Temporal changes in species composition affect a ubiquitous species' use of habitat patches.

Ellen K Bledsoe,S K Morgan Ernest

doi:10.1002/ecy.2869

Abstract

Across landscapes, shifts in species composition often co‐occur with shifts in structural or abiotic habitat features, making it difficult to disentangle the role of competitors and environment on assessments of patch quality. Using over two decades of rodent community data from a long‐term experiment, we show that a small, ubiquitous granivore (Chaetodipus penicillatus) shifted its use of different experimental treatments with the establishment of a novel competitor, C. baileyi. Shifts in residency, probability of movement between patches, and the arrival of new individuals in patches altered which treatment supported the highest abundances of C. penicillatus. Our results suggest that the establishment of a new species worsened the quality of the originally preferred treatment, likely by impacting resource availability. Paradoxically, the presence of the new species also increased C. penicillatus’ use of the less preferred treatment, potentially through shifts in the competitive network on those plots.

Highlights

Species often exist in landscapes consisting of a patchwork of habitats, some of which are conducive to a species’ survival and reproduction and others which are less suitable
Our results suggest that the arrival of a congener changed perceptions of patch quality for one of the abundant rodent species in our ecosystem, C. penicillatus
Increases in new C. penicillatus individuals on the controls and declines in residency on kangaroo rat exclosures suggest that both of these mechanisms may have occurred with the arrival of C. baileyi, shifting patch use by C. penicillatus

Summary

Introduction

Species often exist in landscapes consisting of a patchwork of habitats, some of which are conducive to a species’ survival and reproduction and others which are less suitable. Changes in patch conditions can take place through time (Ernest et al 2008), resulting in patches that vary in their suitability for a species as conditions change. While many studies on habitat selection focus on differences between patches in structural habitat (e.g., vegetation structure) or abiotic conditions (e.g., temperature, soil conditions), species density and composition can affect patch preference (Grant 1971, Morris 1989, Danielson & Gaines 1987, Abramsky et al 1992).

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Results

Conclusion