawk (Accipiter fasciatus) > 

Grey Goshawk (Accipiter novaehollandiae) > 

Black-mantled Goshawk (Accipiter melanochlamys) P 

Moluccan Goshawk (Accipiter henicogrammus) E 

Grey-headed Goshawk (Accipiter poliocephalus) P 

Japanese Sparrowhawk (Accipiter gularis) < 

Besra (Accipiter virgatus ) < 

Small Sparrowhawk (Accipiter nanus ) E 

Collared Sparrowhawk (Accipiter cirrocephalus ) > 

Rufous-necked Sparrowhawk (Accipiter erythrauchen ) E 

Vinous-breasted Sparrowhawk (Accipiter rhodogaster) E 

Meyer’s Goshawk (Accipiter meyerianus ) > 

Chestnut-shouldered Goshawk (Accipiter buergersi) P 

Doria’s Hawk (Accipiter doriae) P 

Rufous-winged Buzzard (Butastur liventer) < 

Grey-faced Buzzard (Butastur indicus) < 

Common Buzzard (Buteo buteo) < 

New Guinea Eagle (Harpyopsis novaeguineae ) P 

Black Eagle (Ictinaetus malayensis) < 

Spotted Eagle (Aquila clanga ) < 

Gurney’s Eagle (Aquila gurneyi) P 

Wedge-tailed Eagle (Aquila audax) > 

Bonelli’s Eagle (Hieraaetus fasciatus) < 

Booted Eagle (Hieraaetus pennatus) < 


R/M 

JB 

T 

S 

K 

C 

M 

I 

C 

R 

- 

- 

S 

K 

C 

M 

- 

LR/SR/SS 

R 

- 

T 

- 

- 

c 

M 

I 

LM/R/SR/SS 

M 

J 

- 

s 

- 

- 

- 

- 

SS/A 

R 


I 

LR/SR 

R/M 

JB 

T 

s 

K 

c 

M 

- 

LR/FE/SS 

R 

- 

- 

- 

- 

c 

- 

- 

LR/FE 

R 

- 

- 

s 

K 

c 

- 

- 

LM/LR/FE 

R 

JB 

T 

s 

K 

c 

- 

I 

LM/FE/G/SS 

R/M 

- 

T 

s 

- 

c 

M 

I 

LM/FE/G/SS 

R 


I 

F/G/SS 

R 

JB 

T 

s 

K 

c 

M 

I 

F/C/G/SS 

R 

JB 

T 

s 

K 

c 

M 

I 

F/C 

R 

- ■ 

- 

s 

K 

c 

- 

- 

F/C 

R 

J 

- 

s 

K 

c 

- 

- 

F 

R 

JB 

T 


LM/FE/G/SS 

R 

JB 

- 

s 

K 

- 

- 

- 

LR/SR/SS 

R 

- 

- 

- 

- 

c 

- 

- 

LR/SR/G/SS 

R/M 

- 

T 

- 

- 

c 

- 

- 

G/SS 

V 

- 

- 

- 

K 

- 

- 

- 

F/G/SS 

V 

- 

- 

s 

- 

- 

- 

- 

F/G 

M 

- 

- 

s 

- 

- 

- 

I 

F/G 

M 


I 

F/S 

R 

J 

- 

s 

K 

- 

- 

- 

LR 

R 

- 

- 

- 

— 

c 

- 

- 

LR 

M 

— 

- 

s 

— 

— 

— 

— 

LR 

M 

JB 

T 

s 

K 

c 

M 

I 

LM/FE/LR 

R 

- 

- 

- 

- 

c 

- 

- 

LR/SR 

R 

- 

T 

- 

- 

c 

M 

I 

LR/SR 

R 

- 

T 

- 

- 

- 

M 

I 

F/LR/G/FE/SS 

R 


I 

MR 

R 

- 

- 

— 

- 

- 

M 

- 

LR 

R 


I 

LR/FE/SS 

M 

JB 

T 

s 

K 

c 

- 

- 

LM/LR/FE/SS 

R 

JB 

T 

s 

K 

- 

- 

- 

LR/SR/MR 

R 

- 

- 

- 

■ 

c 

- 

- 

LR/SR/MR 

R 

- 

- 

- 

- 

- 

- 

I 

LR 

R 

- 

- 

- 

- 

- 

M 

- 

LR 

R 

- 

- 

- 

- 

c 

- 

- 

LR 

R 

- 

- 

— 

- 

— 

M 

I 

LR 

R 

- 

- 

- 

- 

— 

- 

I 

SR 

R 


I 

LR/SR 

R 

J 

- 

- 

- 

c 

- 

- 

LM/LR/SR/G/SS 

M 

J 

p 

s 

- 

c 

M 

I 

FE/LM/LR/G/SS 

M 

JB 


FE/G/SS 

R 


I 

LR/SR/MR/FE 

R 

JB 

- 

s 

K 

c 

M 

- 

LR/SR 

V 

- 

- 

s 

- 

- 

- 

- 

C 

R 

- 

- 

- 

- 

- 

M 

I 

C/F/LR/G 

R 


I 

F/G 

R 

- 

T 


LM/FE 

V 

J 


LR 


March 1998 


Raptors in Indonesia 


63 


Appendix 1. Continued. 


R 1 S Distribution Habitat 


Litde Eagle ( Hieraaetus morphnoides ) 

> 

R 

- 

- 

- 

- 

- 

M 

I 

LR/SR 

Rufous-bellied Eagle ( Hieraaetus kienerii) 

< 

R 

JB 

T 

S 

K 

C 

M 

- 

LR 

Changeable Hawk-eagle ( Spizaetus drrhatus) 

< 

R 

JB 

T 

S 

K 

- 

- 

- 

LM/LR/FE/G/SS 

Javan Hawk-eagle ( Spizaetus bartelsi) 

E 

R 

J 


LR/SR 

Sulawesi Hawk-eagle ( Spizaetus lanceolatus) 

E 

R 

- 

- 

- 

- 

c 

- 

- 

LR/SR 

Blyth’s Hawk-eagle ( Spizaetus alboniger) 

< 

R 

- 

- 

s 

K 

- 

- 

- 

SR/MR 

Wallace’s Hawk-eagle ( Spizaetus nanus ) 

< 

R 

- 

- 

s 

K 

- 

- 

- 

LR 

Black-thighed Falconet ( Microhierax fringillarius) 

< 

R 

JB 

- 

s 

K 

- 

- 

- 

LR/FE/SS 

Brown Falcon ( Falco berigora) 

> 

R 


I 

LR/SR/MR/G/SS 

Eurasian Kestrel {Falco tinnunculus) 

< 

M 

- 

- 

s 

- 

- 

- 

- 

G/SS 

Spotted Kestrel {Falco moluccensis ) 

E 

R 

JB 

T 

- 

K 

c 

M 

I 

G/SS 

Australian Kestrel {Falco cenchroides ) 

> 

V 

J 

T 

- 

- 

- 

M 

I 

G 

Eurasian Hobby {Falco subbuteo) 

< 

V 

J 

T 


FE/G/SS 

Oriental Hobby {Falco severus) 

<> 

R 

JB 

T 

s 

K 

c 

M 

I 

LR 

Australian Hobby {Falco longipennis ) 

> 

R/M 

- 

T 

- 

- 

c 

M 

I 

FE 

Peregrine Falcon {Falco peregrinus) 

<> 

R/M 

JB 

T 

s 

K 

c 

M 

I 

FE/G 


1 R (Range): < — western extension; > — eastern extension; E — endemic Indonesia; P — found in PNG. (S) Status: R — resident; M — 
migrant; V — vagrant. Distribution: JB — -Java/Bali; T — Lesser Sundas; S — Sumatra; K — Kalimantan; C — Sulawesi; M — Moluccas; I — Irian 
Jaya (after Andrew 1992, 1993). Habitat: LM — lowland monsoon forest; LR — lowland rainforest; SR — submontane rainforest; MR — 
montane rainforest; C— coastal and mangrove forest; F — freshwater bodies; S — swamp forest; FE — forest edge; SS — secondary forest/ 
scrub; G — grass and open woodland; A— agricultural land (after MacKinnon and Wind 1980, own observations). 


