Foragers make decisions based on cues, information collected from their environment, processed into strategic behaviours. This information, processed in multiple regions of the brain, ultimately result in the production of stress hormones and visible changes in behaviour of animals - both reflexively to avoid depredation and strategically to avoid an encounter with the predator. In a common-garden experiment we tested how imperfect information from visual cues of a predator impacts foraging and apprehension of a desert rodent, the Egyptian gerbil (Gerbillus pyramidum).
View Article and Find Full Text PDFConstraint-breaking adaptations are evolutionary tools that provide a mechanism for incumbent-replacement between species filling similar ecological roles. In common-garden experiments, we exposed populations of two desert rodents to two different viper species, testing their ability to adjust to novel predators that use different hunting strategies. We aimed to understand whether both predators and prey with constraint-breaking adaptations actually manifest comparative advantage over their counterparts.
View Article and Find Full Text PDFForagers process information they gain from their surroundings to assess the risk from predators and balance it with the resources in their environment. Measuring these perceived risks from the perspective of the forager can produce a heatmap or their "fear" in the environments, a so-called "landscape of fear" (LOF). In an intercontinental comparison of rodents from the Mojave and Negev Deserts, we set to compare families that are used regularly as examples of convergent evolution, heteromyid and gerbilline respectively.
View Article and Find Full Text PDFAbstract: Prey strategically respond to the risk of predation by varying their behavior while balancing the tradeoffs of food and safety. We present here an experiment that tests the way the same indirect cues of predation risk are interpreted by bank voles, , as the game changes through exposure to a caged weasel. Using optimal patch use, we asked wild-caught voles to rank the risk they perceived.
View Article and Find Full Text PDFDesert communities world-wide are used as natural laboratories for the study of convergent evolution, yet inferences drawn from such studies are necessarily indirect. Here, we brought desert organisms together (rodents and vipers) from two deserts (Mojave and Negev). Both predators and prey in the Mojave have adaptations that give them competitive advantage compared to their middle-eastern counterparts.
View Article and Find Full Text PDFLandscapes of Fear (LOF), the spatially explicit distribution of perceived predation risk as seen by a population, is increasingly cited in ecological literature and has become a frequently used "buzz-word". With the increase in popularity, it became necessary to clarify the definition for the term, suggest boundaries and propose a common framework for its use. The LOF, as a progeny of the "ecology of fear" conceptual framework, defines fear as the strategic manifestation of the cost-benefit analysis of food and safety tradeoffs.
View Article and Find Full Text PDFIn environments where food resources are spatially variable and temporarily impoverished, consumers that encounter habitat patches with different food density should focus their foraging initially where food density is highest before they move to patches where food density is lower. Increasing missed opportunity costs should drive individuals progressively to patches with lower food density as resources in the initially high food density patches deplete. To test these expectations, we assessed the foraging decisions of two species of dasyurid marsupials (dunnarts: Sminthopsis hirtipes and S.
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