 |
| Marisora aurulae |
 |
| Copeoglossum aurae |
As of today the two species of skinks on Trinidad and Tobago have new genera and new epithets - they are newly described species. This is just a glimpse of changes to come in the herpetofauna of the islands. Many T&T species though to be widespread species are not, they are cryptic species that evolved in the islands or on the adjacent mainland. Below are parts of the species accounts for these new lizards from Hedges & Conn (cited below).
Copeoglossum aurae Hedges & Conn, 2012
Greater Windward Skink
Mabuia agilis—Boulenger, 1887:191 (part). Mabuia aenea—Garman, 1887:53 (part). Mabuya aenea—Barbour, 1914:322 (part). Mabuya aenea—Barbour, 1930:105 (part).
Mabuya mabouia—Barbour, 1935:129 (part). Mabuya mabouya mabouya—Dunn, 1936:544 (part). Mabuya mabouia—Barbour, 1937:147 (part). Mabuya aenea—Underwood, 1963:83 (part). Mabuya mabouya mabouya—Peters & Donoso-Barros, 1970:200 (part). Mabuya mabouya mabouya—Schwartz & Thomas, 1975:141 (part). Mabuya mabouya mabouya—MacLean et al., 1977:40–41 (part). Mabuya mabouya mabouya—Schwartz & Henderson, 1988:150 (part). Mabuya mabouya mabouya—Schwartz & Henderson, 1991:457 (part). Mabuya bistriata—Powell et al., 1996:82 (part). Mabuya bistriata—Murphy, 1997:150 (part). Mabuya sloanii—Mayer & Lazell, 2000:883 (part). Mabuya mabouya—Miralles, 2005:49 (part?). Mabuya nigropunctata—Miralles et al., 2005:833 (part). Mabuya nigropunctata—Miralles et al., 2009:609 (part). Mabuya mabouya—Henderson & Powell, 2009:292 (part).
Distribution. Copeoglossum aurae sp. nov. is distributed on Grenada, St. Vincent, the Grenadines (Bequia, Carriacou, Mustique, Petit Martinique, and Union Islands), Trinidad (including Huevos Island), and Tobago (Fig. 11D, I–J). The Union Island record is based on image identification (Fig. 25D). A DNA sequence from an uncataloged specimen collected on the nearby Peninsula de Paria (Sucre, Venezuela), reported by Miralles and Carranza (2010), clusters with this species in our tree (Fig. 5), indicating that the species also occurs on the mainland, possibly restricted to that peninsula. Previous distributional data in the literature (Murphy 1997; Daudin & de Silva 2007) cannot be used because it confounds C. aurae sp. nov. and Marisora aurulae sp. nov.
Ecology and conservation. No ecological information is available specifically for this species. Past ecological information reported for skinks from Trinidad and Tobago, summarized in Murphy (1997), probably confounds Copeoglossum aurae sp. nov. and Marisora aurulae sp. nov. In those reports, skinks were noted as occurring in a diversity of habitats, including rainforest, forest edge, coconut trash, and cultivated and disturbed areas. In the Grenadines, skinks have been found usually on the ground "in woody underbrush and between cacti" and climbing among cacti and on tree trunks (Daudin & de Silva 2007). According to Barbour (1937), skinks were already extirpated from the large islands of St. Vincent and Grenada by 1937, by the introduced mongoose. However, one specimen of C. aurae sp. nov. was collected in 1964 at Tempe, Grenada. Many herpetologists have visited Grenada and St. Vincent in the last four decades and no sightings of skinks have been reported. Circumstantial evidence suggests that black rats (Rattus rattus) are also predators, and these are on many islands. Skinks have not been extirpated from Trinidad, despite the presence of the mongoose on that island. In the past, Trinidad has had geological connections with South America and has a continental mammalian fauna that included natural predators of skinks, which may explain how they have survived (Murphy 1997). We identified more than twice as many specimens in museums of C. aurae sp. nov. than of Marisora aurulae sp. nov., suggesting that C. aurae sp. nov. is the more abundant species of the two. Now that these two species have been identified and described, studies are needed to assess their ecological relations and further clarify their conservation status. Based on IUCN Redlist criteria (IUCN 2011), we assess the conservation status of Copeoglossum aurae sp. nov. as Vulnerable (VU A2ace). It faces a primary threat from the introduced mongoose, which has probably led to its extirpation on Grenada and St. Vincent. Secondary threats include habitat destruction from agriculture and urbanization, and predation from other introduced predators, including black rats. Studies are needed to determine if the species still exists on Grenada and St. Vincent, the health of any remaining populations, and threats to the survival of the species.
