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Life Sciences
Occasional Papers

Royal Ontario Museum
August 5, 1970

No. 17

ROYAL ONTARIO MUSEUM LIBRARIES

3 1761 05162568 9

Variation in the Bats of the Genus Harpyionycteris,
with the Description of a New Race

by R. L. Peterson1 and M. Brock Fenton2

The genus Harpyionycteris, established by
Thomas (1896) with H. whiteheadi as the
type species, was based on a single specimen
of unknown sex (BMNH 97.5.2.7) from
Mindoro Island in the Philippine Islands.
The holotype was collected by J. Whitehead
at 5,000 feet altitude in December, 1895.
Thomas (1898) later provided an illustra-
tion, in colour, of the type and figured the
skull. Miller (1907) was unable to establish
any close relationship of this genus, with its
multicuspid dentition, with any other known
taxa in the family Pteropodidae and pro-
posed a distinct subfamily, Harpyionycteri-
nae, to contain this most aberrant genus of
the family. Andersen (1912) provided an
illustration of the holotype skull (Fig. 78,
p. 800) as well as excellent details of the
dentition (Fig. 79, p. 802).

The holotype remained the only known
specimen of the genus until Miller and
Hollister (1921) described H. celebensis
from a single adult female (USNM 219349)
collected by H. C. Raven on 23 August
1917 from Gimpoe, middle Celebes. This
new taxon was said to be ... "like Harpyio-
nycteris whiteheadi Thomas, of Mindoro,
but molars with crowns lower and cusps
relatively higher, and PM:! with a conspicu-
ous secondary cusp on each side of main

1. Department of Mammalogy, Royal Ontario
Museum

2. Department of Biology, Carleton University,
Ottawa, and Research Associate, Department of
Mammalogy, Royal Ontario Museum

outer cusp" (Miller and Hollister, op. cit.,
p. 99).

Tate (1951) reviewed the genus and pro-
vided data on additional specimens, six from
the Buitenzorg Museum collection from
Roeroekan, north Celebes, collected at
1,000 metres (3,300 ft.) in January, 1931,
by G. Heinrich (Buitenzorg Mus. 2828-33),
a male from Tanko Salokko, Mengkoka
Mountains, south Celebes (AMNH 153590;
examined by us) collected by G. Heinrich in
1932 at 1,500 metres (4,950 ft.), and a
female from Negros Island, Philippines
(FMNH 66302?). The latter specimen
from Mambaho Cave, Pagyabunan, Bais,
Negros Island, collected by D. S. Rabor on
13 May 1949, was also listed by Sanborn
(1952), who provided detailed measure-
ments and a sketch of the palate. The alti-
tude of this locality was not stated by the
above authors and is not included on the
data accompanying the specimen (examined
by us). However, judging by maps available
to us, the general region appears to be well
above 1,000 feet in elevation. A specimen
in the Zoologisk Museum, Copenhagen,
taken at Kaatoan, Katanglad Volcano at
an altitude of about 4,000 feet, Bukidnon
Province, Mindanao, and previously re-
ported by Sanborn (1953), was examined
and the skull restored sufficiently to obtain
several measurements. The forearm, hind
foot and tibia lengths were ascertained by
radiograph.

The collections of the ROM now contain

eight additional specimens from the Philip-
pine Islands, including one ( S skin and
skull) collected by D. Empeso on 26 May
1967 at Caterman, Mount Mamajao, Lan-
goangon, Camiquin Island (off Mindanao,
elevation between 2,500 and 3,000 feet),
and seven taken by the same collector on 7
and 8 January 1968 between 500 and 1,000
feet at Balanan, Saiton, Negros Island. The
latter series, together with FMNH 66302 9 ,
represents an age spectrum from subadult to
middle age and provides an opportunity to
detail certain changes that take place in the
skull during the aging process of H. white-
headi.

