Meeting Abstract
Animal coloration can influence multiple aspects of performance. Therefore, color evolution is likely to be mediated by a balance of selection on multiple functions. The White Sands Desert is home to three lizard species that have independently evolved blanched coloration relative to the ancestral color of adjacent dark soil populations. Blanched coloration in the White Sands is thought to be an adaptation to avoid predation via increased background matching. However, it is also likely to have thermal consequences for White Sands lizards by changing the amount of solar radiation they absorb. Are these thermal effects beneficial, detrimental, or neutral? We applied a biophysical modeling approach to estimate the effects of coloration on operative thermal environments and temperature-dependent physiological and behavioral performance. Relative to ancestral coloration, we found that blanched coloration reduces the annual number of hours with overheating risk by 20%. However, relative to ancestral coloration, blanched coloration also reduces the annual number of hours that activity can be achieved within the preferred temperature range, though by only 3%. Our results indicate that the blanched coloration of White Sands lizards has thermal consequences, some of which are positive (reducing overheating risk) and some of which are negative (reducing activity). Therefore, multiple ecological forces may have contributed to color evolution in this system.
