Pollination is an essential ecosystem service that allows for human well-being, maintenance of biological diversity, and production of economically important agricultural crops. Although pollination webs are assumed to be resilient to change, anthropogenic disturbances have been known to alter the way mutualistic networks are structured, especially habitat composition and fragmentation. Here, we address the effect of habitat composition and configuration on hummingbird pollinator networks in a tropical landscape. We quantified the number of plant-pollinator interactions, hereby referred to as links, and measured the level of specialization across different patch sizes using a species specialization index as suggested by Juliard et al. (2006). Our initial hypothesis stated that hummingbirds would become more specialized in smaller patches, and that could be driven by patch size (fragmentation) or landscape composition (proportion of forest cover). Correspondingly, we expected to find a greater number of links in larger patches.
Results/Conclusions
We found greater number of links in larger patches after accounting for the effect of habitat amount. Considering the significant increase in number of links with greater patch size, we ran additional tests taking into account the number of hummingbirds captured. Results showed a strong relationship between the observed number of links and number of captured hummingbirds, which also increased in larger patches. Furthermore, the species specialization index supports our null hypothesis that non-territorial hummingbirds are not becoming more specialized in larger patches.