Intraspecific interference among foraging blue crabs Callinectes sapidus:: interactive effects of predator density and prey patch distribution
Intraspecific interference among foraging blue crabs Callinectes sapidus:: interactive effects of predator density and prey patch distribution
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DOI：
10.3354/meps178069
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发表时间：
1999-01-01
影响因子：
2.5
通讯作者：
Hines, AH
中科院分区：
文献类型：
--
作者：
Clark, ME;Wolcott, TG;Hines, AH
利用超声波遥测技术，在精细时间尺度上研究了捕食者密度和猎物分布对河口重要捕食者觅食行为的交互影响。在不同密度和斑块分布的大型围隔环境中，对青蟹个体的活动和活动进行了监测。与激动性相关的损伤在蓝蟹中很常见，可能代价相当高。以天数为单位。以前的研究表明，蓝蟹在受到同种干扰的情况下会分散，有时会散布到猎物匮乏的地区。在本研究的几分钟到几小时的范围内，捕食者的密度和猎物的分布相互作用，影响蓝蟹的觅食行为和成功。当只有一个贻贝斑块可用时，高密度的蓝蟹通过直接的争斗相遇来干扰彼此的觅食，表现为争斗活动与觅食成功之间的负相关。相反，当猎物被分成两块时，高密度的蓝蟹明显分散在块之间，因此最大限度地减少了直接的竞争冲突。尽管螃蟹将每块斑块上的密度有效地减半，从而进一步减少了竞争相遇的发生，但它们在相当长的一段时间内并没有在实验斑块之间的被捕食者贫穷的地区避难。相反，当另一只同类个体靠近时，它们似乎会对不断变化的风险程度做出即时反应，离开蛤类斑块。
The interactive effects of predator density and prey distribution on the foraging behavior of an important estuarine predator were studied, at a fine temporal scale, using ultrasonic telemetry. The movement and agonistic activity of individual blue crabs Callinectes sapidus were monitored in large field enclosures, in which the density of crabs and the distribution of patches of bivalve prey Macoma balthica were varied. Agonism-related injury in blue crabs is common and may be quite costly. On a scale of days. blue crabs have been shown in previous studies to disperse, sometimes into prey-impoverished areas, in response to conspecific interference. On the scale of minutes to hours addressed in the present study, the density of predators and the distribution of their prey interacted to affect the foraging behavior and success of blue crabs. When only a single clam patch was available, blue crabs at high density interfered with each other's foraging by direct agonistic encounters, shown by an inverse correlation between agonistic activity and foraging success. Conversely, when prey were partitioned into 2 patches, blue crabs at high density apparently dispersed among the patches, thus minimizing direct agonistic clashes. Although crabs reduced the occurrence of agonistic encounters further than the 50 % attributable to their effectively halving their densities on each patch, they did not take refuge in the prey-impoverished areas between experimental patches for significant periods. Instead, they seemed to respond instantaneously to changing degree of risk by moving off the clam patch when another conspecific approached.