Species traits mediate the abundant‐center patterns in ground‐dwelling mammal and bird species in China

The abundance center hypothesis (ACH) posits that species abundance peaks at distribution centers; however, empirical support remains inconsistent. This study tested the generality of the ACH and investigated species traits as mediators of abundance–distance relationships. We compiled relative abundance indices (RAIs) for 81 ground‐dwelling mammal and bird species, comprising 2558 population abundance estimates from standardized camera‐trap surveys in China from 2008 to 2023. We assessed correlations between the RAI and population distance to species geographic and climatic centers to evaluate ACH support. We examined phylogenetic signals in the strength of ACH patterns and analyzed the variation in these patterns across taxonomic orders. We also performed formal meta‐analyses to estimate mean effect sizes of ACH patterns and examine how species traits mediate the direction and strength of the ACH. We found that only 18% of mammal species and 4% of bird species exhibited significant negative abundance–distance correlations geographically, with similarly limited support climatically (9% mammal species, 12% bird species). Meta‐analysis indicated no significant mean effect sizes across species (all p > 0.05), contradicting ACH pattern predictions. No phylogenetic signals were observed in abundance–distance relationships. Species exhibiting larger range sizes showed stronger ACH associations. Mammal species exhibiting smaller body sizes and home ranges showed more robust abundance–distance correlations. This study provides limited support for the ACH and suggests it is a context‐dependent phenomenon rather than a universal biogeographic rule. Given that species traits mediate ACH strength, conservation strategies should move beyond center‐focused approaches to incorporate species‐specific abundance patterns.