J. Raptor Res. 32(l):64-73 
© 1998 The Raptor Research Foundation, Inc. 


STATUS AND CONSERVATION OF RAPTORS IN 

AUSTRALIA’S TROPICS 

Nick Mooney 

Parks and Wildlife Service, GPO Box 44A, Hobart 7001, Tasmania, Australia 

Abstract. — All of Australia’s 34 raptors are found in the tropics. No full species and only one subspecies, 
an island endemic owl, are extinct. All of Australia’s three threatened, diurnal species are endemic to 
the continent. One, the Vulnerable Red Goshawk ( Erythrotriochis radiatus), is endemic to Australia’s 
tropical forests and is under threat from loss of habitat, persecution, and egg collecting. Conservation 
efforts include legal protection, education, and keeping nest sites secret. A second species, the rare 
Square-tailed Kite ( Lophoictinia isura) is widely distributed and, except for clearing of woodland, threats 
are not obvious. Many raptors from arid areas, including the endemic Grey Falcon ( Falco hypoleucos), 
“winter” in tropical woodlands. For adequate conservation, critical habitats of the Grey Falcon must be 
identified. Grey Falcons should be helped in the long term by the anticipated reduction of rabbits in 
arid Australia by rabbit calicivirus disease, but widespread clearing of tropical woodlands for agriculture 
continues as does local, heavy use of pesticides. Although no species of owls are threatened, five sub- 
species are; two are subspecies of the endemic Rufous Owl ( Ninox rufa, one rare and one insufficiently 
known) and two are subspecies of the Masked Owl (Tyto novaehollandiae, both insufficiently known). 
Threats include loss of critical habitat to fire and agriculture. On Christmas Island, the small populations 
of endemic subspecies of the Brown Goshawk ( Acdpiter fasciatus ) and Moluccan Hawk-owl (N. squamipila) 
are Vulnerable and threatened by loss of habitat to urbanization and formerly mining. Besides legal 
protection, conservation efforts have included education and habitat preservation. The tropical Eastern 
Grass-owl ( T. longimembris ) is secure although some populations are under pressure from agriculture 
(including rodenticides) and urbanization. Coastal, tropical raptors appear secure even though per- 
manent reductions in some populations have been caused by agriculture, urbanization, and coastal 
developments such as aquaculture and marinas. 

Key Words: tropical raptors; Australia; conservation; status. 


Estado y conservacion de las aves rapaces en los tropicos de Australia 

ReSUMEN. — Todas las 34 especies de aves rapaces de Australia se encuentran en los tropicos. Una de las 
tres especies amenazadas de Australia, Erythrotriorchis radiatus es endemico a los bosques tropicales de 
Australia y esta amenazada por la perdida de habitat, persecucion, y saqueo de huevos. Los esfuerzos 
de conservacion han incluido su proteccion legal, educacion, y proteccion de nidos. Una segunda 
especie Lophoictinia isura esta ampliamente distribuida, excepto por la deforestacion, las demas amenazas 
no son obvias. Varias aves rapaces de regiones aridas incluyendo al endemico Falco hypoleucos emigran 
hacia los bosqnes tropicales. Desde el punto de vista de la conservacion, los habitats criticos de F. 
hypoleucos deben de ser identificados debido a que la deforestacion para la agricultura continua al igual 
que el uso intensivo de pesticidas. Aunque ningun buho ha sido identificado como amenazado, en 
Australia, dos raras y poco estudiadas subespecies del endemico Ninox rufa y dos subespecies de Tyto 
novaehollandiae estan amenazadas en las areas tropicales. Las amenazas incluyen la perdida de habitats 
criticos debido al fuego y a la agricultura. En la Isla Christmas, las reducidas poblaciones de Acdpiter 
fasciatus y de N. squamipila estan amenazadas debido a la perdida de habitat por actividades mineras y 
el desarrollo urbanistico. Aparte de la proteccion legal, los esfuerzos de conservacion han incluido 
educacion y proteccion del habitat. Aunque aparentemente estables algunas poblaciones de T. longi- 
membris estan bajo presion debido a la agricultura (incluyendo el uso de rodenticidas) y el desarrollo 
urbano. Aunque las poblaciones de aves rapaces costeras estan estables, estas han tenido continuadas 
reducciones causadas por la agricultura, la urbanizacion, y por desarrollos costeros tales como proyectos 
de acuacultura y marinas. 

[Traduccion de Cesar Marquez] 


64 


March 1998 


Status of Tropical Australian Raptors 


65 


Background 

Australia is a continent with an area totaling 
about 7.7 million km 2 . It includes a few small is- 
lands, one of which is Christmas Island in the In- 
dian Ocean, approximately 1400 km northwest of 
Australia near the Indonesian island of Java. Aus- 
tralia is the driest continent and less than 15% is 
covered by tropical forests located on the north 
and northeastern coasts. Although people have 
slowly modified these forests using fire over at 
least 60 000 yr, it has only been in the last 200 yr 
since Europeans arrived that this change has ac- 
celerated. While the size of the continent has shel- 
tered most raptors from threats to tropical forests, 
small islands have not escaped these effects. The 
wet, tropical forests of Australia show distinct sea- 
sonality but have long-term ecological stability. 
The occurrence of irregular, severe inland 
droughts make the continent’s biogeographv 
unique (Nix 1972, Flannery 1994). This instability 
has resulted in many arid and semiarid birds, rap- 
tors included, becoming migrants during drought 
periods with many showing both inland-coastal 
and south-north movements (Baker-Gabb and 
Fitzherbert 1989). These local movements may be 
small in relation to the size of the continent but 
they are still large in absolute terms and their ap- 
parent dispersive rather than routed nature 
makes their study difficult. 

Another unusual movement is the irruptive ten- 
dency of a few raptor species. This type of move- 
ment usually follows heavy rains marked by increas- 
es in rodent numbers, and rapid breeding in pop- 
ulations of Letter-winged Kites (Elanus scriptus) and 
Black Kites ( Milvus migrans) which then disperse 
when dry conditions return and rodent numbers 
crash (Hollands 1977, Lavery and Johnson 1993). 

This paper examines raptors in wet tropics (a 
strongly seasonal environment) and dry tropics (an 
environment stable in the short to medium term 
but unstable in the longer term). It is important 
to make this distinction because tropical raptors 
may be largely dependent on a system with long- 
term stability and they may be slow to adapt to en- 
vironmental changes. 

The Australian wet tropics contain both open 
and closed forests, including rainforest on the con- 
tinent’s northeast coast. Mainly coastal, these for- 
ests extend from nearly half-way down the east 
coast and all the way to the northwest corner of 


Australia. Tropical areas also spread inland along 
permanent rivers and wetlands and include some 
areas of highlands such as the Atherton tablelands. 
Adjacent islands off these areas including Christ- 
mas Island are also wet and support rainforests. 
The dry tropics are comprised of mainly savanna 
woodlands and a variety of permanent and tem- 
porary waterways and wetlands. They are located 
south of the wet tropics but north of a line extend- 
ing across the continent from the mid-east to the 
mid-upper west coast from about Brisbane to about 
Broome (Fig. 1). 

Raptors are very mobile birds and most species 
are able to utilize a variety of habitats. Therefore, 
I was cautious when assigning species to habitats 
and used broad definitions. 

Use of Australia’s Tropics by Raptors 

Presence and Core Range. All 34 species of Aus- 
tralian raptors are found in the tropics. Of Austra- 
lia’s 10 endemic raptor species, only two, the 
monotypic Red Goshawk ( Erythrotriorchis radiatus) 
and Lesser Sooty-owl ( Tyto multipunctata) , are en- 
demic to the tropics as are four and eight subspe- 
cies of Falconiformes and Strigiformes, respective- 
ly. One other monotypic species, the Square-tailed 
Kite ( Lophoictinia isura ) , six subspecies of Falconi- 
formes, and six of Strigiformes have large portions 
of their ranges in the tropics (Blakers et al. 1984, 
Debus and Czechura 1988b, Marchant and Higgins 
1993). Australia is relatively close to Melanesia and 
some raptors interchange between the two includ- 
ing Swamp Harriers ( Circus approximans) , Austra- 
lian Hobbies ( Falco longipennis) , and Nankeen Kes- 
trels (F. cenchroides) . Numbers of raptors that inter- 
change are not known but neither location is 
known to be a major wintering area for interchang- 
ing species (Baker-Gabb and Fitzherbert 1989). 

Wet vs. Dry Tropics. More species of Strigifor- 
mes rely on the wet tropics than do Falconiformes. 
Seven species of Strigiformes are endemic while 
only three species of Falconiformes are exclusively 
found in the wet tropics. All told, 10 of Australia’s 
19 species and subspecies of Strigiformes but only 
10 of 28 species and subspecies of Falconiformes 
are either endemic to or a large segment of their 
core ranges lies within the wet tropics. Conversely, 
the dry tropics are more important to the majority 
of Australia’s tropical Falconiformes. Six species 
are endemic to the dry tropics while this area has 
no endemic owls. 


66 


Mooney 


Vol. 32, No. 1 


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Figure 1. Key raptor wintering grounds (after Marchant and Higgins 1993), reserves, and movement patterns (after Nix 1972, Baker-Gabb and Fitzherbert 
1989) in the Australian tropics. 


