Patterns of host and flea communities along an elevational gradient in Colorado

Patterns in community composition across a landscape are the result of mechanistic responses and species interactions. Interactions between hosts and parasites have additional complexity because of the contingency of host presence and interactions among parasites. To assess the role of environmental changes within host and parasite communities, we surveyed small mammals and their fleas over a dynamic elevational gradient in the Front Range in Colorado, USA. Communities were characterized using several richness and diversity metrics and these were compared using a suite of frequentist and randomization approaches. We found that flea species richness was related to the number of host species based upon rarefaction, but no patterns in richness with elevation were evident. Values of diversity measures increased with elevation, representing that small-mammal and flea communities were more even upslope, yet turnover in composition was not related to examined variables. The results suggest there are strong local effects that drive these small-mammal and flea communities, although the breadth of flea species is tied to host availability.