Morphological Traits and Specialization of Neotropical Flower-hummingbird Networks

Biological specialization plays a central role in species coexistence. While many studies focus on hummingbird pollination, research on the effects of morphological traits of both hummingbirds and plants on the specialization of interaction networks remains scarce. In this study, we aim to address the following questions: i) does the dominance of ornithophilous plant species increase the specialization of hummingbird-plant interaction networks?; ii) do ornithophilous plants exhibit a greater diversity of interactions with hummingbirds compared to non-ornithophilous plants?; iii) do the beak size and body weight of hummingbirds influence the diversity of their interactions? Research was conducted on hummingbird-plant interactions in the Neotropical region. We investigated hummingbird-plant interactions in the Neotropical region by compiling 24 networks from the literature, comprising 1,182 interactions between 34 hummingbird species and 326 plant species. We found no effect of ornithophilous plant dominance on the structure (connectance and modularity) of the networks. However, species-level interactions were influenced by morphological attributes of both plants and hummingbirds. Interaction similarity among plant species was greater for ornithophilous plants than for non- ornithophilous plants. Additionally, beak size positively influenced the degree and specialization of hummingbird interactions. Our findings demonstrate that the morphological characteristics of hummingbird and plant species directly influence the diversity of interactions in Neotropical hummingbird-plant networks and species specialization.