Cranial Variation with Age — This series
from Negros Island, represented by three
females and five males, is not sufficiently
large to detect any consistent cranial charac-
teristics to distinguish the sexes. An attempt
was made to arrange the series in an age-
developmental sequence from youngest to
oldest, and certain characteristics are sum-
marized in Table I. From this series, six
have been selected to show some of the
more apparent aging characteristics illus-
trated in Fig. 1. The change in the angle of
deflection of the occiput, from a strong de-
flection as shown in the two youngest indi-
viduals, to a more moderate one in the older
specimens, is particularly noteworthy, as
this angle of deflection has been used as a
taxonomic character in several pteropodid
genera.

The fusion of sutures follows a fairly
consistent pattern if our sequence has been
correctly arranged by age (see Table I).
There is a general increase in size with age
(as expressed by forearm length, condylo-
basal length, zygomatic and mastoid
breadths), although, as might be expected,
these increases in size are not entirely con-
cordant with the sequence of fusion of
sutures.

An inverse ratio is apparent in the width
of the postorbital constriction. There is an
obvious decrease in width with age, from
6.8 mm in the subadult to 5.3 mm in the
mature adult. This increased constriction
with age is also coincident with changes in
the fronto-parietal region and the develop-
ment of a sagittal crest (Fig. 1).

Specimens FMNH 66302 9 (not illus-

trated) and ROM 46146 9 agreed well in
age characteristics. Specimen ROM 46148 <5
(not illustrated in Fig. 1), similar in age to
ROM 461509, was the most narrow in
zygomatic breadth and equal to the most
narrow in mastoid breadth of the series. It
had an aberrant occiput with a malformed
occipital condyle, and this deformity prob-
ably accounts for the aberrant width meas-
urements in the affected areas of the skull.
It is likely that the age span in our
younger series (all but specimen ROM
46149 <5 ) represents a fairly short period
of time (perhaps only a few weeks) beyond
the juvenile stage, by which time they have
become volant and independent but have
not yet reached full maturity. The three
youngest specimens could be classified as
subadults and are characterized as follows:
occiput strongly deflected, fronto-parietal
and basisphenoid-basioccipital sutures un-
fused, and metacarpo-phalangeal joints no-
ticeably swollen and cartilaginous. The
absence of any appreciable wear on the
dentition of specimen ROM 46149 $ sug-
gests that even this individual was no more
than middle age (possibly no more than
two or three years old). Of other known
specimens, the holotype of H. whiteheadi
appears to be comparable to ROM 46149 $
in age characteristics, perhaps even slightly
younger. Specimen ROM 43669 S from
Mindanao exhibits the same suture-fusion
characteristics as 46149, except that the
jugal-temporal suture is only partially fused,
and the frontal-parietal ridges are not fused
into the sagittal crest as far anteriorly. This
specimen was judged on cranial characters
to be slightly younger, and when the skin
was subsequently examined by radiograph
the metacarpo-phalangeal joints clearly had
cartilaginous pads not yet completely fused
to the bone ends as in 46149 c5 . The speci-
men from Mindanao in the Zoologisk Mu-
seum, Copenhagen, ZM 23719, was an
old individual with well worn teeth (particu-
larly the molars) and a well developed
sagittal crest. The appearance of the mam-
mae suggests that it may have been lactating
at the time of collection. The articulating
ends of the metacarpo-phalangeal joint are
completely ossified (verified by X-ray). The
specimen AMNH 153590 c? from the
Celebes is the oldest specimen seen by us and

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is characterized by excessive wear on all
teeth (Fig. 4). In other respects it exhibits
the same age characteristics as specimen
ROM 46149 6 from Negros Island. Tate
(1951) did not see this skull, as he listed
the specimen as a skin only. Buitenzorg
Museum specimen 2833, illustrated by Tate
(1951), is obviously a subadult. Judging
by the measurements of the northern Celebes
specimens given by him, one was a juvenile,
and the other five were all probably sub-
adults. Almost certainly none were older
than young adult.

