Water is one of the most essential resources organisms need. Those living in deserts are faced with the challenges of conserving water in very dry environments, despite the beneficial cooling effects of evaporation of water through the skin. Organisms have met this challenge with some unique strategies. Being nocturnal reduces your exposure to the hot sun, some frogs will put themselves in a cocoon and bury themselves, others apply a wax like lipid layer, all to reduce the amount of water lost through evaporation across the skin. While there are these unique mechanisms, the question remains if desert dwelling organisms actually exhibit reduced rates of evaporative water loss.
In collaboration with several others from the University of CA, Riverside and Ohio State University, we set out to examine whether mammals from desert environments have reduced rates of total evaporative water loss (this includes water lost through the skin (cutaneous) and respiration). Gathering data from ~130 species of mammals, and using phylogenetic comparative methods, we found that desert dwelling mammals to exhibit reduced rates of total evaporative water loss. This result held when desert was treated as a categorical predictor (desert or mesic) or as a continuous trait by examining various climate variables the species inhabits (e.g., rainfall, aridity, or vapor pressure deficit). So, although these mammals live in the desert and need evaporation to help keep them cool, their rates are reduced compared to mammal species living in wetter environments. To read more check out the paper located in Physiological and Biochemical Zoology. Feel free to email for a reprint if you cannot access it.
Van Sant, M. J., C.E. Oufiero, A. Muñoz-Garcia, K.A. Hammond and J.B. Williams. 2012. A phylogenetic approach to total evaporative water loss in mammals. Physiological and Biochemical Zoology. 85: 526-532.