March 1998 


Status of Tropical Australian Raptors 


67 


Movements. In the Australian tropics, there are 
13 resident Falconiformes, 10 regular “winter” mi- 
grants, and one species, the Black-breasted Buz- 
zard ( Hamirostra melanosternon) , that moves to the 
tropics and other coastal areas in response to ir- 
regular, inland droughts. Although two regular mi- 
grants, the Black-shouldered Kite ( Elanus axillaris) 
and the Black Kite are also irruptive, only the Let- 
ter-winged Kite appears to be adapted for such 
movements through its colonial and early breeding 
(Marchant and Higgins 1993). Interpreting move- 
ments for many species is difficult because their 
extensive ranges include populations which are 
resident while others are migratory on either a reg- 
ular or irregular basis. This difficulty does not exist 
for Australia’s Strigiformes. Although there are sev- 
eral irruptive species, the Barn Owl ( Tyto alba), 
possibly the Grass Owl (T. longimmibris) , and the 
Southern Boobook ( Ninox novaeseelandiae ) on Tas- 
mania seem to be at least partially migratory 
(Schodde and Mason 1980, Blakers et al. 1984, 
Hollands 1991). 

After becoming concentrated in the best breed- 
ing habitats in spring, populations of some species 
barely leave inland breeding areas in the heat of 
summer (e.g., Wedge-tailed Eagles [Aquila audax \ 
and Black Falcons [jF subniger] ; Marchant and Hig- 
gins 1993). Other species such as Black Kites and 
Brown Falcons (F berigora) make partial migrations 
forming concentrations in spring to undertake 
northward and coastward through summer and au- 
tumn. Other species like the Nankeen Kestrel and 
Spotted Harrier ( Circus assimilis) disperse in early 
winter and rapidly return to breeding areas 
through late winter. The Pacific Baza ( Aviceda sub- 
cristata) migrates altitudinally, making it inland and 
coastal at the same time. This is best seen in the 
north-south migration of the Swamp Harrier w r here 
virtually the entire breeding population is in the 
far southeast (mostly in Tasmania) while non- 
breeding immatures are concentrated in grassy 
woodlands to the north. 

Habitats and Areas of Raptor Concentration. A 
higher proportion of Strigiformes (9 of 17 species) 
than Falconiformes (7 of 28 species) rely on trop- 
ical closed forests. Conversely, woodlands support 
a higher proportion of Falconiformes (13 of 28 
species) than Strigiformes (6 of 7 species) . 

During the dry season and during droughts, 
tr opical woodlands become particularly important 
for both residents and wintering migrants. Inland 
grassy, w r oodland areas of the Kimberleys and the 


lower (coastward) catchments of the larger rivers 
around the Gulf Region are particularly important 
since they support the greatest raptor diversity and 
share the greatest abundance (Fig. 1). Grassy 
woodlands support mainly Brown Falcons, Swamp 
Harriers, Spotted Harriers, Black Kites, and Black- 
shouldered Kites while open forests along perma- 
nent waterways support Red Goshawks, Australian 
Hobbies (F longipennis) , Peregrine Falcons (F per- 
egrinus) , and Grey Falcons (F. hypoleucos ) . Open for- 
ests throughout the area support many Brown Gos- 
hawks ( Accipiter fasciatus) and Collared Sparrow- 
hawks ( Accipiter cirrocephalus ) . During this autumn/ 
winter dry period, White-bellied Sea Eagles (Ha- 
liaeetus leucogaster) and Ospreys ( P and, ion haliaetus ) 
sometimes travel far inland up permanent rivers 
(Blakers et al. 1984, Marchant and Higgins 1993) 
and Brahminy Kites ( Haliastur indus ) disperse into 
the Torres Strait (Draffon et al. 1983). 

Other areas of the tropics are important as win- 
tering grounds. For example, the developed grass- 
lands of the Darling Downs area in southeastern 
Queensland support high densities of wintering 
Nankeen Kestrels (Baker-Gabb 1996) and any ar- 
eas of open forest where small passerines are com- 
mon are used by Square-tailed Kites (Debus and 
Czechura 1988b). 

Except for a few large areas of rainforest along 
the north coast, most of Australia’s tropical forests 
and woodlands are fragmented, with indistinct bor- 
ders caused by combinations of soil fertility and 
fire regimes (Flannery 1994). Consequently, in 
most of the Australian tropics, raptors normally as- 
sociated with closed forests such as Rufous Owls 
(N. rufa) and Grey Goshawks ( Accipiter novaehollan- 
diai) , may range far along rivers and between wet- 
lands using riparian forests. 

Status 

Australia’s small tropical islands have dispropor- 
tionate numbers of threatened (Rare, Vulnerable, 
or Endangered, after Garnett 1992) or insufficient- 
ly known species. The only extinct Australian rap- 
tor, the Lord Howe Island Boobook (N. n. albana), 
was endemic to an island as are five of Australia’s 
seven Endangered or Vulnerable raptors. The 
highest proportion of Australia’s threatened or in- 
sufficiently known raptors are those that rely on 
forests, particularly tropical forests (four of five Fal- 
coniformes and six of seven Strigiformes) . Austra- 
lia’s tropical woodlands contain most threatened 
Falconiformes (three of four species) and closed, 


68 


Mooney 


Vol. 32, No. 1 


wet tropical forests contain most threatened Stri- 
giformes (four of seven species) . 

Nearly all of Australia’s threatened and insuffi- 
ciently known raptors are endemic to or have their 
core ranges in the tropics (three of five Falconi- 
formes and five of seven Strigiformes; Raker-Gabb 
1994). Three species of Strigiformes are classified 
as insufficiently known most likely because they are 
difficult to survey (Clark and Mikkola 1989, Gar- 
nett 1992). In reality, many species of raptors re- 
garded as secure need further surveys and actually 
should be classified as insufficiently known. 

Of Australia’s four threatened, endemic and 
monotypic species, only one, the tropical Red Gos- 
hawk, is Vulnerable (IUCN 1994). The other two, 
the largely tropical Square-tailed Kite and the semi- 
arid Grey Falcon, are both Rare. All three of the 
species have naturally low population densities 
(Garnett 1992, Marchant and Higgins 1993). For 
example, the current Red Goshawk population 
consists of about 350 pairs as compared to its his- 
toric population of about 440 pairs spread over 
nearly 1 million ha. Its population decline has 
been more the result of a range contraction rather 
than density reduction (Aumann and Baker-Gabb 
1991b, Debus 1993). 

Conversely, the Vulnerable Brown Goshawk (Ac- 
dpiterf natalis ) and Moluccan Hawk-owl { N. squam- 
pila natalis ), both endemic to Christmas Island, 
have high population densities but very limited dis- 
tributions. There are currently an estimated 50- 
100 pairs of goshawks and about 600 pairs of owls 
on the 13 650 ha island (Hill 1996). The goshawk’s 
naturally small and very tame population is Vul- 
nerable in every sense but the owl has the advan- 
tage of nocturnal seclusion. There is some ques- 
tion as to the identity of the owl and whether the 
goshawk is simply a subspecies of the Grey Gos- 
hawk (Debus 1994a). These taxonomic questions 
must be settled in which case more attention may 
need to be given to the security of these isolated 
raptors. 

Threats and Conservation 

Precaution and Prevention. Threats to Austra- 
lia’s tropical raptors are similar to those which 
threaten raptors in other countries (e.g., Thiollay 
1994). However, Australia has a great advantage in 
that much of the management necessary to pre- 
serve these species is preventative. 

Loss of Habitat — Agriculture. Both productivity 
and survival can be affected by loss of critical hab- 


itat (Newton 1979). In the Australian tropics, this 
loss has been mosdy due to agriculture. Draining 
of wetlands is an important issue. The Convention 
on Wedands of International Importance Especial- 
ly as Waterfowl Habitat (the Ramsar Convention, 
Davis 1994) lists several large Australian tropical 
wetlands for conservation but most are unprotect- 
ed. However, wetlands have been successfully re- 
stored by deliberate management (e.g., Anony- 
mous 1994) and changing public attitudes may 
give more such opportunities. Like many species, 
tropical raptors are heavily reliant on remnant wet- 
lands during the dry season or droughts. Acceler- 
ated destruction is potentially harmful both to 
common species, such as the White-bellied Sea-ea- 
gle, Brahminy Kite, Whisding Kite {Haliastur sphen- 
urus ) and Barking Owl ( N . connivens ), and to al- 
ready Vulnerable species, such as the Red Gos- 
hawk. 

Perhaps more than any other habitat, Australia’s 
woodlands have suffered enormously since Euro- 
pean colonization. In temperate areas, 80% has 
been cleared (Robinson and Traill 1996) and rapid 
inroads are being made into tropical woodlands 
for agriculture, especially in southern Queensland 
(Anonymous 1996). Square-tailed Kites, Red Gos- 
hawks and Pacific Bazas are the species most at risk 
from this deforestation. 

