Multiscale acoustic temporal niche partitioning of pineland birds across a species richness gradient

Abstract Growing evidence suggests birds reduce acoustic competition by minimizing temporal overlap with neighboring species sharing similar vocal characteristics. However, few studies have tested this across ecological contexts at multiple temporal scales. We examined temporal vocalization patterns of five common pine woodland bird species across a species richness gradient in Florida, USA. We predicted that Carolina Wren ( Throthorus ludovicianus) and White-eyed Vireo ( Vireo griseus ) would exhibit temporal avoidance with the acoustically similar, highly abundant and vocal Northern Cardinal ( Cardinalis cardinalis) at fine (1-minute) and coarse (3-hour dawn chorus) temporal scales, with stronger avoidance in species-rich communities. Conversely, we predicted acoustically dissimilar species [Mourning Dove ( Zenaida macroura ) and Pine Warbler ( Setophaga pinus )] would show random temporal associations with Northern Cardinals, unaffected by richness or scale. Consistent with predictions, acoustically similar species exhibited significant temporal avoidance of Cardinals at both scales, while dissimilar species showed no consistent patterning. Contrary to expectations, species richness did not strongly influence temporal avoidance, though fine-scale temporal partitioning trended toward increasing at lower richness. Taken together, these results demonstrate that temporal niche partitioning among acoustically similar bird species operates consistently across multiple temporal scales and is structured more by acoustic similarity and asymmetric species interactions than by species richness.