Macroderma gigas

American Society of Mammalogists 0DFURGHUPDJLJDV $XWKRUV:HQG\6WDUU+XGVRQDQG'RQ(:LOVRQ 6RXUFH 0DPPDOLDQ6SHFLHV 1R0DFURGHUPDJLJDV-XQSS 3XEOLVKHGE\American Society of Mammalogists 6WDEOH85/http://www.jstor.org/stable/3503920 . $FFHVVHG Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at . http://www.jstor.org/page/info/about/policies/terms.jsp JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected]. American Society of Mammalogists is collaborating with JSTOR to digitize, preserve and extend access to Mammalian Species. http://www.jstor.org MAMMALIAN SPECIES No. 260, pp. 1-4, 3 figs. Macroderma gigas. By Wendy Starr Hudson and Don E. Wilson Published 16 June 1986 by The American Society of Mammalogists Macroderma Miller, 1906 56, 47; length of anterior lobe of tragus, 12, 10; length of posterior lobe of tragus, 25.5, 22.0; length of noseleaf, 16, 15; length of Macroderma Miller, 1906:84. Type species Megaderma gigas by forearm, 117.0, 103.5; length of thumb, 21.0, 19.5; length of original designation. metacarpal II, 84.5, 80.5; length of phalanx II, 16, 17; length of CONTEXT AND CONTENT. Order Chiroptera, Suborder metacarpal III, 69, 68; digit III, length of phalanx I, 47, 44; digit Microchiroptera, Family Megadermatidae. The genus Macroderma III, length of phalanx II, 92, 80; length of metacarpal IV, 79, 78; contains only one Recent species, M. gigas, and a fossil form, M. digit IV, length of phalanx I, 25.5, 24.5; digit IV, length of phalanx godthelpi Hand (1985). II, 38.5, 33.0; length of metacarpal V, 84.5, 82.0; digit V, length of phalanx I, 32, 33; digit V, length of phalanx II, 28.5, 23.5; Macroderma gigas (Dobson, 1880) Ghost Bat Megaderma gigas Dobson, 1880:461. Type locality Mount Margaret, Wilson's River, central Queensland, Australia. CONTEXT AND CONTENT. Context same as for genus. Douglas (1962) named M. g. saturata on the basis of specimens^ : *" - from Kalumburu in northern Western Australia, but Koopman < ~ .. (1984a) synonymized it with the nominate form. _ - DIAGNOSIS. The upper incisors are absent as in all megadermatids, but the rudimentary premaxillae are more highly developed in Macroderma than in Megaderma. M. gigas lacks P2, in contrast to species of Megaderma (Miller, 1906). As in other members of the family, the mesostyles of M1 and M2 are displaced lingually, more so in Macroderma than in Lavia or Cardioderma. Reduction or loss of the hypoconulid of m3 characterizes the family, but Macroderma has a better developed m3 hypoconulid than other genera in the family (Hand, 1985). The shield-like interorbital expansion (Fig. 1) is intermediate in size between that of the Asian and African megadermatids. The postorbital and antorbital processes are more prominent than in Megaderma, but less so than in Cardioderma and Lavia (Miller, 1907). The interpterygoid space extends to the level of the posterior border of M2. The posterior lobe of the tragus is proportionally shorter than that of Megaderma and the anterior lobe is much broader at the base, more convex 96..8Z9 anteriorly, and obtuse at the tip (Dobson, 1880). The second finger extends beyond the middle of the first phalanx of the third finger, in contrast to the shorter second -finger of Megaderma spasma. The tail consists of only two vertebrae hidden between the two integumentary layers of the large interfemoral membrane. Short hairs cover the extremity of the carpus, thumb, and propatagium. GENERAL CHARACTERS. The Australian ghost bat, M. gigas, with a body mass from 130 to 170 g (Kulzer et al., 1984; Pirlot and Nelson, 1980; Taylor, 1984), is one of the largest of the - microchiropterans. Head and body length ranges from 100 to 140 mm and forearm length from 105 to 115 mm (Nowak and Paradiso, 1983). The long ears join along the midline for half the length of their inner margin (Fig. 