Hinderer Ross K, Litt Andrea R, McCaffery Magnus
Department of Ecology Montana State University Bozeman MT USA.
Turner Endangered Species Fund Bozeman MT USA.
Ecol Evol. 2020 Dec 9;11(1):536-546. doi: 10.1002/ece3.7074. eCollection 2021 Jan.
Habitat degradation and fragmentation are major drivers of amphibian declines. The loss of environmental features that allow for movement between water sources may be particularly detrimental for amphibians in arid environments. Climate changes will increase the importance of microhabitats to amphibians. Enhancing areas to facilitate movement may be a necessary conservation strategy for many animal species that depend on wetlands, including federally threatened Chiricahua leopard frogs (). Habitat preferences of this frog species are not well understood. We sought to better understand fine-scale habitat selection, to inform conservation of Chiricahua leopard frogs. We conducted our study on the Ladder Ranch, a privately owned working bison ranch in New Mexico, USA that supports a large proportion of the remaining Chiricahua leopard frogs in the state. We attached radio transmitters to 44 frogs during summer 2014. We located each frog daily for up to 8 weeks (median = 30 days). We assessed fine-scale habitat selection by comparing characteristics at each frog location and a random location 5 m away using conditional logistic regression. Frogs preferred features that likely reduce desiccation, even after accounting for the presence of water. Frogs selected areas with more low-lying cover, especially aquatic vegetation and woody debris, a tree overstory, and a mud substrate. We recommend managing potential movement corridors for Chiricahua leopard frogs by ensuring the presence of muddy creek bottoms, woody debris, riparian overstory, low-lying ground cover, and pools. Microclimates created by these features seem especially valuable given warming temperatures and modified precipitation regimes, resulting in decreased surface water, soil moisture, and vegetation cover. Retaining or creating preferred habitat features and microclimates in areas between water sources may increase connectivity among isolated populations of Chiricahua leopard frogs and could improve persistence and recovery of other water-obligate species in arid landscapes.
栖息地退化和破碎化是两栖动物数量减少的主要驱动因素。丧失允许在水源之间移动的环境特征可能对干旱环境中的两栖动物尤为不利。气候变化将增加微生境对两栖动物的重要性。对于许多依赖湿地的动物物种，包括受到联邦威胁的奇里卡华豹蛙（）来说，增加便于移动的区域可能是一项必要的保护策略。人们对这种蛙类的栖息地偏好了解不足。我们试图更好地理解精细尺度的栖息地选择，为奇里卡华豹蛙保护工作提供信息。我们在美国新墨西哥州的阶梯牧场开展了研究，这是一个私人经营的野牛牧场，该州剩余的大部分奇里卡华豹蛙都生活在那里。2014年夏季，我们给44只青蛙安装了无线电发射器。我们每天定位每只青蛙，持续长达8周（中位数 = 30天）。我们通过使用条件逻辑回归比较每只青蛙所在位置和5米外的随机位置的特征，来评估精细尺度的栖息地选择。即使在考虑到水的存在之后，青蛙仍偏好可能减少干燥的特征。青蛙选择了有更多低洼覆盖物的区域，特别是水生植物和木质碎片、树木上层林冠以及泥质基底。我们建议通过确保有泥泞的溪底、木质碎片、河岸上层林冠、低洼地被植物和水塘，来管理奇里卡华豹蛙的潜在移动廊道。考虑到气温上升和降水模式改变导致地表水、土壤湿度和植被覆盖减少，这些特征所创造的微气候似乎特别有价值。在水源之间的区域保留或创造偏好的栖息地特征和微气候，可能会增加奇里卡华豹蛙孤立种群之间的连通性，并有助于干旱地区其他依赖水的物种的存续和恢复。
