The study of migratory songbird transition periods, such as the post-breeding period, is complex because birds undertake different types of movements that vary in space and time. Nonetheless, it is important to understand the extent and duration of the territory and specific sites use to identify human activities likely to affect the species’ survival. Individuals from different regional populations may exhibit specific movements during the various phases of their annual cycle, and therefore conservation actions must be adapted. We studied a population of Canada Warblers (Cardellina canadensis) from the Saguenay region of Quebec, Canada, in the northeastern part of the species’ breeding range. We used a coordinated radio-telemetry network (Motus) to determine the residence time within the breeding territory, dates and times of departure, and early fall migration routes of 18 adult birds. We expected individuals to leave by mid-August and to migrate through the eastern flyway, along the Atlantic Coast. Six tracked individuals remained on their breeding territory until early September, corresponding to a residence time of approximately 90 days. These individuals left just after sunset on their day of departure. Twelve individuals departed earlier, and in the daytime, before the end of August; their earlier departure was likely for a purpose other than migration. Nine individuals were detected outside their breeding territory along the Atlantic migratory flyway: four migrated through the Great Lakes region, one in the Great Appalachian Valley, three along the Atlantic Coast or coastal plain, and one with an undetermined route. Our results suggest that adult Canada Warblers remain in the Saguenay region longer than expected, and that, although some individuals remain close to their breeding territory during the post-breeding period, others may use surrounding territories prior to initiating their fall migration. Our results will allow regional conservation managers to recommend that regional industry postpone the timing of certain activities that could negatively affect the species’ survival. Our study highlights the importance of fine-scale studies focused on specific periods of migratory songbird annual cycles to fill important knowledge gaps for understanding of the ecology of their species.

中文翻译：

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对加拿大莺（Cardellina canadensis）东北部种群繁殖后运动的见解

迁徙鸣禽过渡期的研究，如繁殖后时期，是复杂的，因为鸟类在空间和时间上进行不同类型的运动。尽管如此，重要的是要了解领土和特定地点的范围和持续时间，以识别可能影响物种生存的人类活动。来自不同区域人口的个体可能在其年度周期的各个阶段表现出特定的运动，因此必须调整保护行动。我们研究了加拿大魁北克萨格奈地区的加拿大莺（Cardellina canadensis）种群，该地区位于该物种繁殖范围的东北部。我们使用协调的无线电遥测网络 (Motus) 来确定在繁殖区域内的停留时间、出发日期和时间，18 只成年鸟的初秋迁徙路线。我们预计个人将在 8 月中旬离开，并沿大西洋沿岸通过东部飞行路线迁移。六名被追踪的个体一直停留在其繁殖地直到 9 月初，对应的停留时间约为 90 天。这些人在出发当天日落后离开。12 个人在 8 月底之前在白天离开；他们较早的离开很可能是出于移民以外的目的。沿大西洋迁徙路线在其繁殖区域外发现了 9 只个体：4 只迁徙穿过五大湖地区，1 只在大阿巴拉契亚山谷迁徙，3 只沿大西洋沿岸或沿海平原迁徙，1 只迁徙路线未定。我们的研究结果表明，成年加拿大莺在萨格奈地区停留的时间比预期的要长，尽管有些个体在繁殖后时期仍然靠近它们的繁殖地，但其他人可能会在开始秋季迁徙之前使用周围的领土。我们的结果将允许区域保护管理者建议区域产业推迟可能对物种生存产生负面影响的某些活动的时间安排。我们的研究强调了以迁徙鸣禽年度周期的特定时期为重点的精细研究的重要性，以填补了解其物种生态学的重要知识空白。其他人可能会在开始秋季迁移之前使用周围的领土。我们的结果将允许区域保护管理者建议区域产业推迟可能对物种生存产生负面影响的某些活动的时间安排。我们的研究强调了以迁徙鸣禽年度周期的特定时期为重点的精细研究的重要性，以填补了解其物种生态学的重要知识空白。其他人可能会在开始秋季迁移之前使用周围的领土。我们的结果将允许区域保护管理者建议区域产业推迟可能对物种生存产生负面影响的某些活动的时间安排。我们的研究强调了以迁徙鸣禽年度周期的特定时期为重点的精细研究的重要性，以填补了解其物种生态学的重要知识空白。