Dissertation Research: Why Animals Form Groups: Predator Avoidance Versus Foraging Success in Fiddler Crabs

9701063为什么动物是群体是社会生物学领域的中心问题。 研究人员提出了五个模型来解释为什么社会聚合的形成。 其中三个表明群体的形成是因为它们帮助保护群体成员免受捕食者的伤害。 从数学上讲，群体成员应该降低每个个体被捕食的风险，而牺牲邻居的利益。 相反，许多实验表明，在捕食者的攻击过程中，一个群体的快速分散可以通过混淆捕食者和让猎物逃跑来降低捕食的风险。 其他研究表明，群体中捕食的风险降低，因为有更多的眼睛来观察可能的危险。 另外两个解释社会聚集的模型表明，群体的形成会增加每个成员寻找食物的能力。 实验表明，许多动物能够观察彼此的行为，并从彼此那里了解良好的食物来源，而且在大群体中这种机会比在小群体中更高。 此外，较大的动物群体往往比较小的群体走得更直，数学上已经表明，这将导致进入原始、未觅食地区的可能性增加。 为了测试这五个模型，本研究将研究定期形成大型集群的穴居甲壳类动物的群体形成，并且在沿海沼泽中数量非常多。 使用现场实验，直接观察和视频记录的计算机分析，将确定哪种模型最好地解释了为什么动物形成群体。

9701063 Wethey Why animals for groups is central question in the field of sociobiology. Researchers have proposed five models to explain why social aggregations form. Three of these suggest that groups form because they help protect group members from predators. Mathematically, group membership should lower the risk of predation to each individual at the expense of its neighbors. Conversely, many experiments have demonstrated that rapid scattering of a group during a predator's attack can decrease the risk of predation by confusing the predator and allowing the prey to escape. Other work has shown that predation risk is decreased in groups because there are more sets of eyes to watch for possible danger. The other two models that explain social aggregation suggest that group formation would increase each member's ability to find food. Experiments have demonstrated that many animals are capable of watching each other's behavior and learning about good food sources from one another, and the opportunity for this would be higher in large groups than in small ones. Additionally, larger groups of animals tend to move in straighter lines than smaller groups, and it has been shown mathematically that this will lead to an increased likelihood of entering pristine, un-foraged areas. To test these five models, this study will examine group formation in burrow-building crustaceans that regularly form large flocks, and are extremely numerous in coastal marshes. Use of field experiments, direct observations, and computer analysis of video recordings, will determine which model best explains why animals form groups.