Spatial and Temporal Changes in Habitat Heterogeneity Promote Partition of Resources of Small Mammals in a Midlatitude Temperate Forest

Abstract One basic issue in ecology is to understand how seasonal spatiotemporal shifts in habitat heterogeneity shape spatial patterns in the distribution and coexistence of organisms. For example, how do spatial dispersion of syntopic species reflects their respective resource preferences and partition, during microhabitat seasonal shifts? To address this, we assessed changes in microhabitat structure heterogeneity, between the two annual seasons (dry and rainy seasons) in a midlatitude temperate forest by analyzing 23 habitat variables using multivariate statistics. Furthermore, to determine how such microhabitat changes affected the spatial segregation of two congeneric species of small mammals (Peromyscus difficilis, P. melanotis), we used second-order spatial statistics to detect changes in their microdistribution changes and general linear models to evaluate their habitat preferences. In accordance with their respective morphology and ambulatory habits, the medium-sized, semi-scansorial P. difficilis was resident year-round and preferred microhabitats with high amounts of log ground cover, while the small, opportunistic, cursorial P. melanotis varied its occupancy area depending on the density of herbaceous and cover of woody plants. Both species showed more similar microdistribution patterns under the more benign microhabitat conditions of the rainy season (denser plant coverage, humid-cool weather), but became more segregated form each other during the less favorable conditions of the dry season (scarcer plant coverage, dry-cold weather). Therefore, seasonal changes in microhabitat heterogeneity influenced the dispersion patterns of both Peromyscus species and revealed their temporal preferences for microhabitat resources. Footnotes All text has changed