Temporal dynamics of flower use by hummingbirds in a highland temperate forest in Mexico

Abstract

In pollination mutualisms, new resource patches are constantly being created as new flowering species come into bloom. The patch dynamics can have effects on the organization of multispecies pollination guilds, depending on the temporal and spatial variation of floral resources. The goal of this work was to investigate the temporal dynamics of the flower use by a hummingbird community in a highland temperate forest in central Mexico. The system was studied in terms of the seasonal changes in (1) specific composition and abundance of hummingbirds and their plants, (2) use of floral resources, and (3) nectar characteristics of hummingbird-pollinated plants. Eight plant species were visited by hummingbirds. These species differed in nectar and sugar characteristics and flowering intensity throughout the year. The highest floral abundance was recorded from May to October. Three plant species showed blooming peaks in this period; these species, Salvia elegans, Bouvardia ternifolia, and Penstemon roseus, were the most abundant and most visited flowering species over the year. Eight species of hummingbirds were recorded: two resident hummingbirds, three altitudinal migrants, and three winter visitors. Hummingbirds showed seasonal preferences and changes in foraging behaviour with respect to visitation rates and the use of floral resources among habitats. This work suggests that the availability and quality of resources can explain the temporal and spatial composition of the hummingbird community on a local scale.