A well-constructed nest is a key element of successful reproduction in most species of birds, and nest morphology varies widely across the class. Macroecological and macroevolutionary studies tend to group nest design into a small number of discrete categories, often based on taxonomic inference. In reality, however, many species display considerable intraspecific variation in their nest-building behaviour, and broad-level categories may include several functionally distinct nest types. To address this imprecision in the literature and facilitate future studies of broad-scale variation in avian parental care, we here introduce a detailed, global comparative database of nest building in birds, together with preliminary correlations between these traits and species-level environmental variables.

中文翻译：

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世界鸟类的巢穴特征

结构良好的巢穴是大多数鸟类成功繁殖的关键因素，而且不同类别的巢穴形态差异很大。宏观生态学和宏观进化研究往往基于分类学推断，将巢穴设计分为少数离散类别。然而，实际上，许多物种在筑巢行为方面表现出相当大的种内差异，并且广泛的类别可能包括几种功能不同的巢类型。为了解决文献中的这种不精确性并促进未来对鸟类亲代照顾的大范围变异的研究，我们在此介绍了鸟类筑巢的详细全球比较数据库，以及这些性状与物种水平环境变量之间的初步相关性。