Intercontinental-wide consequences of compromise-breaking adaptations: the case of desert rodents

Abstract

Desert rodent assemblages from around the world provide convergent, but independent crucibles for testing theory and deducing general ecological principles. The heteromyid rodents of North America and the gerbils of the Middle East and their predators provide such an example. Both sets of rodents face predation from owls and vipers, but the North American species possess unique traits that may represent macroevolutionary breakthroughs: rattlesnakes have infra-red sensitive sensory pits, and heteromyids have cheek pouches. To test their significance, we brought together two gerbils (Middle East), two heteromyid rodents (a kangaroo rat and a pocket mouse; North America) in a common setting (a vivarium in the Negev Desert), and quantified the “opinions” of the rodents towards the North American sidewinder rattlesnake and the Middle Eastern Saharan horned viper and the foraging behavior of each in the face of these snake predators plus owl predators. Gerbils are fairly evenly matched in their anti-predator abilities, while the heteromyids differ widely, and these seem to match well with and may determine the types of mechanisms of species coexistence that operate in the communities of each continent. Evolutionary history, macroevolutionary traits, and risk management therefore combine to determine the characteristics of the organisms and the organization of their communities.

Keywords:

• intercontinental community convergence
• desert rodents
• risk management and tradeoffs of food and safety
• Predator–prey foraging games
• compromise-breaking adaptations
• macroevolution and microecology

Acknowledgements

This work is dedicated to Dr. Keren Embar, as is this entire issue. In many ways, it is our grandest work in community ecology, and so is the deepest tribute that we could pay her. Teaching her, advising her, working with her, and learning from her were unforgettable privileges. We hope that this article will help to keep her memory bright. Through the years, many, many people helped make this work possible. They worked with us, inspired us, challenged us, and taught us. Of these many, we especially would like to single out Michael L. Rosenzweig for helping to make us the evolutionary ecologists we aspire to be. This is publication number 891 of the Mitrani Department of Desert Ecology.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was generously supported by the Israel–United States Binational Science Foundation [BSF grant number 2008163] to Burt P. Kotler and Joel S. Brown.