Seasonal and Within‐Day Variation on Hummingbirds Visits and Dominance Hierarchy in a Brazilian Cerrado Area

ABSTRACT Plant‐hummingbird interaction networks can be influenced by environmental conditions and resources, which vary seasonally and daily. We aimed to understand how variations in these parameters across these two temporal windows influence patterns of plant‐hummingbird interactions and hummingbirds dominance hierarchies in a Brazilian Cerrado located on Bahia state. We recorded hummingbird species, the plants they visit, and their agonistic interactions for 13 months. We register 2233 visits from four hummingbird species to 15 plants, with only 0.02% being illegitimate. The frequency of visits was positively correlated with flower availability, and the ornithophilous species Calliandra dysantha (Fabaceae) was the most visited plant. The annual interaction network displayed low specialisation (H 2 ' = 0.42, Δ = 0.41) and modularity (Qw = 0.25, Δ = 0.22). We did not observe significant differences in the hummingbird's visitation frequencies at different periods of the day. Most visits occurred during the rainy season (70.9%) when the network showed lower modularity, higher specialisation and greater trophic niche overlap. We recorded 101 agonistic interactions, with Chrysolampis mosquitus and Chlorostilbon lucidus involved in approximately 80% of them. Eupetomena macroura was the dominant species overall and during the dry season, while C. mosquitus males dominated in the rainy season. Dominance was not associated with the number of visits (R 2 = 0.32, p = 0.25). Increased flower abundance during the rainy season was linked to higher visiting frequency and agonistic interactions. These results underscore the role of resource availability, especially ornithophilous plants, in shaping plant‐hummingbird interactions.