SICB 2017: Thermal Ecology and Invasion Biology: Anolis cristatellus Invades Dominica

Jeanel Georges with her poster at SICB.

Jeanel Georges with her poster at SICB.

The beautiful island of Dominica used to be home to only one anole (Anolis oculatus), but about 20 years ago, the Puerto Rican crested anole (Anolis cristatellus) showed up. Jeanel Georges, a graduate student in Matt Watson’s lab at Midwestern State University in Wichita Falls, Texas who is originally from Dominica, noticed that while A. oculatus occurs in all the ecological zones of the island, A. cristatellus is absent from the cooler, wetter uplands. With an international group of collaborators, Jeanel examined the thermal habitat use, sprint speed, and bite force of both species to determine what may limit the spread of A. cristatellus across the island.

At a lowland site where the two species co-occur, both species had higher body temperatures that the operative temperatures randomly available in the environment. In the much cooler upland site, A. oculatus had much higher body temperatures than the operative models, but these body temperatures were cooler than that species experiences in the lowland site. Jeanel also found that the two species had stronger bite forces and higher sprint speeds in the lowland site than A. oculatus had in the upland site. These data suggest that A. cristatellus and A. oculatus are partitioning the thermal environment of Dominica, and as climate change alters the temperatures available to lizards on the island, the interactions between these two species may change.

4 thoughts on “SICB 2017: Thermal Ecology and Invasion Biology: Anolis cristatellus Invades Dominica

    1. When last there in ’08, cristatellus was quite common (and oculatus pretty much absent) along the leeward coast from just south of Roseau to a little bit north of St. Joseph. We also repeatedly saw a single adult male on the fence or an adjacent tree at the entrance to Cabrits National Park (probably a hitchhiker). I’m guessing (and Jeanel could certify) that the invaders are probably found all along the leeward coast these days, have probably moved up into some of the lower valleys, and might even be spotty on the windward side of the island. I fear only the upland populations of oculatus are safe.

      1. Cristatellus seems to have established itself along both windward and leeward coasts. Interestingly, the two species appear to be coexisting in north-west and along the east coast at the sites we visited…but I say this is the absence of population density data.

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