Ecophysiology of a lacertid community in the high Moroccan mountains suggests conservation guidelines.

Lizard species may differ in their ecophysiology due to adaptation, plasticity and/or phylogeny. In restrictive environments, ecophysiological differences of species living in sympatry are expected to reveal long-term evolutionary responses to the abiotic environment while competitive interactions should be limited. These influences can be disentangled by combining field monitoring with experimental tests. Here, three lacertid lizard species, Atlantolacerta andreanskyi, Scelarcis perspicillata and Podarcis vaucheri sharing high mountain habitats in Oukaimeden (High Atlas, Morocco), were studied. In the field, spatiotemporal variation of the thermal and hydric environment used by the lizards was monitored using data-loggers. In the lab, thermal and hydric ecophysiology was estimated through assessments of preferred temperatures (Tp) and water loss (WL) rates. Species differed in microhabitat use and, hence, in their exposure to variations in temperature and humidity. However, they only differed in their WL (A. andreanskyi > S. perspicillata > P. vaucheri) while their Tp were similar. Such partial differences of species in in the fundamental niche, likely derived from their long-term independent phylogenetic trajectories, can be used to predict their responses to climate and habitat shifts in this and other parts of their respective ranges. Results also confirm previous suggestions that, together with thermal physiology, hydric physiology plays a prominent role in the organisation of lizard communities in the temperate region.

Environmental temperatures shape thermal physiology as well as diversification and genome-wide substitution rates in lizards.

Climatic conditions changing over time and space shape the evolution of organisms at multiple levels, including temperate lizards in the family Lacertidae. Here we reconstruct a dated phylogenetic tree of 262 lacertid species based on a supermatrix relying on novel phylogenomic datasets and fossil calibrations. Diversification of lacertids was accompanied by an increasing disparity among occupied bioclimatic niches, especially in the last 10 Ma, during a period of progressive global cooling. Temperate species also underwent a genome-wide slowdown in molecular substitution rates compared to tropical and desert-adapted lacertids. Evaporative water loss and preferred temperature are correlated with bioclimatic parameters, indicating physiological adaptations to climate. Tropical, but also some populations of cool-adapted species experience maximum temperatures close to their preferred temperatures. We hypothesize these species-specific physiological preferences may constitute a handicap to prevail under rapid global warming, and contribute to explaining local lizard extinctions in cool and humid climates.