Brushett Aidan, Whittington Jesse, Macbeth Bryan, Fryxell John M
Parks Canada, Banff National Park Resource Conservation, PO Box 900, Banff, AB, T1L 1K2, Canada.
Department of Integrative Biology, University of Guelph, Guelph, ON, N1G 2W1, Canada.
Mov Ecol. 2023 Jul 4;11(1):36. doi: 10.1186/s40462-023-00404-2.
Parturition and the early neonatal period are critical life history stages in ungulates with considerable implications for population growth and persistence. Understanding the changes in behaviour induced by ungulate parturition is important for supporting effective population management, but reliably identifying birth sites and dates presents a challenge for managers. Rocky Mountain bighorn sheep (Ovis canadensis canadensis) are one such highly valued and ecologically important species in montane and subalpine ecosystems of Western North America. In the face of changing patterns of anthropogenic land use, wildlife managers increasingly require site-specific knowledge of the movement and habitat selection characteristics of periparturient sheep to better inform land use planning initiatives and ensure adequate protections for lambing habitat. We used movement data from GPS collared parturient (n = 13) and non-parturient (n = 8) bighorn sheep in Banff National Park, Canada to (1) identify lambing events based on changes in key movement metrics, and (2) investigate how resource selection and responses to human use change during the periparturient period. We fit a hidden Markov model (HMM) to a multivariate characterization of sheep movement (step length, daily home range area, residence time) to predict realistic lambing dates for the animals in our study system. Leave-one-out cross validation of our model resulted in a 93% success rate for parturient females. Our model, which we parameterized using data from known parturient females, also predicted lambing events in 25% of known non-parturient ewes in a test dataset. Using a latent selection difference function and resource selection functions, we tested for postpartum changes in habitat use, as well as seasonal differences in habitat selection. Immediately following lambing, ewes preferentially selected high-elevation sites on solar aspects that were more rugged, closer to escape terrain, and further from roads. Within-home range habitat selection was similar between individuals in different reproductive states, but parturient ewes had stronger selection for low snow depth, sites closer to barren ground, and sites further from trails. We propose that movement-based approaches such as HMMs are a valuable tool for identifying critical parturition habitat in species with complex movement patterns and may have particular utility in study areas without access to extensive field observations or vaginal implant transmitters. Furthermore, our results suggest that managers should minimize human disturbance in lambing areas to avoid interfering with maternal behaviour and ensure access to a broad range of suitable habitat in the periparturient period.
分娩和新生儿早期是有蹄类动物生命历程中的关键阶段，对种群增长和延续具有重大影响。了解有蹄类动物分娩引起的行为变化对于支持有效的种群管理很重要，但可靠地确定出生地点和日期对管理者来说是一项挑战。落基山大角羊（Ovis canadensis canadensis）是北美西部山地和亚高山生态系统中此类极具价值且在生态上很重要的物种之一。面对人为土地利用模式的变化，野生动物管理者越来越需要特定地点的围产期母羊的移动和栖息地选择特征的知识，以便更好地为土地利用规划举措提供信息，并确保对产羔栖息地有足够的保护。我们使用了来自加拿大班夫国家公园佩戴GPS项圈的围产期（n = 13）和非围产期（n = 8）大角羊的移动数据，以（1）根据关键移动指标的变化识别产羔事件，以及（2）调查围产期资源选择和对人类利用的反应如何变化。我们将一个隐马尔可夫模型（HMM）应用于羊移动的多变量特征（步长、每日家域面积、停留时间），以预测我们研究系统中动物的实际产羔日期。我们模型的留一法交叉验证对围产期母羊的成功率为93%。我们使用来自已知围产期母羊的数据对模型进行参数化，该模型在一个测试数据集中还预测了25%已知非围产期母羊的产羔事件。使用潜在选择差异函数和资源选择函数，我们测试了产后栖息地利用的变化以及栖息地选择的季节性差异。产羔后，母羊优先选择朝南的高海拔地点，这些地点更崎岖，更靠近逃生地形，且离道路更远。不同繁殖状态个体的家域内栖息地选择相似，但围产期母羊对低雪深、更靠近裸地的地点以及离小径更远的地点有更强的选择。我们提出，基于移动的方法，如隐马尔可夫模型，是识别具有复杂移动模式物种关键产羔栖息地的宝贵工具，并且在无法进行广泛实地观察或使用阴道植入式发射器的研究区域可能具有特殊用途。此外，我们的结果表明，管理者应尽量减少产羔区域的人为干扰，以避免干扰母性行为，并确保在围产期能获得广泛的适宜栖息地。
