Evol Ecol Res 19: 61-70 (2018) Full PDF if your library subscribes.
Foraging efficiency in the face of predation risk:
a comparative study of desert rodents
Sara E. Emerson1, Burt P. Kotler2 and Franklin Sargunaraj2
1Department of Biology, CSU Stanislaus, Turlock, California, USA and 2Mitrani Department of Desert Ecology, Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Sede Boqer, Israel
Correspondence: S.E. Emerson, Department of Biology, CSU Stanislaus, 1 University Circle, Turlock, CA 95382, USA. email: email@example.com
Question: What is the adaptive significance of the heteromyid cheek pouch?
Organisms: Two heteromyid rodents (Merriam’s kangaroo rat, Dipodomys merriami, and desert pocket mouse, Chaetodipus penicillatus) from the Mojave Desert, and two gerbils (greater Egyptian gerbil, Gerbillus pyramidum, and Allenby’s gerbil, Gerbillus andersoni allenbyi) from the Negev Desert, Israel.
Site: An outdoor vivarium on the Sede Boqer campus of Ben-Gurion University of the Negev, Israel.
Methods: We measured foraging time in seed trays for heteromyids and gerbils. We also measured the number of trips to food patches, and giving-up densities (GUDs, the amount of seed left behind when an individual left a seed tray).
Predictions: We expected cheek pouches to confer improved heteromyid foraging efficiency by reducing the number of trips between food patches and caching sites. We further expected that, compared with the other species, kangaroo rats would be less inhibited by barn owls, by moonlight, and by risky microhabitats.
Results: The two heteromyid species harvested more food per trip than the two gerbil species. Kangaroo rats had lower GUDs than any other species, particularly in risky microhabitats and at the full moon. Harvest rate curves for greater Egyptian gerbils and kangaroo rats indicated that these two larger bodied species were more vigilant than the two smaller bodied species.
Conclusion: Adaptations such as body size and the external cheek pouch appear to allow kangaroo rats to manage risk and harvest food more effectively than smaller and non-heteromyid rodents.
Keywords: foraging efficiency, gerbil, giving-up density, heteromyid.
DOWNLOAD A FREE, FULL PDF COPY
IF you are connected using the IP of a subscribing institution (library, laboratory, etc.)
or through its VPN.
© 2018 Sara E. Emerson. All EER articles are copyrighted by their authors. All authors endorse, permit and license Evolutionary Ecology Ltd. to grant its subscribing institutions/libraries the copying privileges specified below without additional consideration or payment to them or to Evolutionary Ecology, Ltd. These endorsements, in writing, are on file in the office of Evolutionary Ecology, Ltd. Consult authors for permission to use any portion of their work in derivative works, compilations or to distribute their work in any commercial manner.
Subscribing institutions/libraries may grant individuals the privilege of making a single copy of an EER article for non-commercial educational or non-commercial research purposes. Subscribing institutions/libraries may also use articles for non-commercial educational purposes by making any number of copies for course packs or course reserve collections. Subscribing institutions/libraries may also loan single copies of articles to non-commercial libraries for educational purposes.
All copies of abstracts and articles must preserve their copyright notice without modification.