sign in sign up
<<
Home , Common moorhen, Red owl, Tyto

SHORT COMMUNICATIONS 417

Mariana Common on Guam. Microne- STINSON, D. W., M. W. RITTER, AND J. D. REICHEL. sica 27:127-132. 199 1. The Mariana Common : decline of RITTER, M. W. AND T M. SWEET. 1993. Rapid colo- an island endemic. Condor 93:38-43. nization of a human-made wetland by Mariana TAYLOR, P. B. 1996. Family Rallidae (Rails, Galli- Common Moorhen on Guam. Wilson Bull. 105: nules, and Coots). Pp. 108-209 in Handbook of 685-687. the of the world. Vol. 3, Hoatzin to auks (J. ROSELAAR, C. S. 1980. Moorhen. Pp. 578-588 in Del Hoyo, A. Elliott, and J. Sargatal, Eds.). Lynx Handbook of the birds of Europe, the Middle East Editions, Barcelona, Spain. and North . Volume II, hawks to bustards U. S. FISH AND WILDLIFE SERVICE. 1984. Nine Mariana (S. Cramp, Ed.). Oxford Univ. Press, London, Islands listed as endangered. Tech. Bull. 9(9):1, 5-6. U.K. U.S. FISH AND WILDLIFE SERVICE. 1991. Recoverv STEADMAN, D .W. 1992. Extinct and extirpated birds plan for the Mariana Common Moorhen (= Ga<- from Rota, Mariana Islands. Micronesica 25:71- linule), Gallinula chloropus guami. U. S. Fish and 84. Wildlife Service, Portland, Oregon. STINSON, D. W. 1993. Commonwealth of the Northern U. S. FISH AND WILDLIFE SERVICE. 1996. Character- . Pp. 263-283 in Directory of wet- istics of Mariana Common Moorhens and wetland lands in Oceania. (D. A. Scott, Ed.). International within the U.S. Department of the Navys’ Waterfowl and Wetlands Research Bureau, Slim- military lease area and exclusive use area on the bridge, Gloucester, U.K.; Asian Wetlands Bureau, island of Tinian, Commonwealth of the Northern Kuala Lumpur, Malaysia. Mariana Islands, July 1994.August 1995. Unpubl. STINSON, D. W. 1994. Birds and recorded Report. from the Mariana Islands. Nat. Hist. Res. Special WILES, G. J. AND D. J. WORTHINGTON. 1996. Mixed Issue 1:333-344. flocks of White-winged Terns and Whiskered STINSON,D. W. 1995. Status and conservation of birds Terns in the southern Mariana Islands. Microne- in the Mariana Islands. Nat. Hist. Res. 3:21 l-218. sica 28:303-206.

Wilson Bull., 110(3), 1998, pp. 417-421

The Diet of the Red ( soumagnei) on the Masoala Peninsula, Madagascar

Steven M. Goodman1J,4 and Russell Thorstrom

ABSTRACT.-Based on pellets collected at the first extremely rare and restricted to primary rain known nest of this endemic species, data are presented in the eastern portion of Madagascar on the diet of the Madagascar (Tyto soumag- (Collar and Stuart 1985, Langrand 1995). nei). This owl feeds almost exclusively on small mam- Over the past five years this species has been mals, the vast majority of which are native to the is- land. There is evidence that this species hunts at the recorded at numerous localities in eastern forest edge and uses open human-degraded habitats. Madagascar, and it is becoming increasingly There is virtually no overlap in the diet of the Mada- clear that it is at best reclusive, rather than gascar Red Owl and the (T. a&z). Received rare, and is widespread in disturbed habitats 17 July 1997, accepted 10 May 1998. (Halleux and Goodman 1994; Powzyk 1995; Thorstrom 1996; Goodman et al. 1996; Thor- Strom et al. 1997). Although information on Until recently, the endemic Madagascar the distribution and natural history aspects of Red Owl (Tyto soumagnei) was thought to be the Madagascar Red Owl have been signifi- cantly augmented in the past few years, cer- ’ ’ Field Museum of Natural History, Roosevelt Road tain aspects of its life history remain poorly at Lake Shore Drive, Chicago, IL 60605; known and some published information is E-mail: [email protected]. contradictory to that gathered from recent WWF‘ BP 738, Antananarivo (lOl), Madagascar. 3 The Peregrine Fund, 566 West Flying Hawk Lane, field work. Boise, ID 83709. With the capture and radiotagging of an 4 Corresponding author. adult female Madagascar Red Owl in October 418 THE WILSON BULLETIN * Vol. 110, No. 3, September 1998

