Broad-tailed Hummingbird Life History

Habitat

Broad-tailed Hummingbirds breed in meadows and open woodlands, especially pinyon-juniper, pine-oak, evergreen, and montane scrub and thickets from around 5,000–10,500 feet elevation. During migration they move through highland meadows to lowlands with abundant flowers. In winter, they forage in pine-oak forests, dry thorn forests, and tropical highlands throughout MexicoBack to top

Food

Broad-tailed Hummingbirds drink nectar from flowers, especially species such as larkspur, red columbine, indian paintbrush, sage, and scarlet gilia as well as sugar water from feeders. During spring migration, they also feed on flowers that are not typically used by other hummingbirds, including pussy willow, currant, and glacier lily. Nectar is a low-protein food, so they also eat small insects, especially nesting females, and feed insects to their nestlings. They glean insects from leaves, snatch them from midair, or pick them out of spiderwebs. Sometimes they use sap as a nectar substitute, visiting sapwells excavated by Red-naped Sapsuckers.Back to top

Nesting

Nest Placement

The female looks for a place sheltered from cold high-elevation nights to build her nest. She often places her nest on an evergreen or aspen branch with overhead cover or in a willow or alder thicket, anywhere from 1–5 feet above the ground.

Nest Description

Females build and tend the nests alone. The female builds a tiny cup-shaped nest out of spiderwebs and gossamer, which provides excellent insulation, and helps conserve heat in the cold of high altitudes. It is often placed under overhanging branches, keeping the nest warmer than surrounding areas, and reducing nighttime energy requirements of the incubating female. She forms the nest cup by twisting the material around with her body and feet while sitting in the nest. The thick inner cup is made out of spiderweb and gossamer, and after forming the cup, she camouflages the outside of it with bits of lichen, moss, and bark fragments. Material may be stolen from other nests and is frequently added during incubation, with the nest sometimes becoming taller over time. It takes about 4–5 days for her to build a nest, less if built upon a previous nest. The nest has an outer diameter of about 2 inches and a 0.8-inch inside diameter, but it stretches as the chicks grow, becoming more platform shaped. Sometimes the female will reuse a nest from a previous season, adding fresh material to what was left.

Nesting Facts

Behavior

Broad-tailed Hummingbirds hover to snatch insects from the air or above flowers to drink nectar. When hovering, they beat their wings at about 50 wingbeats per second. Males also hover above tall vegetation to keep an eye out over their territory, chasing away unwelcome visitors. During courtship males perform spectacular aerial displays for females, involving a series of climbs and dives while loudly trilling their wings. Males climb high into the sky and rapidly dive toward the ground, pulling out of the dive in front of a female. If a male loses sight of a female, he hovers high above the ground and looks around for her. Despite the elaborate displays, males don't form pair bonds and are promiscuous; males often mate with several females in one breeding season. Males also do not feed incubating females or care for the young even after they fledge. When the nights are cold or if they cannot obtain enough food to keep their body temperature up, it is not uncommon for both sexes, to go into a hypothermic torpor at night. In torpor they slow their heart rate and drop their body temperature to save energy. Because males are not caring for their young, they can also leave their territories at night when cold air descends into the breeding area, seeking warmer areas elsewhere. Back to top

Conservation

Broad-tailed Hummingbirds are fairly common, but their numbers declined by over 1% per year resulting in a cumulative decline of approximately 45% between 1966 and 2019, according to the North American Breeding Bird Survey. Partners in Flight estimates a global breeding population of 9.8 million birds and rates them 13 out of 20 on the Continental Concern Score. It is included on the Yellow Watch List for birds most at risk of extinction without significant conservation actions to reverse declines and reduce threats. Causes of the decline are not clear, but climate may affect both breeding success and overwinter survival. In some parts of the breeding range, increasing temperatures have caused plants at high elevation breeding sites in the Rocky Mountains to flower earlier, shortening the time Broad-tailed Hummingbirds have to take advantage of these nectar sources. This mismatch in nectar availability could decrease nesting success. Severe winter temperatures on the wintering grounds could also affect survival. In the late 1950s, Colorado reported that fewer hummingbirds returned to breed following an apparently severe winter in Mexico. Window strikes, collisions with cars, and electric fences are also threats to Broad-tailed Hummingbirds. Broad-taileds, like other hummingbirds, may benefit from the popularity of hummingbird feeders, which may allow for increases in population, at least in settled areas, due to increased nectar availability.

Credits

Camfield, Alaine F., William A. Calder and Lorene L. Calder. (2013). Broad-tailed Hummingbird (Selasphorus platycercus), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.

Dunne, P. (2006). Pete Dunne's essential field guide companion. Houghton Mifflin Harcourt, New York, USA.

Karlson, Kevin and D Rosselet. (2015). Birding by Impression. Living Bird 25:34-42.

Lutmerding, J. A. and A. S. Love. (2020). Longevity records of North American birds. Version 2020. Patuxent Wildlife Research Center, Bird Banding Laboratory 2020.

Partners in Flight. (2020). Avian Conservation Assessment Database, version 2020.

Rosenberg, K. V., J. A. Kennedy, R. Dettmers, R. P. Ford, D. Reynolds, J. D. Alexander, C. J. Beardmore, P. J. Blancher, R. E. Bogart, G. S. Butcher, A. F. Camfield, A. Couturier, D. W. Demarest, W. E. Easton, J. J. Giocomo, R. H. Keller, A. E. Mini, A. O. Panjabi, D. N. Pashley, T. D. Rich, J. M Ruth, H. Stabins, J. Stanton, and T. Will (2016). Partners in Flight Landbird Conservation Plan: 2016 Revision of Canada and Continental United States. Partners in Flight Science Committee.

Sauer, J. R., D. K. Niven, J. E. Hines, D. J. Ziolkowski Jr., K. L. Pardieck, J. E. Fallon, and W. A. Link (2019). The North American Breeding Bird Survey, Results and Analysis 1966–2019. Version 2.07.2019. USGS Patuxent Wildlife Research Center, Laurel, MD, USA.

Sibley, D. A. (2014). The Sibley Guide to Birds, second edition. Alfred A. Knopf, New York, NY, USA.

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