On bats from the limestone caves of North Borneo.

On Bats from the Limestone Caves of North Borneo By F. N. CHASEN The collection on which this report is based was submitted for ~xamination by Mr. H. G. Keith, Acting Conservator of Forests in British North Borneo. It was made by Senior Forest Ranger P. Orolfo at various times in T930 in the caves of the limestone hills at Gomantong on the left bank of the Kinabatangan River ~bout twenty miles south of Sandakan on the north-east coast and rn other caves known as the Madai, Baturong and Tapadong caves near Lahat Datu in Darvel Bay on the east coast of the State. ~ otice of a small collection I made at Gomantong in 1929 is also mcluded. Such caves, which also exist in other parts of Borneo and elsewhere, are often the breeding places of small swifts of the genus Collo calia of which certain species produce the edible birds' nests of commerce. . In the Malay Peninsula the extensive Batu Caves near Kuala L.umpur in Selangor are in the undisputed possession of bat colonies, but in British North Borneo bats and swifts live side by side in the caves and the c.onduct of the former has at times caused anxiety to the Government. Mus. 5, 1931 [ 10 7 ] F. X. CHASEN Several charges have been made against the bats but none is well substantiated. They have been accused of encroaching on the areas occupied by the swifts but there is no direct evidence that this is the case. Although it is certain that in most of the larger caves the bats occupy their own particular recesses, these being in the darkest and most remote part of the cave, odd individuals can usually be seen perched near or actually among the birds and their nests and it is said that under these circumstances the nests are often accidentally dislodged by the bats. It has furthermore been suggested that this is the reason why the produce of some of the small caves on the lower Kinabatangan River is not regular. Definite offensive action on the part of the bats has also been alleged: the urine is also said to be offensive to the birds and to give' a bad colour to the nests. Far morc detailed observation is necessary before any of these charges can be regarded as anything more than hearsay and any definite action taken to red nee the number of bats would at the moment be ill-advised: it should never be undertaken at any time in the absence of very cogent reasons. Mixed associations like those seen in the North Bornean caves are not uncommon. My own impression of the balance at Gomantong' was that birds and bats were living in harmony and that large sections of the caves remained uninhabited by either. Mr. Keith also forwarded the stomach contents of some bats from Gomantong. Mr. H. M. Pendlebury kindly examined these and reported that those of the large Hipposideros diadema contained beetles (including fragments of Longicorna sp.) Blattidae, Herniptera and possibly some ants. It is also noteworthy that in the three specimens of this species examined some hair was found in the intestines. Stomach contents of Rhinolopltus creaghi and Hipposuleros gaierita contained matter in a highly comminuted condition. Recognisable fragments included the remains of Lepidoptera, Hemiptera, Carabidae, Tenebrionidae, Blattidae, some ants and possibly a cicada. The daily exodus of bats from a hole in the top of the cave at Gomantong is justly famous. In the late afternoon they emerge in a long ribbon-like procession. The stream is only a few feet wide and accordingto several independent observers it may continue uninterrupted for nearly an hour. On the occasion of my visit it was estimated that three thousand bats left the cave every minute for half an hour giving a minimum population of 90,000. The return to the cave takes place sometime before day-break but it is said that the bats travel independently and not in formation. [ ro8 ] BULL. RAFFLES O~ BATS FROM THE LnmSTONE CAVES OF NORTH BORNEO Various large Accipitres are enemies of the bats. Chief among them is the BrahminyKite tHotiast.ur indus Intermedius) a number of which are usually founel near the caves. The kites also prey on the swifts but the maj or part of their food seems to consist of bats. The collection submitted includes the following seventeen specIes: - M egachiroptem (Fruit-eating bats). 