Selasphorus platycercus is a migratory species with some resident populations in Mexico. Migratory populations breed in Colorado and Wyoming, while tropical resident populations breed in central Mexico. Their winter range expands from northern Guatemala to northern Mexico. Information on non-migratory populations is lacking (Calder and Calder, 1992).
The breeding habitat of broad-tailed hummingbirds includes willows around wet or dry stream beds, pinion, juniper, spruce and oak woodlands. They are known to nest as high as 3,230 m. In their winter range, which overlaps with the breeding range of resident populations in Mexico, broad-tailed hummingbirds use thorn and oak forests at lower elevations, and mixed oak-pine and cypress as well as fir forests at higher elevations. Because of the year-round availability of hummingbird feeders in some areas, some individuals have taken up residence in urban and suburban areas of southwestern United States (Calder and Calder, 1992).
Broad-tailed hummingbirds are sexually dimorphic. Males have a metallic iridescent-rose colored gorget, green colored sides and back with some rufous color in the tail. The females are less colorful, lacking a complete gorget, and exhibiting buffy colored sides and a green back. Females are larger than males but body mass can vary during the course of a day based on nectar intake. Juvenile males look like adult females and are difficult to distinguish. (Kaufman, 2000).
Broad-tailed hummingbirds have a promiscuous mating system in which male and female only interact for copulation. Males may mate with as many as six females in a season. (Calder and Calder, 1992)
Males court females by doing a series of diving displays. A lek display of three males has been observed, but it could have been a misinterpreted territorial stand. After the copulation, the female may stay and preen for a few minutes before flying away. Nests are built by the female alone. Nests take a hemisphere shape with a depression on top. Their inner diameter is 1.9 cm. Eggs are laid in clutches of two. (Calder and Calder, 1992)
Female broad-tailed hummingbirds make the nest and raise the young on their own. Ten to twelve days after hatching, females start to roost away from the nest, where there is almost not enough space for the young to huddle together. Females feed young mostly small insects through their development, and then they abandon them to start their south-bound migration (Calder and Calder, 1992).
Life expectancy is 1.6 years based on the 50% mark on a survivorship curve in males and 1.9 years in females. The highest recorded age for wild females is 12 years and 8 years in males. (Calder and Calder, 1992)
Males in the breeding season are active for an average of 910 minutes/day out of an 878 minute solar day, and active for 608 minutes/day during a 602 minute solar day in an Arizona winter range. In the Mexico winter, they average 592 active minutes/day for a 657 minute solar day. Females spend 78% of their day on the nest during incubation and 62% of day on the nest during brooding.
Males are territorial and will vigorously defend their territory from intruders during mating season. Individuals will challenge vocally and chase other individuals off of their territory. Territory size will depend on food availability as well as density of birds.
Individuals from migratory populations migrate north in the spring abandoning the non migrant populations in central Mexico. They reach southern Arizona from late February to early March. By late April-early May individuals reach northern Arizona and Colorado. They reach the upper limit of their distribution (Idaho) by mid May. After breeding, they start their south-bound migration into their winter range in Mexico, arriving there by August. Males arrive before females and juveniles, occupying the best quality territories (Calder and Calder, 1992).
Broad-tailed hummingbirds feed on floral nectar and small insects. They usually visit flowers with red tubular corollas like the Scarlet Gilia (Ipomopsis aggregata). In the wintering grounds Broad-tailed Hummingbirds are not the dominant species and may have to forage on less preferred flowers. A study done with Ruby Throated, Rufous and Broad-tailed Hummingbirds suggested that there may be an element of observational learning involved in learning to forage on novel food resources. Insects are caught in air as well as by gleaning from foliage. There is a daily steady gain in body mass of individuals from foraging over the course of a day, with a total gain of 30 to 34% of their body mass just before flying to their roosting sites. This large foraging bout before roosting is probably needed to store energy for overnight thermoregulation.
Nectar used by hummingbirds contains large amounts of water that a hummingbird has to pass through its body either by absorbing it into the intestinal tract to be processed by the kidneys or just letting it pass through the tract without absorption. Water intoxication would be a major problem for most vertebrate species under these conditions but hummingbirds are able to excrete large amounts of dilute urine and handle large amounts of water being processed by the kidneys. They do however vary the amount of nectar taken in based on the sugar concentration of that nectar.
Nectar is taken from the following plants: Ipomopsis aggregata, Aquilegia elegantula, A. triternata, Penstemon spp., Castilleja spp., Salvia spp., Echinocereus grandiflorum, Mertensia oblongiforum, Delphinuim nelsoni, Ribes ciliatum, Cestrum terminale, Buddleia dara and Senecio angulifolius.
(Calder and Calder, 1992; Calder, 1994; McWhorter and Martinez del Rio, 1999; Altshuler and Nunn, 2001)
Broad-tailed hummingbirds are important pollinators of the plant species they forage on. (Calder and Calder, 1992).
Hummingbirds, especially in areas where feeders are present, can be popular attractions for tourists to want to visit. Broad-tailed hummingbirds can be incorporated into ecotourism in areas where they are prevalent.
Increased use of feeders help to sustain populations in times of resource scarcity (Calder and Calder, 1992).
Erin Olson (author), University of Arizona, Jorge Schondube (editor), University of Arizona.
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
living in the southern part of the New World. In other words, Central and South America.
uses sound to communicate
young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
uses smells or other chemicals to communicate
humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
parental care is carried out by females
union of egg and spermatozoan
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
fertilization takes place within the female's body
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
makes seasonal movements between breeding and wintering grounds
having the capacity to move from one place to another.
This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.
the area in which the animal is naturally found, the region in which it is endemic.
an animal that mainly eats all kinds of things, including plants and animals
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
Referring to something living or located adjacent to a waterbody (usually, but not always, a river or stream).
scrub forests develop in areas that experience dry seasons.
breeding is confined to a particular season
reproduction that includes combining the genetic contribution of two individuals, a male and a female
living in residential areas on the outskirts of large cities or towns.
uses touch to communicate
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
Living on the ground.
defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
living in cities and large towns, landscapes dominated by human structures and activity.
uses sight to communicate
Altshuler, D., A. Nunn. 2001. Observational Learning in Hummingbirds. The Auk, 118 No. 3: 795-799.
Calder, W. 1994. When do Hummingbirds use Torpor in Nature. Physiological Zoology, 67: 1051-1076.
Calder, W., L. Calder. 1992. Broad-tailed hummingbird: Selasphorus platycercus. A Poole, F Gill, eds. The Birds of North America. Philadelphia: American Ornithologists' Union.
Kaufman, K. 2000. Birds of North America. New York, NY: Houghton Mifflin Company.
McWhorter, T., C. Martinez del Rio. 1999. Food ingestion and Water turnover in Hummingbirds: How much dietary water is absorbed?. The Journal of Experimental Biology, 202: 2851-2858.