New birds from Camiguin South, Philippines

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MATURAL HISTORY SURVEY

ULC t 1969
FIELDIANA . ZOOLOGY

UBRARV

Published by
FIELD MUSEUM OF NATURAL HISTORY

Volume 51 September 30, 1969 No. 13

New Birds from Camiguin South, Philippines

Austin L. Rand
Chief Curator, Zoology, Field Museum of Natural History

AND

DiOSCORO S. Rabor

Associate, Birds, Field Museum of Natural History

Research Professor, Biology, Mindanao State University,

Marawi City, Philippines

There is an island in the western Mindanao Sea called on the
maps simply Camiguin, but we will call it Camiguin South to dis-
tinguish it from the island of the same name to the north of Luzon,
which we will call Camiguin North as McGregor did in 1909. There
has been confusion in the earlier literature.

In 1968 Rabor, as part of his continuing studies, stayed briefly
on Camiguin South and made a collection there. Later, in making
a preliminary study of the collection, he picked out several species
for more study and sent them, along with his notes, to Rand to
complete comparisons and descriptions. This paper is a report on
four species. Further field work and a complete report on the birds
of the island are contemplated.

Camiguin South, in the Mindanao Sea, lies about ten miles north
of Mindanao and 50 miles southeast of Bohol. This volcanic island
is about 9 by 13 miles in size, with a peak rising to over 5,000 feet.
Although heavily populated, there are still forest areas.

Its ornithological history is short. The historic H.M.S. Challeri-
ger stopped here and sent a party ashore for a few hours on the
afternoon of January 26, 1875. The following five species of com-
mon, widespread Philippine birds were collected, four of them from
second growth and open country, and one a sandpiper: Corvus macro-
rhynchus, Aplonis panayensis, Halcyon Moris, Nectarinia jugularis,
and Actitis hypoleucos (Tweeddale, 1877, Proc. Zool. Soc. London,
p. 536).

Library of Congress Catalog Card Number: 79-9976A

No. 1081 167

158 FIELDIANA: ZOOLOGY, VOLUME 51

The next ornithological visitor was in 1921 when W. Cameron
Forbes, Governor-General of the Philippines, "visited most of the
islands of the gi'oup." He was accompanied at times by such lumi-
naries as Leonard Wood, Worcester, McGregor, and Celestino.
When the collections came to the Museum of Comparative Zoology
Outram Bangs, 1922, Bull. Mus. Comp. Zool., 65, pp. 77-84, re-
ported on the more interesting specimens which included at least
two species labeled from Camiguin [South]: Lalage niger and two
specimens of "Zosterops jorhesi"=Z. everetti hasilanica collected on
August 2, 1921. Until Rabor's 1968 work, no other bird work for
this area has come to our attention. Rabor plans more work for
1968-69.

Four species are discussed in this paper: Hypsipetes everetti, Hypo-
thymus azurae, Dicaeum trigonostigma, and Zosterops nigrorum, each
with new subspecies^ — five in all.

Hypsipetes everetti

Delacour, in Delacour and Mayr, 1945, Zoologica, 30, p. 112; Delacour. in Dela-
cour and Mayr, 1946, Birds of the Philippines, p. 176; Rabor, 1955, Silliman
Jour., 2, p. 103; Rand and Rabor, 1959, Auk, 76, pp. 102-104; Deignan, 1960,
Peter's Check-list of Birds of the World, 9, p. 288; deSchauensee and duPont,
1962, Proc. Acad. Nat. Sci. Phila., 114, p. 163.

The treatment of the species limits of everetti and its naar relatives
in the Mindanao area has changed several times in recent decades.
This has resulted from the progressive increase in our knowledge of
the ranges of the forms involved, an increase due to the progressive
field work, especially that of Rabor, in Mindanao.

Basic was the discovery that philippinus did not range over all
western Mindanao (Rabor, 1955, contra Delacour, 1946), and that
both everetti and philippinus from the east, and rufigularis from the
west, all met in the Lake Lanao area of western central Mindanao
(Rabor, 1955; Rand and Rabor, 1959; deSchauensee and duPont,
1962).

Obviously, rufigularis cannot be conspecific with either everetti
(contra Delacour, 1946) nor with philippinus (contra Rand and Rabor,
1959; Deignan, 1960).