Wing Variation with Age — Measurements of
the wing elements of the Negros series are
summarized in Table II. The metacarpo-
phalangeal joints are normally quite swollen
in appearance in many pteropodid bats, but
the joints of three youngest alcoholic speci-
mens (ROM 461469, 66302 9 and
46151 S ) are obviously less ossified than
those of older individuals when examined
externally. Radiographs were taken on the
entire Negros series, and the swollen carti-
laginous pads are clearly evident in the
three subadults, somewhat less swollen but
clearly distinct in all four young adults and
absent in the adult. The length of the fore-
arm varies from 82 to 86.5 mm in the sub-
adult-young adults, as compared to 89.5 mm
in the mature adult. The length of the hu-
merus, as determined by radiographs, is
fairly consistent in the Negros series. The
subadults and young adults vary from 51.2
to 55.0 mm, whereas the adult is 56.0 mm.
It is apparent that the thumb with claw
(pollex) and second digit elements (with
claw) reach maximum length early in life,
and no further growth is obvious in this
series. Moreover, there is little change in
the length of the elements of the third, fourth
and fifth digits in the younger series. The
mature adult, however, has all of these ele-
ments consistently longer. Of the six north
Celebes specimens measured by Tate
(1951), one was a juvenile, and the other
five, thought by us to be subadults, had fore-
arms varying from 79 to 84 mm in length,
whereas the holotype of H. celebensis was
listed as 90 mm and the old adult from south
Celebes as 91 mm (92.5 by us). These
measurements are remarkably consistent
with those of our Negros series. The humerus

of the south Celebes specimen (AMNH
153590 $ ) is 58.5 mm long compared with
56.0 in the adult from Negros (ROM
46 149 6; both measured by radiograph).

Variation in Hind Limbs — The genus Har-
pyionycteris is characterized by a short tibia.
Unfortunately, precise measurements are
difficult to obtain by ordinary methods in
either study skins or preserved specimens.
Radiographs taken with the feet and tibias
positioned as near horizontal as possible
yield much greater accuracy. The Negros
series is notably consistent in lengths of
both hind feet and tibias, and both are
virtually identical in length, varying from
22.0 to 23.5 mm in both cases. It is obvious
that these members, like the thumb or first
digit of the wing, reach maximum size early
in life with no apparent increase beyond the
subadult age.

The femur is only slightly shorter than the
tibia in five of the Negros series (properly
exposed for measuring), varying from 21.0
to 22.0 mm. The Camiquin specimen
(ROM 43669 6 ) measures 21.6 mm and
the Mindanao specimen (ZM 2371 9 )
measures 22.0 mm. By contrast the Celebes
specimen (AMNH 153590 & ) has a femur
length of 25.0 and a tibia length of 26.0
mm, both above the upper limits observed in
Philippine specimens. The holotype of H.
celebensis is said to have a tibia length of
30 and hindfoot length of 29 mm. Tate
(1951) shows measurements of AMNH
153590 <$ from south Celebes as tibia, 31,
and hindfoot, 22 mm, whereas by X-ray
technique these prove to be 26 mm in both
cases. It seems likely that, by using our
X-ray technique, these measurements for the
holotype will prove to be somewhat less and
to be closer to those of the south Celebes
specimen.

Individual Variation in Dentition — The cusp
and dental patterns of mammal teeth tend
to be relatively stable elements and have
long been relied on for species discrimina-
tion, especially in fossils. The only basic
distinguishing character ascribed to H. cele-
bensis by the original authors was the de-
velopment of an extra cusp on P3 and the
greater height development of the cusps in
general. The series of eight specimens from

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46151

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46149

Figure 2

Variation in the cusp pattern of M1 and M- of Harpyionycteris whiteheadi from Negros Island, Philippine
Islands. No. 66302 is from Mambaho Cave, Pagyabunan, Bais (FMNH); all others are from Balanan,
Saiton (ROM ). See Table I for sex and age development of each specimen.