Marisora aurulae Hedges & Conn, 2012
Lesser Windward Skink
Mabuia agilis—Boulenger, 1887:191 (part). Mabuia aenea—Garman, 1887:53 (part). Mabuya aenea—Barbour, 1914:322 (part). Mabuya aenea—Barbour, 1930:105 (part). Mabuya mabouia—Barbour, 1935:129 (part). Mabuya mabouya mabouya—Dunn, 1936:544 (part). Mabuya mabouia—Barbour, 1937:147 (part). Mabuya aenea—Underwood, 1963:83 (part). Mabuya mabouya mabouya—Peters & Donoso-Barros, 1970:200 (part). Mabuya mabouya mabouya—Schwartz & Thomas, 1975:141 (part). Mabuya mabouya mabouya—MacLean et al., 1977:40–41 (part). Mabuya mabouya mabouya—Schwartz & Henderson, 1988:150 (part). Mabuya mabouya mabouya—Schwartz & Henderson, 1991:457 (part). Mabuya bistriata—Powell et al., 1996:82 (part); Murphy, 1997:150 (part). Mabuya sloanii—Mayer & Lazell, 2000:883 (part). Mabuya mabouya—Miralles, 2005:49 (part?). Mabuya falconensis—Miralles et al., 2009:609 (part). Mabuya mabouya—Henderson & Powell, 2009:292 (part).
Distribution. The species is distributed in the southern Lesser Antilles and on Trinidad and Tobago. Specifically, it occurs on Young's Island (off St. Vincent), the Grenadines (Mayero Island, Carriacou, and Petit Bateau in the Tobago Cays), Grenada, Trinidad, and Tobago (Fig. 11D, I–J).
Ecology and conservation. Because of confusion between this species and the sympatric species Copeoglossum aurae sp. nov., published ecological information on skinks from the region cannot be applied to either species with certainty. Past ecological information reported for skinks from Trinidad and Tobago, summarized in Murphy (1997), probably confounds C. aurae sp. nov. and Marisora aurulae sp. nov. In those reports, skinks were noted as occurring in a diversity of habitats, including rainforest, forest edge, coconut trash, and cultivated and disturbed areas. In the Grenadines, skinks have been found usually on the ground "in woody underbrush and between cacti" and climbing among cacti and on tree trunks (Daudin & de Silva 2007). Apparently this species, and C. aurae sp. nov., have been extirpated from the large islands of St. Vincent and Grenada (Barbour 1937), both of which have the introduced mongoose. The mongoose is present on Trinidad, although C. aurae sp. nov. has been collected there in recent years (Murphy 1997); it may have adapted to continental mammalian predators on that island. Photographs of that species confirm its recent presence in the Grenadines (Fig. 25D). However, the last date of collection for M. aurulae sp. nov. on any island, from material we examined, was 1967 (Trinidad), although two specimens from Tobago (ZFMK 62602–03), not examined here, were collected more recently. Black rats (Rattus rattus) are also likely predators, and these are on many islands. We identified more than twice as many specimens in museums of C. aurae sp. nov. than of M. aurulae sp. nov., suggesting that M. aurulae sp. nov., over the years, has been less frequently collected (for whatever reasons) than C. aurae sp. nov.
Based on IUCN Redlist criteria (IUCN 2011), and considering that this species has not been seen on any island within its range (except Tobago, which is mongoose-free) in nearly a half-century, we assess the conservation status of Marisora aurulae sp. nov. as Critically Endangered (CR A2ace). It faces a primary threat from the introduced mongoose, which has apparently led to its extirpation from Grenada and Trinidad, and near-extinction. A secondary threat is predation from other introduced mammals, including black rats. Studies are needed to determine if the species still exists, the health of any remaining populations, and threats to the survival of the species. Captive breeding programs should be considered, if the species still exists, because eradication of introduced mammalian predators is not possible on large islands.
Citation
Hedges, S.B & C.E, Conn. 2012. A new skink fauna from Caribbean islands (Squamata, Mabuyidae, Mabuyinae). Zootaxa 3288:1-244.
No comments:
Post a Comment