Rabor, 1955, suggested that rufigularis, the only Hypsipetes of
western Mindanao and Basilan was not monotypic but conspecific
with haynaldi of the Sulu islands as the only Hypsipetes occurring
there. This last is a form that is somewhat intermediate in appear-

RAND AND RABOR: BIRDS OF CAMIGUIN SOUTH 159

ance between the yellow-olive everetti and the brown-tawny, white-
bellied rufigularis, even if it is not intermediate geographically.

However, the discovery of another dark race of everetti on the
isolated island of Camiguin South (where it is the only Hypsipetes),
adds weight to keeping the dark haynaldi also in everetti, leaving
rufigularis monotypic.

The following arrangement seems preferable:

H. philippinus; Luzon to eastern and central Mindanao; sev-
eral races.

H. rufigularis; western central Mindanao west to Basilan ; mono-
typic.

H. everetti; Samar to eastern and central Mindanao; also Sulu
islands and Camiguin South; four races, see below.

Hypsipetes everetti samarensis Rand and Rabor

Range. — Samar and Leyte; probably Panaon birds are the same.

Diagnosis.- — Upperparts predominantly olive green, crown little
different but with lighter lanceolate tips to some feathers: throat
buffy ochraceous (deep tawny) breast olive-tinged tawny; lower
breast and abdomen yellow; flanks, yellowish olive.

Wing c^ (10) 113-121 (av. 117 mm.); 9 (10) 105-115 (av. 110.8
mm.); culmen cf (10) 28-31 (av. 29.9 mm.); 9 (10) 27—28 (av.
27.7 mm.).

Hypsipetes everetti everetti Tweeddale

Range. — Dinagat and east and central Mindanao west to Lake
Lanao area.

Diagnosis. — Like samarensis but upperparts brighter, clearer
green (less golden or olive green) ; throat and upper breast brighter
ochraceous; lower breast and abdomen being brighter, clearer yellow,
and in flanks being less heavily washed with olive.

Wing cT (6) 118-125 (av. 122.3 mm.); 9 (6) 112-118 (av. 114.8
mm.); culmen cf (6) 28-31 (av. 29.3); 9 (6) 26-30 (av. 27.3 mm.).

Remarks. — There is considerable variation in Mindanao birds,
and this results in an overlap with Samar and Leyte series.

Hypsipetes everetti haynaldi Blasius

Range. — Sulu Archipelago (Sulu and Tawi Tawi Islands).

160 FIELDIANA: ZOOLOGY, VOLUME 51

Diagnosis. — Like everetti in having crown about like back, but
differs in upperparts being considerably duller, darker, more brown-
ish olive; in the throat and upper breast being darker and duller
brownish without tawny tinge, and flanks deeper olive; also wing
shorter (but not bill).

Wing cf (6) 107-116 (av. 110 mm.); 9 (6) 107-112 (av. 109 mm.);
culmen cT (6) 27-29 (av. 28 mm.); 9 (6) 27-30 (av. 28 mm.).

Remarks. — This is a well-marked, but not a strikingly different
race. I have to thank Dr. R. L. Zusi of the United States National
Museum for the loan of the 12 Sulu Archipelago specimens. They
were collected in September -November, 1891 by Worcester and
Bourns.

Neither this form nor everetti is known from Basilan or western
Mindanao where its place is taken by H. rufigularis of which it ap-
pears to be the ecological equivalent.

Hypsipetes everetti catarmanensis, new subspecies

Type. — Field Museum Natural History no. 284,445 from Camig-
uin South Island, Catarman Mt. between 2,000 and 4,000 feet.
Adult male collected June 16, 1968 by D. S. Rabor.

Diagnosis.- — Differs from the above three races in having the
crown brownish black contrasting sharply with the rest of upper-
parts; differs in rest of upperparts being considerably darker green-
ish olive, in the darker brownish breast, in the darker olive flanks,
and in larger size.

Wing cT (9) 126-136 (av. 129 mm.); 9 (10) 118-124 (av. 121.9
mm.); culmen cf (9) 32-34 (av. 32.8 mm.); 9 (10) 29-31 (av.
30 mm.).

