Hummingbirds’ interactions and their floral resources in an anthropized environment at the south of Brazil

Although hummingbirds are common inside cities, little is known about their feeding habits, which allows their existence in those modified environments. During one year I recorded which species of hummingbirds occur in urban gardens in the city of Getúlio Vargas, their behaviors and which plants are used by them. Eight species of hummingbirds could be found, being the species Eupetomena macroura and Amazilia versicolor occurrences at the North region of the State of Rio Grande do Sul. A total of 51 agonistic interactions were registered, being Leucochloris albicollis and Chlorostilbon lucidus the most aggressive and also the ones that visited the higher number of plants. It is also possible to suggest an altitudinal migration of C. lucidus at the State during the cold months. Twenty-two plant families were visited by those birds, with Bignoniaceae, Fabaceae and Malvaceae the most visited ones. The main flowering season of the observed plants was of September to December. Out of the 31 visited plants, 19 are considered exotics (61.3%) and 12 natives (38.7%); eight are classified as ornithophilous (25.8%) and 23 entomophilous (74.2%), which indicates an adaptation of these birds to the food availability inside cities. Handroanthus chrysotrichus had the shortest flowering period; however, it attracted a high number of hummingbirds; Callistemon viminalis was in bloom during the entire year and also attracted a high number of hummingbirds. All the visited plants have colors varied between white, yellow and red tones, and those with tubular corolla were the most visited (51,6%).