Abstract

LOPEZ-ALCAIDE, Saúl; GONZALEZ-SALAZAR, Constantino; MACIP-RIOS, Rodrigo  and  MARTINEZ-MEYER, Enrique. Using microhabitat thermal heterogeneity to avoid lethal overheating: an empirical approximation in reproductive oviparous and viviparous lizards. Rev. Mex. Biodiv. [online]. 2017, vol.88, n.3, pp.683-690. ISSN 2007-8706.  https://doi.org/10.1016/j.rmb.2017.07.005.

Global warming has been recognized as a great threat for biodiversity. Particularly, it has been predicted that temperature raise could be lethal for ectothermic species in tropical regions, because their physiological and ecological traits are linked to specific ranges of environmental temperatures. However, some species may have been exposed for decades at temperatures exceeding their maximum thermal limit for embryonic development. Understanding how these organisms have faced historical extreme temperatures will allow us to improve inferences of species responses to the expected temperature increase. Here, we assessed whether 2 lizards, Sceloporus horridus (oviparous) and Sceloporus stejnegeri (viviparous) have been exposed to potential lethal thermal regimes where they inhabit, and whether behavioral use of microhabitat thermal heterogeneity has enabled them to avoid overheating on their offspring. We found that historical, current, and future environmental temperatures exceed the maximum limit tolerated by developing embryos of both species. However, the available temperature at microhabitat level for viviparous and potential nesting places for oviparous lizards offer thermal refuges with temperatures lower than maximum threshold tolerated. Our data suggest that thermoregulatory behavior and nesting adjustments, jointly with microhabitat thermal heterogeneity might buffer damages of warmest environmental temperature expected on developing offspring of these 2 lizards.

Keywords : Behavioral and nesting responses; Overheating; Temperature rise; Thermal heterogeneity; Reproductive mode.

        · abstract in Spanish     · text in English     · English ( pdf )