Negros affords an opportunity to assess the
range of individual variation in dental pat-
tern. A careful examination of M1 and M-
shows the cusp pattern to be extremely
variable (see Fig. 2). In fact, no two of the
eight specimens can be said to be even close
to identical. The basic pattern of six cusps
as defined by Andersen (1912, pp. 801-3)
is altered in this genus by the addition of
accessory cusps or by the division of primary
cusps into two. Not only do the cusps vary
in size, position and number in each indi-
vidual, but there is also a comparable
amount of difference in the left and right
teeth of individuals. Minor variations are
apparent in the other teeth as well. None
show even a trace of the secondary cusp on
the buccal side of P3 seen in H. celehensis.
Tate (1951) was in error when he stated
that the Negros Island specimen (FMNH
66302 9 ) had the supplemental cuspule on
P2 [= P3] as in celehensis. The known ex-
amples of that taxon, as well as the holotype

of H. whiteheadi and ROM 43669 & from
off Mindanao, have a well-developed an-
terior supplemental cuspule on P:!. In the
Negros series this cuspule is absent from
three specimens and weakly developed in
five, none being as distinct as in the above
examples. The single pair of lower incisors
are quite small and probably non-functional.
Of the specimens seen by us, the holotype
of H. whiteheadi, FMNH 66302 9 and
ROM 46151 £ have only one incisor (on
one side only) present, and all others have
none.

Although individual variation in dental
patterns is normal and to be expected, as
in many species of mammals, the variability
in the cusp patterns exhibited by Harpyio-
nycteris is unique among bats and must
certainly rank high among all mammals.

Adaptive Significance of Dentition — There
has been some speculation as to the affinities
of Harpyionycteris with other bats. Tate

(1951) summarized this question by sug-
gesting that it ..."undoubtedly branched off
from the pteropid stem in very ancient times.
... and that the multicuspid state of the
molars, and indeed of the whole dentition,
of Harpyionycteris must be regarded as
secondary rather than as a surviving example
representing a formerly widespread con-
dition in the Megachiroptera." If Harpyio-
nycteris has as old a history as has been
suggested by Tate, why the cusp pattern has
not become genetically fixed within much
narrower limits, as we have seen in most
mammals, poses a most interesting question.
The adaptive significance of the multicuspid
condition in the genus remains a mystery.
To our knowledge its food habits are still
unknown. An examination of the digestive
tracts of the ROM specimens showed them
all to be empty of any diagnostic food items.
The meagre evidence from our examination
suggests animal matter is not a prime food
because of the absence of insect chitin.
bone, scales or hair. We can only speculate
that, like most of its allies, it is a fruit eater,
perhaps adapted for a particular type of
tough-textured fruit for which the multicusp
teeth would be advantageous in extracting
the juice. Possibly the fruit fibres are dis-
carded and not normally ingested - this
might explain the absence of diagnostic
material in the digestive tracts! This sug-
gests that Harpyionycteris may represent
yet another line of highly specialized feeders
- fruit juice-feeding bats.

Geographic Variation — The known range of
the genus Harpyionycteris, based on 18
specimens, extends from Mindoro ( 1 speci-
men) in the north, southward through
Negros Island (8 specimens), Camiquin
Island, offshore from Mindanao ( 1 speci-
men), Mindanao Island ( 1 specimen) to the
Celebes, including the north (6 specimens),
middle ( 1 specimen) and south portions
of the island (1 specimen) (Fig. 3). Of this
total, only six are mature adults that can

be critically compared, and these have been
taken from five separate areas (Table III;
Fig. 4).

Mature specimens from the five localities
are approximately similar in head and body
length. The two Celebes adult specimens
have the longest tibia, forearm and thumb,
while one has the maximum lengths of femur
and humerus. Of the other wing elements, all
seem to be of approximately the same mag-
nitude, although the Mindoro, Camiquin and
Mindanao specimens tend to be slightly
smaller than the others. The Negros speci-
men has the longest metacarpals on the
third, fourth and fifth digits.