Dry tropical regions are also disappearing due 
to the development of irrigation in desert areas. 
This practice has the potential to increase saltation 
and change tiooding regimes with widespread ef- 
fects on many thousands of km 2 . Extensive mono- 
culture crops are susceptible to pests requiring the 
use of pesticides (insecticides and rodenticides) 
which may have consequences for raptors. How- 
ever, Australia’s National Landcare Program 
(McLennan 1996) is slowing this and other large- 
scale land degradation problems such as saltation 
and erosion. 

Loss of Habitat — Forestry. Forestry has had lim- 
ited effects on Australia’s tropics but the increasing 
demand for woodchips from native hardwood for- 
ests may change this. Plantations of exotic pines 
make areas unsuitable for most raptors ( acdpiters 
occasionally use them; Marchant and Higgins 
1993) and, even if the original forest is retained, 
often the structure and age is so altered that rap- 
tors can no longer rely on them. This is a problem 
particularly for large owls needing large tree hol- 
lows such as the Rufous Owl ( N , rufa), Powerful 


March 1998 


Status of Tropical Australian Raptors 


69 


Owl (N. strenua) and Sooty Owl ( T tenebricosa) (De- 
bus 1994b). 

Codes of Practice have been established for most 
Australian forest operations (Anonymous 1993) 
and contain protocols and recommendations 
based on specific research (e.g., Mooney and Hold- 
sworth 1991, Brereton and Mooney 1994). In Tas- 
mania, for example, state codes regulating every 
operation selling timber has been effective in con- 
serving nesting Wedge-tailed Eagles (Mooney and 
Taylor 1996). Survey techniques must be improved 
to make pre-logging planning effective (Kavan- 
augh and Peake 1993, Mooney 1996). 

Loss of Habitat — Urbanization. The penchant of 
Australians to live on coastal and subcoastal resi- 
dential blocks is a further local threat to raptors. 
This type of land use is becoming increasingly de- 
structive to tropical habitats in Queensland and 
New South Wales and brings with it all the hazards 
of people beyond the initial alteration of habitats 
(e.g., pets, persecution, egg collecting, overhead 
wires, vehicles, and fuel reduction burns). These 
rural-residential developments are particularly 
problematic for large owls and aggressive raptors, 
the latter which occasionally attack stock. Such ur- 
banization should be more conservatively planned 
and education programs aimed at reducing peo- 
ple’s expectations of what they can do in these en- 
vironments should be undertaken (Wood 1996). 
Living With Wildlife Programs (Anonymous 1988, 
Temby 1992) should be more aggressively promot- 
ed by wildlife authorities. 

Loss of Habitat — Other Development. The 
clearing of mangroves and reclamation of coastal 
wetlands for aquaculture, marinas, and urban areas 
are growing problems, most likely to affect Brah- 
miny Kites and White-bellied Sea-eagles. Ospreys in 
Australia, as elsewhere, seem remarkably tolerant 
of humans and have adapted to many artificial 
nesting sites (Marchant and Higgins 1993, Ewins 
1996). Mining is potentially a problem for raptors 
through its resulting habitat loss and pollution. For 
example, 25% of Christmas Island was badly de- 
graded from mining (Hill 1996) and a large ura- 
nium mine (Ranger Mine) exists in Kakadu Na- 
tional Park, Australia’s premier tropical reserve. 

Loss of Habitat — Fire. Fire is more a qualitative 
problem than other more recent threats to habitat; 
closed forest is turned to open forest, open forest 
is turned to woodlands and woodland to grassland. 
Fire is a fundamental ecological shaper in Austra- 
lia’s tropics (Flannery 1994). Although some spe- 


cies directly benefit from it, such as Black Kites, 
Whistling Kites, and Brown Falcons that forage in 
front of fires (Marchant and Higgins 1993), fire 
occasionally kills nestling raptors (Aumann and Ba- 
ker-Gabb 1991a). However, more serious is fire’s 
attritive affects on remnants of closed forest that 
are so important to raptors such as the Rufous Owl. 
Not only can traditional nest trees be burned and 
nest stands reduced in size but they can also be 
degraded by weeds and introduced predators (Ba- 
ker-Gabb 1994). Fire is a traditional and necessary 
land management tool in much of Australia (Flan- 
nery 1994) but it is not always the right took 

Disturbance. Disturbance can have severe effects 
on raptor productivity. Tourism is now one of the 
most important industries in the Australian tropics 
and amongst raptors its disturbing effects are most 
felt by breeding White-bellied Sea-eagles on large 
wetlands and coastal rivers which are favorite tour 
stops. The ground-nesting Grass Ow4 may be at spe- 
cial risk from tourism (Gamauf 1994). National 
park authorities need to consider temporary zon- 
ing restrictions and tour operators should develop 
other tours that do not come into close proximity 
with nesting owls. There is a great deal of oppor- 
tunity for innovation in such ecotourism. Inexpe- 
rienced photographers can also cause nesting fail- 
ures, possibly effecting marginal populations (Gar- 
nett 1992). 

Loss of Prey. The rapid spread of rabbit calici- 
virus disease is expected to decimate populations 
of rabbits in Australia (Coman 1996). Rabbits do 
occur in the dry tropics (Williams et al. 1995) but 
in far lower densities than in more southern 
regions. Hence, they are far less important in the 
diets of tropical raptors. Species most likely to be 
affected are Wedge-tailed Eagles and Little Eagles 
(Hieraaetus morphnoides ) , but the effects will prob- 
ably be small and restricted to locally diminished 
productivity. The effect of this disease on raptor 
populations is being monitored both locally and 
nationwide using a road transect survey called Bird 
of Prey Watch (Baker-Gabb 1996). In the long 
term, the removal of rabbits should allow vegeta- 
tion to recover in large areas increasing its value 
for wildlife (Mutze 1996). However, there are pri- 
vate plans to increase livestock grazing (the density 
of sheep and cattle) in these areas immediately af- 
ter the rabbits are eradicated, perhaps negating 
some of the benefits for wildlife. Agricultural au- 
thorities should consider stocking restrictions to 
balance these pressures. Black-breasted Buzzards, 


70 


Mooney 


Vol. 32, No. 1 


Black Falcons, Grey Falcons, and Letter-winged 
Kites are the most susceptible to grazing pressures. 

Collecting. Egg collecting is a small but persis- 
tent problem targeting uncommon species. Once 
nests of species such as Red Goshawks or Grey Fal- 
cons become well known they may be robbed 
(Cupper and Cupper 1981, Hollands 1984, Garnett 
1992, Raker-Gabb 1993, Marchant and Higgins 
1993) and it is the responsibility of researchers and 
photographers to restrict this knowledge. At worst, 
it is a local problem for a few species. Recreational 
falconry is not allowed in Australia and there is 
little consequent nest robbing and no pet trade. 

Persecution. Australia is a member of CITES and 
all raptors in Australia have full legal protection 
under state and territory laws (Aumann et al. 
1989). However, wildlife authorities retain the right 
to issue special permits to control raptors. Perse- 
cution of raptors in the Australian tropics is only a 
local problem. Beyond random vandalism the big- 
gest problems are associated with the defense of 
stock. Accipiters are commonly shot near poultry 
and aviary birds; the Brown Goshawk was heavily 
persecuted on Christmas Island (Van Tets 1967) 
but this now has diminished. Wedge-tailed Eagles 
are still reported to cause losses of lambs and even 
calves (Keough 1994), and are frequently shot, 
trapped, or poisoned. Such shooting is still com- 
mon in western Queensland and several stockmen 
shoot eagles from helicopters (Czechura, pers. 
comm.). Persecution maybe an important contrib- 
uting factor to the range contraction of the Red 
Goshawk from northern New South Wales and 
most of southeastern Queensland (Debus and Cze- 
chura 1988a, Baker-Gabb 1993). Besides policing, 
education (especially use of peer pressure) is one 
of the few ways to limit such persecution. Present 
efforts (Holdsworth and Marmion 1993) should be 
consolidated and expanded. Australia’s new, strict, 
national gun laws can only help reduce persecu- 
tion of raptors. 

Pesticides. Pesticides can affect both productivity 
and survival of raptors. The effects of some persis- 
tent organochlorine pesticides such as DDT and 
dieldrin are reasonably well known (Riseborough 
1987) but today they are probably of little conse- 
quence for populations of Australian raptors (Ful- 
ler and Maples 1993). The increasing problem of 
malaria in the nearby Solomon Islands brings 
greatly increased use of DDT and if climates 
change, the possibility of malaria establishing in 
Australia exists. 


The effect of most pesticides, especially when 
used as cocktails, is little known and perhaps pre- 
sents new dangers for Australian raptors. This es- 
pecially applies to cotton crops on which large 
amounts of pesticides are traditionally used. 

