Perching behavior

Fish avoid more vigorously the odor of predators that have fed on members of their species than that of those on different diets. For example, young Arctic chart avoid water from brown trout fed on Arctic chart and are less wary of that from pellet-fed trout (Hirvonen et ah, 2000). Prey fish also reduce their predator inspection behavior vis-a-vis predators that have eaten members of their own species. For instance, finescale dace, Phoxinus neogaeus, dash toward predators such as yellow perch, Percaflavescens, and withdraw. Dace inspect perch models less often if the model is accompanied by water from perch that had eaten dace than if accompanied hy water from perch on a swordtail, Xiphophorus hdleri, diet. Dace produce alarm pheromone, while swordtails do not. The Central American swordtails do not cooccur with finescale dace (Brown etal, 2001). 

E1 Arab AE, Attar A, Ballhom L, et al. 1990. Behavior of diazinon in a perch species. Chemosphere 21 193-199. 

Controlling chaos, even in the rather limited fashion described here, is a powerful and attractive notion. Showalter (1995) compares the process to the instinctive, apparently random motions of a clown as he makes precise corrections aimed at stabilizing his precarious perch on the seat of a unicycle. A small, but carefully chosen, variation in the parameters of a system can convert that system s aperiodic behavior not only into periodic behavior, but also into any of a large (in principle, infinite) number of possible choices. In view of the appearance of chaos in systems ranging from chemical reactions in the laboratory, to lasers, to flames, to water faucets, to hearts, to brains, our ability first to understand and then to control this ubiquitous phenomenon is likely to have major consequences. 

After three years of competition, the green lizards changed their behavior and perched twice as high in the trees. In 2010, the scientists returned and examined... 

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