In greatest skull length, condylobasal
length and palatal length, the six adults are
remarkably similar. In the measurements
of breadth, the Negros Island specimen has
the narrowest zygomatic, mastoid, brain-
case, M2-M2, P3-P3, interorbital, postorbi-
tal and upper C-C measurements. The
Mindoro, Camiquin and Mindanao speci-
mens are strikingly similar to each other in
most skull measurements and tend to be
either equal to or smaller in breadth mea-
surements than the Celebes specimens.
Maximum size is found in the latter in the
mastoid, braincase, P3-P:\ interorbital and
the upper C-C breadth measurements.

In the length of the lower jaw, all adults
are similar. However, the Negros specimen
has the lowest height of ascending ramus
and is lighter in build, having the least
depth between P4 and Mi as well as behind
M3. In the dentition, the length of C-M-
and C-M.i tend to be similar in all adults,
although there are a number of variations in
the conformation of the individual teeth.

The Camiquin specimen (ROM 43669 $ )
has been compared with the holotype of H.
whitehead i and agrees remarkably well in all
essential details of both the skull and the
skin (including colour of pelage). Even in
the highly variable M- the cusp pattern
agrees well, with only a better development
of the posterior buccal cusp (pc, of Ander-

Figure 3

Map of the Philippines-Celebes area showing the distribution of the known specimens of Harpyionycteris.
1. Mindoro Island (type locality of H. whiteheadi whiteheadi). 2. Mambaho Cave, Pagyabunan, Bais,
Negros Island. 3. Balanan, Saiton, Negros Island (type locality of H. whiteheadi negrosensis) . 4. Cater-
man, Mount Mamajao, Langoangon, Camiquin Island. 5. Kaatoan, Katanglad Volcano, Bakidnon, Min-
danao. 6. Gimpoe, middle Celebes (type locality of//, celebensis). 7. Tanko Salokko, Mengkoka Moun-
tains, south Celebes. 8. Roeroekan. north Celebes.

TABLE III

Measurements (in mm) of the known full adult specimens of the genus Harpyionycteris: 1. H. whiteheadi

whitehead! 2. H. w. negrosensis 3. H. celebensis. AMNH = American Museum of Natural History;

BMNH = British Museum (Natural History); ROM = Royal Ontario Museum; USNM = United States

National Museum; ZM = Zoologisk Museum, Copenhagen.

1.

2.

3.

South

Middle

Mindoro IV

indanao

Camiquin

Negros

Celebes

Celebes

BMNH

ZM

ROM

ROM

AMNH

USNM

97.5.2.7

2371 9

43669 d*

46149 d"

153590 &

219349 9

Holotype

Holotype

Holotype

Total length

140

145

152

143

*
153

Hindfoot

23

24t

23. 5t

23. 5t

26t

29(?)

Tibia

24.5

24t

23. 5t

23. 5t

26t

30(?)

