Neotropical felids claws: morphological variation and its relationship with locomotion, prey size, and habitat

This study investigates the morphological variation of claws in Neotropical felines and their relationship with ecological factors within a phylogenetic framework. Employing traditional morphometrics and phylogenetic comparative methods we evaluated claw shape patterns (considering claw length, height, and curvature) on 435 claws from 10 species (plus Felis catus) and their association with locomotion, habitat type, and prey size. Results demonstrate a different functional divergence: anterior claws are significantly more curved—linked to predatory behaviour—while posterior claws vary according to species, but in general tend to be longer and straighter, facilitating locomotion. Morphological variation was primarily driven by habitat type, particularly the use of mixed environments. While hind claw curvature exhibited a strong phylogenetic signal, foreclaws appeared more influenced by stabilizing selection. Notably, Herpailurus yagouaroundi displayed a unique morphology (the greatest differentiation between fore- and hindlimb claws) likely shaped by its use of mixed environments and/or the evolutionary history of cursoriality within the puma lineage.