Shrubs lower construction and maintenance costs for burrowing central-place rodent foragers in a sandy habitat

Choosing a location for building a home base is an important decision for central-place foragers – animals that return to a fixed location after each foraging bout to feed, store their food, or raise their offspring. Factors influencing the decision of where to place the home base include the energetic costs for its construction and maintenance. Here, we examined the factors influencing this decision in a group of burrow-dwelling, central-place foraging desert rodents (gerbils). We focused on shrubs, the most prominent environmental feature in dune habitats, and the maintenance and construction costs of burrows by rodents inhabiting dunes. Based on a field experiment and a model, we found that shrubs moderate these costs, providing a favorable microhabitat for burrows. We further conducted a field survey to assess whether rodents prefer to build burrows near shrubs. This preference was confirmed, supporting our conclusion. Our study emphasizes the role of shrubs in the economics of constructing and maintaining a burrow, an effect that may influence the distribution of many burrow-dwelling animals. We also discuss other factors that may influence burrowing, generalizing the results for sand-dwelling burrowing animals.