Proc. Nati. Acad. Sci. USA Vol. 81, pp. 4448-4451, July 1984 Evolution Fossil vertebrates from Antigua, Lesser Antilles: Evidence for late Holocene human-caused extinctions in the West Indies (anthropology/island biogeography/vertebrate paleontology) DAVID W. STEADMAN*, GREGORY K. PREGILLt, AND STORRS L. OLSON* *National Museum of Natural History, Smithsonian Institution, Washington, DC 20560; and tNatural History Museum, P.O. Box 1390, San Diego, CA 92112 Communicated by Jared M. Diamond, March 30, 1984 ABSTRACT Vertebrate remains recovered from a lime- fissure was in an active working face of the quarry and was stone fissure filling on Antigua, Lesser Antilles, are associated presumably but a remnant of a larger cave or crevice that with radiocarbon dates ranging from 4300 to 2500 yr B.P., had been quarried away. Five stratigraphically concordant contemporaneous with the earliest aboriginal human occupa- radiocarbon ages range from 2560 ± 70 yr B.P. in the upper tion of the island. Nine taxa of lizards, snakes, birds, bats, and vertical unit to 4300 ± 150 yr B.P. in the lower vertical unit rodents (one-third of the total number of species represented (Table 1). Contemporaneity of man with the extinct fauna is as fossils) are either completely extinct or have never been re- demonstrated by the presence of shell remains of molluscan corded historically from Antigua. These extinctions came long food items and several lithic artifacts, including a blade from after any major climatic changes of the Pleistocene and are the horizontal portion of the fissure associated with a radio- best attributed to human-caused environmental degradation in carbon age of 3695 ± 100 yr B.P. The first Amerindians on the past 3500 yr. Such unnatural influences have probably al- Antigua (the "Archaic" culture) are believed to have arrived tered patterns of distribution and species diversity throughout during the time interval represented at the Burma Quarry the West Indies, thus rendering unreliable the data tradition- site. Of the 24 Archaic sites known on Antigua, the only reli- ally used in ecological and biogeographic studies that consider able radiocarbon age, aside from those for Burma Quarry, is only the historically known fauna. 3725 ± 90 yr B.P. for the Jolly Beach site on the west-central coast (7). Episodes of vertebrate extinction are well documented for The Burma Quarry sediments contained nine species of continental areas in the Quaternary Period, although the rel- vertebrates that were unrecorded in the historic period on ative role of man versus climate in these extinctions is still Antigua and three others that became extinct in the historic the subject of considerable debate (1). In North America, the period (Table 2). The nine prehistorically extinct species arrival of humans coincided with terminal Pleistocene cli- make up 33% of the total number of species in the fossil fau- matic changes, and extinctions are concentrated near the na, which itself, of course, is only a subset of the late Holo- Pleistocene/Holocene boundary (2), making it difficult to cene fauna of Antigua; other extinct taxa would be expected separate the effects of the two processes. In the West Indies, with a more complete fossil sample. Species recovered as the extinction or reduction in range of many vertebrates has fossils from Burma Quarry that are still extant on Antigua been thought to be associated with climatic changes at the include the frog Eleutherodactylus johnstonei; the lizards end of the Pleistocene (3), although a number of extinct taxa Thecadactylus rapicauda and Anolis bimaculatus leachi; the found in archeological sites are known to have persisted snake Typhlops monastus; the birds Calidris spp., Zenaida longer (4, 5). Man did not arrive in the West Indies until well aurita, Columbina passerina, Orthorhynchus cristatus, cf. after the end of the Pleistocene-about 4500 yr B.P. to per- Tyrannus dominicensis, Margarops fuscatus, and Loxigilla haps 7000 yr B.P. in the case of the Greater Antilles (6), and noctis; and the bats Brachyphylla cavernarum, Natalus stra- 3700 yr B.P. in the Lesser Antilles (7). It should, therefore, mineus, Tadarida brasiliensis, and Molossus molossus. be possible to sort out the effects of man versus climate in Whereas artifacts and marine mollusks used as food prob- the West Indies, just as in the case of other islands where ably were washed into the fissure from the surrounding the fossil record has clearly demonstrated a direct correla- ground surface, the majority of vertebrates from Burma tion between the extinction of vertebrates and human colo- Quarry are quite small species that appear to have been con- nization-e.g., Madagascar (8), New Zealand (9), Hawaii centrated as prey remains of an owl, possibly an undescribed (10), and Galapagos (unpublished data). form of barn owl (Tyto). Bones of two species of Tyto have We now present paleontological