Broad-tailed Hummingbirds prefer meadows with abundant wildflowers flanked by forests. Broad-tailed Hummingbirds are migratory and fly to summer breeding grounds in the western Rocky Mountains in the spring then return to Mexico and Guatemala to winter. Their breeding range stretches from central California to as far east as eastern Kansas and from southern Idaho to southwest Texas.
These tiny birds weigh only about 3.5 grams, or a bit over one tenth of an ounce. They are well adapted to their feeding habits with hovering wings, long thin beaks, and grooved tongues that allow them to harvest the nectar of flowers and catch tiny insects. Broad-tailed Hummingbirds emit a loud “trill” with their wings to attract mates and defend their territories. The ability to enter torpor to survive frigid mountain nights is also an amazing evolutionary adaptation of these and other hummingbirds. In a torpid state, the birds lower their metabolic rate and drop their body temperature dramatically until it is close to the ambient (surrounding) temperature. Without this trait the birds would risk starving to death as they try to maintain physiological homeostasis, including an elevated body temperature.
Hummingbirds benefit some flowering plants by providing pollination services and those plants reward the hummingbirds with nectar. Hummingbirds can also reduce insect populations on the flowering plants they visit. Adult hummingbirds have few predators, but nests, eggs, and nesting birds are food for raptors and other birds, snakes, and foraging carnivorous mammals.
In the 1980s and 1990s, several RMBL researchers trained male Broad-tailed (and Rufous) Hummingbirds to visit hand-held Ipomopsis aggregata flowers in a temporary aviary in Gothic. The flowers in all of these experiments could be manipulated by painting to alter flower color, changing flower shape, etc. Below we see Dr. Mary Price in 1988 with the experimental subjects. For details, see Campbell et al. 1991.
Learn more about Selasporus platycercus at the Encyclopedia of Life.
homeostasis - The condition of any system in which its internal properties are maintained within narrow limits. When referring to living organisms, the internal properties are physiological ones such as rate of metabolism, pH of the blood, body temperature, and the like.
torpor - A state of short-term hibernation in which an animal reduces its rate of metabolism and hence its body temperature, thus conserving energy.