Foraging of gray squirrels on an urban-rural gradient: Use of the GUD to assess anthropogenic impact
Foraging of gray squirrels on an urban-rural gradient: Use of the GUD to assess anthropogenic impact
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DOI：
10.2307/2269597
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发表时间：
1996-11-01
影响因子：
5
通讯作者：
Breland, B
中科院分区：
文献类型：
--
作者：
Bowers, MA;Breland, B
生物对城市化的反应可能涉及行为的调整。为了使这种行为的可塑性合格，我们测量了灰松鼠（松鼠carolinensis）在弗吉尼亚州78个地点的城乡梯度分布的平底锅中利用向日葵籽的程度。我们的目标是使用松鼠GUD作为城市化影响的功能性，相对论性措施。结果表明，比例较高的平底锅觅食，GUD较低（更多的种子被删除）在相对高密度的城市和郊区比在更多的农村农业地区，或在相对人类自由的森林控制。对于人类住区附近或人类住区内的地点，GUD在靠近人类居住结构的地方比在离它们更远的地方低，在那里观察到更多的松鼠，树木密度较高; GUD在有大量地面覆盖物和家养宠物（即，猫/狗）都在附近。生活在人类附近的松鼠似乎比生活在更自然的地区的松鼠更容易受到食物的限制，或者对捕食风险不太敏感。我们认为，GUD代表了一个有价值的度量工具，用于测量人类活动在个人和人口水平上的单独和综合影响。
Responses of organisms to urbanization may involve adjustments in behavior. To qualify such behavioral plasticity we measured the degree to which gray squirrels (Sciurus carolinensis) exploited sunflower seeds in pans distributed over an urban-rural gradient of 78 sites in Virginia. Our objective was to use squirrel GUDs as a functional, relativistic measure of the effects of urbanization. Results showed that a higher proportion of pans were foraged from and that the GUDs were lower (more seeds were removed) in relatively high-density urban and suburban areas than in more rural agricultural areas, or in relatively human-free forest controls. For sites near or within human settlements, GUDs were lower nearer to human-occupied structures than at a greater distance from them, where more squirrels were observed, and where the density of trees was higher; GUDs were higher where there was substantial ground cover and where domestic pets (i.e., cats/dogs) were present nearby. Squirrels living in close proximity to humans appear to be either more limited by food or less sensitive to predatory risk than those living in more natural areas. We argue that the GUD represents a valuable metric with utility for measuring the separate and combined impact of anthropogenic actions at the individual and population levels.