Reintroduction projects are gaining popularity; however, their relatively elevated cost and chance of failure make them debatable, hence assessing their effectiveness is essential. Within the early stages of raptors, the post-fledging dependency period (PFDP) is the one in which individuals must face dangers without having completely developed their skills. Thereby, comparing PFDP patterns concerning reintroduced and wild individuals is of major interest as it would help to plan and improve future conservation actions. We analyzed the behavior of 38 juvenile Bonelli’s Eagles (Aquila fasciata) (15 reintroduced and 23 wild) tracked through GPS telemetry, tagged as nestlings in 2 insular environments. The study period encompassed 9-yr movement data from reintroduced chicks in Mallorca (Spain) and wild chicks from Sicily (Italy). Movement parameters (i.e., age of first flight, age of dispersal, length of the PFDP, revisits to the natal or release area, and residence time in them) were analyzed together with their behavior for reintroduced and wild individuals. Similar movement patterns were obtained for both origins, although wild individuals revisited the natal site more often and dispersed earlier. Behavior was also similar, though it varied throughout the PFDP, observing a more abrupt progress in wild individuals and an earlier development of travelling and hunting behaviors. Observed differences are probably related to food availability, which can improve body condition and thus delay onset of dispersal, together with parental presence, which can prompt an earlier ending of the PFDP by encouraging juvenile independence. In conclusion, our study provides valuable insights into the behavior of reintroduced Bonelli’s Eagles during their PFDP and how it compares to their wild counterparts. Our results suggest that reintroduced individuals can successfully adapt to their environment and behave similarly to wild individuals. These findings can aid in the planning and improvement of future reintroduction projects and conservation actions for this endangered species.

中文翻译：

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在两个地中海岛屿的野生和重新引入的幼年博内利鹰中观察到类似的羽翼后行为

重新引入项目越来越受欢迎；然而，它们相对较高的成本和失败的可能性使它们受到争议，因此评估其有效性至关重要。在猛禽的早期阶段，羽翼后依赖期（PFDP）是个体在尚未完全发展技能的情况下必须面对危险的时期。因此，比较有关重新引入和野生个体的 PFDP 模式具有重要意义，因为它将有助于规划和改进未来的保护行动。我们分析了通过 GPS 遥测技术跟踪的 38 只幼年博内利雕 (Aquila fasciata)（15 只放归的，23 只野生）的行为，这些幼鸟被标记为 2 个岛屿环境中的雏鸟。研究期间涵盖了马略卡岛（西班牙）放归雏鸡和西西里岛（意大利）野生雏鸡的 9 年运动数据。分析了重新引入个体和野生个体的运动参数（即首次飞行年龄、分散年龄、PFDP 长度、重返出生或释放区域以及在其中的停留时间）及其行为。尽管野生个体更频繁地重新访问出生地并且更早地分散，但两个起源地都获得了相似的运动模式。行为也很相似，尽管在整个 PFDP 中有所不同，观察到野生个体的进展更为突然，旅行和狩猎行为的发展也更早。观察到的差异可能与食物供应有关，食物供应可以改善身体状况，从而延迟分散的开始，再加上父母的存在，可以通过鼓励青少年独立来促使 PFDP 提前结束。综上所述，我们的研究为重新引入的博内利雕在 PFDP 期间的行为及其与野生同类的比较提供了宝贵的见解。我们的结果表明，重新引入的个体可以成功地适应环境，并且行为与野生个体相似。这些发现可以帮助规划和改进未来的重新引入项目和该濒危物种的保护行动。