Gilbert-Norton Lynne B, Shahan Timothy A, Shivik John A
Department of Wildland Resources, Utah State University, Logan, UT 84322, United States.
Behav Processes. 2009 Oct;82(2):178-83. doi: 10.1016/j.beproc.2009.06.005. Epub 2009 Jun 23.
Environmental change is accelerating due to anthropogenic influence. Species that have greater behavioral flexibility may be better adapted to exploit new or constantly changing habitats. There are few mammals and even fewer carnivores that better illustrate widespread adaptability and behavioral flexibility in the wake of human disturbance than coyotes (Canis latrans). Yet how such predators successfully track resources, enabling them to survive and extend their range in stochastic environments remains unknown. We tested eight wild-born, captive coyotes individually on an operant two-choice test using concurrent variable interval (VI) schedules. We held the overall rate of reinforcement constant but manipulated the ratio of reinforcement available from the two choices. We analyzed sensitivity of coyotes' tracking of resource change by fitting the generalized matching equation to the data. Results showed all coyotes efficiently tracked changes in reinforcement ratios within the first few sessions of each new condition and matched their relative rate of foraging time to relative rate of resources. We suggest the matching paradigm provides a methodology to explore coyote foraging strategies, and a potential framework to compare behavioral flexibility across species, by measuring the ability to track resource change under variable resource conditions.
由于人为影响，环境变化正在加速。具有更大行为灵活性的物种可能更善于利用新的或不断变化的栖息地。在人类干扰之后，很少有哺乳动物，甚至更少的食肉动物比郊狼（犬属）更能体现出广泛的适应性和行为灵活性。然而，这类捕食者如何成功追踪资源，从而使其在随机环境中生存并扩大其活动范围，仍然未知。我们使用并发可变间隔（VI）时间表，对八只野生出生的圈养郊狼分别进行了操作性双选测试。我们保持总体强化率不变，但操纵了两种选择中可获得的强化比例。我们通过将广义匹配方程拟合到数据中，分析了郊狼追踪资源变化的敏感性。结果表明，所有郊狼在每个新条件的最初几个实验环节中都能有效地追踪强化比例的变化，并将其相对觅食时间率与资源相对率相匹配。我们认为，匹配范式提供了一种探索郊狼觅食策略的方法，以及一个通过测量在可变资源条件下追踪资源变化的能力来比较物种间行为灵活性的潜在框架。
