Abstract:
Conserving threatened species relies on an understanding of their habitat requirements. This is especially relevant for granivorous birds, whose habitat use and movement patterns are intricately linked to the spatial and temporal availability of resources such as food and water. In this study, we investigated the habitat use, home range and daily activity patterns of the Endangered Southern Black-throated Finch (SBTF; Poephila cincta cincta) within a 75,000 ha savanna woodland study area in northeastern Australia. This semi-arid region is one of the key remaining strongholds for the species and is characterised by substantially different habitat and climatic conditions than areas where previous research on this species has been undertaken. We radio tracked 142 SBTF using both manual tracking and an array of 27 automated radio towers, which revealed a strong preference for eucalypt-dominated grassy woodland communities. The preference for these habitats also increased with decreasing distance to permanent water. While SBTF occupied large home ranges, individual SBTF were largely sedentary during the radio tracking period (21.8, range = 0.83-120 days), with few landscape-scale movements of more than 4.5 km. Daily foraging activity of SBTF exhibited bimodal peaks in the early morning and late afternoon, while other activities were greatest from the late morning to the early afternoon. Compared to other estrildid finches, our research suggests that SBTF track resources at a local scale across a large home range. We postulate that in times of resource scarcity SBTF may use dietary diversification, instead of landscape or regional-scale nomadic movements, to meet their resource needs. The species\' movement patterns underscore the importance of local scale habitat management to facilitate resource availability throughout the year. Furthermore, our research helps target monitoring designs for granivorous birds that focus on the species\' diurnal activity patterns.
摘要:
保护受威胁的物种取决于对其栖息地要求的了解。这对肉食鸟类尤其重要,其栖息地的使用和移动模式与食物和水等资源的时空可用性有着千丝万缕的联系。在这项研究中,我们调查了栖息地的使用情况,在澳大利亚东北部75,000公顷的稀树草原林地研究区内,濒危的南部黑喉芬奇(SBTF;Poephilacinctacincta)的家庭范围和日常活动模式。这个半干旱地区是该物种的主要剩余据点之一,其特征是栖息地和气候条件与先前对该物种进行研究的地区大不相同。我们使用手动跟踪和27个自动无线电塔阵列对142个SBTF进行无线电跟踪,这表明强烈偏爱以桉树为主的草地林地群落。对这些栖息地的偏好也随着与永久水的距离的减少而增加。而SBTF占据了很大的家庭范围,个体SBTF在无线电跟踪期间大部分是久坐的(21.8,范围=0.83-120天),很少有超过4.5公里的景观尺度运动。SBTF的每日觅食活动在清晨和下午晚些时候表现出双峰。而其他活动从早上晚些时候到下午早些时候都是最多的。与其他雌鸟相比,我们的研究表明,SBTF在很大的家庭范围内以本地规模跟踪资源。我们假设在资源匮乏的时候,SBTF可能会使用饮食多样化,而不是景观或区域尺度的游牧运动,以满足他们的资源需求。物种的运动模式强调了本地规模栖息地管理对全年促进资源可用性的重要性。此外,我们的研究有助于针对食肉鸟类的目标监测设计,重点关注物种的昼夜活动模式。