Range.- — Camiguin South Island.
Hypothymis azurae

Mayr, 1945, Zoologica, 30, p. 113; Parkes, 1965, Ann. Carnegie Mus., 38,
pp. 61-62.

The range of this species is from India to Formosa and south
through Malaysia to Java, Flores, and the Philippines. There is a
geographical representative species, H. puella in Celebes, and in the
Philippines are two other, very distinct species, endemic, rare, and
of limited distribution. In the Philippines, including the Palawan
group and Sulus, the subspecies H. a. azurae is common and wide-
spread in lowland and mid-altitude forests, and recorded on 30 is-

RAND AND RABOR: BIRDS OF CAMIGUIN SOUTH 161

lands by McGregor. Minor variation in shade of color and extent
of pattern have been pointed out by Mayr and Parkes, but not of
subspecies rank.

The widespread Philippine subspecies is blue with abdomen and
flanks white and with band on forehead, broad patch on nape, and
narrow collar on upper breast black. The female differs in having
upperparts dull olive brown, breast greyish, and in lacking black
marks.

The new collection from Camiguin South yielded eight specimens
of this species that indicate a unique population, worthy of subspe-
cies designation.

Hypothymis azurae catarmanensis, new subspecies

Type. — Field Museum of Natural History no. 284513 from Catar-
man Mountain, 4,950 feet, Catarman, Camiguin South Island, Philip-
pine Islands. Adult female, collected June 20, 1968 by D. S. Rabor.

Diagnosis. — Male like that of H. a. azurae in general pattern but
with blue parts of plumage deeper and more purplish blue; also black
area on nape reduced in size (absent in 1 of 3 specimens). Wing,
70, 73, 75; tail, 69, 76, 77; culmen, 16, 16, 17 mm.

Female (4 of 5 specimens).— Strikingly different from that of
H. a. azurae in having the back and wings and tail blue, not brown,
and in having the throat and breast deeper blue. In effect, these
females look like rather dull, paler males, without the black throat
band and without the black nape patch. Wing, 71, 71, 73, 76; tail,
68, 70, 70, 72; culmen, 16, 16, 17, 17 mm.

Female (1 of 5 specimens) .^ — Like female of H. a. azurae but part
of back with a bluish tinge (not olive brown), upper wing coverts
blackish, glossed purplish blue (not brownish) and outer edges of
wing quills and tail quills with a bluish tinge (not brownish). (On
immature plumage only?) Wing, 74; tail, 72; culmen, 16 mm.

Wing length

from various

localities:

H. a. azurae

Negros

d" 68-74

9 67-70 mm.

Siquijor

cf 72-75

9 70-73

Bohol

cf 67, 69, 70

9 66-68

Samar

d^ 65-70

9 63-68

Mindanao

d^ 67-70

9 64-69

162 FIELDIANA: ZOOLOGY, VOLUME 51

H. a. catarmanensis

Camiguin South cf 70-75 9 71-76 mm.

Range. — Camiguin South; lowlands to 4,950 feet on peak of
Mount Camiguin.

Remarks. — For comparison we have large series of H. a. azurae
from Luzon, Negros, and Mindanao, moderate series from Palawan,
Bohol, Siquijor, Samar, Cebu, and one or a few specimens from each
of Polillo, Sibuyan, Romblon, Mindoro, Guimaras, and Basilan.
Males and females are about equally represented in all these series,
every blue-backed bird has the black nape patch, usually of consid-
erably greater extent than in that of the Camiguin South birds with
the largest patch. The size of the black throat band is variable,
rarely absent. All the females have brown backs (of various shades
of brown or greyish-brown) .

There is always a possibility of some mis-sexing of specimens in
the field, but the blue-backed females from Camiguin South are not
like any specimens, male or female, from any other islands.

The following tentative conclusions are advanced.

There is a reduction in sexual dimorphism through the female
becoming partly cock-feathered, notably in the blue back, and the
male becoming more like this new type female through the partial
loss of the black nape patch.

There is an indication, from this collection, that the female may
be dimorphic, most (4 out of 5) are much like dull males but without
black markings; a few (1 out of 5) are more like the female of H. a.
azurae. However, this may be an earlier plumage, special to the
immature female in this population.