1994 and the discovery of the first known nest RESULTS of this species in August 1995 near Ambani- The minimum number of individuals of the zana (see below), new information is now total sample was 111, representing 8 different available on aspects of this species ’ ranging species of land vertebrates including reptiles behavior, roosting sites, and vocalization and mammals (Table 1). All the prey species (Thorstrom et al. 1997). Further, on the basis are endemic to the island except for Rattus of a preliminary analysis of pellet and prey rattus, an introduced rodent. No volant ani- remains found near roosts in 1994, it is known mals (bats or birds) or amphibians were iden- that small mammals are the dominant prey tified from the remains. The largest sample is type taken by this owl (Thorstrom et al. 1997). from 1995, with a MN1 of 78. Herein we present further information on the Endemic mammals make up the vast ma- food habits of the Madagascar Red Owl based jority of this ’ diet both by MN1 and body on pellets collected between 1994 and 1996 mass. Prey species ranged in size from the near Ambanizana. These data are compared to 12.8 g Microgale cowani to the 102.7 g Rattus the diet of a congeneric owl, T. alba, occur- rattus. The largest endemic taken ring sympatrically with T. soumagnei in the was webbi with a mean body weight rain of Madagascar. of 71.9 g. Over the course of the three seasons for which dietary information is available, STUDY AREA AND METHODS over 99% of the MN1 and biomass of prey The study site is located near Ambanizana (15” 37 ’ were mammals. Further, endemic S, 49” 58 ’ E), on the western side of the Masoala Pen- mammals made up the vast majority of the insula, in extreme northeastern Madagascar, and is a prey species taken, both by MN1 (95%) and few meters above sea level. This area of the peninsula biomass (97%). is relatively remote and composed of a mosaic of slash and burn agricultural fields, secondary growth, and pri- mary forests. The lowland rain forest of the area has DISCUSSION a canopy height less than 30 m with few emergent All of the prey species taken by the Mad- trees and high floristic diversity. Average annual rain- agascar Red Owl have been reported to occur fall recorded at another site on the peninsula between on the Masoala Peninsula or surrounding ar- 1992 and 1996 was 6106 mm. Monsoon rains and cy- clones occur between December and April, whereas eas (Carleton 1994, Glaw and Vences 1994, rain falls steadily between May and August (Donque Mittermeier et al. 1994, Stephenson 1995). 1972). The majority of these species are forest-dwell- The radio-tagged adult female Madagascar Red Owl ing, although a few can be found at the forest was located at 22 roost sites; 50% of the locations were edge or in disturbed habitats (e.g., Oryzorictes at the ecotone between forest and swidden fields, 36% hova, Microgale talazaci, and Microcebus ru- in rice paddies, and 14% in large areas of swidden fus). Rattus on Madagascar generally live fields. Nine diurnal roost sites were discovered during the period from October 1994 to December 1996. Af- commensally or in open agricultural areas, but ter the discovery of the nest, a fledgling female was they are also known to invade both disturbed radio-tagged and followed to 12 diurnal roost sites. and intact native forest. All of the native ro- Regurgitated pellets were collected below 3 of 9 di- dents in the sample, belonging to the subfam- urnal sites for the adult and 5 of 12 for the fledgling. ily Nesomyinae, are thought to be forest- In 1995 and 1996, regurgitated pellets, bone and fur dwelling, but several species are known to tol- samples were removed from the nest by a 1 m long erate moderate levels of disturbance. stick with tape wrapped at one end. The stick had a tacky tape side exposed to adhere and extract pellet On the basis of this analysis, the Madagascar material resting on the floor of the cavity. Red Owl predominantly hunts small mam- The pellet and prey remains were identified using mals, and we found no evidence that frogs the comparative osteological collections at the Field make up any part of its diet (contra Lavauden Museum of Natural History. Paired bones of any 1932), although in captivity this owl readily were separated and the largest number of elements consumed frogs (Halleux and Goodman from either the left or right side was considered the 1994). minimum number of individuals (MNI) among prey items. Body masses of identified prey species are pre- Movements of the radio-tagged individual sented in Table 1, and when possible these data are indicate that the maximum convex polygon from areas in northeastern Madagascar. home range was 210 ha (Thorstrom et al.

