Schally Gergely, Tóth Dániel, Márton Mihály, Bijl Hanna, Palatitz Péter, Csányi Sándor, Maimela Modiba Maxwell, Tharwat Mohamed Ibrahim Hanaa, Simon Barbara
Department of Wildlife Biology and Management Institute for Wildlife Management and Nature Conservation, Hungarian University of Agriculture and Life Sciences Gödöllő Hungary.
Red-Footed Falcon Conservation Working Group MME/BirdLife Hungary Budapest Hungary.
Ecol Evol. 2024 Aug 6;14(8):e70136. doi: 10.1002/ece3.70136. eCollection 2024 Aug.
The Eurasian woodcock prefers habitats where its main prey, earthworms, can be found in higher densities. Although they are forest-dwelling birds, they regularly visit pastures and natural grasslands at night, where earthworm abundance is generally higher. However, there is little information on fine-scale habitat use in relation to variation in habitat characteristics and prey availability, particularly beyond the breeding season. In our study, we investigated if the nocturnal occurrence of woodcocks during migratory stopover periods differed between two neighbouring fields, or management units, with similar vegetation structure, and if within-field variation in the spatial patterns of woodcock sightings were associated with fine-scale earthworm densities and soil parameters. Specifically, we used GPS tracking data of two tagged woodcocks and direct observation data to study patterns of occurrence of birds in a mixed forest-pasture landscape in Hungary during pre- and post-breeding periods. We compared these patterns with fine-scale soil characteristics and earthworm abundance, acquired by field sampling. We found that the field with higher earthworm abundance was visited by woodcocks more frequently, and this correlation was similarly observed at the intra-field level. Our results demonstrate that woodcocks select foraging sites with higher earthworm densities at multiple spatial scales, both between fields (coarse scale), and within fields (fine-scale). Considering that woodcocks tended to return to the same field to forage at night, the strong associations between occupancy and resources provide a basis for developing habitat management strategies at the field level for conservation. As earthworm densities and soil parameters are good indicators of woodcock foraging habitat, measuring those variables, at least at a coarse scale, could aid in predicting important habitats for the species across the landscape.
欧亚丘鹬偏好其主要猎物蚯蚓密度较高的栖息地。尽管它们是栖息于森林的鸟类，但它们夜间经常会前往牧场和天然草原，那里蚯蚓的数量通常更多。然而，关于与栖息地特征变化和猎物可获得性相关的精细尺度栖息地利用情况的信息很少，尤其是在繁殖季节之外。在我们的研究中，我们调查了在迁徙中途停留期间，欧亚丘鹬在两个植被结构相似的相邻田地或管理单元中的夜间出现情况是否存在差异，以及田地内欧亚丘鹬目击空间模式的变化是否与精细尺度的蚯蚓密度和土壤参数相关。具体而言，我们使用了两只佩戴追踪器的欧亚丘鹬的GPS跟踪数据以及直接观察数据，来研究匈牙利一个森林与牧场混合景观中鸟类在繁殖前和繁殖后的出现模式。我们将这些模式与通过实地采样获得的精细尺度土壤特征和蚯蚓数量进行了比较。我们发现，蚯蚓数量较多的田地，欧亚丘鹬的到访频率更高，这种相关性在田地内部层面也同样被观察到。我们的研究结果表明，欧亚丘鹬在多个空间尺度上选择蚯蚓密度较高的觅食地点，包括田地之间（粗尺度）和田地内部（精细尺度）。考虑到欧亚丘鹬夜间倾向于回到同一田地觅食，其栖息地占用情况与资源之间的紧密关联为制定田间层面的栖息地管理保护策略提供了依据。由于蚯蚓密度和土壤参数是欧亚丘鹬觅食栖息地的良好指标，至少在粗尺度上测量这些变量有助于预测该物种在整个景观中的重要栖息地。
