Summer distribution patterns of southern resident killer whales Orcinus orca:: core areas and spatial segregation of social groups
Summer distribution patterns of southern resident killer whales Orcinus orca:: core areas and spatial segregation of social groups
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DOI：
10.3354/meps07117
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发表时间：
2007-01-01
影响因子：
2.5
通讯作者：
Osborne, Richard W.
中科院分区：
文献类型：
--
作者：
Hauser, Donna D. W.;Logsdon, Miles G.;Osborne, Richard W.
多种多样的海洋野生动物物种对动态环境和零散资源作出反应，其分布模式各不相同。对于许多鲸类物种来说，高度结构化的社会系统增加了模拟分布模式和理解对种群生存能力影响的复杂性。南方居民虎鲸Orcinus orca由3个不同的，但有凝聚力的，母系相关的社会群体组成，称为豆荚，最近的人口下降促使美国和加拿大采取保护行动，包括列为濒危物种。栖息地保护是每个列表的一个主要组成部分，但很少有人知道豆荚特定的核心区域或空间使用模式为这一人口。使用6年内的近岸沃茨的华盛顿和不列颠哥伦比亚省的目击信息，我们模拟豆荚特定的夏季分布和测量的相对变化密度的目击一个统一的空间网格。我们的研究结果表明，豆荚表现出复杂的，不均匀的夏季空间使用模式。虽然有些区域是所有pod共同使用的，但有些区域几乎只被单个pod或某些pod组合使用，这表明特定区域的专业化。我们的研究结果表明，豆荚组显示可变的空间利用模式，因此，每个豆荚可能会遇到独特的栖息地条件或暴露于潜在的风险因素。当考虑豆荚特定的死亡率和每个豆荚对总体种群趋势的相对贡献时，这一结果是高度相关的。我们的分析突出了保护的重要领域，并提供了必要的描述豆荚为重点的保护措施。
A diverse range of marine wildlife species respond to dynamic environments and patchy resources with variations in their distribution pattern. For many cetacean species, highly structured social systems add to the complexity of modeling distribution patterns and understanding the effects on population viability. Southern resident killer whales Orcinus orca are comprised of 3 distinct, yet cohesive, matrilineally related social groups called pods, and recent population declines have prompted conservation actions in the US and Canada, including listings as an endangered species. Habitat protection is a major component of each listing, yet little is known about pod-specific core areas or patterns of space use for this population. Using 6 yr of sighting information within the inshore waters of Washington and British Columbia, we modeled pod-specific summer distribution and measured relative variation in the density of sightings on a uniform spatial grid. Our results indicate that the pods exhibit complex, non-uniform summer space-use patterns. Although some regions are used in common by all pods, some areas are used almost exclusively by individual pods or certain combinations of pods, indicating specialization to particular areas. Our results indicate that pod groups display variable patterns of space use; therefore, each pod may experience unique habitat conditions or exposure to potential risk factors. This result is highly relevant when considering pod-specific mortality rates and the relative contribution of each pod to overall population trends. Our analyses highlight important areas of conservation, and provide the necessary description for pod-focused conservation initiatives.