Temporal dynamics and central species in a plant-hummingbird interaction network in an inter-Andean valley in the southern Peruvian Andes

Plant-hummingbird interactions are key components of Neotropical ecosystems, yet they remain poorly documented in arid inter-Andean valleys of southern Peru, which are characterized by marked climatic seasonality. We evaluated the structure, temporal dynamics, and central species of a plant-hummingbird interaction network in the Sogay valley, Arequipa. From March to August 2025, feeding, perching, and competitive interactions were recorded through direct observation surveys. The feeding network comprised 10 plant species, four hummingbird species, and 21 observed links. It showed moderately high connectance (0.525), intermediate specialization (H2’ = 0.550), moderate modularity ( Q = 0.386), and presence-absence-based nestedness (NODF = 65.23). Visits were concentrated on Tecoma fulva (47.5%), Ligaria cuneifolia (25.1%), and Nicotiana glauca (10.3%), whereas Rhodopis vesper was the most central hummingbird species. Activity peaked in May and June, which also showed the highest temporal similarity. Nectar concentration was not associated with visitation frequency (ρ = 0.018; p = 0.969), and floral length showed only a non-significant positive trend. These results reveal a temporally dynamic feeding network in which interaction frequency was concentrated around a small set of floral resources, while plants were also used as perches and sites of agonistic interactions. Overall, this study highlights the ecological importance of floral and structural resources for hummingbird activity in arid Andean landscapes.