Tropical forests have been facing high rates of deforestation driven by multiple anthropogenic disturbances, with severe consequences for biodiversity. However, the understanding of such effects on functional diversity is still limited in tropical regions, especially considering different ecological groups responses. Here, we evaluated the functional responses of birds to forest loss at the threatened Brazilian Atlantic forest, considering the complete assemblage, and both forest‐dependent and non‐forest‐dependent species. Birds were surveyed in 40 forest sites with a forest cover gradient, located in two regions showing different land use types. We tested different models to assess the responses of functional diversity indices to forest loss in these sites. Although functional diversity did not differ between regions, forest and non‐forest birds showed divergent responses to forest loss. Deforested landscapes presented an increase in functional richness (SESFRic) and evenness for forest species and an increase of functional dispersion for non‐forest birds. Additionally, forested landscapes harbor birds presenting lower body mass and wing length, and non‐forest species with lower tarsus length. The maintenance of some functional metrics through forest loss resulted from a compensatory dynamic between forest and non‐forest birds, indicating that only evaluating the complete assemblage may mask important idiosyncratic patterns of different ecological groups. Although non‐forest species are relatively capable to maintain bird functional diversity in deforested landscapes, forest birds are facing a drastic ongoing collapse in these sites, representing an alarming signal for the maintenance of forest ecosystem function.

中文翻译：

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热带森林的丧失导致森林和非森林鸟类功能多样性的差异模式

由于多种人为干扰，热带森林面临着很高的毁林率，对生物多样性造成严重后果。然而，在热带地区，特别是考虑到不同的生态群体反应，对这种对功能多样性的影响的了解仍然有限。在这里，我们评估了受威胁的巴西大西洋森林中鸟类对森林流失的功能响应，同时考虑了它们的完整组合以及与森林有关和与非森林有关的物种。在两个具有不同土地利用类型的区域中，在40个森林覆盖率梯度不同的森林地点对鸟类进行了调查。我们测试了不同的模型，以评估功能多样性指数对这些地点森林砍伐的响应。尽管地区之间的功能多样性没有差异，森林和非森林鸟类对森林流失的反应不同。砍伐森林的景观使森林物种的功能丰富度（SESFRic）和均匀度增加，对非森林鸟类的功能性分散度增加。此外，森林景观中的鸟类具有较低的体重和翅膀长度，而非森林物种的体长度较小。森林和非森林鸟类之间的补偿动态导致了通过森林丧失而维持的某些功能指标，这表明仅评估完整的组合可能会掩盖不同生态群体的重要特质模式。尽管非森林物种在砍伐森林的景观中相对具有维持鸟类功能多样性的能力，但是在这些地点，森林鸟类正面临着持续的严重破坏，