Population and community dynamics and habitat selection of rodents in complex desert landscapes

Abstract

A review of population and community dynamics and habitat selection of rodents in complex desert landscapes is presented. Population dynamics of rodents in all deserts are driven mainly by resource pulses induced by rainfall events. In a long-term perspective, this pattern is sometimes interrupted by rare extreme weather events and by habitat transformation due to wildfire or climate change. Rainfall-population density relations were found to be modified by intrinsic (population autoregulation, habitat selection) and extrinsic (interspecific competition, predation) processes, but the relative importance and geographic specificity of these processes are unclear. Density-dependent habitat selection was found in all studied desert rodent species inhabiting more than one habitat. Density-dependent habitat selection was expressed in different types of population regulation, resulting in density-dependent or density-independent habitat distribution. However, processes of density-dependent habitat selection have been studied in only one region; there are no data yet to analyze how different strategies of habitat selection vary among different desert regions. Dynamics of community composition include one widely distributed pattern, an increase in species richness with density. Another pattern, zero-sum community dynamic, was found in North American deserts. Dynamics of the niche community structure is expressed in the increase of niche overlap with density growth. In Palaearctic deserts, this increase in niche overlap was accompanied by stronger aggregation of niches in spatial guilds. The last phenomenon was not recorded in North American deserts, which reflects differences in expression of spatial guilds between Palaearctic and Nearctic rodent communities.