Shrub avoidance by an open-adapted ground squirrel in a shrub-encroached environment

Area of Science:

• Ecology
• Wildlife Conservation
• Desert Ecology

Background:

• Habitat loss and degradation are primary drivers of wildlife population declines.
• Small mammals are ecologically significant but vulnerable to rapid environmental changes.
• The Harris' antelope squirrel (Ammospermophilus harrisii), a Sonoran Desert endemic, faces anthropogenic landscape alterations.

Purpose of the Study:

• To quantify resource selection in the Harris' antelope squirrel using radio telemetry.
• To understand how environmental changes may impact squirrel behavior and distribution.
• To inform conservation strategies for desert small mammals.

Main Methods:

• Radio collars were fitted to Harris' antelope squirrels (Ammospermophilus harrisii).
• Resource selection functions were analyzed at different spatial scales (third- and fourth-order selection).
• Selection for habitat features like cacti and shrubs was quantified relative to behavior and scale.

Main Results:

• Squirrels selected microsites with cacti and shrubs for burrowing and alarm calling (fourth-order selection).
• However, overall habitat selection within home ranges (third-order selection) showed avoidance of shrub patches.
• Differential selection indicates complex habitat use influenced by behavior and scale.

Conclusions:

• Shrub encroachment may negatively affect Harris' antelope squirrel behavior and habitat use.
• Understanding scale-dependent resource selection is crucial for predicting species responses to landscape change.
• Conservation efforts should consider the specific habitat needs of this endemic species.