Pteropus melanopogon ( Peters, 1867 )

Tsang, Susan M., Wiantoro, Sigit & Simmons, Nancy B., 2015, New records of flying foxes (Chiroptera: Pteropus sp.) from Seram, Indonesia, with notes on ecology and conservation status, American Museum Novitates 2015 (3842), pp. 1-24 : 11-16

Pteropus melanopogon ( Peters, 1867)

Black-bearded flying fox

TYPE LOCALITY: Amboina (= Ambon), Central Maluku, Indonesia .

NEW MATERIAL: Pulau Marsegu , Seram Bagian Barat Regency , Maluku Province, Indonesia. Collected by Sigit Wiantoro and Susan M. Tsang , 1 female MZB 36927 .

OTHER SPECIMENS EXAMINED: MZB 1059, MZB 1074, MZB 1075, MZB 13566, MZB 13569, MZB 13570, FMNH 8228, ZMB 4752, ZMB 4701, ZMB 4703, and ZMB 4962.

OCCURRENCE AND IDENTIFICATION: Pteropus melanopogon were found roosting in a colony of approximately 200 individuals in two patches of mangrove trees ( Rhizophora sp. ) on Pulau Marsegu, an island named for the presence of the bat colony (marsegu is the local word for “flying fox”). Only a single injured juvenile was captured, meaning we could not corroborate species identity by using available adult craniodental or external measurements. Photographic and video documentation of the roosting groups were collected to corroborate species identity by SMT since no adults were captured at this site. The adult P. melanopogon we observed in the colony in Seram fit the description of the nominotypical form of this species provided by Andersen (1912): “blackish back, chestnut head and collar, golden-buffy underside of body.” These individuals all appear to be part of a single colony of bats that moves between trees on the island of Pulau Marsegu throughout the course of the day; at dusk, there is only one large group that was observed exiting from the roost. We are confident that the juvenile we collected is P. melanopogon because we opportunistically collected this individual from under the roosting tree after the main colony of adult P. melanopogon had departed.

Occasionally, P. melanopogon were spotted roosting with the main P. chrysoproctus colony, though they remained on separate trees. When we visited the Sawai site in June 2012, a small

Coll.ID Age/Sex WT FA HB EAR TIB HF Pteropus chrysoproctus

*ZMB 2626 A 3 145 52

MZB 13568 A 3 174 82.00

ZMA 16.369 a A 3 166

MZB 36911 SA 3 420 144 220 30.91 65.72 52.66

MZB 36909 A ♀ 780 180 265 30.81 79.91 52.00

MZB 1078 A ♀ 670

ZMA 16.370 a A ♀ 170

MZB 36908 SA ♀ 290 138 190 27.08 62.39 48.73

MZB 36910 SA ♀ 380 150 210 32.09 66.14 49.26

MZB 0219 A 140

Pteropus melanopogon

MZB 13566 A 3 510 188

MZB 13569 A 3 882 205

MZB 13570 A 3 900 204

MZB 1075 A 3 192

MZB 36927 Juv 3 150 91 146 23.71 38.31 45.33

MZB 1074 A ♀ 192

FMNH 8228 SA 169

MZB 1059 A 198

var. keyensis

*ZMB 4752 A 3 172 55

* ZMB 4701 A ♀ 174 31 80 53

var. aruensis

*ZMB 4703 A 3 181 38 87 66

*ZMB 4962 A 3 183

Pteropus ocularis

*ZMB 2958 A 3 138

AMNH 234939 A 3 118

MZB 36928 SA 3 400 144 195 26.29 60.89 44.38

MZB 13361 A ♀ 220 142 24 37

MZB 0112 A ♀ 132 18.41

Pteropus temminckii

MZB 36925 A 3 150 97 160 23.92 45.59 30.09

MZB 14839 A 3 150 100 155 22 22

MZB 36924 A ♀ 200 106 155 22.71 47.10 32.38

MZB 36926 A ♀ 160 102 140 22.88 44.86 31.51

MZB 8341 A ♀ 175 100

MZB 15597 A ♀ 105 46

MZB 2155 A ♀ 104 ZMA 3084 a A ♀ 101 a From Bergmans, 2001.

group of P. melanopogon was seen roosting a short distance away from the main P. chrysoproctus colony. The P. melanopogon colony we located on Pulau Marsegu has previously been seen feeding on flowers of durian trees ( Durio sp. ), which are very abundant in this part of Seram. No colonies of P. melanopogon are currently known from Ambon, but more surveys are needed to verify this claim. As indicated in the earlier discussion of P. chrysoproctus , a small group of P. melanopogon was found roosting in disturbed forest near Mosso, but none were captured nor seen emerging at dusk.

Pteropus melanopogon and P. chrysoproctus are sympatric but are easily distinguished from one another. While P. melanopogon has highly variable pelage coloration across its geographic range, its massive size (FA> 185 mm) and robust skull (GSL> 75 mm, ZB> 40 mm, LIOW> 10 mm) make it unmistakable ( tables 2 and 3, fig. 2 ). Like the colony sighted in our survey, the specimens at MZB are similar to the nominotypical form according to Andersen (1912) in both coloration and size with a brownish-yellow head, darker brown mantle, pale yellowish-buff abdomen, massive overall body size, ears shorter than CM2 length, an interfemoral membrane that is short in the center, and a practically naked forearm and tibia. Given its size, it is likely that P. melanopogon is one of the heavier pteropodid species; one of our specimens weighed 900 g ( table 3).

Despite being abundant in the 19th century, previous modern survey efforts had failed to locate a single colony of P. melanopogon on either Buru or Seram ( Flannery, 1995). Morphological similarities of previously collected specimens suggest an affinity between the populations of P. melanopogon on Buru and Seram, but comparisons with specimens from other Moluccan islands, especially Aru and Kai, are needed for a thorough review. A comprehensive analysis of the P. melanopogon complex (inclusive of P. keyensis and P. aruensis ) is a high priority since P. aruensis is severely threatened by conversion of the Aru Islands into corporate plantations ( Amianti, 2015). Like P. chrysoproctus , P. melanopogon is also likely no longer extant on Ambon, as there have been no recent reports of colonies, but more surveys are needed.

HUMAN DISTURBANCE: The roosting colony of P. melanopogon in West Seram is extremely vulnerable to hunting. While the local fishermen do not hunt bats, the site is easily accessible to bushmeat hunters from other provinces. Disturbance from hunting affects both the numbers and distribution of the bats. We were unsuccessful in capturing any individuals during our 2012 visit because a hunter from a different province had apparently killed many bats with a gun at the roost a few days prior to our arrival, and this proved enough of a disturbance to disperse the colony. We were informed by the local villagers that disturbed bat colonies moved from their original isolated roosts to suboptimal sites (e.g. shorter trees in the forest closer to villages), which were often actually easier for hunters to reach. Clearly such events can threaten the stability of the colony.

CONSERVATION: Currently, IUCN lists P. melanopogon as Endangered under criteria A3c, d since it has not been recorded within the entirety of its range on any Moluccan islands in the past 20 years ( Helgen and Salas, 2013a). This threat categorization means that there is a projected decline of ≥50% of the population in the next three generations due to deforestation and hunting. Our results indicate that the Pulau Marsegu roost is the only known colony found on Seram within the past several decades. But the Pulau Marsegu roost is not in a protected area and merits protection for its high conservation value.

Figures

FIG. 2. Dorsal views of skulls of A, Pteropus chrysoproctus (MZB 36909♀); B, Pteropus melanopogon (MZB 10753); C, Pteropus ocularis (MZB 369283); D, Pteropus temminckii (MZB 369253).