Forearm

82.5

84

85

89.5

92.5

90

Thumb with claw

33.0

31±

33.7

35.0

36.1

39.0

Second Digit: Metacarpal

36.5

38.2

40.0

41.0

43.7

—

1st Phalanx

11.5

8.0

10.0

10.0

11.7

—

2nd Phalanx

13.0

11.5

11.3

12.5

12.0

—

Third Digit: Metacarpal

59.0

60 ±

60.0

64.5

64.4

63.0

1st Phalanx

43.5

44.0

43.1

46.0

50.2

—

2nd Phalanx

54.0

59.5

55.0

62.0

58.0

—

Fourth Digit: Metacarpal

54.5

56 ±

57.0

62.5

60.7

—

1st Phalanx

35.5

36.6

36.0

36.8

42.5

—

2nd Phalanx

36.0

36.7

36.5

39.6

37.3

—

Fifth Digit: Metacarpal

55.5

54 ±

59.0

64.4

61.0

—

1st Phalanx

29.0

28.5

27.9

30.5

32.6

—

2nd Phalanx

29.0

30.8

30.5

34.0

35.4

—

Skull: Greatest length

43. 0±

43 ±

43.1

43.7

43. 5±

43.0

Condylobasal length

40. 0±

41 ±

41.7

42.6

42. 0±

41.6

Palatal length

23.0

23 ±

22.5

22.3

23. 5±

—

Zygomatic breadth

24.0

—

24.3

23.1

24.3

24.0

Mastoid breadth

15.6

15. 5±

15.7

14.8

16.0

—

Braincase breadth

16.7

16.5 ±

16.5

15.7

16.9

—

M2 — M2 breadth

11.6

—

11.2

11.0

11.6

—

P3 _ p3 breadth

9.2

—

9.3

8.9

9.5

—

Interorbital breadth

6.5

6.4±

6.9

6.1

7.0

7.0

Postorbital constriction

6.0

5.9±

6.4

5.3

5.6

6.2

Canine — Canine (upper)

7.8

—

7.8

7.4

7.9

—

Height of braincase

13.5

14.6

14.0

13.4

13.6

—

C — M2 length

17.8

17.5

17.6

17.8

17.5

16.6

Length of mandible

35.0

34. 8±

33.1

34.0

34.0

35.0

Height of ascending ramus

16.5

16.8

16.3

15.8

16.1

—

Depth of mandible between

P4 and Mi

4.4

4.4

4.4

3.7

4.1

—

Depth of mandible behind M3

5.6

5.6

6.1

5.0

5.4

—

C — M3 length

19.2

19.3 ±

18.8

19.4

18.9

17.8

*vide Miller and Hollister (1921) and Tate (1951)

fdetermined by X-ray

10

Figure 4

Dorsal and ventral views of skulls of Harpy ionycteris.

Left: H. whiteheadi whitehead! ROM 43669 <£ from Camiquin Island, off Mindanao Island.

Centre: H. whiteheadi negrosensis subsp. nov. Holotype ROM 46149 c? from Balanan, Saiton,

Negros Island, Philippine Islands.

Right: H. celebensis AMNH 15390 <S from Tanko Salokko. Mengkoka Mountains, South Celebes.

11

sen, 1912). The palatal ridges of the Cami-
quin specimen (Fig. 4), however, do not
conform with the illustrations of the Negros
Island specimen given by Sanborn (1952).
Even though there are minor individual dif-
ferences among our specimens, all, including
our Negros series, are similar in having five
undivided anterior ridges and three pairs of
divided posterior ridges, the latter exhibiting
the greatest variation in length, shape and
position. There is also an undivided ridge
near the posterior edge of the palate in all
the specimens.

Figure 5

Details of the face of H. w. negrosensis ROM
46150, young adult female, prior to extraction of
skull. Note lateral deflection of the nostrils.

The Negros Island population appears to
have been isolated a sufficient length of time
to have developed distinctive characteristics
consistent with subspecific variation and may
be known as

Harpyionycteris whiteheadi negrosensis,
subsp. nov.

Holotype— ROM No. 46149 adult male
preserved in alcohol with skull extracted;
collected on 7 January 1968 between 500
and 1 ,000 feet elevation at Balanan, Siaton,
Negros Island, Philippines, by D. E. Em-
peso (see Figs. 1,2,4, and 6).

Range — Known only from Negros Island,
Philippine Islands.

12

Diagnosis — Allied with H. whiteheadi
whiteheadi and of the same general size but
with narrower skull proportions, including
zygomatic breadth, mastoid breadth, rostrum
breadth (C-C and P3-P3), interorbital
breadth, and breadth of braincase. Nasal
aperture, viewed from the front, noticeably
higher than deep rather than as wide or
wider than deep. Mandibles are lighter in
build, shallower at the junction of P4 and M:
and behind M3 (see Table III). The last
upper molars (M2) lie much closer to the
shelf of the zygomatic plate.

