PREDATION RISK AND THE FORAGING BEHAVIOR OF COMPETING STREAM INSECTS
PREDATION RISK AND THE FORAGING BEHAVIOR OF COMPETING STREAM INSECTS
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DOI：
10.2307/1938114
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发表时间：
1989-12-01
期刊：
影响因子：
4.8
通讯作者：
MCPEEK, MA
中科院分区：
文献类型：
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作者：
KOHLER, SL;MCPEEK, MA
在密歇根州[美国]的冷水溪中，吃石头上生长的附着生物的无脊椎动物最有可能被底栖动物捕食（斑点杜父鱼，白杜父鱼），而在基质的顶部表面，附着生物最丰富，白天，杜父鱼觅食最活跃。我们进行了实验室实验，幼虫的两个强大的exoploitative竞争对手的附着生物（蜉蝣Baetis tricaudatus和石蛾Glossosoma nigrior），以测试是否以及如何影响他们的觅食行为的存在，杜父鱼时，杜父鱼不允许攻击猎物。我们纳入了四个实验因素的析因设计：杜父鱼的存在/不存在，丰富（低，高）或食物，斑块分布在上表面或基板，食草动物饥饿水平（美联储，饥饿），和一天的时间（白天，晚上）。在饲养试验中，Baetis比Glossosoma更容易受到杜父鱼的捕食。同样，只有贝提斯的觅食行为受到杜父鱼的强烈影响。Baetis幼虫对杜父鱼的反应是：（1）显着减少在基质顶面上的时间，以及在食物斑块内和之间移动时的移动速率，（2）显着增加在食物斑块中的时间比例，以及通过向下游漂流离开基质的个体比例。当顶部的食物丰富度高且幼虫饥饿27 h时，Baetis幼虫接受更大的捕食风险（通过在顶部花费更多时间）。此外，Baetis的行为强烈影响杜父鱼的存在在白天，但不是在晚上。总的来说，这些结果表明，Baetis幼虫之间的适应性妥协进食和避免杜父鱼。相比之下，舌体鱼的行为不受杜父鱼的存在。舌体类对食物密度和自身饥饿水平的变化反应最强烈。我们的研究结果表明，杜父鱼的存在，即使鱼不吃幼虫，可能间接影响的结果Baetis和Glossosoma之间的竞争相互作用，通过食草动物的差异行为反应的捕食者。
Invertebrates that graze periphyton growing on stones in coldwater streams in Michigan [USA] are at greatest risk of predation from a benthic-feeding fish (the mottled sculpin, Cottus baidi) while on the top surface of substrates, where periphyton is most abundant, and during the day, when sculpin feed most actively. We conducted laboratory experiments with larvae of two strong exoploitative competitors for periphyton (the mayfly Baetis tricaudatus and the caddisfly Glossosoma nigrior) to test if and how their foraging behavior was affected by presence of sculpin when sculpin were not allowed to attack prey. We incorporated four experimental factors in a factorial design: sculpin presence/absence, the abundance (low, high) or food that was patchily distributed on the top surface or substrates, grazer hunger level (fed, starved), and time of day (day, night). In feeding trials, Baetis was much more vulnerable than Glossosoma to sculpin predation. Similarly, only the foraging behavior of Baetis was strongly affected by the presence of sculpin. Baetis larvae responded to the presence of sculpin by: (1) significantly reducing the time spent on the top surface of substrates, and their movement rate while moving within and between food patches, and (2) significantly increasing the proportion of time spent in food patches, and the proportion of individuals that left the substrate by drifting downstream. Baetis larvae accepted greater risk of predation (by spending more time on top) when food abundance on top was high and when larvae had been starved for 27 h. Also, Baetis behavior was strongly affected by sculpin presence during the day but not at night. Collectively, these results suggest that Baetis larvae made adaptive compromises between feeding and avoiding sculpin. In contrast, Glossosoma behavior was not affected by the presence of sculpin. Glossosoma responded most strongly to alterations in food density and their own hunger level. Our results suggest that the presence of sculpin, even though the fish consumed no larvae, might indirectly affect the outcome of competitive interactions between Baetis and Glossosoma through the grazers'' differential behavior responses to the predator.