Power for Hovering Flight in Relation to Body Size in Hummingbirds

Previous experiments indicated that a 10 g hummingbird had the same energetic cost per gram-hour for hovering as a 3 g hummingbird. The theoretical equations relating power for hovering flight and body weight indicate that energetic costs for hovering per gram-hour are not statistically different for hummingbirds of different sizes. Thus, a large hummingbird expends more energy to hover per unit time than a small hummingbird. Since hummingbirds normally hover to obtain energy (from nectar), this relationship has important implications for understanding their foraging strategies, the pollination strategies of plants that provide them with nectar, and factors governing their habitat occupancy, as well as theoretical limits on body size in these birds, which rely on energetically costly foraging strategies.