A New Eastern Limit of the Pacific Flying Fox

A New Eastern Limit of the Pacific Flying Fox, Pteropus tonganus (Chiroptera: Pteropodidae), in Prehistoric Polynesia: A Case of Possible Human Transport and Extirpation1 Marshall I. Weisler,2 Robert Bollt,3 and Amy Findlater4 Abstract: Five bones, representing one adult of the Pacific Flying Fox, Pteropus tonganus, were recovered from an archaeological site on Rurutu (151 21 0 W, 22 270 S), Austral Islands, French Polynesia, making this the most eastern extension of the species. For the first time, flying fox bones from cultural deposits were directly dated by accelerator mass spectrometry, yielding an age of death be- tween A.D. 1064 and 1155. Their stratigraphic position in an Archaic period archaeological site and the absence of bones in the late prehistoric to historic layers point to extirpation of the species. No flying fox bones were found in prehuman deposits and human transport of the species cannot be ruled out. During the past few decades archaeo- 1994), and possibly low coral atolls (Weisler zoology (the study of animal bones from 2001). In essence, no insular landscape was archaeological sites) has made important con- immune from the effects of colonizing hu- tributions to island biogeography by recover- mans who cleared land for horticulture ing bones of birds previously unknown to (Kirch 1983, Athens and Ward 1993) and in- science (Steadman 1995), extending the range troduced commensal animals such as pigs, of extant species (Wragg 1995), and under- dogs, chickens, and rats (Green and Weisler standing the dynamic relationships of people, 2004, Matisoo-Smith and Robins 2004) as fauna, and flora within Pacific island eco- well as vital cultigens, including medicinal systems during the late Pleistocene and and ornamental plants (Barrau 1963, Yen throughout the Holocene. It is now relatively 1973, Kirch 1982). commonplace to document human-caused In this paper we report what is now the avian extinctions on high volcanic islands most easterly occurrence of the Pacific Flying such as Hawai‘i (Olson and James 1982, Bur- Fox (Pteropus tonganus), recovered from ar- ney et al. 2001), the large continental islands chaeological deposits dating to as early as the of New Zealand (Anderson 1989, Worthy eleventh century A.D. on Rurutu (151 21 0 1998), makatea landforms in the southern W, 22 27 0 S), one of the seven Austral Is- Cooks (Steadman and Kirch 1990) and Hen- lands, located @470 km south of Tahiti in derson, Pitcairn Islands (Wragg and Weisler central East Polynesia (Figure 1). The sample size of five bones represents at least one adult individual. Their stratigraphic position in an 1 This project was supported by a National Science Archaic period archaeological site, and the Foundation doctoral dissertation improvement grant distance of Rurutu from documented popu- (No. BCS04-37581) to R.B. Manuscript accepted 3 Au- lations of flying foxes in the southern Cook gust 2005. Islands, @600 km to the west, may suggest 2 School of Social Science, University of Queensland, human introduction. No flying fox bones St. Lucia 4072, Queensland, Australia. 3 Department of Anthropology, University of Hawai‘i were recovered in prehuman deposits, and at Ma¯noa, Honolulu, Hawai‘i 96822. the small number of bones in the oldest cul- 4 Department of Anthropology, University of Otago, tural layer suggests that the Pteropus popula- Dunedin, New Zealand. tion was never very large. We also provide the first direct radiocarbon age determina- Pacific Science (2006), vol. 60, no. 3:403–411 tions on Pacific Flying Fox from prehistoric : 2006 by University of Hawai‘i Press contexts and discuss some probable causes of All rights reserved its extirpation on Rurutu. 403 404 PACIFIC SCIENCE . July 2006 Figure 1. Map showing the location of Rurutu in the Austral Islands. The archaeological excavations were conducted at Marae Uramoa near a pass, just south of Peva on the east coast. The Pacific Flying Fox is one of the most Ethnographic and Archaeological Evidence of the widespread Pteropus species and is currently Flying Fox in Polynesia found from the Solomon Islands to the southern Cook Islands (Flannery 1995, Miller and The Pacific Flying Fox was clearly a food Wilson 1997). Martin (1968) documented that item, although it was considered sacred on flying foxes were taken to Tahiti in the mid- some islands. Beginning in Uvea, West Poly- nineteenth century, and Flannery (1995) nesia, the flying fox was sometimes captured believes that because Polynesians carried fly- by shaking the branches from which it hangs ing foxes as pets it is possible that some pop- to sleep, although by 1932 it was only taken ulations result from introductions. This is with shotguns (Burrows 1937). During his merely the historic continuation of mid- fieldwork in Tonga during 1920–1921, Gif- Holocene introductions of animals by hu- ford (1929) recorded that the flying fox was mans in island Melanesia that extended