Evidence for historical human-induced extinctions of vertebrate species on La DÉsirade (French West Indies)

Abstract

Pit cave 6 on Pointe Gros Rempart (Baie-Mahault, La Désirade, French West Indies) is a stratified fossil-bearing site. While the archaeological material and faunal remains from the oldest assemblage demonstrate it to have formed during the Amerindian period, the second assemblage dates to the first one-hundred years of the island's colonial period (mid-18th to mid-19th centuries). Faunal analysis revealed the presence of 4 now locally extinct or extinct species, three of which have never before been documented on La Désirade (Ameivasp.,Leiocephaluscf.cuneusandAlsophissp.). Changing faunal spectrums (invertebrates and vertebrates) due to environmental destabilisation combined with aspects of the island's colonial economy demonstrate habitat degradation and over-grazing to be the principal causes of extinctions and or extirpations.

A new species of skink from the Guadeloupe Archipelago (Squamata, Mabuyidae, Mabuya)

“…However, the ameivas, curlytails, and racers known from the pre-and post-Columbian fossil record of La Désirade apparently did not survive past the 19th century (Boudadi-Maligne et al 2015). Unusually intense habitat alteration by livestock and agriculture on La Désirade has been suggested to have caused the extinctions (Boudadi-Maligne et al 2015). Certainly, the decline and extinction of species from habitat destruction is widely-known globally, so that is possible.…”

“…However, these ground-dwelling reptiles are not known to be so sensitive to habitat alteration on other islands, but rather are especially sensitive to predation by the mongoose (Hedges & Conn 2012). Boudadi-Maligne et al (2015) excluded the mongoose from consideration because they assumed La Désirade to be mongoose-free.…”

Bats of Saint Lucia, Lesser Antilles

“…These fac¬ tors clearly indicate that it is island populations of bats that are most at risk of extinction, relative to mainland species of bats. There is an adequate fossil record for bats in the Greater Antilles and a developing record for the Lesser Antilles, but these come from the northern Limestone Caribbees (Pregill et al 1994;Orihuela and Tejedor 2015;Boudadi-Maligne et al 2016;Stoetzel et al 2016) and little or no fossil record is available for bats in the southern Lesser Antilles including St. Lucia. Without a fossil record, we cannot determine which species have failed in natural dispersal events on the islands, but our data on the modern fauna will allow an assessment of the St. Lucia fauna and its place in the Lesser Antilles.…”

“…Human impact.-An increasing number of studies are reporting new fossil records of bats and other vertebrates, in each case attributing population declines, extirpation, and extinction of Caribbean bats to humans (Steadman et al 1984b(Steadman et al , 2015Pregill et al 1988;Bailon et al 2015;Soto-Centeno and Steadman 2015;Boudadi-Maligne et al 2016;Stoetzel et al 2016;Valente et al 2017), rather than to sea level and climate change during the Holocene (sensu Davalos and Russell 2012).…”

A new fossil species ofBoaLinnaeus, 1758 (Squamata, Boidae), from the Pleistocene of Marie-Galante Island (French West Indies)

“…This isolated extinction event remains difficult to explain, partly because the remains of this fossil snake have never undergone a detailed paleontological study. In addition, the case of the Marie-Galante Boa raises the possibility of a Pleistocene extinction of this genus in the Guadeloupe Archipelago, where it was never reported in historical texts (Du Tertre, 1654;Rochefort, 1658) or the archeological record (Pregill et al, 1994;Grouard, 2001Grouard, , 2010de Waal, 2006;Boudadi-Maligne et al, 2016), although its past occurrence in Guadeloupe is considered likely.…”