Multiple foraging strategies in a marine apex predator, the Galapagos sea lion Zalophus wollebaeki
Multiple foraging strategies in a marine apex predator, the Galapagos sea lion Zalophus wollebaeki
复制标题
海洋顶级捕食者加拉帕戈斯海狮 Zalophus wollebaeki 的多种觅食策略
DOI：
10.3354/meps07457
复制
发表时间：
2008
影响因子：
2.5
通讯作者：
D. Aurioles‐Gamboa
中科院分区：
文献类型：
--
作者：
S. Villegas;D. Costa;Y. Tremblay;Sandie K. Salazar;D. Aurioles‐Gamboa
呼吸空气的海洋脊椎动物有三种基本的觅食模式：上层、中层和底栖。许多海狮物种可以进入广阔的大陆架，被描述为底栖觅食者。这些物种被认为是受威胁的。加拉帕戈斯海狮Zalophus wollebaeki是加拉帕戈斯群岛的顶级捕食者，也被认为是这一生态系统的威胁。群岛中部的海狮可以进入广阔的大陆架。出于这个原因，我们假设这一地区的海狮会潜入海底。此外，有效的保护和养护这一物种需要他们的觅食模式和栖息地利用的知识。本文对雌性中华绒螯蟹的潜水行为和栖息地利用进行了研究。利用时间深度记录器和卫星遥测技术，对位于人口密度最高地区内的一个中心殖民地wollebaeki进行了调查。三种不同的觅食模式被发现和描述（浅，深和底部潜水员），和个人利用每种模式觅食在不同的位置。在海狮的潜水行为中，海洋层、中层和底栖潜水都有表现，但这些潜水类型并不完全与觅食模式有关。在觅食之旅之间，雌性在其他岛屿上比在繁殖地更频繁地外出。3个不同的觅食模式，不同的空间发现有直接的影响管理，特别是在渔业的相互作用。海洋保护区可以在Z. wollebaeki觅食区。Z.在未来的研究中，当确定觅食行程长度和栖息地利用率时，应考虑Wolle-baeki的广泛觅食范围以及它们使用多个搬运地点，因为殖民地的存在/不存在并不反映觅食行程长度。
Three fundamental foraging patterns in air-breathing marine vertebrates have been described: epipelagic, mesopelagic and benthic. Many sea lion species with access to extensive con- tinental shelves have been described as benthic foragers. Coincidently these species are considered threatened. The Galapagos sea lion Zalophus wollebaeki, a top predator in the Galapagos Islands, is also considered threatened in this ecosystem. Sea lions at the central part of the archipelago have access to a vast continental shelf. For this reason we hypothesized that sea lions within this region would dive benthically. In addition, effective protection and conservation of this species requires knowledge of their foraging patterns and habitat utilization. We investigated the diving behaviour and habitat utilization of female Z. wollebaeki of a centrally located colony situated inside the high- est density area of the population using time-depth recorders and satellite telemetry. Three distinct foraging patterns were found and described (shallow, deep and bottom divers), and individuals uti- lizing each pattern foraged in different locations. Epipelagic, mesopelagic and benthic dives were exhibited in the sea lions' diving behaviour, but these dive types were not exclusively associated with a foraging pattern. Between foraging trips females hauled out more frequently on other islands than they did on their breeding colony. The finding of 3 distinct foraging patterns that differ spatially has direct implications for management, particularly with regard to fisheries interactions. Marine pro- tected areas can be implemented in the regions described as Z. wollebaeki foraging areas. Z. wolle- baeki's wide foraging range coupled with their use of multiple haul-out sites should be considered in future studies when determining foraging trip lengths and habitat utilization since presence/absence from the colony does not reflect foraging trip length.