1. Rousettus ample xicaudatus amplexicaudatus (E. Geoff.). 2. Balionycteris maculata maculata (TJlOs.). 3. Eonycreris spelaea spelaea (Dabs."). Micro cliiro pt era (Insect-eating bats). 4. Rhinolophus creaghi T hos . 5. Ehinolophus philippinensis Til aterli. 6. Rhinolophus borrieensis borneensis Peters. 7· Hipposideros diaderna vicarius And. 8. Hipposideros galer itus galeritus Cant. 9. Hipposideros insolens Lyon. 10. Myotis (Leuconoe) horsfieldi carimatae lvliller. II. My otis (Leuconoc) sp. 12. Miniopterus blepotis Tcnim.. 13. Miniopterus witkarnpi So d». 14. Emballonura rivalis Tli as. 15. Erriballonura moriticola rnonticola T emm16. Taphozous melanopogon fretensis Tho s. 17. Chaerephon plicatus (Euch.-Ham.). Most of the above species are common and well-known but there are several interesting features about the collection. The typical form of Eonycteris sp elaea is shewn to exist in Borneo. Rhinoloplucs philippinensis has not hitherto been recorded from Borneo. Minioptents blep oiis is another addition to the Bornean list: three species of the genus are now known from the island, witkampi, medius and blep otis . The lvl')'otis sp. also appears to represent a species unknown from Borneo but most unfortunately the only specimen sent is a skin without a skull. 'Mus. S, J931 [10 9 J F. N. CHASEN MEGACHIROPTERA 1. Rousettus amplexicaudatus amplexicaudatus (E. Geoff.). I !i1 Madai Caves (No. 75)· Forcarm.t--Bo mm. Four skins of immature animals (Nos. 73, 74, 76, - ) also appear to belong to annple xicaudatus but in the absence of skulls no more can be .said. Andersen's remarks concerning the occurrence of this specres in the Malay Peninsula are not very clear. In Mon. Chir. I, p. lxix it is included with a query under "Lower Siam" and "Malay Peninsula." On p. Ixxxii, ample ricaudaius is mentioned as being common to the three areas, the Malay Peninsula, Sumatra and Borneo but on p. 42 the first named locality is neither mentioned nor implied in the given range of the species: furthermore no Malayan specimens are listed. Actually R. arn ple xicau datus does occur in the Malay States: specimens from the Flatu Caves in Selangor are in the Raffles Museum. 2. Balionycteris maculata maculata (Thos.). I J, I 'i! Baturong Caves (Nos. 13 2, 133). Forearms.- t 44; 't 42 mm. The Malayan form of this bat is B. m, s eimuntli Kloss'. Dr. Darnrnermanhas recorded it from Pulau Durian in the Rhio Archipelago and there are unrecorded specimens in the Raffles Museum from Pulau Galang in the same archipelago. 3. Eonycteris spelaea spelaea (Dobs.). 6 t Tapadong Caves (Nos. 445-450). Forearrns.i--fiy, 66, 67, 67, 68 mrn. Andersendoes not recognize E. sp elaea as a Bornean form and considers that it is replaced in that island by the larger E. major And. This latter animal, however, seems to be either a distinct species or a high level form; for a bat which seems inseparable fr0111 typical sp elaea as represented by specimens from Tenasserim, the Malay States and Singapore certainly does occur in northeast Borneo (and apparently also in Sarawak) as correctly shewn by Matschie-. An adult but not aged male in the present collecti on measures: -head and body 110; tail 12; forearm 67; pollex, total length 23; 3rd digit, metacarpal 46, rst phalanx 29.5, znd phalanx 39; 4th digit, metacarpal 45, rst phalanx 24, znd phalanx 25; 5th digit, metacarpal 41, 1st phalanx 20, znd phalanx 19; lower leg c. n. 46 111m. ~ -- . -- .