Abstract Species distribution and persistence have long been known to vary with landscape structure; however, continued human activities in altered landscapes raise many questions as to how habitat fragmentation impacts the biology of persistent animal populations. Using carbon and nitrogen stable isotope analysis, we examined interspecific variation in the diet of frugivorous bats among remnant habitat patches of Brazil’s Atlantic Forest. We hypothesized that the diet of individuals captured in habitat patches would be different than those captured in contiguous habitats. We predicted that bats would alter their realized dietary niche breadth, taking food items (i.e., fruits or insects) according to landscape structure. However, more mobile species should be less impacted by small-scale landscape changes. We predicted that (1) a wide-ranging species (Artibeus lituratus), which move through open areas, will be less affected by small-scale landscape attributes, patch size, composition, and isolation; while (2) two narrow-ranging species (Carollia perspicillata and Sturnira lilium) will have more variation between populations in niche breadth and isotopic ratio ranges dependant on the local environment. Using Akaike’s Information Criterion (AIC) to rank a priori selected candidate models to explain variation, we found that fragment composition, largely involving vegetation density rather than spatial aspects of landscape structure (i.e., patch area, isolation) best explained diet variation in frugivorous bats. Additionally, there was evidence that wide-ranging A. lituratus were less impacted by differences in the landscape than narrow-ranging species. This supports the prediction that bats resident to fragments have altered feeding behavior, in response to environmental perturbation.

中文翻译：

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巴西大西洋森林碎片中食果蝙蝠的饮食变化与植被密度有关

摘要 人们早就知道物种分布和持久性会随着景观结构而变化。然而，在改变的景观中持续的人类活动引发了许多关于栖息地破碎化如何影响持久性动物种群的生物学的问题。使用碳和氮稳定同位素分析，我们检查了巴西大西洋森林残余栖息地斑块中食果蝙蝠饮食的种间差异。我们假设在栖息地斑块中捕获的个体的饮食将不同于在连续栖息地中捕获的个体。我们预测蝙蝠会根据景观结构改变它们实现的饮食生态位广度，摄取食物（即水果或昆虫）。然而，更多的移动物种应该受到小规模景观变化的影响较小。我们预测（1）在开阔地区移动的广泛物种（Artibeus lituratus）受小尺度景观属性、斑块大小、组成和隔离的影响较小；而（2）两个范围窄的物种（Carollia perspicillata 和 Sturnira lilium）在生态位宽度和同位素比率范围内的种群之间将有更大的差异，具体取决于当地环境。使用 Akaike 的信息标准 (AIC) 对先验选择的候选模型进行排名以解释变异，我们发现片段组成，主要涉及植被密度而不是景观结构的空间方面（即斑块面积，隔离），最能解释食果蝙蝠的饮食变化. 此外，有证据表明，与分布范围窄的物种相比，分布广泛的 A. lituratus 受景观差异的影响较小。