Heffelfinger Levi J, Hewitt David G, Vasquez Joshua P, Fulbright Timothy E, DeYoung Randy W, Harveson Louis A, Conway Warren C, Gray Shawn S
Caesar Kleberg Wildlife Research Institute, Texas A&M University - Kingsville, Kingsville, TX, USA.
, 700 University Blvd. MSC 218, Kingsville, TX, 78363, USA.
Mov Ecol. 2025 Jun 6;13(1):38. doi: 10.1186/s40462-025-00566-1.
Habitat fragmentation can influence the spatial ecology of wildlife populations, with downstream effects on population dynamics and sustainability. Row-crop farming is a common anthropogenic landscape alteration, yet the effects on animal movement and space use is understudied in some species. Cropland can benefit wildlife nutritionally but may result in habitat loss because of changes in landscape composition and human disturbance.
We quantified the influence of cropland presence and coverage on mule deer spatial ecology in the southern Great Plains. We GPS-collared 146 adult mule deer in four regions of the Texas Panhandle and monitored movement relative to spatio-temporal fluctuations in cropland and particular crop species availability for 2 years. We modeled the effects of cropland on space use and resource selection at multiple spatio-temporal scales to characterize population and individual habitat components of mule deer.
We observed a functional response in cropland use, where at low coverage, use was proportional to availability but decreased with > 20% cropland coverage at the home range and within-home range scales. Few mule deer exhibited long-distance movements towards cropland. Individuals within 1.6 km of cropland exhibited greater cropland use, whereas deer > 4.2 km from cropland rarely used these areas. At the population level, mule deer selected cropland during the winter and late summer, probably for nutritional benefit when rangeland nutrients are low. At a finer scale, step-selection functions identified individual heterogeneity in crop species selection. Winter wheat, alfalfa, and fallow fields had greater use relative to other crop types. Generally, 15-60% of mule deer with access to cropland selected alfalfa year-round, and up to 63% of deer selected winter wheat post-reproduction.
Our results suggest that at a low spatial coverage, cropland alters the spatial ecology of mule deer at several spatio-temporal scales and may provide nutritional benefits, but at a cost of lost habitat when cropland exceeds 20% of the landscape. Declining groundwater resources and an exponentially growing human population will alter future farming practices. Understanding how species occupying these environments, such as mule deer, are influenced by human-induced landscape changes can enhance mitigation of human-wildlife interactions and aid conservation actions as policy and social pressures shape future agricultural practices.
栖息地破碎化会影响野生动物种群的空间生态，进而对种群动态和可持续性产生下游效应。行栽作物种植是一种常见的人为景观改变，但在某些物种中，其对动物移动和空间利用的影响尚未得到充分研究。农田可以在营养方面使野生动物受益，但由于景观组成的变化和人类干扰，可能会导致栖息地丧失。
我们量化了农田的存在和覆盖对大平原南部骡鹿空间生态的影响。我们在得克萨斯州狭长地带的四个区域给146只成年骡鹿佩戴了GPS项圈，并在两年内监测了它们相对于农田时空波动和特定作物物种可利用性的移动情况。我们在多个时空尺度上模拟了农田对空间利用和资源选择的影响，以描述骡鹿的种群和个体栖息地组成部分。
我们观察到在农田利用方面存在功能反应，即在低覆盖率下，利用程度与可利用性成正比，但在家庭范围和家庭范围内尺度上，当农田覆盖率超过20%时，利用程度会下降。很少有骡鹿表现出向农田的长距离移动。距离农田1.6公里以内的个体对农田的利用更多，而距离农田超过4.2公里的鹿很少使用这些区域。在种群水平上，骡鹿在冬季和夏末选择农田，可能是为了在牧场营养物质含量低时获取营养益处。在更精细的尺度上，步长选择函数确定了作物物种选择中的个体异质性。冬小麦、苜蓿和休耕地相对于其他作物类型的利用更多。一般来说，有机会进入农田的骡鹿中，15%至60%的个体全年选择苜蓿，繁殖后高达63%的鹿选择冬小麦。
我们的结果表明，在低空间覆盖率下，农田会在几个时空尺度上改变骡鹿的空间生态，可能提供营养益处，但当农田超过景观的20%时，会以栖息地丧失为代价。地下水资源的减少和人口的指数增长将改变未来的农业实践。了解占据这些环境的物种，如骡鹿，如何受到人为引起的景观变化的影响，可以加强对人类与野生动物相互作用的缓解，并在政策和社会压力塑造未来农业实践时有助于保护行动。
