The Lucifer Hummingbird breeds primarily on the arid plateau and mountain slopes of central and northern Mexico, barely entering the United States to breed in west Texas, southwest New Mexico, and southeast Arizona. Most wintering birds are found at middle elevations of central Mexico. The species uses a wide elevational range throughout the year, but breeding is restricted to dry, open habitats. Over most of its range, little is known about this species' abundance or migrations.
The only detailed natural history and behavioral studies of the Lucifer Hummingbird have been of migratory populations in Mexico City ( Villada 1873 , Wagner 1946b ) and of breeding populations in Big Bend National Park, Texas ( Kuban et al. 1983 , Scott 1993d and unpublished data). Although much of the biology is poorly known, observation of nesting Lucifer Hummingbirds has revealed a courtship behavior apparently unique among hummingbirds studied to date. Males perform flight displays at the nests of females, especially during nest-building and egg-laying. In other species, males court away from nests at flower territories, prominent perches, or lek sites. No pair bond is formed by adult Lucifer.
Hummingbirds, however, and males spend little time near nests except to find them and to display. Dependence on nectar involves a hummingbird in ecological interactions with a variety of plants and nectar-feeding animals. For the Lucifer Hummingbird, the most interesting of these associations may be its interaction with agaves (Agave spp.) and associated animals. Agaves are common in the Lucifer Hummingbird's aridlands range.
The larger species are adapted for pollination by specialized bats and produce far more nectar than hummingbird-adapted flowers do. The Lucifer Hummingbird takes advantage of any diurnal surplus, acting as a nonpollinating nectar thief (because flower design results in no contact between sexual parts and a small hummingbird). Dead agave flower stalks, however, provide nest sites for a competing nectar feeder, the large carpenter bee Xylocopa californica, which cuts the bases of hummingbird flowers, at times severely depleting nectar and thereby excluding the Lucifer Hummingbird from plants such as ocotillo (Fouquieria splendens) ( Scott et al. 1993 ).