caribbean herpetology

The Curaçao Whiptail (Cnemidophorus murinus) (Squamata: Teiidae) was once considered to have two subspecies, C. m. murinus (endemic to Curaçao and Klein-Curaçao) and C. m. ruthveni (endemic to Bonaire and Klein-Bonaire), but the two are now considered separate species (Ugueto and Harvey 2010). Little has been published on the natural history of C. murinus. Most of the literature on the natural history of “C. murinus” actually pertains to C. ruthveni and includes studies on diet (Dearing and Schall 1992, Schall 1996), body temperature (Schall and Dearing 1994), metabolic expenditure (Bennett and Gleeson 1979), population density and energetics (Bennett and Gorman 1979), signaling behavior (Cooper et al. 2004), escape behavior (Cooper et al. 2003), and learning (Schall 2000). In contrast, published literature on C. murinus that deals with topics other than its taxonomy, morphology, and distribution is limited to a few notes on its parasites (Specian and Whittaker 1980), pathology (Hughes and Delis 2014), clutch size (van Buurt 2011), conservation (van Buurt 2006), and interactions with tourists (van Buurt 2011). Herein I add to the published knowledge of C. murinus with observations on diet and foraging.

A common response among lizards to the approach of a predator is to attempt to avoid detection by moving out of the predator’s view. This may involve moving to the opposite side of a twig or tree trunk, moving into a burrow, or moving into vegetation or other structures (McElroy 2019). Here, I report an unusual behavior to avoid detection in the Aruba Whiptail (Cnemidophorus arubensis), a teiid endemic to the island of Aruba. This behavior involves movement into a shadow in the open, with no further concealment.A common response among lizards to the approach of a predator is to attempt to avoid detection by moving out of the predator’s view. This may involve moving to the opposite side of a twig or tree trunk, moving into a burrow, or moving into vegetation or other structures (McElroy 2019). Here, I report an unusual behavior to avoid detection in the Aruba Whiptail (Cnemidophorus arubensis), a teiid endemic to the island of Aruba. This behavior involves movement into a shadow in the open, with no further concealment.

Three teiid species (Squamata: Teiidae) are endemic to the ABC islands (Aruba, Bonaire, and Curaçao) of the former Netherlands Antilles: the Aruba Whiptail (Cnemidophorus arubensis) of Aruba, the Bonaire Whiptail (C. ruthveni) of Bonaire and Klein-Bonaire, and the Curaçao Whiptail (C. murinus) of Curaçao and Klein-Curaçao. Before now, social displays have been described only for one of these three species: C. ruthveni (Baird et al. 2003). All three species engage in an arm-waving display that involves forelimb circumduction (Baird et al. 2003; van Buurt 2005; van Buurt 2011), which conveys social signals to conspecifics in some iguanian and lacertid lizard species (Carpenter et al. 1970; Verbeek 1972; Mitchell 1973). However, this behavior in the ABC island species of Cnemidophorus has not been shown to have a social function (Baird et al. 2003). Instead, experimental evidence demonstrates that in C. ruthveni it functions as a pursuit deterrent display that is performed in response to approaching humans, whom the lizard may view as potential predators (Cooper et al. 2004), although there are not yet any published reports of C. ruthveni performing the display in response to the approach of a non-human predator. My observations and those of others (van Buurt 2011) also confirm that in C. arubensis the display is performed in response to approaching humans.

The Common House Gecko (Hemidactylus frenatus) is recently being reported from multiple islands across the Lesser Antilles: Antigua, Dominica, St. Barthélemy, St. Eustatius, St. Kitts, St. Lucia, and St. Martin (Brisbane et al. 2021, Dewynter et al. 2022, Griffing et al. 2022, Thorpe 2022, Questel et al. 2023, Thibaudier et al. 2023, Lindsay et al. 2023). Here, we report on the establishment of the species on Saba, Dutch Caribbean.