420 THE WILSON BULLETIN * Vol. 110, No. 3, September1998

jority of prey taken by T. alba, whether mea- TABLE 2. Comparison of the food habits of the Barn Owl at Andasibe and Manombo (Goodman et al. sured by individuals or biomass, is small 1993) and the Madagascar Red Owl on the Masoala mammals and almost exclusively introduced Peninsula. species. This is in contrast to T. soumagnei which feeds mostly on native small mammals. Ban Owl Red Owl In general, T. alba is a species of open hab- Manomba MaSiX& Andasibe (MN1 = Peninsula itat, avoiding closed forest throughout much (MN1 = 176) (MN1 = 111) 90) of its African and Malagasy range (Fry et al. Amphibia 1988, Langrand 1995). Goodman and Lan- MN1 38 8 grand (1993) proposed that T. alba was able % total individuals 21.7 8.9 to colonize new areas of Madagascar in the % total biomass 4.6 0.7 wake of the opening of forested areas and the Reptilia subsequent spread of introduced small mam- MN1 2 1 mals. If this is indeed the case, it is conceiv- % total individuals 1.1 0.9 able that in disturbed areas, particularly at the % total biomass 0.1 0.5 ecotone between forest and open areas, there Aves could be overlap in prey species between T. MN1 15 1 alba and other species of owls. On the basis % total individuals 8.5 1.1 of our dietary analysis for T. soumagnei and % total biomass 7.4 0.8 published literature on T. alba from rain forest Native Mammalia” sites on Madagascar, the prey species taken by MN1 19 108 these two owls is different and there is no ev- % total individuals 10.8 97.2 idence of competition for food resources be- % total biomass 4.8 96.0 tween them. Introduced Mammalia MN1 102 81 2 ACKNOWLEDGMENTS % total individuals 57.9 90.0 1.8 We thank R. Watson and B. Bumham for making % total biomass 83.1 98.4 3.5 this study possible. Special thanks to A. Andrianar a Includes Suncus madagascariensis. imisa for helping to organize aspects of this study. We are grateful to the Direction des Eaux et For&, Com- mission Tripartite, Projet Masoala, and Association Nationale pour la Gestion des Aires ProtTCTCes for their help and collaboration. The Peregrine Fund co- 1997). A large portion of its roost sites and operates with CARE International-Madagascar in the home range encompass slightly to heavily dis- Masoala Integrated Conservation and Development turbed habitat. The was not recorded in Project. The work was supported by grants from En- nearby closed canopy forest. The Barn Owl is vironment Now, John D. and Catherine T MacArthur a relatively common species across eastern Foundation, and USAID. L. Kiff and S. Swengel pro- Madagascar and is often found in open and vided most useful comments on an earlier version of this paper. cultivated areas. Given the roosting sites and areas that the Madagascar Red Owl apparently LITERATURE CITED hunts, it is almost certain that there is some overlap in the habitat used by these two owls. ATSALIS, S., J. SCHMID, AND F? M. KAPPELER. 1996. The Barn Owls’ diet has been studied on Mad- Metrical comparisons of three species of mouse lemur. J. Human Evol. 31:61-68. agascar at other sites. Barn Owl pellets were CARLETON, M. D. 1994. Systematic studies of Mada- collected at Andasibe in an area of disturbed gascars’ endemic rodents (Muroidea: Nesomyi- forest, within 400 m of a relatively intact and nae): revision of the Eliurus. Amer. Mus. extensive forest block and near Manombo Nov. 3087:1-55. (Farafangana) in a disturbed and open area, COLLAR, N. J. AND S. N. STUART. 1985. Threatened about 1 km from a relatively intact natural for- birds of Africa and related islands: the ICBP/ IUCN Red Data Book, part 1, third ed. Interna- est (Goodman et al. 1993). In Table 2 we com- tional Council for Bird Preservation and Intema- pare the food habits of T. alba from these two tional Union for the Conservation of Nature and sites with information on T. soumagnei from Natural Resources, Cambridge, UK. the Masoala Peninsula. In general the vast ma- DONQUE, G. 1972. The climatology of Madagascar. SHORT COMMUNICATIONS 421

