1. Movement has been studied extensively in stream salmonids, and most data suggest that population‐level behaviour is best described by a leptokurtic distribution. This distribution emphasises the large proportion of sedentary individuals in a population, which can implicitly lead to assumptions of low population connectivity and overlook the ecological significance of rare individuals with more mobile phenotypes.
2. We report findings of a multi‐season radio telemetry study conducted on four adjacent populations of wild brook trout (Salvelinus fontinalis) connected by Loyalsock Creek in north‐central Pennsylvania. We used these data to investigate temporal and spatial patterns in movement and fitness trade‐offs associated with behavioural phenotype.
3. Similar to previous studies, we found that 59 of the 120 radio‐tagged individuals (49%) were sedentary and moved less than 200 m. Only 18% of individuals dispersed more than 1 km, but the maximum distance moved exceeded 13 km. We also found that mobile individuals had significantly higher summer and autumn survival than did sedentary fish, which could indicate that there are fitness benefits associated with vagility.
4. Most long‐distance movements were the result of fish migrating from small tributaries into a larger mainstem river in the days after spawning. Therefore, even though mobility was only expressed for a short duration and by relatively few individuals in the population, the behaviour appears to maintain metapopulation connectivity throughout the catchment.
5. Our study highlights the ecological significance of rare phenotypes for population demography across large spatial scales and the need to understand movement across multiple temporal and spatial scales to ensure adequate conservation of critical forms of cryptic life history diversity.

中文翻译：

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在短时间尺度上的行为驱动着河鳟（Salvelinus fontinalis）的传播种群中的扩散动态和生存。

1. 溪流鲑鱼的运动已经得到了广泛的研究，大多数数据表明，通过瘦腰肌分布可以最好地描述种群水平的行为。这种分布强调了人口中久坐的个体的很大比例，这可能隐含地导致人口连通性低的假设，而忽略了具有更多活动表型的稀有个体的生态意义。
2. 我们报告了对宾夕法尼亚州中北部的Loyalsock Creek连接的四个相邻的野河鳟鱼（Salvelinus fontinalis）进行的多季节无线电遥测研究的结果。我们使用这些数据来研究与行为表型相关的运动和适应性权衡的时空模式。
3. 与先前的研究类似，我们发现120名带有无线电标签的人中有59名（49％）久坐不动，并且移动距离小于200 m。只有18％的人分散超过1公里，但最大移动距离超过13公里。我们还发现，流动个体的夏季和秋季生存期比久坐的鱼类高得多，这可能表明与流动性相关的健身益处。
4. 大多数长距离运动是鱼在产卵后几天从小支流迁移到更大的主干河的结果。因此，即使流动性只是在很短的时间内表达的，而人口中相对较少的个体也表现出这种行为，但这种行为似乎在整个流域保持了种群的连通性。
5. 我们的研究强调了在大空间尺度上稀有表型对人口人口统计学的生态学意义，以及需要理解跨多个时空尺度的运动以确保充分保护关键生命形式的隐秘生活史的需求。