Overwintering Pacific salmon Oncorhynchus spp. are vulnerable to mortality. Ecosystem degradation exacerbates salmonid vulnerability to mortality; thus, knowledge of winter movement dynamics is essential for guiding holistic management and restoration to safeguard population viability. In northeast Oregon, long‐term population performance metrics (e.g., survival) exist for parr of two neighboring Chinook Salmon O. tshawytscha populations (Catherine Creek [CC] and Grande Ronde River [GRR]); however, knowledge of their winter ecology is lacking. Our objective was to spatiotemporally characterize the movements and rearing distributions of naturally produced CC and GRR spring Chinook Salmon parr during fall and winter. Using radiotelemetry techniques (October–February), we identified the movement dynamics of CC (2009–2012) and GRR (2014–2016) spring Chinook Salmon fall migrants (i.e., parr overwintering downstream from natal areas). For both populations, median weekly linear range (i.e., movement) was high during fall migration, while sedentary behavior was associated with anchor and surface ice. Fall emigration occurred during declining thermographs, while overwintering parr movement and water temperature peaks were proximate. Fall migrant CC parr predominantly overwintered in the upper Grande Ronde Valley (GRV), while GRR conspecifics primarily reared upstream from the GRV. Extensive portions of CC and the GRR were not included in either population’s 99% kernel density estimate (KDE); however, each population’s 99% KDE extended into the lower GRV. The GRR population’s 50% KDE (i.e., core area) was small and proximate to several North American beaver Castor canadensis impoundments, while the CC population’s core area was relatively large and situated in the upper GRV. Overall, CC and GRR fall migrant populations exhibited divergent rearing and movement patterns; however, each population’s winter core area was proximate to lentic‐like habitats (e.g., beaver ponds). For Chinook Salmon parr, natal‐stream‐specific overwintering ecology knowledge appears critical to guide winter habitat conservation and restoration, while management for lentic‐like habitats may be advisable throughout the Pacific Northwest.

中文翻译：

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西北太平洋纳塔尔河两岸内陆天然产的奇努克鲑鱼幼虫的秋冬运动动力学

越冬的太平洋鲑鱼Oncorhynchus spp。容易死亡。生态系统退化加剧了鲑鱼对死亡的脆弱性；因此，冬季运动动态知识对于指导整体管理和恢复以保障人口生存能力至关重要。在俄勒冈州东北部，存在两个相邻的奇努克鲑鱼O. Parr的长期种群表现指标（例如生存）。人口（凯瑟琳溪[CC]和朗德河[GRR]）；但是，他们缺乏冬季生态知识。我们的目标是时空表征秋季和冬季自然生产的CC和GRR春季奇努克鲑鱼幼崽的运动和饲养分布。使用无线电遥测技术（10月至2月），我们确定了CC（2009-2012年）和GRR（2014-2016年）春季奇努克鲑鱼秋天移民（即，产区下游越冬的帕尔）的运动动态。对于这两个种群，秋季迁徙期间的每周中位数线性范围（即运动）较高，而久坐行为与锚和表层冰有关。在温度下降的过程中发生了秋天的迁徙，而越冬的帕尔运动和水温峰值则最接近。秋季移民CC居民主要在朗德河谷（GRV）上游越冬，而GRR物种主要在GRV上游繁殖。CC和GRR的大部分均未包含在这两个人群的99％内核密度估计（KDE）中；但是，每个人的99％KDE扩展到了较低的GRV。GRR种群的KDE（即核心区域）的50％很小，接近几个北美海狸加拿大蓖麻种群，而CC种群的核心区域相对较大，位于GRV的上部。总体而言，CC和GRR下降的移民人口呈现出不同的饲养和移动方式。但是，每个人口的冬季核心区域都靠近象透镜一样的栖息地（例如海狸池塘）。对于奇努克鲑鱼来说，特定于幼年的越冬生态学知识对于指导冬季栖息地的保护和恢复显得至关重要，而在整个西北太平洋地区，建议对象鼻样栖息地进行管理。