Measurements — See Tables I, II and III.

Comparisons — The pelage coloration is un-
known from fresh skins, but preserved speci-
mens, including the holotype, ROM 46 1 50 2 ,
and one skin prepared from a preserved
specimen (ROM 46148 c?) are darker
than H. w. whiteheadi, with the underparts
approaching Bister (Ridgway, 1912)
rather than Buffy Brown or Dresden Brown.
The dorsum is more rusty coloured, ap-
proaching Angus Brown or Brussels Brown
rather than Sepia or Proufs Brown. In
general the fur appears to be somewhat
longer and thicker, both above and below.
Light spots are also present on the wings
but are more pinkish than yellowish in
colour; these as well as pelage characters
may be of limited taxonomic significance.

The darker pelage coloration is closer to
H. celebensis as represented by AMNH
153590 c! , but the length of the fur, both
above and below, is noticeably shorter and
is more nearly unicolour on the middle of
the back, rather than bicolour, with a much
paler base.

The ears of H. w. negrosensis are nar-
rower and more pointed than either H. w
whiteheadi or H. celebensis.

The great variability in the dental cusps,
as illustrated in the Negros Island series
suggests that caution should be exercised in
using dental characters in this genus for
taxonomic discrimination. The well-de
veloped extra cusp on P3 found in H. cele
bensis has not been observed in any Philip
pine specimen and may prove to be a ge
netically fixed character of taxonomic value
Examination of AMNH 153590^ and th
illustrations provided by Tate (1951) sug

gest the possibility that the distinctive shape
and angle of projection of the upper canine
may be equally significant, if not more so,
to distinguish H. celebensis from H. white-
headi (see Fig. 6). In H. celebensis the
upper canine is relatively shorter and
broader with a less anterior angle of for-
ward projection and has a much wider
posterior cusp (viewed from the side).

Systematic Discussion — The past paucity of
specimens of the genus Harpyionycteris has
precluded any meaningful analysis of taxo-
nomic characters and evolutionary trends.
The addition of eight new specimens helps
in an assessment of some trends but still
falls far short of an adequate appraisal. If
our assignment is correct, there are still only
three examples of the nominate taxon now
known, the holotype from Mindoro, the
specimen from Mindanao (UZ 2371 9 ) and
our specimen from Camiquin. These repre-
sent two widely separated localities lying
both north and south of Negros Island but
apparently separated by smaller water gaps
from each other than from Negros Island.
This presupposes that ultimately this species
will be found in suitable habitat, should it
exist, on the islands of Leyte, Samar and
southern Luzon. If our suspicion concerning
its food habits is confirmed, then its distri-
bution may well be correlated with a specific
type of fruiting plant, probably occurring
primarily at higher elevations (about 1,000
feet or more).

The systematic relationships of the known
populations of Harpyionycteris pose interest-
ing problems common to other insular taxa.
Tate (1951) suggested that the Celebes
population probably represents only a sub-
species of H. whiteheadi, a view also ac-
cepted by Laurie and Hill (1954). Such a
conclusion would presuppose that there is,
or has been in the recent past, some gene
flow between these insular populations. If it
is assumed that the species exists throughout
Mindanao, the distance between the south-
ernmost point of land and northernmost
Celebes would be about 250 miles. Although
there are small islands between that might
serve as "stepping stones," there are still
nearly 100 miles of open water to be trav-
ersed— a distance usually more than ade-
quate to serve as an effective barrier with

most species of bats. If the diet of these
bats proves to be a specialized one requiring
high altitude species of fruit, the smaller
islands would be of limited value as "step-

Figure 6

Diagram comparing the shapes of the rostrums
and dentitions of H. w. whiteheadi (ROM
43669c? ), top; H. w. negrosensis, Holotype, centre;
H. celebensis (AMNH 153590 c? ), bottom.

