Convergent mechanisms, divergent strategies: a comparison of nectar intake between a generalist and a specialized bat species

Nectar-feeding bats exhibit a range of specialized adaptations that allow them to efficiently extract nectar from flowers. These adaptations include diverse tongue morphological traits and feeding strategies that reflect varying degrees of specialization for nectarivory. While the feeding mechanisms of highly specialized nectar-feeding bats are well-studied, little is known about the feeding behaviors of non-specialized species like Phyllostomus discolor. This study compares the nectar extraction behaviors of P. discolor and the specialized Anoura geoffroyi, examining morphological and biomechanical adaptations that affect nectar-feeding efficiency and foraging strategies. Using high-speed videography, we analyzed the feeding behaviors of both species, focusing on tongue kinematics, and feeding efficiency. Both species used a brush-tongue lapping technique but exhibited notable behavioral and kinematic differences, resulting in efficiency variations. P. discolor has a shorter, less flexible tongue than A. geoffroyi, though its tongue shows similar mobility capacities (licking frequency). Unlike A. geoffroyi, which hovers to feed, P. discolor lands, allowing for longer visits and greater nectar extraction per visit. However, P. discolor demonstrated lower feeding efficiency, likely due to its reduced tongue specialization for nectarivory. These findings reveal convergence in the general feeding mechanism but highlight differences in morphological and behavioral specialization that affect feeding kinematics and efficiency. Our study illuminates how foraging strategy and tongue morphology impact feeding efficiency, pointing to evolutionary pathways that promote niche differentiation within nectar- feeding bat communities.