Some pesticides (rodenticides and insecticides) 
are highly toxic and raptors have been killed by 
them in Australia. Experiences in Israel have 
shown how catastrophic the use of topical, organo- 
phosphate rodenticides or insecticides can be for 
raptors (Mendelssohn and Puz 1977). A recent ac- 
cidental kill of up to 20 000 Swainson’s Hawks (Bu- 
teo swainsoni ) by the organophosphate insecticide 
monocrotophos on their Argentine wintering 
grounds (Krapovickas and Lyons 1997) shows the 
potential of organophosphate insecticides to seri- 
ously affect populations of Nankeen Kestrels, 
Brown Falcons, Little Eagles, Masked Owls ( T. no- 
vaehalla ndiae) , Barn Owls, Grass Owls, Whistling 
Kites, Black Kites, Black-shouldered Kites, and Let- 
ter-winged Kites in Australia. The use of pesticides 
should be under severe restrictions in areas where 
these species are likely to winter or concentrate to 
breed. Even in established agricultural areas, large 
concentrations of wintering raptors can be found 
(e.g., Nankeen Kestrels on the Darling Downs), 
benefiting from limited agriculture, but the use of 
highly-toxic chemicals must be controlled in these 
places. Agricultural Codes of Practice along the 
lines of Forestry Codes of Practice could have ob- 
vious use. 

Dingo/feral dog (Canis familiaris ) and feral pig 
( Sus scrofa ) poisoning programs use sodium mon- 
oflouroacetate (1080), a chemical to which Austra- 
lian raptors are somewhat resistant (Mcllroy 1984, 
1986). Nevertheless, illegal baiting using organo- 
phosphates (lucijet, a fenthion-ethyl derivative, and 
phosdrin) can and does kill raptors (DuGuesclin 
et al. 1983). 

Exotic Species. Besides the risks of nontarget 
poisoning, introduced species present many prob- 
lems to raptors. The cane toad (Bufo marinaris ) is 
highly toxic and it may have killed raptors after its 
release. Today, it is a common prey item of the 
Black Kite (Marchant and Higgins 1993). Foxes 
( Vulpes vulpes) and feral cats (Felis domesticus ) can 
compete with and prey on raptors and both are 
found in the dry and wet tropics. Their potential 
effect is greatest for ground nesters such as the 
Grass Owl and small, colonial nesters such as the 
Letter-winged Kite (Cupper and Cupper 1981). 
Such depredation may increase because of prey 


March 1998 


Status of Tropical Australian Raptors 


71 


switching when rabbit calicivirus disease decimates 
rabbits. 

Beyond plantation forestry or agriculture, intro- 
duced plants can change large areas. Afro-Asian 
prickly acacia ( Acacia nilotica) has changed nearly 
50 000 km 2 of grassland in Queensland to tall scrub 
(Anonymous 1990). Much of this was potentially 
valuable wintering habitat for raptors. 

Under the federal Endangered Species Protec- 
tion Act 1992, research and management phases of 
Recovery Programs for species threatened nation- 
ally are funded by the Australian Nature Conser- 
vation Agency. Funding to carry out follow-up re- 
commnedations is not guaranteed. Fortunately, 
there is no remedial action urgently needed for 
any threatened species except perhaps for the Red 
Goshawk in New South Wales and southeast 
Queensland (Auman and Baker-Gabb 1991b). 

Reserved Status. A common conservation mea- 
sure for wildlife is to protect land through the es- 
tablishment of reserves. For this to be effective, the 
most important areas of habitat must first be iden- 
tified. Some rare species, such as the Square-tailed 
Kite, have an enormous distribution, are migratory 
through dispersive rather than routed mecha- 
nisms, and seem always at low population densities 
making accurate assessment of their status and 
identification of crucial wintering areas very diffi- 
cult. The large home ranges of many breeding rap- 
tors necessitates enormous reserves to support vi- 
able populations (Thiollay 1989). About 5.9% of 
Australia is under reservation for conservation, 
compared to 10.5% for the U.S., 7% for Canada 
and a world average of 4.9% (McLennan 1996). 
Although Australia’s proportion seems small, pro- 
tected areas in the north are well connected by 
relatively intact habitat. Most of the islands, Christ- 
mas Island included, are now well reserved. Al- 
though all Australian raptors are found in at least 
one reserve, Australia has no large reserves dedi- 
cated to raptors similar to those found in Israel, 
Spain, and the U.S. This is due to the fact that 
Australia’s reserves are generally for the conserva- 
tion of mammals, a group in far more need of spe- 
cial attention than raptors (Flannery 1994), 

Conclusion 

The vast majority of tropical Australia is still 
sparsely populated by people and environmental 
degredation is at a low level. As a result, problems 
for raptors in Australia’s tropics are generally lo- 
calized but development has resulted in significant 


contraction of range for at least one species, the 
Red Goshawk. Fortunately, no raptor in Australia 
is in need of intensive management. Beyond mak- 
ing deliberate efforts to preserve a few subspecific 
island populations, further researching insuffi- 
ciently known and rare species, and confirming the 
security of most species through regular monitor- 
ing of populations and threats, aggressive educa- 
tion and development of Codes of Practice are 
probably all Australia’s raptors need for security 
well into the 21st century. 

Ackn o wledgments 

I would like to thank Henry Nix, Richard Hill, Penny 
Olsen, and Stephen Debus for their thoughts on raptors 
in Australia’s tropics. Will Steele, Dave Baker-Gabb, and 
Richard Hill kindly let me use their unpublished data 
Dave Baker-Gabb and Jean-Marc Thiollay kindly reviewed 
the text and the Raptor Research Foundation helped me 
attend the conference in Boise where this paper was pre- 
sented. 

Literature Cited 

Anonymous. 1988. Living with hawks. Wildlife Note- 
sheet, TASPAWS, Hobart, Australia. 

. 1990. Atlas of Australian resources: vegetation. 

AUSLIG, Canberra, Australia. 

. 1993. Forest practices code. Forestry Tasmania, 

Hobart, Australia. 

. 1994. Wetland Restoration. In D. Navid [Ed,], 

Ramsar Newsletter 17. 

. 1996. Australia: State of the environment 1996, 

biodiversity. ANCA, Canberra, Australia. 

Aumann, T. and D.J. Baker-Gabb. 1991a. The ecology 
and status of the Red Goshawk in Northern Australia. 
RAOU Report 75. RAOU, Melbourne, Australia. 

and . 1991b. A management plan for the 

Red Goshawk. RAOU, Melbourne, Australia. 

, N.J. Mooney and P.D. Olsen. 1989. The legal 

status of birds of prey in Australia. Pages 591-596 in 
B.-U. Meyburg and R.D. Chancellor [Eds.], Raptors 
in the modern world. World Working Group for Birds 
of Prey, London, U.K. 

Baker-Gabb, D.J. and K. Fitzherbert. 1989. An overview 
of raptor movement and wintering places in Australia 
and New Zealand. Pages 159-166 in B.-U. Meyburg 
and R.D. Chancellor [Eds.], Raptors in the modern 
world. World Working Group for Birds of Prey, Lon- 
don, U.K. 

. 1994. Threatened raptors of Australia’s tropical 

forests. Pages 241-254 in B.-U. Meyburg and RD 
Chancellor [Eds.], Raptor conservation today. World 
Working Group for Birds of Prey, London, U.K. 

. 1996. When rabbit calicivirus strikes, whither the 

raptors? Wingspan 6. RAOU, Melbourne, Australia. 
Blakers, N., S.J.J.F. Davies and P.N. Reilley. 1984. Atlas 


72 


Mooney 


Vol. 32, No. 1 


of Australian birds. Melbourne Univ. Press, Mel- 
bourne, Australia. 

Brereton, R.N. and N. Mooney. 1994. Conservation of 
the nesting habitat of the Grey Goshawk Accipiter no- 
vaehollandiae in Tasmanian state forests. Tasforests 6: 
79-91. 

Coman, B.J. 1996. Environmental impacts associated 
with the proposed use of rabbit calicivirus disease in 
Australia, CSIRO, Canberra, Australia. 

Cupper, J. and L. Cupper. 1981. Hawks in focus. Jaclin 
Enterprises, Mildura, Australia. 

Clark, R.J. AND H. Mikkola. 1989. A peliminary revision 
of threatened and near threatened nocturnal birds of 
prey in the world. Pages 371-388 in B.-U. Meyburg 
and R.D. Chancellor [Eds.], Raptors in the modern 
world. World Working Group for Birds of Prey, Lon- 
don, U.K. 

Davis, T.J. 1994. The Ramsar convention manual. Ram- 
sar Convention Bureau, Gland, Switzerland. 

Debus, S.J.S. 1993. The status of the Red Goshawk Ery- 
throtriorchis radiatus in New South Wales. Pages 182- 
191 in P. Olsen [Ed.], Australian raptor studies. 
RAOU, Melbourne, Australia. 

