Disentangling functional spaces: a multidimensional framework for ecology and conservation

Trait‐based ecology often relies on a single functional space, where diverse traits are combined into one multivariate framework. While convenient, this approach risks masking ecological strategies because variance is often dominated by a few traits, such as body size. Here, we propose a modular alternative: function‐related trait spaces, each representing a specific ecological role such as locomotion, reproduction, or diet. Using global data for > 10 000 bird species as study case, we show that function‐related trait spaces capture complementary ecological information that is obscured in the combined trait space. The combined space consistently underestimates functional distinctiveness, overlooking more than 800 species identified as unique in function‐related trait spaces. We call for integrating function‐related trait spaces into biodiversity assessments to improve the detection and protection of irreplaceable ecological roles.