Reilly Emily, Lawton Colin
Zoology, School of Natural Sciences, Ryan Institute University of Galway Galway Ireland.
Ecol Evol. 2024 Oct 25;14(10):e70482. doi: 10.1002/ece3.70482. eCollection 2024 Oct.
Translocations, a conservation tool used to conserve and restore dwindling species, are often associated with high failure rates. Inadequate long-term monitoring of both populations and their introduction sites beyond the initial years post-translocation creates a gap in our understanding of the factors that determine translocation success or failure, resulting in less informed projects in the future. This lack of long-term monitoring is partly caused by the absence of a well-defined framework by which the success of the translocation can be measured, leading to premature and sometimes inaccurate assessments of their outcome. We investigated the long-term outcome of a red squirrel translocation in the west of Ireland, specifically assessing the habitat changes in the translocation site since the introduction in 2005, and their impact on the capacity of the forest to sustain a population of a given size. Using digitised historical map data, we showed that the translocation site experienced a 53% reduction in suitable habitat. Additionally, there was a 41%-81% reduction in the total number of red squirrels the forest could support, according to feeding survey data. Clear-felling, a forest fire and a shift in tree species composition collectively contributed to this decline in site suitability. This investigation underscores the complexity of translocation projects and emphasises the pivotal role of habitat quality in their outcomes. We advocate for detailed habitat assessments during the planning phase, avoidance of unstable habitats as translocation sites, and the implementation of long-term monitoring practices.
物种迁移是一种用于保护和恢复数量不断减少的物种的保护手段,但往往伴随着高失败率。在迁移后的最初几年之后,对种群及其引入地点缺乏足够的长期监测,这使得我们在理解决定迁移成功或失败的因素方面存在差距,导致未来的项目缺乏充分的信息依据。这种缺乏长期监测的部分原因是缺乏一个明确的框架来衡量迁移的成功与否,从而导致对其结果的评估过早且有时不准确。我们调查了爱尔兰西部红松鼠迁移的长期结果,特别评估了自2005年引入以来迁移地点的栖息地变化,以及这些变化对森林维持特定规模种群能力的影响。利用数字化的历史地图数据,我们发现迁移地点的适宜栖息地减少了53%。此外,根据觅食调查数据,森林能够支持的红松鼠总数减少了41% - 81%。皆伐、森林火灾和树种组成的变化共同导致了该地点适宜性的下降。这项调查强调了迁移项目的复杂性,并强调了栖息地质量在其结果中的关键作用。我们主张在规划阶段进行详细的栖息地评估,避免将不稳定的栖息地作为迁移地点,并实施长期监测措施。