. 1994a. What is the Christmas Island goshawk? 

Aust. Bird Watcher 15:377-379. 

. 1994b. The Sooty Owl Tyto tenebricosa in New 

South Wales. In P. Roberts [Ed.], Large forest owls of 
New South Wales. Australian Birds 28 (Supplement). 

and G.V. Czechura, 1988a. The Red Goshawk 

Erythrotriorchis radiatus: a review. Aust. Bird Watcher 12: 
175-199. 

and . 1988b. The Square-tailed Kite Lo- 

phoictinia isura: a review. Aust. Bird Watcher 13:81-98. 

Draffon, R.D.W., S.T. Garnett and G. Malone. 1983. 
Birds of Torres Strait. Emu 83:207-234. 

DuGuesclin, P.B., W.B. Emison and I.B. Temby 1983. 
Deliberate misuse of the organophosphate pesticide, 
fenthion-ethyl, to poison birds in Victoria. Corella 7: 
37-39. 

EwiNS, P.J. 1996. The use of artificial nests by an increas- 
ing population of Ospreys in the Canadian Great 
Lake Basin. Pages 109-125 in D. Bird, D. Varland and 
J. Negro [Eds.], Raptors in human landscapes. Aca- 
demic Press, London U.K. 

Flannery, T. 1994. The future eaters. Reed Books, Lon- 
don, U.K. 

Fuller, P. And T.G. Maples. 1993. Pesticide-related egg- 
shell thinning in Australian raptors. Emu 93:1-11. 

Gamauf, A, 1994. The influence of tourism on Marsh 
Harriers Circus aeruginosis in the Neusiedlersee-See- 
winkel National Park, Austria. Pages 103-108 in B.-U. 
Meyburg and R.D. Chancellor [Eds.], Raptor conser- 
vation today. World Working Group for Birds of Prey, 
London, U.K. 

Garnett, S. [Ed.]. 1992. Threatened and extinct birds 
of Australia. RAOU, Melbourne, Australia. 

Hill, F.A.R. 1996. The Christmas Island hawk-owl: its 


distribution, population size and conservation status. 
Unpubl. Rep., Australian Nature Conservation Agen- 
cy, Darwin, Australia. 

Holdsworth, M. and P. Marmion. 1993. Raptors and 
education in Tasmania. Pages 220-226 in P. Olsen 
[Ed.], Australian raptor studies. RAOU, Melbourne, 
Australia. 

Hollands, D. 1977. The Letter-winged Kite irruption of 
1976-77. Aust. Bird Watcher 8:1-18. 

. 1984. Eagles, hawks and falcons of Australia. 

Nelson, Melbourne, Australia. 

. 1991. Birds of the night. Reed Books, London, 

U.K. 

IUCN. 1994. IUCN relist categories. IUCN Species Sur- 
vival Commission, Gland, Switzerland. 

Kavanaugh, R.P. and P. Peake. 1993. Distribution and 
habits of nocturnal forest birds in south-eastern New 
South Wales. Pages 101-125 in P. Olsen [Ed.], Austra- 
lian raptor studies. RAOU, Melbourne, Australia. 

Keough, H. 1994. Easy-care herefords suit prairie con- 
ditions. Aust. Hereford Quarterly Feb. 

Krapovickas, S. And J.A. Lyons. 1997. Swainson’s Hawk 
in Argentina: international crisis and cooperation. 
World Birdwatch 19:12-15. 

Lavery, H.J. and P.H. Johnson. 1993. The Black Kite 
Milvus migrans in the Townsville District of Queens- 
land: a comparison or irruption and nonirruption 
years. Pages 209-219 in P. Olsen [Ed.], Australian rap- 
tor studies. RAOU, Melbourne, Australia. 

Marchant, S. and P.J. Higgins [Eds.]. 1993. Handbook 
of Australian, New Zealand and Antarctic birds. Vol 2: 
Raptors to lapwings. RAOU, Melbourne, Australia. 

McLennan, W. 1996. The Ramsar convention on wet- 
lands: its history and development. Ramsar Conven- 
tion Bureau, Gland, Switzerland. 

Mendelssohn, H. and U. Puz. 1977. Mass mortality of 
birds of prey caused by azodrin, an organophospho- 
rus insecticide. Biol. Conserv. 11:163-170. 

McIlroy, J.C. 1984. The sensitivity of Australian animals 
to 1080 poison. VII. Native and introduced birds. 
Aust. Wildl. Res. 11:373-385. 

. 1986. The sensitivity of Australian animals to 

1080 poison. IX. Comparisons between the major 
groups of animals, and the potential danger nontar- 
get species face from 1080-poisoning campaigns. Aust. 
Wildl. Res. 13:39-48. 

Mooney, N. 1996. Establishing priorities for searching 
forestry coupes for nests of Wedge-tailed Eagles. ARA 
News 17 ( 1 ) :9— 1 1 . 

and M. Holdsworth. 1991. The effects of dis- 
turbance on nesting Wedge-tailed Eagles Aquila audax 
fleayi in Tasmania. Tasforests 3:15-33. 

and R. Taylor. 1 996. Value of nest-site protec- 
tion in ameliorating the effects of forestry operations 
on Wedge-tailed Eagles in Tasmania. Pages 275-282 
in D. Bird, D. Varland and J. Negro [Eds.], Raptors 
in human landscapes. Academic Press, London U.K. 


March 1998 


Status of Tropical Australian Raptors 


73 


Mutze, G. 1996. Flinders ranges: rabbit-free and thriv- 
ing. Rabbit Calicivirus Update, May. 

Newton, I. 1979. Population ecology of raptors. Buteo 
Books, Vermillion, SD U.S.A, 

Nix, H.A. 1972. Environmental control of breeding, post 
breeding dispersal and migration of birds in the Aus- 
tralian region. Proc. Int. Ornithol. Congr. 16:272-305. 

Riseborough, R.W. 1987. Toxic chemicals and birds of 
prey: discussion at Eilat in 1987. In B.-U. Meyburg and 
R.D. Chancellor [Eds.], Raptors in the modern world. 
World Working Group for Birds of Prey, Berlin, Ger- 
many. 

Robinson, D. and B.J. Traill. 1996. Conserving wood- 
land birds in the wheat and sheep belts of southern 
Australia. RAOU Conservation Statement 10. 

SCHODDE, R. AND IJ- Mason. 1980. Nocturnal birds of 
Australia. Landsowne, Melbourne, Australia. 

Temby, I. 1992. A guide to living with wildlife. Dept. Con- 
serv. and Environ., Victoria Government Publ. 


THIOLLAY, J.M. 1989. Area requirments for the conser- 
vation of rainforest raptors and game birds in French 
Guinea. Conserv. Biol. 3:128-137. 

. 1994. A world review of tropical forest raptors 

Current trends, research objectives and conservation 
strategy. Pages 231-232 in B.-U. Meyburg and R.D. 
Chancellor [EDS.], Raptor conservation today. World 
Working Group for Birds of Prey, London, U.K. 

Van Tets, G.F. 1967. A report on the resident birds of 
the territory of Christmas Island. Emu 66:309-319 

Williams, K., I. Parer, B. Coman, J. Burley and M 
Braysher. 1995. Managing vertebrate pests: rabbits. 
Bureau of Resource Sciences/CSIRO, Aust. Govt. 
Printers, Canberra, Australia. 

Wood, D. 1996. Tassie’s five-acre nightmare. The Sun- 
day Tasmanian, 4/7/96: 6-7, Hobart, Australia. 

Received 16 October 1996; accepted 15 October 1997 


BOOK REVIEW 


Edited by Jeffrey S. Marks 

Buteo Books is pleased to sponsor the Book Review section of the Journal of Raptor Research. 
Buteo Books stocks a comprehensive selection of ornithology books, both new and used. 


J. Raptor Res. 32(1): 74-75 
© 1998 The Raptor Research Foundation, Inc. 


The Prairie Falcon. By Stanley H. Anderson and 
John R. Squires. 1997. University of Texas Press, 
Austin, TX. viii + 162 pp., 19 color photos, 10 fig- 
ures, 5 tables. ISBN 0-292-70473-9. Cloth, $29.95.— 
When I discovered that the cover of this book 
bears a photograph of my hunting companion of 
10 years, I knew we were off to a good start. Like 
many people, I had been waiting for someone to 
amass under one cover much of the existing but 
disconnected information about the only falcon in- 
digenous solely to North America. Finally, Ander- 
son and Squires have shouldered the burden, cre- 
ating a useful addition to the literature that focuses 
on the subject and broaches many of the topics 
one associates with the field of raptor biology. Be- 
cause the Prairie Falcon ( Falco mexicanus) is neither 
a glamour species nor ecologically endangered, 
this compilation has been a long time coming. 