There are two other species of the genus in Philippines: H. helenae,
Camiguin North, Luzon (series Field Museum), Samar, Mindanao;
and H. coelestis, Luzon, Negros, Sibuyan, Dinagat, Mindanao, Basi-
lan; and neither is known to occur on Camiguin South. One may be
tempted to consider the possibility that this absence has allowed sex-
ual dimorphism to decrease. But, there are other islands in the
Philippines, with only H. azurae; and over most of the range of
H. azurae it is the only representative of the genus. Birds from
Nepal have the same male and female mode of plumage as do those
of H. a. azurae of Philippines.

Dicaeum trigonostigma

Salomonsen, 1960, Amer. Mus. Novit., No. 1991, pp. 28-37.

RAND AND RABOR: BIRDS OF CAMIGUIN SOUTH 163

This is a widespread species presumably originating in the Philip-
pines (though absent from Palawan) where Salomonsen recognized
nine subspecies, most of them with striking and clear-cut characters.
In all the rest of the range (Java and Borneo to Assam), only five
subspecies have developed and most of them with rather trivial char-
acters. Five of the nine subspecies recognized in the Philippines are
small island subspecies: on Romblon and Tablas (intermedium);
Sibuyan (sibuyanicum) ; Siquijor (besti); Jolo, Tawi-tawi, Siasi (as-
simile) ; and Sibutu (sibutuense) . An additional subspecies proves to
have been developed on Camiguin South, raising the number of
Philippine subspecies to ten, and six of them small island subspecies.

The near relatives of the Camiguin South form seem to be the
geographically adjacent cinereigularae of Mindanao-Samar-Leyte-
Bohol area, and besti of Siquijor, and it is with these that comparison
is needed, differing as they do chiefly in color of chin and throat, and
in size.

Dicaeum trigonostigma besti Steere

Diagnosis. — Male, chin and upper throat yellow; rest of throat
and sides of neck uniform grey, without a yellow wash. Size, small.
Male, wing (10), 50-53 (av. 51.8 mm.); culmen (10), 13-14 (av.
13.3 mm.).

Dicaeum trigonostigma cinereigulare Tweeddale

Diagnosis. — Male, chin and upper throat yellow; lower throat and
side of neck grey washed with yellow. Size, small.

wing culmen

Samar, male (10) 50-52 (av. 51) (10) 11-13.5 (av. 12.4)
Bohol, male (4) 49-52 (av. 50) (4) 12-13 (av. 12.5)

Mindanao, male (10) 49-52 (av. 51.2) (10) 12-13.5 (av. 12.7)

Dicaeum trigonostigma isidroi, new subspecies'

Type.— Field Museum of Natural History no. 284521 from Ka-
sangsangan, Catarman, Camiguin South Island, Philippine Islands.
Adult male collected June 11, 1968, by D. S. Rabor.

Diagnosis.— Like both of the above subspecies but differs in the
male having the chin and upper throat much paler yellow; in having

» This new race is named in honor of Dr. Antonio Isidro, president of Mindanao
State University, and in appreciation of his great interest in biological research.

164 FIELDIANA: ZOOLOGY, VOLUME 51

the lower throat pale, whitish grey (without any yellowish wash)
becoming darker toward the sides of the throat; size larger. Wing
cf (10), 55-57 (av. 55.6 mm.); culmen (10), 13.5-15 (av. 14 mm.).

Range. — Camiguin South Island, 1,000-2,500 feet altitude.

Remarks. — Most races of this species in Philippines have wing
48-53 mm.; but there are two larger subspecies, the present one (see
above) and sihuyanicum wing 54-57 mm., both small island species.

Zosterops nigrorum

Mees, 1957, Zool. Verh. Rijk. Mus. Nat. Hist. Leiden, No. 35, pp. 160-170;
Mayr, 1967, Peter's Check-list of Birds of the World, 12, pp. 299, 300.

This is the only species of Zosterops in the Philippines that has
completely yellow underparts. It is a species of large and small
islands: large islands in the north, and the western central islands —
Luzon, Mindoro, Masbate, Panay, and Negros; a very few scattered
small islands^ — Camiguin North (north of Luzon); and a few small
islands in the central Philippines with southern outposts on Cagayan-
cillo (west of Negros, in Sulu Sea) and Camiguin South in Minda-
nao Sea.