still considered a deity on Tongatapu. In Tu- species beyond their natural range (Flannery tuila, Samoa, Buck (1930) reported that flying et al. 1988). Our contention here is that P. foxes ( pe‘a) were caught at night in a fowling tonganus may have been transported from the net with a long handle as they flew low to the southern Cook Islands to the Australs some- ground; occasionally they were hunted with time during the eleventh century A.D. Direct bow and arrow. Polynesians built permanent transfer is unlikely because the first apprecia- platforms in the tops of tall trees in Niue ble landfall from the southern Cooks is Rima- where, in the late afternoon, a snare was tara, some 150 km west of Rurutu, although used to trap a flying fox ( peka) that was used no records of flying foxes are known from as a decoy to attract other individuals that there. This opens up the possibility that pre- were caught in a net. Up to 200 could be cap- historic records of flying foxes may be discov- tured in one night (Loeb 1926). There is also ered in other islands in the Australs. a Niuean legend that describes how the flying Eastern Limit of Pteropus tonganus in Prehistoric Polynesia . Weisler et al. 405 fox carries her ‘‘children’’ clinging to her agree with Worthy’s conclusion that the breast instead of leaving them behind in the Niue bones are contemporaneous with pre- nest like a pigeon (Loeb 1926). Henry’s historic occupation but do not provide evi- (1928) major treatise on ancient Tahiti was dence for prehuman existence of fruit bats based on observations made by Reverend on the island, although it could well be an in- Orsmond in the early nineteenth century and digenous taxon based on its widespread oc- no mention was made of the flying fox, currence throughout the Southwest Pacific suggesting that it was of little importance, (T. Worthy, pers. comm., 2005). Three of extirpated, or perhaps never present prehis- the southern Cook Islands have prehistoric torically. The flying fox was, however, a records of P. tonganus (known locally as moa mid-nineteenth-century introduction (Martin kirikiri). From the west coast of Aitutaki, a 1968). The Pacific Flying Fox is thought to sandy archaeological deposit dating to <1000 be indigenous to the southern Cook Islands, B.P. contained a molar and wing phalanx where historically it is known from Mangaia (Steadman 1991). Walter (1998) found a sin- and Rarotonga (Hill 1979, Flannery 1995), gle flying fox mandible in an Archaic period which, until now, was thought to be the east- deposit on Ma‘uke, and the small quantity of ern limit of the species. F. Alan Seabrook, flying fox bone suggests that the taxon was who did extensive ethnographic fieldwork on extirpated soon after human occupation. The Rurutu in the 1930s, stated (1938), ‘‘The most extensive assemblage of Pacific Flying Cook Islands bat did not reach Rurutu.’’ By Fox bones from any prehistoric site in Poly- the early 1920s, there was no record of the nesia was recovered from a habitation rock- flying fox in Tubuai, Austral Islands, when shelter on Mangaia from layers dating to the Aitken (1930) spent eight months inventory- eleventh to fourteenth centuries (Steadman ing the flora, fauna, and customs. and Kirch 1990). The frequency of the bones The published archaeological occurrence at the site diminishes over time, suggesting of Pacific Flying Fox in Polynesia is limited local depression of the population. There is to Tonga, Niue, and the southern Cook Is- no evidence of flying fox bones in the Cook lands. On ‘Eua, southern Tonga, Koopman Islands before human occupation, but, as on and Steadman (1995) recovered 17 bones of Niue, we would expect indigenous popu- P. tonganus (including a mandible, lower lations. These sites of the southern Cook Is- incisor, three radii, three metacarpals, seven lands are contemporaneous with one another, manal phalanges, a femur, and a tibia) from as well as with the site on Rurutu—all dating excavations at three limestone caves. Only to the Archaic period of East Polynesia, when one of these bones was reported as coming most insular extinctions took place. from prehuman deposits, and two specimens were from the cultural layer in ‘Anatu´ cave The Study Area dated to 570 G 70 to 2710 G 70 B.P. (Koop- man and Steadman 1995). An additional 17 The Austral Islands of French Polynesia in- specimens were mostly fragmentary and may clude the volcanic islands Rimatara, Rurutu, represent either P. tonganus or P. samoensis Tubuai, Raivavae, Rapa, and two uninhabited (Koopman and Steadman 1995). On the ma- islets, Maria (formerly Hull), an atoll, and katea island of Niue, 11 bones and one tooth the small isolated rock spires of Marotiri. of P. tonganus were recovered from surface The Australs have the smallest total landmass and excavated layers from one archaeological (144 km2) of any East Polynesian archipelago and one ‘‘non-cultural’’ context (Worthy et except the Pitcairn group (43 km2).

Load more