Pp. 87-144 in Biogeography and ecology of Mad- AND V. SOARIMALALA. 1996. Patterns of eleva- agascar (R. Battistini and G. Richard-Vindard, tional distribution of birds and small mammals in Eds.). Junk, The Hague, The Netherlands. the humid forests of Montagne dAmbre,’ Mada- FRY, C. H., S. KEITH, AND E. K. URBAN. 1988. The gascar. Ecotropica 2:87-98. birds of Africa. Vol. III. Academic Press, London. HALLEUX, D. AND S. M. GOODMAN. 1994. The redis- CLAW, I? AND M. VENCES. 1994. A fieldguide to the covery of the Madagascar Red Owl Tyto soumag- amphibians and reptiles of Madagascar, second ed. nei (Grandidier 1878) in north-eastern Madagas- Zoologisches Forschungsinstitut und Museum Ko- car. Bird Conserv. Int. 4:305-3 11. enig, Bonn. LANGRAND, 0. 1995. Guide des oiseaux de Madagas- GOODMAN, S. M. AND M. D. CARLETON. 1998. The car Delachaux et Niestlt, Lausanne, Switzerland. rodents of the Reserve Speciale dAnjanaharibe-’ LAVAUDEN, L. 1932. Etude dune’ collection doiseaux’ Sud, Madagascar. Fieldiana: Zool., new series 90: de Madagascar. Bull. Mus. Hist. Nat., , 2e 201-221. serie, 4:629-640. GOODMAN, S. M. AND P D. JENKINS. 1998. The insec- MITTERMEIER, R. A., I. TATTERSALL,W. R. KONSTANT, tivores (Insectivora: Tenrecidae) of the Reserve D. M. MEYERS, AND R. B. MAST. 1994. Lemurs Speciale dAnjanaharibe-Sud,’ Madagascar, Field- of Madagascar. Conservation International, Wash- iana: Zool., new series 90:139-161. ington, D.C. GOODMAN, S. M., G. K. CREIGHTON,AND C. RAXWOR- POWZYK, J. 1995. Sighting of Madagascar Red Owl THY. 1991. The food habits of the Madagascar (Tyto soumagnei) in Mantadia National Park. Long-eared Owl Asio madagascariensis in south- Work. Group Birds Madagascar Reg. Newsl. 5(2):5. eastern Madagascar. Bonn. Zool. Beitr. 42:21-26. STEPHENSON,P J. 1995. Small mammal microhabitat GOODMAN, S. M. AND 0. LANGRAND. 1993. Food hab- use in lowland rain forest of north+ast Madagas- its of the Barn Owl Tyto &a and the Madagascar car. Acta Theriol. 40:425-438. Long-eared Owl Asio madagascariensis on Mad- THORSTROM,R. 1996. Preliminary study and the first agascar: adaptation to a changing environment. nesting record of the Madagascar Red Owl, Tyzo Proc. Pan-Afr. Omith. Congr. 8:147-154. soumagnei. Work. Group Birds Madagascar Reg. GOODMAN, S. M., 0. LANGRAND, AND C. J. RAXWOR- Newsl. 6(1):9-12. THY. 1993. The food habits of the Barn Owl Tyto THORSTROM, R., J. HART, AND R. T WATSON. 1997. a&a at three sites on Madagascar. Ostrich 64: 160- New record, ranging behaviour, vocalization and 171. food of the Madagascar Red Owl Tyto soumagnei. GOODMAN, S. M., A. ANDRIANARIMISA, L. E. OLSON, Ibis 139:477-48 1.

Wilson Bull., 110(3), 1998, pp. 421-423

Getting Stuck: A Cost of Communal Cavity Roosting

Mark T. Stanback,*’

ABSTRACT-Multiple Acorn Woodpeckers (Mela- nerpes formicivorus) perished as a result of two group members getting stuck while attempting to exit a com- Here I report an observation suggesting a munal roost cavity simultaneously. Both birds died, as potentially important cost of communal cavity did other individual(s) trapped behind them. Although roosting that may help explain its relative rar- communal roosting may have many benefits, such ity. That communal roosting is typically ad- mortality constitutes a risk of communal roosting that may help explain why Acorn Woodpeckers choose not vantageous is, of course, well documented. In- to roost as communally as they could. Received 28 dividuals utilizing communal roosts compete July 1997, accepted 17 April 1998. for preferential access to the more protected interior roost sites (Swingland 1977, Weath- erhead and Hoysak 1984), suggesting benefits ’ ’ Dept. of Zoology, NJ-15, Univ. of Washington, Se- of roosting both communally and in sheltered attle, WA 98105 2 Current Address: Dept. of Biology, PO. Box 1719, areas (Weatherhead 1983). Benefits of a shel- Davidson College, Davidson, NC 28036; tered roost site include not only greater pro- E-mail: [email protected]. tection from predators, but also lessened ex-