- .. ------~-----_ •... ~~-_ .. ---_._~ r , Journ. Fed. Mal. States Mus. X, 1921, p. 229; Pahang, 2. T'reubia , VIII, IC)26, p. 304. 3· Ann. Mag. Nat. Hist, (8) VI, 1910, p. 625 et Cat. Chic 1912, p. 735. 4· Megachir. 1899, p. oo, [ lIO ] BULL. RAFFLES ON BATS FROM THE LIMESTONE CAVES OF NORTH BORNEO Sku11.-Tota1 length 33 ..1; condylo-basal length 33; rostrum orbit to nares IO; zygomatic width 20; upper tooth-row to front of canine 11.4 mrn. MICROCHIROPTERA 4. Rhinolophus creaghi Thos. 8 ~, 7 'i' Baturong, Madai and Tapadong Caves (Nos. 49, 62, 63, 167, 168, 214, 215, 330, 331, etc.). Forearms.- (; 48, 49, 49, 49, 4Y, 49, 49, 51; 'i' 48, 49, 49, 49, 50, 50, 51 mm. This bat is also common in the Gomantong Caves. The wings arise from the tibia about a quarter of an inch above the ankle and although this is a variable feature it seems likely that the half an inch mentioned in the original description is an error. 5. Rhinolophus philippinensis Waterh. 6 (;,'3 'i' Madai and Tapadong Caves (Nos. 48,353-360). Forearms.- (; 50, 50, 51, 51, 52, 53; 'i' 51, 53, 54 rnrn. This is an addition to the Bornean fauna. Unfortunately no comparative material is available and the specimens have been identified entirely on description: it is of course improbable that the Bornean race is the same as that inhabiting the Philippine Islands. The common member of Andersen's lucius group of Rhinolopliu.s in Borneo is R. trii oliat us a species not represented in the present collection. 6. Rhinolophus borneensis borneensis Peters. I 'i' Madai caves (No. 45)· Forearm.s--aa rnm , 7. Hipposideros diadema vicarius And. Fourteen s , 5 'i' Gomantong, Baturong, Madai and Tapadong caves (Nos. 24, 25, 52-56, 58-60, 144, 145, 243, 322, 324, 340, 34 1, 3 2 5, - ). Forearms.- s 79, 82, 82, 83, 83, 84, 85, 86, 86, 86, 86, 87, -; 6 83, 84, 86~-, - mm. 8. Hipposideros galeritus galeritus Cantor. Seven (;, 13 'i' Gomantong, Baturong, Madai and Tapadong caves (Nos. 17,64,80, 81, 159, 326, 3:27, 363, 36 4, 366). Forearms.- (; 45,47, 47,48,48,48,49; 'i' 47,47, 49 mm. In a series of twenty-six from the Gomantong caves the forearm varies in length from 45-47 mm. with 48 mm. once and 49 mm , once. The fur is very variable in colour irrespective of sex. Mus. 5, 1931 [ III ] F. ". CHASEK 9. Hipposideros insolens Lyon. Hip p osideros Lnsotens Lyon. Proc. U. S. Nat. Mus. 40, 1911 p. 129: Lowatsi, upper Pasir River, south-eastern Borneo. ' Three s , 5 ~ Baturong caves (Nos. 117-120, 160, 169, 234, 235)· Forearms.- 6 48, 48, 49·5; ~ 49, 49, 49·5, So, 50 mm. When skins are compared the difference between galeritus and ins olens is very slight. In th e former the base of the fur on the upperparts is whitish 'whereas in the latter the fur is concolorous throughout its lengtth. Judging by the specimens in the present collection the difference in the length of the forearm in the two forms is very small but ins olens certainly averages larger: measured in the skin the lower leg (with claw) of galeritus ranges 24-26.5 mm. and that of ins ole ns 27.8-28.5 mm. 1\1r. Orolfo's measurements taken in the flesh confirm Lyon's remark that insolens may be distinguished from galeriius by its longer tail i-cH. galcritus , head and body, 47---49; tail 23-27 mm. H. ins olens , head and body, 4455; tail 33-38 mm. This oat has not yet been taken at Gomantong; all the specimens examined from that locality being galeritus as are a few from Miri on the coast of Sarawak. 10. Myotis (Leucanoe) horsfieldi carimatae Miller. One 6, 4 ~ Tapadong caves (Nos. 348-351, 35 2). Forearms.- s 38.5; ~ 38, 38, 39, 39 mm. Four of these specimens have the skull rather more inflated than in t\VO horsfieldi from the Malay Peninsula thereby, on description at least, agreeing with carimatae Miller,' to which Thomas provisionally referred the Bornean race of horsfieldi. Another skull is noticeably less swollen: it may represent Leuconoe lepidus Thomas.