The relationships of this species are not clear, but the general
appearance of the various subspecies, and their differences from other
species, in appearance and range, seem to indicate a natural group,
foiming an endemic Philippine species, as treated in recent revisions.

Up until now the known ranges of the related everetti, with under-
parts partly grey or white as well as yellow, and nigrorum have been
allopatric. However, on Camiguin South Rabor found both species,
everetti at low altitudes and nigrorum at higher altitudes. This is the
only locality where both species occur. (It may be recalled that the
old records of Z. everetti siquijorensis for Negros are in error, surely
due to a mis-identification of specimens of Z. montana pectoralis.)

Seven subspecies of Z. nigrorum are recognized in the following,
and are arranged in three groups.

Group I. — Four races, generally bright to moderately bright in
coloration; eye ring complete; little or no black or dusky in side of
head; size smaller; wing cf 50-56 mm.

Zosterops nigrorum meyleri McGregor

/?a?/gfe.- Camiguin North.

Diagnosis. — A small race, separable from all other races by wide,
complete eye ring, especially wide below the eye, according to Mees

RAND AND RABOR: BIRDS OF CAMIGUIN SOUTH 165

whose scant material was variable in color. His pen and ink draw-
ing of head indicates a short dusky streak below white eye ring only.

McGregor, 1908, Manual Philippine Birds, pp. 618-619, says this
race is similar to richmondi but lacks the black under eye and has eye
ring wider.

Wing (4), 53.5-56 (av. 54.4); culmen (4), 12.8-13.8 (av. 13.2 mm.).
(Mees) no specimens seen.

Zosterops nigrorum aureiloris Ogilvie Grant

Range. — Northwestern Luzon, south certainly to Mountain and
Abra Provinces and Benguet; farther south intergradation with the
next two races to be expected; also on Mindoro; sea level to 5,000
feet.

Diagnosis. — A small, brightly colored race, complete eye ring,
with, at most, a dusky smudge below it ; loral area and a narrow area
on forehead golden yellow and sharply contrasting with rest of upper-
parts; upperparts bright yellowish olive gi*een; underparts bright
yellow with flanks lightly tinged olive.

Male, wing (10), 49-56 (av. 53.0); culmen (10), 11-13.5 (av.
12.3 mm.).

Remarks. — Series from Ilocos Norte, Abra, and Mountain prov-
inces. Collected by Rabor, in Field Museum of Natural History.

Zosterops nigrorum sierramadrensis new subspecies

Type. — Field Museum of Natural History no. 259880 from Luzon
Island, Cagayan Province, Gonzaga, Mt. Cagua (in the Sierra Ma-
dre), 2,000-4,000 feet altitude. Adult male collected April 30, 1960.

Diagnosis. — Like aureiloris of northwestern Luzon, but upper-
parts darker, less yellowish, forehead darker yellow usually with an
ochraceous tinge; underparts deeper yellow on the throat, and with
more of an olive wash on breast and flanks; bill slightly longer. Thus,
a more intensely colored, darker race.

Wing cT (10), 50-54 (av. 51.2 mm.); culmen (10), 12-14 (av.
13.1 mm.).

Range. — Northeastern Luzon in Cagayan Province. Presumably
ranges southward to intergrade with the next race in central Luzon.

Remarks. — Series from Cagayan Province in Field Museum of
Natural History. This is an additional example of northwestern
and northeastern Luzon birds representing different subspecies, as

166 FIELDIANA: ZOOLOGY. VOLUME 51

discovered by Dr. Rabor's field work in 1959 and 1960. (See Rand
and Rabor, 1967, Fieldiana: Zool., 51, pp. 85-89.)

Tlie moderately well-marked characters of this new race show
very plainly in series, and there is little trouble in allocating most
individual male specimens from Ilocos Norte Mountain and Abra
specimens on the one hand, and Cagayan specimens on the other.
Females are duller.

The earlier lack of recognition of this northeastern subspecies was
due to lack of adequate material, and there is the probability that
central Luzon, easily reached by collectors, may be where three sub-
species merge.

Zosterops nigrorum luzonica Ogilvie Grant

Range. — Southern Luzon; probably meeting and intergi-ading with
the above two races in central Luzon.