2). The noseleaf is long and has convex sides and its anterior concave disk is large with a vertical process above (Troughton, 1926). The eyes are relatively large for microchiropterans and the claws are strong and curved (Taylor, 1984). The lower lip projects farther than the upper and the nostrils are depressed within an area of naked skin. In most populations, the terminal third of the dorsal hairs is pale grayish brown, and the pale white of the ventral pelage matches the ears, noseleaf, and membranes (Troughton, 1926). The species also encompasses individuals with darker fur and membranes (Koopman, 1984a). The wing span of M. gigas is approximately 0.6 m (Breeden and Breeden, 1967). The female is smaller than the male, although the measurements of the tibia and first phalanx of the fifth finger are greater in the female (Waite, 1900). External measurements (in mm) of the male holotype and of FIG. 1. Dorsal, ventral, and lateral views of cranium and a female from the Australian Museum (Waite, 1900) are: head and lateral view of mandible of female Macroderma gigas, USNM body length, 135, 110; head length, 48.5, 41.0 (broken); ear length, 396829. Greatest length of skull is 38.7 mm. MAMMALIAN SPECIES 260 120 140 25 25'- 0 KMS 1000 KMS 120" 140 FIG. 2. Macroderma gigas photographed in Australia by Frank Greenwell in 1973. tibia length, 44, 45; calcaneum length 28.5, 28.0; and length of hindfoot, 28.5, 23.5. Douglas (1962) listed the following skull measurements (in mm) for a specimen from Western Australia: length, 38.5; breadth, 24.3; interorbital constriction, 4; and palate, 13. Molnar et al. (1984) described several fossil specimens referable to the Recent species, and listed the following measurements (in mm) for a Recent specimen from the Queensland Museum; length of mandibular ramus, 29.2; length and width of p4, 3.2, 1.9; length and width of ml, 3.5, 2.6; length and width of m2, 3.7, 2.6; length and width of m3, 3.6, 2.4. DISTRIBUTION. Macroderma presently occurs throughout the northern two-thirds of Australia south to 28?S in Western Australia and 27?S in western Queensland (Fig. 3). It is found both in dry country and in humid rainforests (Molnar et al., 1984). A sighting on Mt. Kenneth, Western Australia, in 1854 is the southernmost record; however, most records at the southern limits consist of isolated individuals rather than permanent populations. Records of large, permanent populations at the southern border of its range extend from the Pilbara district in Western Australia to Mt. Etna in Queensland (Molnar et al., 1984). Pleistocene localities coincide with the present distribution only in northeastern Queensland. Macroderma occurred much farther south in the Pleistocene than it does today (Cook, 1960). Finlayson (1961) considered the species to be relictual in central Australia and suggested that its range is receding from the south. Baynes et al. (1976) suggested that the absence of dry, smooth-walled caves in southern Australia limits its range. The genus may occur in suitable habitat in New Guinea (Filewood, 1983), although no specimens have been taken there. FOSSIL RECORD. The most southerly fossil occurrence is approximately 600 km SSW of Mt. Kenneth, Western Australia, the southernmost record of living ghost bats. The Wanneroo-Yanchep region has yielded occasional skeletal material and may represent only a recent southward expansion of the range of the species (Bridge, 1975). Large guano piles and skeletal material were found at the Ledge Point-Dongara and Coorow-Watheroo areas. Bridge (1975) suggested that the distribution and abundance of the guano piles and skeletal material represent expansions and contractions of the range during the Holocene. In Drover's Cave, Lundelius (1960) discovered M. gigas remains at all depths up to 1.5 m in association with rodent and marsupial material. Subfossils have been collected from limestone caves in Western Australia and the Flinders Ranges of South Australia (Hamilton-Smith, 1974). All fossil specimens found to date seem to differ only in minor ways from modern representatives of the species (Molnar et al., FIG. 3. Distribution of Macroderma gigas (shaded area). Open circles denote extralimital localities from which Holocene fossils are known. 