Giving their all for their offspring: physiological trade-offs in an Andean-Patagonian viviparous lizard in response to global warming

Abstract

Global warming threatens biodiversity, particularly affecting ectothermic animals, which must seek refuge to avoid overheating when ambient temperatures exceed their critical thresholds. Extended shelter use limits the time for essential activities such as foraging, social interactions, and reproduction, potentially reducing survival and increasing local extinction risk. Viviparous Liolaemids inhabiting cold-temperate Andean regions are considered vulnerable to rising temperatures and are predicted to experience local extinctions this century. We evaluated the effects of thermal restriction on pregnancy outcomes and offspring in the viviparous lizard Liolaemus pictus under two conditions. One group of pregnant females experienced simulated future thermal restrictions (restriction group, RG; n=12), while another group experienced identical laboratory conditions without thermal restrictions (no-restriction group, NRG; n=14). In RG females, 41.7% were removed due to feeding cessation or spontaneous abortions (vs. 12.3% in NRG), reflecting the consequences of thermal restriction. The remaining RG females selected lower preferred body temperatures after two weeks of experimentation and maintained a stable body condition throughout pregnancy. However, both groups of offspring showed similar body condition and locomotor performance, suggesting physiological compensation by RG females. This physiological plasticity of L. pictus may help buffer the adverse effects of global warming on reproductive success.