Diagnosis. — Like sierramadrensis but differs most notably in the
much less, and paler yellow in the forehead and lores. There is also
a better developed dark line below the eye ring and average slightly
richer yellow below, and a slightly clearer green above.

Wing d" (10), 50-56 (av. 52.8); culmen d^ (10), 13-14 (av.
13.3 mm.).

Remarks. — Series from Camarines Sur and Sorsogon of extreme
southern Luzon.

Again, material has been scarce in collections from southern
Luzon. For example, in 1957 Mees had seen but two specimens.

Group II. — One race; dull; eye ring interrupted by black spot in
front; black line in lower lores — below eye ring area definite and dis-
tinct; size medium, wing, cf 54-58 mm.; culmen, 13-14 mm.

Zosterops nigrorum nigrorum

Range. — Masbate, Caluya, Ticao, Cresta de Gallo, Panay, Negros.

Diagnosis. — Differs from all three Luzon races in the white eye
ring being interrupted in front by a black spot and the black line
below the eye ring being better developed, in the underparts being
much colder, duller yellow and the much more extensive and heavier
greyish olive wash over breast and sides of body; size slightly larger.

Wing cf (10), 54-58 (av. 55.6) ; culmen (10), 13-14 (av. 13.6 mm.).

Remarks. — Field Museum of Natural History has a good series of
Negros birds (Rabor collection). Mees (loc. cit., p. 164) found no

RAND AND RABOR: BIRDS OF CAMIGUIN SOUTH 167

differences between populations from Negi'os, Panay, and Masbate.
Field Museum also has two specimens from Ticao (McGregor and
Celestino collection) which agi'ee with Negi'os birds on the main
characters, although differ somewhat in shade of general coloration.
Wing, cf 58, 9 57 mm.; culmen, 13-14 mm.

The habitat on Negi'os is the rain forest and second growth.

Group III.— Two races, bright, eye ring incomplete, interrupted
by black spot in front; black below eye ring distinct; size larger; wing,
57-62 mm.; culmen, 14-16 mm.

Zosterops nigrorum richmondi McGregor, 1904

i?awgre.— Cagayancillo Island (Cagayan Islands), in the Sulu Sea.

Diagnosis. — Like nigrorum in the pattern of the side of the head
with black spot interrupting eye ring in front and confluent with the
distinct black line below lores and eye ring. Differs from nigrorum
in larger size, in upperparts much lighter and more yellow green ; in
whole underparts being much brighter more intense yellow, with re-
duced olive tinge in flanks.

Wing, cf 58, 9 59; culmen, 15, 15 mm.

Remarks. — Known only from Cagayancillo (now called Cagayan),
the largest (5 miles by 1 mile) island of the Cagayanes group west of
Negros and about 70 miles southwest of Panay, the nearest island.
The habitat is described by McGregor, 1904, Bull. Phil. Mus., No. 3,
p. 5: the island reaches several hundred feet altitude: surface, coral
rock; vegetation scanty, coconut palms along shore, occasional man-
goes, small clumps of bamboo, some mangrove, various shrubbery,
trees, masses of rank grass and tall weeds; no streams, little marsh.
This Zosterops was very common throughout.

Zosterops nigrorum catarmanensis new subspecies

r^pe.^Field Museum of Natural History no. 284585 from Catar-
man Mountain, Catarman, Camiguin South Island; 2,000-4,500 feet
altitude. Adult male collected June 20, 1968 by D. S. Rabor.

Diagnosis. — Like nigrorum and richmondi in having the white eye
ring interrupted anteriorly by a black spot confluent with the black
line below lores and eye ring; like richmondi in large size; differs from
richmondi in the brighter, clearer green of upperparts; in yellow of
super-loral being clearer, brighter yellow, and in yellow of under-
parts being much brighter and clearer.

168 FIELDIANA: ZOOLOGY, VOLUME 51

Male, wing (7), 57-62 (av. 60); culmen (6), 14-16 (av. 14.6 mm.).

Range. — Camiguin South in Mindanao Sea, between 2,000 and
5,700 feet altitude.

Remarks. — In the yellow of the underparts catarmanensis is very
similar to aureiloris of northeastern Luzon, although the green of the
upperparts is slightly brighter, clearer green; and, of course, there is
the difference in size and in the loral area.