1984). Analyses of current and past distribution patterns suggest the possibility of successive waves of expansion and contraction of range, perhaps related to changing climatic conditions (Bridge, 1975; Molnar et al., 1984). FORM. Although the predominant pelage color is pale gray or whitish, the relatively long and lax hair ranges in color from almost white through shades of gray to almost brown (Douglas, 1962). Although most species of bats have only a single pair of pectoral mammae, Macroderma has a pair of inguinal "false mammae" which serve as holdfasts for the young, in addition to the normally functioning pectoral pair. The skeletal arrangement in the thoracic region is somewhat unusual in megadermatids. The anteriorly widened presternum is fused to the first pair of ribs, the first thoracic vertebra, and the seventh cervical vertebra to form a solid ring of bone (Miller, 1907). The pelvic girdle is more like that of other microchiropterans, with the ischia free posteriorly. The thread-like fibula is only half as long as the tibia (Koopman, 1984b). A distinct sagittal crest frequently develops on the large, robust skull of older individuals. The pentagonal frontal shield is flat and its angles are defined distinctly. The dental formula is i 0/2, c 1/1, p 1/2, m 3/3, total 26. The teeth are large, robust, and highly cuspidate. The metastyle of M1 has shifted posteriorly, and the mesostyle, almost obliterated, has shifted lingually between the parastyle and the metacone. The anterolingual cingular cusp of C1 is greatly developed (Andersen and Wroughton, 1907). Volumes of 11 brain structures indicate that M. gigas is intermediate between insectivorous microchiropterans and the carnivorous species from South America (Pirlot and Nelson, 1980). M. gigas is the least encephalized member of its family with an encephalization index of approximately 142 (Stephan et al. 1981). Stephan and Nelson (1981) described Macroderma as having a clear midbrain exposure, a large hemispherical part of the paraflocculus, and a relatively small lobulus petrosus. Compared to other species of bats, higher development of the brain was indicated by the partial cover of the midbrain, traces of a dorsal sulcus, and a well-developed cerebellum (Stephan and Nelson, 1981). FUNCTION. Body temperature is maintained between 35 and 39?C at ambient temperatures of 0 to 35?C. Oxygen consumption increases above and below the thermal neutral zone, 30 to 35?C. As ambient temperatures decrease to 25?C, sufficient oxygen is obtained through an increased depth of breathing. Below 25?C, the breathing rate is directly proportional to oxygen consumption. At 20?C, elevated oxygen requirements of the tissues are met by increased stroke volume, the arteriovenous difference in the blood, and shivering. Within the thermal neutral zone, heart rate remains - - -0 - - -6 a_ I_ n 2 MAMMALIAN SPECIES 260 minimal and increases with oxygen consumption. The species does not hibernate or undergo daily torpor (Leitner and Nelson, 1967). When a Macroderma is moving towards detected prey, it emits echolocation pulses that are shorter in duration and average 0.8 ms (n = 11); duration increases to a mean of 1.7 ms (n = 13) during landing (Kulzer et al., 1984). Macroderma has unusually good vision for a microchiropteran, with a spatial resolution approaching two cycles/degree based on retinal morphology (Guppy and