13

ping stones" between the widely separated
populations of Harpyionycteris. Celebes lies
east of Wallace's Line and its fauna normally
has been associated with the Australian
zoogeographic region, whereas the Phillip-
pines lie west (and north) of Wallace's
Line and its fauna is more related to that of
Borneo as an insular extension of the Orien-
tal zoogeographic region. It is of interest that
no Harpyionycteris has been recorded from
Borneo, which is separated from nearest
contact with Celebes by only about 75 miles.
The apparent isolation of the population on
Negros Island, with only 25 or 30 miles of
water separating them from possible land
contact with other populations, suggests to
us that any normal contact between the
Celebes and Philippine populations is un-
likely. Although dental characters are
highly variable in this genus, the distinctive
shapes of the upper canines and P3 repre-
sent morphological differences that would
normally be regarded as greater than a sub-
specific level of variation in any other species
of bat. In the absence of any specific evi-
dence to the contrary, we therefore take the
view that the Celebes population probably
has been isolated from the Philippine ones
for a considerable period of time and is suf-
ficiently distinct to be regarded as a full
species.

Acknowledgments — We wish to acknow-
ledge the continued co-operation of Mr.

Domingo Empeso for conducting systematic
collection of bats in the Philippines which
provided the ROM specimens here reported
on. Co-operation and assistance was pro-
vided by the following institutions and indi-
viduals for loan of specimens or study of
material in their care: British Museum
(Natural History), G. B. Corbet and John
Edward Hill; American Museum of Natural
History, Richard G. Van Gelder and Karl F.
Koopman; Field Museum of Natural His-
tory, Joseph C. Moore; Zoologisk Museum,
Copenhagen, F. W. Braestrup. Line draw-
ings were prepared by Paul Geraghty and
Mrs. Sophia Poray. The photograph of the
face (Fig. 5) was made by Lee Warren. The
entire staff of the Department of Mammal-
ogy of the ROM deserve our special thanks
for continued assistance and co-operation,
and especially J. R. Tamsitt for editorial
council. The radiographs used in this study
were provided by the Laboratory of Sys-
tematic and Evolutionary Zoology of the
University of Toronto established in the
Royal Ontario Museum with National Re-
search Council of Canada Negotiated
Development Grant funds. This study, aris-
ing out of our bat research program, has had
the financial assistance of the Canadian
National Sportsmen's Show, the Pure and
Applied Sciences Committee of the Uni-
versity of Toronto through the Department
of Zoology, and the National Research
Council of Canada, as well as the Royal
Ontario Museum.

Literature Cited

Andersen. Knud

1912 Catalogue of the Chiroptera in the collection of the British Museum. 2d. ed. Vol. 1:
Megachiroptera. London, Brit. Mus. (Nat. Hist.), pp. 1-854.
Laurie, Eleanor M. O. and J. E. Hill

1954 List of land mammals of New Guinea, Celebes and adjacent islands, 1758-1952
London, Brit. Mus. (Nat. Hist.), pp. 1-1 75.
Miller, GerritS., Jr.

1907 The families and genera of bats. Bull. U. S. Natn. Mus.. no. 57, pp. 1-282.
Miller, Gerrit S., Jr. and N. Hollister

1 92 1 Twenty new mammals collected by H. C. Raven in Celebes. Proc. Biol. Soc. Wash.
vol. 34, pp. 93-104.
Ridgway, Robert

1912 Color standards and color nomenclature. Washington, D.C., Published by the author
pp. 1-44, 53 pis.

14

Sanborn, Colin C.

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no. 2, pp. 87-158.

1953 Mammals from Mindanao, Philippine Islands, collected by the Danish Philippine
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283-288.

Tate, G. H. H.

1951 Harpyionycteris, a genus of rare fruit bats. Am. Mus. Novit. no. 1522, pp. 1-9.
Thomas, Oldfield

1 896 On the mammals from Celebes, Borneo, and the Philippines, recently received at the

British Museum. Ann. Mag. Nat. Hist., vol. 18, ser. 6, pp. 241-250.
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15

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