Data from: Optimal foraging of Little Egrets and their prey in a foraging game in a patchy environment

We explored the behavioral game between a predator, the little egret (Egretta garzetta), and a prey, the common goldfish (Carassius auratus), in a laboratory theater containing three fish pools. We tested the hypotheses that the egrets maximize their total capture success by responding to the fish’s antipredatory behavior and that the behaviors of both players respond adaptively to the density distribution of fish among the pools. One experiment presented egrets with 15 fish per pool. The second experiment used a heterogeneous environment: pools 1, 2, and 3 had 10, 15, and 20 fish, respectively. Within each pool, fish could move between a safe, covered microhabitat and a risky, open microhabitat. Only the risky habitat had food, so fish were trading off food and safety by allocating the time spent in the two habitats. Egrets spent more total time in pools with more fish and returned to them sooner. Egrets maximized the number of fish they captured by following the matching rule of the ideal free distribution. The fish used the risky but productive habitat 65% of the time during experiments without egrets, but only 9% during experiments with 15 fish and egrets present somewhere in the theater. In addition, with egrets present, fish fine-tuned their behavior by reducing their use of the risky habitat as the egrets increased the frequency of their visits.本研究针对捕食者小白鹭（Egretta garzetta）与猎物普通金鱼（Carassius auratus）之间的行为博弈展开探究，实验设置了包含3个鱼池的实验室生态剧场。本研究验证了两项假说：其一，白鹭可通过响应鱼类的反捕食行为，最大化自身总捕获成功率；其二，博弈双方的行为均会适应性地响应各鱼池内的鱼类密度分布。第一项实验中，每个鱼池投放15尾鱼类。第二项实验采用异质性环境设置：1号、2号、3号鱼池分别投放10尾、15尾、20尾鱼类。在每个鱼池内部，鱼类可在带有遮蔽的安全微生境与开阔无遮蔽的风险微生境之间移动。仅风险微生境存在食物来源，因此鱼类需通过分配在两种微生境中的停留时间，在食物获取与生存安全之间进行权衡。白鹭会在鱼类密度更高的鱼池中花费更长总停留时间，且更快返回该类鱼池。白鹭通过遵循理想自由分布（ideal free distribution）的匹配法则，最大化了自身的捕获鱼类数量。在无白鹭参与的对照实验中，鱼类会将65%的时间用于风险但高产的微生境；而在投放15尾鱼类且实验室生态剧场内存在白鹭的实验组中，该比例仅为9%。此外，当白鹭存在时，随着白鹭到访频次提升，鱼类会通过降低对风险微生境的使用比例，对自身行为进行微调。