Vardi Reut, Abramsky Zvika, Kotler Burt P, Altstein Ofir, Rosenzweig Michael L
Department of Life Sciences, Ben-Gurion University of the Negev, P.O.B 653, 84105, Beer Sheva, Israel.
Mitrani Department of Desert Ecology, Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, 84990, Midreshet Ben-Gurion, Israel.
Oecologia. 2017 Jul;184(3):597-607. doi: 10.1007/s00442-017-3884-6. Epub 2017 May 17.
Behavioral games predators play among themselves may have profound effects on behavioral games predators play with their prey. We studied the behavioral game between predators and prey within the framework of social foraging among predators. We tested how conspecific interactions among predators (little egret) change the predator-prey behavioral game and foraging success. To do so, we examined foraging behavior of egrets alone and in pairs (male and female) in a specially designed aviary consisting of three equally spaced pools with identical initial prey (comet goldfish) densities. Each pool was comprised of a risky microhabitat, rich with food, and a safe microhabitat with no food, forcing the fish to trade off food and safety. When faced with two versus one egret, we found that fish significantly reduced activity in the risky habitat. Egrets in pairs suffered reduced foraging success (negative intraspecific density dependence) and responded to fish behavior and to their conspecific by changing their visiting regime at the different pools-having shorter, more frequent visits. The time egret spent on each visit allowed them to match their long-term capture success rate across the environment to their capture success rate in the pool, which satisfies one aspect of optimality. Overall, egrets in pairs allocated more time for foraging and changed their foraging tactics to focus more on fish under cover and fish 'peeping' out from their shelter. These results suggest that both prey and predator show behavioral flexibility and can adjust to changing conditions as needed in this foraging game.
食肉动物之间进行的行为博弈可能会对它们与猎物之间的行为博弈产生深远影响。我们在食肉动物的社会觅食框架内研究了食肉动物与猎物之间的行为博弈。我们测试了食肉动物（小白鹭）之间的种内相互作用如何改变捕食者 - 猎物行为博弈以及觅食成功率。为此，我们在一个专门设计的鸟舍中观察了白鹭单独和成对（雄性和雌性）的觅食行为，鸟舍中有三个等距的水池，初始猎物（彗星金鱼）密度相同。每个水池都由一个食物丰富的危险微生境和一个没有食物的安全微生境组成，迫使鱼在食物和安全之间进行权衡。当面对两只白鹭和一只白鹭时，我们发现鱼在危险栖息地的活动显著减少。成对的白鹭觅食成功率降低（种内负密度依赖性），它们通过改变在不同水池的访问模式来应对鱼的行为和它们的同种个体——访问时间更短、更频繁。白鹭每次访问所花费的时间使它们能够使整个环境中的长期捕获成功率与水池中的捕获成功率相匹配，这满足了最优性的一个方面。总体而言，成对的白鹭分配更多时间觅食，并改变觅食策略，更专注于隐蔽处的鱼和从藏身之处“探出头”的鱼。这些结果表明，猎物和捕食者都表现出行为灵活性，并且能够在这种觅食博弈中根据需要适应不断变化的条件。
