Broad-tailed Hummingbird is most easily detected by the male’s wing-trill, heard even at elevations below its high altitude breeding grounds. Its nesting ecology is influenced by the female’s need to keep her eggs and nestlings warm during the cold nights at these elevations while she enters torpor to survive Calder and Calder 1992).
DISTRIBUTION. During the 1987-1992 field work period of the TBBA project observers found 6 confirmed, 4 probable and 6 possible breeding records, 10 of these (including all the confirmed records) in latilong 31104 (the Guadalupe Mountains), 4, including 3 probables, in 30104 (the Davis Mountains) and 1 possible each in 30102 and 35101. These last 2 possible records are not associated with the usual upper elevation habitats in which Broad-tailed Hummingbirds typically nest. They may be migrants. Lockwood and Freeman (2004) describe the species as uncommon to locally common in the Chisos, Davis and Guadalupe mountains. North American Breeding Bird Survey field workers found <1 Broad-tail per route in the northern Trans-Pecos region (Sauer et al. 2005).
Outside Texas this hummingbird breeds from the highlands of southern Idaho and Wyoming south through eastern California, Nevada, Utah, Colorado, Arizona, New Mexico and mainland Mexico south to Oaxaca. An isolated population is resident in Chiapas, Mexico. Migratory populations winter from Central Mexico to Oaxaca (Howell and Webb 1995, Sauer et al. 2005).
SEASONAL OCCURRENCE. North bound migrant Broad-tailed Hummingbirds have been found in Texas from March 23 to May 31 with peak migration between late March to late April. The breeding season is late March or early April to mid-June and south bound migrants have been reported between July 21 and November 24 with the highest numbers between early August and mid- or late October. There have been many instances of this species wintering at feeders throughout the state (Oberholser 1974, Lockwood and Freeman 2004).
In Arizona where a larger sample of nesting dates was obtained, breeding evidence was found from April 10 to July 20 (Grossi and Corman 2005).
BREEDING HABITAT. In Texas Broad-tailed Hummingbirds breed in pine-oak woodlands and juniper scrub (Oberholser 1974). In Arizona nesting was found through a larger variety of habitats, 72% of nesting was in area containing at lest some pinyon or ponderosa pine (Grossi and Corman 2005).
Nests are placed on conifer, aspen, alder, cottonwood, willow or scrub oak branchs, generally just under an overhanging branch and usually 0.3 to 1.5 m (1-5 ft) above ground. The female builds the nest in 4-5 days of plant down, lashed together and to the supporting bough with spider silk. The exterior of the compact cup is decorated with lichens, The structure, lined with fine plant down, and its placement are designed to retain heat on cold nights when the female goes into torpor to survive.
The female lays 2 white eggs, indistinguishable from those of other similar-sized hummingbirds. She incubates for 16-19 days, starting after laying the first egg,. As the nestlings grow older they perch on the nest rim, gradually flattening the cup into a platform (Harrison 1979, Calder and Calder 1992).
STATUS. Data from 190 Breeding Bird Survey routes (40 km [25 mi] in length) provide a 95% confidence interval (There is a 95% chance that the actual population trend will be between these two numbers.) of -1.6 to +0.4% population change per year for the period 1966-2004 (Sauer et al. 2005). This relatively small population change, combined with Lockwood and Freeman’s (2004) description of the species as uncommon to locally common suggests that Broad-tailed Hummingbird will continue to breed (at least in the Guadalupe Mountains) for some years.
Text by Robert C. Tweit (2006)
Calder, W. A. and L. L. Calder. 1992. Broad-tailed Hummingbird (Selasphorus platycercus). In The birds of North America, No. 16 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.
Grossi, B. and T. E. Corman. 2005. Broad-tailed Hummingbird (Selasphorus platycercus). In Arizona breeding bird atlas.pp. 262-263 (T. E. Corman and C. Wise-Gervais, eds.), University of New Mexico Press, Albuquerque.
Harrison, H. H. 1979. A field guide to western birds’ nests. Houghton Mifflin, Boston, MA.Howell, S. N. G. and S. Webb. 1995. A guide to the birds of Mexico and northern Central America. Oxford University Press, New York.
Lockwood, M. W. and B. Freeman. 2004. The TOS handbook of Texas birds. Texas A&M University Press, College Station.
Oberholser, H. C. 1974. The bird life of Texas. University of Texas Press, Austin.
Sauer, J. R., J. E. Hines, and J. Fallon. 2005. The North American Breeding Bird Survey, results and analysis 1966-2004. Version 2005.1. USGS Patuxent Wildlife Research Center, Laurel MD (Web site, http://www.mbr-pwrc.usgs.gov/bbs).