Sound, P., F. W. Henkel, C. Langner & A. Seitz

Thermal ecology and habitat utilization of Rhacodactylus leachianus from New Caledonia (Squamata: Diplodactylidae). pp. 117-122.

Abstract. Five specimens (2 ♀, 3 ♂) of the gecko species Rhacodactylus leachianus were radio-tracked for 14 days on Île de Bayonnaise, New Caledonia. Using thermo-sensitive transmitters, specimens were mapped continuously every hour. All movements, behavioural expressions and core temperatures were manually recorded, while data loggers simultaneously recorded the temperatures of microhabitat structures. In an additional trial, all geckos captured on the island were marked with Passive Integrated Transponders (PITs): Twenty-two adults (13 ♀, 9 ♂) and one subadult were marked in total. The mapping of R. leachianus on this island was repeated during 2005, 2007 and 2013. Average core temperatures of 23.4°C (♀) and 24.1°C (♂) were recorded ranging of 18.2–32.0°C (♀) and 18.0–32.2°C (♂), respectively. No sex-dependent differences were noted, but a clear relation to the local air temperature was found. Gravid females showed higher core temperatures (by up to 3°C) during oviposition. The test for equality of variances showed differences between the core temperatures of both sexes and the air temperature, indicating the ability of both sexes for active thermoregulation. Although no strict territorial borders were noted, males were observed marking their territories vocally. The females showed no territorial behaviour. Home ranges varied between 551 and 3,464 m² for all specimens. Areas within which the geckos were active averaged around 5 m per night, with some rare instances of movements over up to 200 m in one night. We observed that females often left their preferred home ranges for nesting, usually laying their eggs in coastal dunes. We presume that this occurred in search of higher, more stable soil temperatures.

Key words. Gekkota, Île de Bayonnaise, life history, PITs, radio tracking, thermoregulation.