Coles, 1983). It may well use vision extensively to locate or discriminate prey. Mastication is thorough and passage through the digestive system is slow compared to fruit-eating bats (Douglas, 1967). M. gigas also may be able to balance their water budget without recourse to free drinking water (Kulzer et al., 1984). Douglas (1967) described a musty odor from Macroderma that he could distinguish readily from that of other species. ONTOGENY AND REPRODUCTION. Females congregate in maternity colonies during the breeding season and each gives birth to a single young at the end of the breeding season (Thornback and Jenkins, 1982). The breeding season is late October to early November in the south and somewhat earlier in the far north (Thornback and Jenkins, 1982). In the Pilbara District, Douglas (1967) found a female with an embryo 10 mm in crown-rump length in August, and three others with embryos of 52, 65, and 70 mm in October. In November, he found neonates ranging from 60 to 80 mm in length. In the Northern Territory, he found a 45-mm embryo in June, and a hairless neonate of 96 mm in September. The flaccid pectoral and inguinal mammae of nulliparous Macroderma become turgid after pregnancy. The mammae and clitoris are more easily detected in parous than in nulliparous females (Douglas, 1967). ECOLOGY. Although buildings may be used as feeding stations, Macroderma roosts only in caves, rock crevices, and mines (Douglas, 1967). Colonies of up to several hundred individuals may form, but small groups or individuals are more common (Taylor, 1984). Macroderma gigas feeds on mice, small bats, small birds, legless lizards (Pygopodidae), geckos (Gekkonidae), small snakes, and insects. Mus musculus remains were found most commonly in discarded food material in caves of the Pilbara District. Twenty species of birds also were identified in the material (Douglas, 1967). Wilson (1973) classified Macroderma as primarily a specialized carnivore and as a foliage gleaner secondarily. The occasional finding of large quantities of insect chitin in the stomachs of M. gigas suggests that the bat is an opportunistic feeder (Kulzer et al., 1984). Vestjens and Hall (1977) reported termites in the stomach of one individual. Live prey is eaten more frequently and normally is eaten near the point of capture (Douglas, 1967). The ghost bat has few natural predators, Medium-sized owls (Strigidae) co'mpete for insects and small mammals, but no correlation exists between presence of these owls and Macroderma. Local movements of colonies and individuals most likely result from fluctuations in prey availability (Molnar et al., 1984). Although the range seemingly has contracted during the Holocene Period, probably several thousand Macroderma remain alive. Some areas of southern Australia underwent a transition from open savanna to dense woodland during the Pleistocene and Recent. These changes may have led to the contraction of the range of the species in Australia (Thornback and Jenkins, 1982). The species is threatened by vandalism (McKean and Price, 1967), mining of limestone caves, and quarrying (Hamilton-Smith, 1980). There are few national parks or reserves to provide refugia (Hamilton-Smith, 1980). M. gigas is classified as a vulnerable species by the International Union for the Conservation of Nature and Natural Resources (Thornback and Jenkins, 1982). A species of tick, Argas (C.) macrodermae, was described in 1977 from specimens of the ghost bat (Hoogstraal et al., 1977). Douglas (1967) suggested that Macroderma is conspicuously free of ectoparasites in comparison with other microchiropterans. The only reported endoparasite is a filarial nematode, Josefilaria mackerrasae (Moorhouse et al., 1979). BEHAVIOR. Macroderma is inactive during daylight hours and leaves the roost from one to several hours after