Environmental factors affecting patch use in two species of gerbilline rodents

Examined the nocturnal, seed-eating desert rodents, Gerbillus allenbyi (Allenby's gerbil) and G. pyramidum (greater Egyptian sand gerbil), in a sand-dune habitat in the NW Negev Desert of Israel. Overall, there were significant positive correlations between giving-up densities and cloud cover, microhabitat, and moon phase. There were also significant negative correlations between giving-up densities and relative humidity, minimum overnight temperature, and the interaction between loud cover and moon phase. Patch use by gerbils was most intense (giving-up densities were lowest) in the bush microhabitat and on warm, damp, and dark nights. Warm nights may represent lower metabolic costs of foraging, damp nights may represent greater ease of foraging because of heightened olfaction, and dark nights and the bush microhabitat may represent reduced predatory risk in time and space, respectively. -from Authors