evidence that documents been found on Barbuda (unpublished observation), an island the loss within the past 3500 yr of 14 species of small verte- on the same bank as Antigua (Fig. 1), although no such owls brates from the island of Antigua, Lesser Antilles (Fig. 1), are known historically from Antigua or elsewhere in the presumably as a result of habitat destruction and predation northern Lesser Antilles, nor were remains of large owls by man and introduced mammals. Some of these species are found in Burma Quarry. totally extinct, whereas others still survive elsewhere in the Among the extinct taxa from Burma Quarry, the bat Phyl- Antilles. These findings raise serious doubts about the valid- lonycteris major was previously known only from Quaterna- ity of biogeographical studies in the West Indies that rely ry deposits in Puerto Rico (11) and the lizard Leiocephalus solely on modern, but unnatural, patterns of distribution. cuneus only from the late Quaternary (Pleistocene?) of Bar- In 1980 and 1983 we excavated fossiliferous sediment from buda (13). The Burma Quarry deposits show that these spe- a limestone fissure filling at a site known as Burma Quarry in cies, heretofore often assumed to have died out in the Pleis- northern Antigua (Fig. 2). This fissure consisted of a narrow tocene, still existed up to -3500 yr ago. No boid snakes vertical crevice bisected by a wide horizontal chamber. The occur anywhere in the Leeward Islands today; the indeter- minate boid from Burma Quarry may be allied to Greater The publication costs of this article were defrayed in part by page charge Antillean forms. The trembler (Cinclocerthia ruficauda) is a payment. This article must therefore be hereby marked "advertisement" medium-sized passerine bird restricted to Lesser Antillean in accordance with 18 U.S.C. §1734 solely to indicate this fact. islands to the northwest and south of Antigua. Its absence 4448 Downloaded by guest on September 26, 2021 Evolution: Steadman et aL Proc. NatL Acad Sci. USA 81 (1984) 4449 63°W 62°W 61 0W l1 71- :'.-SOMBRERO ATLANTIC OCEAN . ~ ~ ~ .. *---::~~~~~~~~~~~ 1- -;ANGUILLA- N ST. MARTIN 180ON 0 - 18° N .A. ST. BARTHOLOMEW :. ARBUDA - . $:SABA . : :ST. EUSTATIUS *.'. I ST. KIT *NEV. *ANTIGUA 17?. dh I'7°N o<C.t REDQNDA'.- CARIBBEAN SEA MONTSERRAT GUADELOUPE LA DESIRADE 0 25 50 75 KM l I I I , I 0 25 50 MILES I I ISLAND MARIE tLES .-: .BANK (200 M ISOBATH) DES SAINTES ....- GA LANTE *_________ 62oW 61 W FIG. 1. The.northern Lesser Antilles. from Antigua and Barbuda would be inexplicable without a to the loss of roosting sites. Pteronotus parnellii and Mor- fossil record showing that tremblers were indeed present, at moops blainvillei are insectivorous, whereas Phyllonycteris least on Antigua, in the recent past. poeyi, the living counterpart of Phyllonycteris major, feeds The Burma Quarry fossils provide the first Lesser Antille- mainly on nectar and plant material (14). The extinct species an records for the bats Pteronotus parnellii and Mormoops of cricetid rodent (Oryzomyini sp.) is very common at Bur- blainvillei, and the yelloyv-breasted crake Porzana flavi- ma Quarry, as well as in later archeological sites. Although venter, all known in the West Indies today only from the such rice rats frequently appear to have been used as food by Greater Antilles. Thus, the paleontological record shows Amerindians in the northern Lesser Antilles (15), the extinc- that the faunal distinctions between the Greater and Lesser tion of these rodents may not have occurred until the intro- Antilles, while undeniable, are perhaps less marked than duction of Old World rats (Rattus) in historic times. Native would be apparent from modem distributions alone. rodents in Galapagos (16) and Fernando de Noronha (17) Porzana flaviventer requires bodies of fresh water with also seem to have been unable to coexist with Old World lush emergent vegetation. Although no such habitats exist on rats. Antigua today, their disappearance within the past 3500 yr Additional extinct vertebrates have been recorded from may be due to siltation from agricultural erosion. Because archeological sites on Antigua that postdate the Archaic cul- the three species of bats lost from Antigua all would have ture. Indian Creek and Mill Reef are two large ceramic cul- roosted in caves (14), their extinction could be related to a tural sites (Fig. 2), the former ranging in age from 1915 + 80 decrease in available food through forest destruction, but not yr B.P. to 845 + 80 yr B.P. (6), and the latter from approxi- Downloaded by guest on September 26, 2021 4450 Evolption: Steadman et aL Proc. NatL Acad Sci. USA 81 (1984) 1710l- 17-05 I- GREEN 1. -? OYORK 1. 1700' 61050' 61-45' 61-401 FIG. 2. Antigua and its satellite islands. mately 1450 to 800 yr B.P. (12). Bones from these two sites terus ruber) do not necessarily indicate resident populations, add several other taxa to the fauna of Antigua (Table 2).