sunset. Some individuals may remain in the roost all night. They leave singly, in pairs, or in small groups. During flight, they hold the head high and appear to scan the countryside (Douglas, 1967). Hunting behavior began 3 to 5 h after dark in a captive colony (Kulzer et al., 1984). The bats use a sit-and-wait hunting strategy. From roosts, the bats look in the direction of noises from prey and direct their pinnae to detect movement. Hearing is used initially to detect prey, and perch position is altered occasionally to "listen" to prey from a different angle. Echolocation emissions reach a peak frequency before the bat flies and hovers over prey. The precise location of the prey is attained through a pulse series emitted during a variable number of reconnoitering flights over potential prey. When located, the victim is seized quickly from above, pressed to the ground, and held by the thumb claws for the killing bite into the neck or head delivered by the canine teeth. Small mammals are manipulated by the thumb claws and eaten from head to tail (Guppy and Coles, 1983). Captive M. gigas can capture prey up to 80% of their body mass. When able to catch large prey, Macroderma may not hunt daily (Kulzer et al., 1984). When food is scarce under captive conditions, two or more individuals may fight to obtain the same prey item. While fighting, they emit high-pitched squeals (Douglas, 1967). They often produce a cricket-like chirp when hungry and the young continuously chirp when separated from the mother. Usually, the bats make no noise at all (Douglas, 1967). Human intruders to a cave colony may cause the group to become nervous and leave inconspicuously (Douglas, 1967). The extent of daily and seasonal movements is unknown, but Douglas (1967) suggested that there were differences in night roosting behavior during wet and dry seasons. During the wet season, bats at Kulumburu frequented buildings as feeding roosts, but were not known to do so during the dry season. GENETICS. Nothing is known about the genetics of this species. REMARKS. The name Macroderma is from the Greek roots makros, meaning large, and derma, meaning skin. The specific epithet gigas is Greek, meaning giant, and refers to the fact that this is the largest species in the family. LITERATURE CITED ANDERSEN, K., AND R. C. WROUGHTON. 1907. On the bats of the family Megadermatidae. Ann. Mag. Nat. Hist., 19:129145. BAYNES, A., D. MERRILEES, AND J. K. PORTER. 1976. Mammal remains from the upper levels of a late Pleistocene deposit in Devil's Lair, Western Australia. J. Royal Sci. W. Australia, 58:97-126. BREEDEN, S., AND K. BREEDEN. 1967. Animals in eastern Australia. Australasian Publ. Co., Sydney, 128 pp. BRIDGE, P. J. 1975. Paleo-distribution of Macroderma gigas in the southwest of Western Australia. Helictite, 13:35-36. COOK, D. L. 1960. Some mammal remains found in caves near Margaret River. W. Australia Nat., 7:107-108. DOBSON, G. E. 1880. On some new or rare species of Chiroptera in the collection of the G6ttingen Museum. Proc. Zool. Soc. London, 1880:461-462. DOUGLAS, A. M. 1962. Macroderma gigas saturata (Chiroptera, Megadermatidae) a new subspecies from the Kimberly Division of Western Australia. W. Australia Nat., 8:59-61. . 1967. The natural history of the ghost bat, Macroderma gigas, in Western Australia. W. Australia Nat., 10:125138. FILEWOOD, L. W. 1983. The possible occurrence in New Guinea of the ghost bat (Macroderma gigas; Chiroptera, Megadermatidae). Australian Mamm., 6:35-36. FINLAYSON, H. H. 1961. On central Australian mammals. Part IV-the distribution and status of central Australian species. Records S. Australian Mus., 14:141-191. GUPPY, A., AND R. B. COLES. 1983. Feeding behavior of the Australian ghost bat, Macroderma gigas (Chiroptera: Megadermatidae) in captivity. Australian Mamm., 6:97-99. HAMILTON-SMITH, E. 1974. The present knowledge of Australian Chiroptera. Australian Mamm., 1:95-108. 