Stanley H. Anderson, Professor of Zoology and 
leader of the Wyoming Cooperative Wildlife Re- 
search Unit, and John R. Squires, Research Scien- 
tist for the U.S. Forest Service, bring strong aca- 
demic credentials and a fresh approach to under- 
standing this under-explored raptor. Those of us 
who have searched for in-depth information on 
the Prairie Falcon and struggled through the works 
of Bent, Gabrielson and Jewett, Brown and Ama- 
don, and other dated sources, owe the authors a 
debt of gratitude. For those who seek information 
on the Prairie Falcon, this is the new starting point. 

In format, the book is a hybrid between popular 
and scientific literature, one that may expose the 
reader to new topics without burying him or her 
in technical terminology. It is arranged in accessi- 
ble, well-defined sections. As one might expect, The 
Prairie Falcon offers much natural history informa- 
tion and provides scientific documentation. I par- 
ticularly liked the brief inserts that highlight vari- 


ous topics. Some general, some specific, the inserts 
focus on many of the curious aspects of raptor bi- 
ology. For compulsive readers, sources of infor- 
mation are conveniently listed by topic at the end 
of each chapter. 

Starting with general life-history information, 
the book explores the Prairie Falcon's behavior, 
hunting and food habits, ecological and interspe- 
cific interactions, and its predatory nature. In ad- 
dition to familiar topics like breeding distribution, 
territoriality, and reversed sexual size dimorphism, 
the unusual topic of tree nesting by Prairie Falcons 
is discussed. 

Under Coloration (p. 5), the authors refer to 
several color morphs of the Prairie Falcon, which 
may be misleading. Prairie Falcon plumages vary 
between light and dark, but there are no distinct 
color morphs as found in Gyrfalcons (F. rusticolus ) 
and some other raptors. In the next section (p. 
15), the authors discuss nest-site fidelity, a strong 
characteristic in this species. Although this aspect 
of behavior is well documented, there is no evi- 
dence that Prairie Falcons mate with the same part- 
ner from year to year, a point that should have 
been included. 

I particularly enjoyed the section on Hunting 
Techniques (p. 28) , which includes information on 
foraging behavior, kleptoparasitism, and food cach- 
ing. However, I should note a slight discrepancy in 
the interpretation of data from my study of forag- 
ing behavior. Although most of the attacks I ob- 
served were of the low coursing type at moderate 
speeds, some attacks were initiated from a soar and 
ended in an extremely fast, low-trajectory ap- 
proach close to the ground. The phenomenon is 
described by the aeronautical term “ground ef- 
fect.” Clearly, these two methods were not the 
same. The soaring technique, when applied to prey 
spotted on the ground, gave the falcon great in- 
coming speed and made it difficult for prey to de- 
tect the approaching falcon. I suspect that all large 
falcons use this soaring technique to some degree. 


74 


March 1998 


Book Review 


75 


Table 2 describes the food habits of Prairie Falcons 
collected throughout the western United States. It 
clearly shows that these falcons are adaptable pred- 
ators, able to glean whatever food resources the 
local environment has to offer. 

Chapter 2 covers seasonal patterns of courtship, 
breeding, and nesting. Information on fledging ac- 
tivities and fall and winter dispersal patterns also 
are included. I wish Figure 6 (p. 82) had included 
a map of current band-recovery information for all 
age groups, as well as data from breeding popula- 
tions in the southern part of the falcon’s range. 
Data for this figure were collected in 1964. How- 
ever, most of the information on the species has 
been collected since the 1970s. Jim Enderson was 
the first researcher to recognize the importance of 
the Great Plains to the wintering ecology of this 
species, including falcons from as far west as Cali- 
fornia and Oregon. Considering that most Prairie 
Falcons nest west of the Continental Divide, and 
that human-caused alterations in the Plains States 
have vastly changed the ecology of that region, 
there is still much to be learned by investigating 
the eastern movements during fall and winter. The 
authors’ comments on the fragility of the Prairie 
Falcon’s environment lead one to conclude that 
winter habitat may, in fact, be one of the most crit- 
ical elements for the long-term survival of the spe- 
cies. 

Early on, the authors mention that nestlings 
fledge at two months of age. But on p. 73, they 
correctly state that fledging age is between 33 and 
35 days of age. It seemed curious that no mention 
was made of the adult male’s role in incubation (p. 
63) . Although undoubtedly there is wide variation 
among pairs, it should be noted that males share 
this duty during daylight hours. 

The third chapter concentrates on the juxtapo- 
sition of the Prairie Falcon in relation to other rap- 
tors found in North America and around the 
world. It serves primarily as a review of nomencla- 
ture, physiology, and evolution. The Taxonomy sec- 
tion (p. 100) seems to support the conclusion that 
Tom Cade reached in The Falcons of the World : that 
Prairie Falcons are part of the “desert falcon” 


group that includes Gyrfalcons, Saker Falcons (F 
cherrug), and Lanner Falcons (F. biarmicus ). How- 
ever, at the very end of the book (p. 138), the au- 
thors acknowledge that recent DNA studies show 
that Prairie Falcons are more closely related to Per- 
egrine Falcons (F. peregrinus ) . 

Chapter 4 begins with an overview of the Prairie 
Falcon’s role in falconry and captive breeding. The 
authors state that stocks of Prairie Falcons can be 
managed to provide both viable populations of 
wild birds and a falconry harvest. Under Captive 
Breeding (p. 119), a method of semen collection 
is described that would be appropriate for large 
poultry, but not for raptors. (It should be noted 
that Prairie Falcons breed readily in captivity. Yet, 
since the initial flurry of captive-breeding technol- 
ogy two decades ago, little effort has been expend- 
ed on breeding them in any number.) The authors 
then present current information on the effects of 
pesticides, human influences, and mitigation mea- 
sures. 

The book concludes by suggesting that the spe- 
cies be viewed holistically — as one important link 
in the food chain of its habitat — linking predator 
with prey, prey with habitat, and habitat with hu- 
manity. We must make this connection if Prairie 
Falcons, and indeed all raptors, are to have a fu- 
ture on this continent. 

Finally, the Raptor Etiquette section in the Ap- 
pendix offers sound suggestions on how to watch 
nesting falcons without disturbing them. Overall, I 
appreciated the high quality of the book, including 
good paper and a sturdy cover. Simple line draw- 
ings, augmented by striking photographs by LuRay 
Parker and Rick Kline, enhance its visual appeal. 
Although the angled layout of the photographs 
may be artistically appealing to some, I found them 
mildly distracting. The book comes complete with 
a well-stocked section of references. There were 
some minor typos, but these are hard to avoid. The 
Prairie Falcon belongs in the libraries of serious 
scholars, budding researchers, fans of western wild- 
life, and avid birders of all descriptions. At $29.95, 
it is a bargain. — Bruce Haak, Idaho Department of 
Fish and Game, 3101 South Powerline Road, Nam- 
pa, ID 83686 U.S.A. 


J Raptor Res. 32(1) :76 

© 1998 The Raptor Research Foundation, Inc. 

Manuscript Referees 

The following people reviewed manuscripts for the Journal of Raptor Research in 1997. Peer review plays a vital role 
in the publishing process and in improving the quality of the Journal. The names of individuals who reviewed two or 
more manuscripts are followed with an asterisk. 

Beatriz Arroyo*, Eric C. Atkinson, James C. Bednarz, Maria Isabel Bellocq*, James R. Belthoff, Keith L. Bildstein*, 
David M. Bird, Clint W. Boal*, Gary R. Bortolotti*, Thomas Bosakowski, Joseph B. Buchanan, Javier Bustamente*, 
Tom J. Cade*, William S. Clark, Randy Craft, Dick Dekker, Stephen DeStefano, Alfred M. Dufty, Jr., Gary E. Duke*, 
James H, Enderson*, Allen M. Fish*, Eric Forsman*, Alan B. Franklin, Frederick R. Gehlbach*, Richard P. Gerhardt, 
James A. Gessaman, Richard Glinski, Daniel N. Gossett, Teryll Grubb, Ralph J. Gutierrez*, Alan R. Harmata*, Eliza- 
beth Haug, Gregory D. Hayward, William Heinrich, Charles J. Henny*, Geoffrey L. Holroyd, Denver W. Holt*, C. 
Stuart Houston*, C. Hubert, Jerome A. Jackson, Fabian M, Jaksic*, Paul James*, Robert S. Kennedy, Steven Knick, 
Jeffrey S. Marks*, Carl D. Marti*, John M. Marzluff, Carol L. McIntyre, Michael McGrady*, Heimo Mikkola*, Brian 
A. Milsap, Helmut C. Mueller*, Ian Newton*, Alan Poole*, Charles R. Preston*, Patrick T. Redig*, Gary Ritchison, 
James A. Rodgers, Jr,, Robert N. Rosenfield, Sievert A. Rohwer, Philip F. Schempf, Josef K. Schmutz*, Dwight G. 
Smith*, Karen Steenhof*, Stephen Sweeney*, Theodor Swem, Paul W. Sykes, Jr., Ethan J. Temeles, Jean-Marc Thiollay, 
Kimberly Titus*, Helen M. Ulmschneider, S. Van Balen, Daniel E. Varland, Ian G. Warkentin*, Richard T. Watson, 
David Whitacre, Clayton M. White, Per Widen. 