On 27 November 2023, between 19.30–20.30 h, we surveyed buildings, walls, rock crevices and piles of wood, brick, concrete, and metal, including building supplies, on the Fort-Bay Road, adjacent to the Fort Bay harbor on Saba (17.61615, -63.25039). We found H. frenatus at eight locations along a 520-meter stretch of road, either on walls, next to the road between rocks, or between aforementioned materials. At each location one animal was captured, totaling four adults and four juveniles. The lamellae on the 4th and 5th digit were used to confirm species identity (Krysko and Daniels 2005). We collected one adult (Figure 1) that has been provided to Naturalis Biodiversity Center, Leiden, The Netherlands, for deposition in their collections. We note that Hemidactylus mabouia was also found at three sites within the 520-meter stretch, but never closer than ~30 meters to Hemidactylus frenatus, which is a known competitor of other gecko species (Petren & Case 1996).

Within the northern Lesser Antilles, the island of Saint Martin, including the Dutch part (St. Maarten, a constituent country of The Netherlands) and the French part (the Collectivity of Saint Martin), is considered the main hub for established non-native reptiles, currently numbering ten species (Table 1) (Dewynter et al. 2022; Thorpe 2022). The islands of Saba and St. Eustatius are special municipalities of The Netherlands and frequently trade with St. Maarten. During the last five years, several new non-native reptile species have been reported on Saba and St. Eustatius, which originate from the non-native populations already present on Saint Martin: the Green Iguana, Iguana iguana (van den Burg et al. 2018, 2022) on St. Eustatius, and the Brahminy Blindsnake, Indotyphlops braminus (van den Burg et al. 2021) and Smooth-scaled Tegulet, Gymnophthalmus underwoodi on Saba (van den Burg et al. 2021). It is believed that these newly established populations have been facilitated by poor biosecurity between the islands. Here, we describe the establishment of two species, G. underwoodi and the Common House Gecko, Hemidactylus frenatus, on St. Eustatius.

On the 14th of December, 2020, an individual of Lepidodactylus lugubris was found and photographed in Bonaire (Dutch Caribbean) by Hans Smulders in a garden at the following address: Sabadeco Shores 28 (12.198174, -68.302846), 16 m elevation. The animal was found around some potted plants. This species has not been reported previously from Bonaire (Behm et al. 2019).

The native herpetofauna of the Lesser Antillean island of Saba (13 km2; 17.63°N, -63.24°W) includes one snake, Alsophis rufiventris, and four species of lizards, Anolis sabanus, Iguana melanoderma, Sphaerodactylus sabanus, and Thecadatylus rapicauda (Powell et al. 2015). Here, we report the establishment of both Gymnophthalmus underwoo-di Grant, 1958 and Indotyphlops braminus (Daudin, 1803) on the island.

The Leeward Blindsnake (Antillotyphlops geotomus) is a near threatened species according to the IUCN Red list (Powell et al., 2016), and was known only to occur on Antigua, Barbuda, St. Kitts, and Nevis, where it is considered a native species (Thomas 1966). Here we report the discovery of A. geotomus on St. Eustatius, Caribbean Netherlands. We obtained a DNA sequence of the mitochondrial 16S rRNA gene from a specimen collected on St. Eustatius in 2018 using the primers 16Sar (5’-CGCCTGTTTATCAAAAACAT-3’) and 16Sbr (5’-CCGGTCTGAACTCAGATCACGT-3’) (Palumbi 1996). The sequence was deposited in Genbank (MT256921). Blast analysis of the sequence resulted in 100% and 99.8% identity to sequences in Genbank of A. geotomus from Nevis (KF993199) and Antigua (AF366789) respectively. A 98.5% identity match was found with its nearest relative Antillotyphlops monastus (AF366708, KF993209). This species identification (A. geotomus) is consistent with the absence of pigment on the underside of the tail, a diagnostic trait of A. geotomus compared with A. monastus (Thomas 1966). The collected specimen had a total length of 125 mm, although they are known to reach lengths of up to 213 mm (Hedges et al. 2014). Furthermore, St. Eustatius is geographically in close proximity to St. Kitts & Nevis, which lie on the same shallow submarine bank only to be separated by the sea after the last ice age. Therefore, A. geotomus is likely native to St. Eustatius and not introduced. The other snake known from the island is the Red-bellied Racer (Alsophis rufiventris, native).