> 11. Myotis (Leucanoe) sp. One t Madai caves (No. 46). Forearm.-47 mm. This skin which is unfortunately without a skull and therefore useless for critical examination appears to represent a large form of Leu canoe, The upperparts are fairly uniform in colour, the base of the fur dark and the tips silvery grey: underparts white. --- ..• -.---_ .. _--~ I. Proc. U. S. Nat. Mus. XXXI, )906, p. 62: Karimata Island. 2. Ann. Mag. Nat. Hist. (8) XV, )915, p. 171: Baram, Sarawak. [ II2 ] BULL. RAFFLES ON BATS FROM THE LIMESTONE CAVES OF NORTH BORNEO The only large-footed .iHyotis hitherto definitely kn?wn from. Borneo are horsfieldi and lepidus, both much smaller animals, 12. Miniopterus blepotis (Temm.). Three is, 2 ~ Baturong, Madai and Tapadong caves (Nos. 47, 57, 82, 83, 334)· Forearms.- i!; 47, 49, 50; ~ 48, So mm. No species of Minio pt.erus was known from Borneo until Mr. Sody described witlwmpi (vide infra) in 1930 and at the same time recorded M. medius Thos., from the island: blep oiis is another addition to the known Bornean fauna. 13. Miniopterus witkampi Sody. Miniopt.erus 'witkampi Sody, Nat. Tijds. Ned. Ind., 1930, p. 272: Lobang Ipoe, Koetei, East Borneo. Four is, 4 ~ Madai and Tapadong caves (Nos. 38, 51, 344-347, 4 0 4, 4 0 5). Forearms.-- e 37, 3 8, 38, 3 8 .5; ~ 37, 3 8, 3 8, 39 mrn , 14. Emballonura rivalis Thos. Embollonura monticola riualis Thomas, Ann. Mag. Nat. Hist. (8) XV, 1915, p. 140: Sarawak. Four s , I ~ Baturong and Tapadong caves (Nos. 134, 135, 361, 362, 464). Forearms.- i!; 47, 47·5, 4 8, 48; ~ 48.5 111m. The measurements of three adults are: -head and body 45-55; tail 12-13; third finger, metacarpal 41-4-3, first phalanx 13; lower leg and hind-foot (c. u.) 25--26.5 mm. ' Skulls.-Occiput to anterior base of canine 14.8-15.3; condyle 10 front of canine 13.5-14; zygomatic breadth 9-4 9.5; mastoid breadth 8; front of canine to back of rna 6 mm. 15. Emballonura monticola monticola Temm. One ~ Tapadong caves (No. 465). Forear111.- ~ 45.5 mm. E. monticola and E. riualis occur side by side in Borneo and are distinct species and not sub-species as is suggested by Thomas' nomenclature: both occur in Sarawak and in British North Borneo. The measurements of three adults from British North Borneo are: -head and body 37-41; tail II-IS; third finger, metacarpal 40-41, first phalanx 12.5-13; lower leg and hind-foot (c. u.) 23.724 rnm, J\Ius. 5, 1931 [ II3 ] r' I I F. N. CHASEN Skulls.-Ckciput to anterior base of canine 13.8-14; condyle to front of canine 12.3-12.9; zygomatic breadth 8.3-8.9; mastoid breadth 7-4--7.5; front of canine to back of ms 5-5.1 mm. Foreanns.-43-45.S mm. 16. Taphozous melanopogon fretensis Thos. Taph oeous rnelano pog on [reiensis Thomas, Journ. F. M. S. Mus. VII, 1916, p. 5: Pulau Terutau, Straits of JVIalacca. Two (" 3 <;> Baturong and Tapadong caves (Nos. 561-56S). Forearms.- (; 62, 62; <;> 60, 64, 64 mm. The material of typical melanopogon available for comparison is not good but these rather pale specimens can be matched, or nearly so, by topotypes of [ret e nsis which is a very variable form. One of the females listed above has the underparts white washed with grey on the throat and chest. 17. Chaerephon plicatus (Bueh. Ham.). One (; Madai caves (No. 281). Forearm.s--qg mm. Like a few specimens from Sarnarang in Java (forearms 4245 mrn.) this single example from Borneo seems rather small but a good series of both sexes from West Java have the forearms measuring 46-49.5 mrn . which is about the same range shewn by some from Tenasserim and the South Shan States. The type locality is India. [Mr. Keith later forwardecl some bats from the small caves on the islet of Berhala in Sandakan Bay. These included iff egaderma spasma trifolium (Geoffr.), To.pho sous melanop ogon [ret ensis Thos., and Hipposideros g. galeritus Cantor.]