[ 


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The following Birds of North America Species Accounts are available through Buteo Books, 3130 Laurel Road, 
Shipman, VA 22971. TOLL-FREE ORDERING: 1-800-722-2460; FAX: (804) 263-4842. 

Barn Owl (1). Carl D. Marti. 1992. 16 pp. 

Boreal Owl (63). G.D. Hayward and P.H. Hayward. 1993. 20 pp. 

Broad-winged Hawk. (218). L.J. Goodrich, S.C. Crocoll and S.E. Senner. 1996. 28 pp. 

Burrowing Owl (61). E.A. Haug, B.A. Millsap and M.S. Martell. 1993. 20 pp. 

Common Black-hawk (122). Jay H. Schnell. 1994. 20 pp. 

Cooper’s Hawk (75). R.N. Rosenfield andj. Bielefeldt. 1993. 24 pp. 

Crested Caracara (249). Joan L. Morrison, 1996. 28 pp. 

Eastern Screech-owl (165). Frederick R. Gehlbach. 1995. 24 pp. 

Ferruginous Hawk (172). MarcJ. Bechard and Josef K. Schmutz. 1995. 20 pp. 

Flammulated Owl (93). D. Archibald McCallum. 1994. 24 pp. 

Great Gray Owl (41). Evelyn L. Bull and James R. Duncan. 1993. 16 pp. 

Gyrfalcon (114). Nancy J. Clum and Tom J. Cade. 1994. 28 pp. 

Harris’ Hawk (146). James C. Bednarz. 1995. 24 pp. 

Long-eared Owl (133). J.S. Marks, D.L. Evans and D.W. Holt. 1994. 24 pp. 

Merlin (44). N.S. Sodhi, L. Oliphant, P. James and I. Warkentin. 1993. 20 pp. 

Northern Saw-whet Owl (42). Richard J. Cannings. 1993. 20 pp. 

Northern Goshawk (298). John R. Squires and Richard T. Reynolds. 1997. 32 pp. 

Northern Harrier (210). R. Bruce MacWhirter and Keith L. Bildstein. 1996. 32 pp. 

Red-shouldered Hawk (107). Scott T. Crocoll. 1994. 20 pp. 

Red-tailed Hawk (52). C.R. Preston and R.D. Beane. 1993. 24 pp. 

Short-eared Owl (62). D.W. Holt and S.M. Leasure. 1993. 24 pp. 

Snail Kite (171). P.W. Sykes, Jr., J.A. Rodgers, Jr. and R.E. Bennetts. 1995. 32 pp. 

Snowy Owl (10). David F. Parmelee. 1992. 20 pp. 

Spotted Owl (179). R.J. Gutierrez, A.B. Franklin and W.S. Lahaye. 1995. 28 pp. 

Swainson’s Hawk (265). A. Sidney England, MarcJ. Bechard and C. Stuart Houston. 1997. 28 pp. 
Swallow-tailed Kite (138). Kenneth D. Meyer. 1995. 24 pp. 

White-tailed Hawk (30). C. Craig Farquhar. 1992. 20 pp. 

White-tailed Kite (178). Jeffrey R. Dunk. 1995. 16 pp. 


76 


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and three copies to the Editor. All submissions must be typewritten and double-spaced on one side of 216 
X 278 mm (8A£ X 11 in.) or standard international, white, bond paper, with 25 mm (1 in.) margins. The 
cover page should contain a title, the author’s full name(s) and address(es). Name and address should be 
centered on the cover page. If the current address is different, indicate this via a footnote. A short version 
of the title, not exceeding 35 characters, should be provided for a running head. An abstract of about 
250 words should accompany all research articles on a separate page. 

Tables, one to a page, should be double-spaced throughout and be assigned consecutive Arabic numer- 
als. Collect all figure legends on a separate page. Each illustration should be centered on a single page 
and be no smaller than final size and no larger than twice final size. The name of the author (s) and figure 
number, assigned consecutively using Arabic numerals, should be pencilled on the back of each figure. 

Names for birds should follow the A.O.U. Checklist of North American Birds (6th ed., 1983) or another 
authoritative source for other regions. Subspecific identification should be cited only when pertinent to 
the material presented. Metric units should be used for all measurements. Use the 24-hour clock (e.g., 
0830 H and 2030 H) and “continental” dating (e.g., 1 January 1990). 

Refer to a recent issue of the journal for details in format. Explicit instructions and publication policy 
are oudined in “Information for contributors,”/. Raptor Res., Vol. 27(4), and are available from the editor. 


INTERNATIONAL DIRECTOR #3: 

Michael McGrady 

DIRECTOR AT LARGE #1: Patricia L. Kennedy 
DIRECTOR AT LARGE #2: John A. Smallwood 
DIRECTOR AT LARGE #3: James C. Bednarz 
DIRECTOR AT LARGE #4: Cesar MArquez Reyes 
DIRECTOR AT LARGE #5: Lloyd Kiff 
DIRECTOR AT LARGE #6: Robert Kenward 


1998 ANNUAL MEETING 


The Raptor Research Foundation, Inc. will hold its 1998 annual meeting in Ogden, Utah from 
30 September through 4 October at the Ogden Egyptian Conference Center. Details about the 
meeting and a call for papers will be mailed to members in the spring of 1998. A site on the 
World Wide Web contains information about the meeting and setting (http://www.weber.edu/ 
rrf). Contact Carl D. Marti for more information (801/626-6172; cmarti@weber.edu). 


Raptor Research Foundation, Inc., Awards 
Recognition for Significant Contributions 1 

The Dean Amadon Award recognizes an individual who has made significant contributions in the field of 
systematics or distribution of raptors. Contact: Dr. Clayton White, 161 WIDB, Department of Zoology, 
Brigham Young University, Provo, UT 84602 U.S.A. Deadline August 15. 

The Tom Cade Award recognizes an individual who has made significant advances in the area of captive 
propagation and reintroduction of raptors. Contact: Dr. Brian Walton, Predatory Bird Research Group, 
Lower Quarry, University of California, Santa Cruz, CA 95064 U.SA. Deadline: August 15. 

The Fran and Frederick Hamerstrom Award recognizes an individual who has contributed significantly to 
the understanding of raptor ecology and natural history. Contact: Dr. David E. Andersen, Department 
of Fisheries and Wildlife, 200 Hodson Hall, 1980 Folwell Avenue, University of Minnesota, St. Paul, 
MN 55108 U.SA. Deadline: August 15. 

Recognition and Travel Assistance 

The James R. Koplin Travel Award is given to a student who is the senior author of the paper to be 
presented at the meeting for which travel funds are requested. Contact: Dr. Petra Wood, West Virginia 
Cooperative Fish and Wildlife Research Unit, P.O. Box 6125, Percival Hall, Room 333, Morgantown, 
WV 26506-6125 U.SA Deadline: established for conference paper abstracts. 

The William C. Andersen Memorial Award is given to the student who presents the best paper at the annual 
Raptor Research Foundation Meeting. Contact: Ms. Laurie Goodrich, Hawk Mountain Sanctuary, Rural 
Route 2, Box 191, Kempton, PA 19529-9449 U.SA. Deadline: Deadline established for meeting paper 
abstracts. 


Grants 2 

The Stephen R. Tully Memorial Grant for $500 is given to support research, management and conservation 
of raptors, especially to students and amateurs with limited access to alternative funding. Contact: Dr. 

Kimberly Titus, Alaska Division of Wildlife Conservation, P.O. Box 20, Douglas, AK 99824 U.SA. Dead- 
line: September 10. 

The Leslie Brown Memorial Grant for $500-$l,000 is given to support research and/or the dissemination 
of information on raptors, especially to individuals carrying out work in Africa. Contact: Dr. Jeffrey L. 
Lincer, 15644 Kingman Rd., Poway, CA 92064 U.SA. Deadline: September 15. 


1 Nominations should include: (1) the name, title and address of both nominee and nominator, (2) the 
names of three persons qualified to evaluate the nominee’s scientific contribution, (3) a brief (one page) 
summary of the scientific contribution of the nominee. 

2 Send 5 copies of a proposal (^5 pages) describing the applicant’s background, study goals and methods, 
anticipated budget, and other funding.