Establishment of the Common House Gecko, Hemidactylus frenatus (Duméril & Bibron), on Saba, Dutch Caribbean

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).