1980. The status of Australian Chiroptera. Pp. 199206, in Proceedings of the Fifth International Bat Research Conference (D. E. Wilson and A. L. Gardner, eds.). Texas Tech Univ. Press, Lubbock, 434 pp. 3 MAMMALIAN SPECIES 260 HAND, S. J. 1985. New Miocene megadermatids (Chiroptera: Megadermatidae) from Australia with comments on megadermatid phylogenetics. Australian Mamm., 8:5-43. HOOGSTRAAL, H., D. E. MOORHOUSE, G. WOLF, AND H. Y. WASSEF. 1977. Bat ticks of the genus Argus (Ixodoidea: Argasidae). A. (Carios) macrodermae, new species from Queensland, Australia. Ann. Entomol. Soc. Amer., 70:861-870. KOOPMAN, K. F. 1984a. Taxonomic and distributional notes on tropical Australian bats. Amer. Mus. Novitates, 2778:1-48. 1984b. Bats. Pp. 145-186, in Orders and families of Recent Mammals of the world (S. Anderson and J. K. Jones, Jr., eds.). John Wiley and Sons, New York, 686 pp. KULZER, E., J. E. MCKEAN, AND F. P. MOEHRES. 1984. Prey catching behaviour and echolocation in the Australian ghost bat, Macroderma gigas (Chiroptera: Megadermatidae). Australian Mamm., 7:37-50. LEITNER, P., AND J. E. NELSON. 1967. Body temperature, oxygen consumption and heart rate in the Australian false vampire bat, Macroderma gigas. Comp. Biochem. Physiol., 21:6574. LUNDELIUS, E. 1960. Post Pleistocene faunal succession in Western Australia and its climatic interpretation. Proc. Twentyfirst Internatl. Geol. Congr., 4:142-153. McKEAN, J. L., AND W. J. PRICE. 1967. Notes on some Chiroptera from Queensland, Australia. Mammalia, 31:101-119. MILLER, G. S. 1906. Twelve new genera of bats. Proc. Biol. Soc. Washington, 19:83-85. 1907. The families and genera of bats. Bull. U.S. Natl. Mus., 57:1-282. MOLNAR, R. E., L. S. HALL, AND J. H. MAHONEY. 1984. New fossil localities for Macroderma Miller, 1906 (Chiroptera: Megadermatidae) in New South Wales and its past and present distribution in Australia. Australian Mamm., 7:63-73. MOORHOUSE, D. E., O. BAIN, AND G. WOLF. 1979. Josefilaria mackerrasae gen. et sp. nov. (Nematoda:Filarioidea) parasite de la chauve-souris Macrodermc gigas Dobson. Ann. Parasitol. Hum. Comp., 54:645-651. NOWAK, R. M., AND J. L. PARADISO. 1983. Walker's mammals of the World. Fourth ed. Johns Hopkins Univ. Press, Baltimore, Maryland, 1:1-568. PIRLOT, P., AND J.. NELSON. 1980. Quantitative aspects of brain morphology in Macroderma gigas (Megadermatidae, Chiroptera). Australian Mamm., 3:105-108. STEPHAN, H., AND J. E. NELSON. 1981. Brains of Australian Chiroptera I. Encephalization and macromorphology. Australian J. Zool., 29:653-670. STEPHAN, H., J. E. NELSON, AND H. D. FRAHM. 1981. Brain size comparison in Chiroptera. Z. Zool. Syst. Evolut.-forsch, 19: 195-222. TAYLOR, J. M. 1984. The Oxford guide to mammals of Australia. Oxford University Press, New York, 148 pp. THORNBACK, J., AND M. JENKINS. 1982. Macroderma gigas. Pp. 101-102, in The IUCN mammal red data book. Part 1. Internatl. Union Conserv. Nature, Gland, Switzerland, 515 pp. TROUGHTON, E. L. G. 1926. The bats of Australia and New Guinea. Pp. 21-88, in The wild animals of Australasia (A. S. Le Souef and H. Burrell, eds.). George C. Harrap and Co., Ltd., Sydney, 388 pp. VESTJENS, W. J. M., AND L. S. HALL. 1977. Stomach contents of forty-two species of bats from the Australasian region. Australian Wildl. Res., 4:25-35. WAITE, E. R. 1900. Recurrence of Megaderma gigas, Dobson. Records S. Australian Mus., 3:188-189. WILSON, D. E. 1973. Bat faunas: a trophic comparison, Syst. Zool., 22:14-29. Editors of this account were B. J. VERTS and SYDNEY ANDERSON. Managing Editor was TIMOTHY E. LAWLOR. W. S. HUDSON AND D. E. WILSON, WELLS COLLEGE, AURORA, NEW YORK 13026 AND U. S. FISH AND WILDLIFE SERVICE, NATIONAL MUSEUM OF NATURAL HISTORY, WASHINGTON, D.C. 20560. 4