Calliope Hummingbird

Stellula calliope

Sally Conyne
  • TROCHILIDAE
  • Hummingbirds
  • 1 million

The Calliope Hummingbird is the smallest breeding bird in North America and the smallest long-distance avian migrant in the world! This 3.25" long pollinator travels some 9,000 km round-trip on migration from northwestern U.S. and southwestern Canada to south-central Mexico. This tiny bird is threatened by a small winter range, which renders it vulnerable to a disease outbreak, large landscape changes, and severe weather events.

Identification
The latin name Stellula means "little star," given to the Calliope for the male's streaked bright red gorget or throat patch over a white background. His upperparts are all green which extends to the sides of his white belly. The female and juveniles also have green upperparts and solid buffy underparts. Adult females and subadult males can show some red spotting on the throat. Calliopes have a short, square tail that has very little rufous, as distinguished from Broad-tailed and Rufous Hummingbirds, and a thinner and shorter bill than Rufous or Allen's. Its shorter wings make it sound more like a bumblebee than other larger hummingbirds. Adult males can be distinguished in the field by their unique aerial display, consisting of a series of U-shaped dives starting and ending at the same points. A pfft or bzzt sound is made from the bottom of these dives.

Distribution and Population Trends
Calliope breeds in the mountains of western North America from British Columbia and Alberta south through Nevada and California, and east to Montana and Wyoming. The Upper McCloud River Important Bird Area (IBA) in California supports breeding Calliopes. It winters in a small area in south-central Mexico from the states of Sinaloa and Durango south to Oaxaca, and can be found in Tancitaro and Tacambaro, two Mexican IBAs. Breeding Bird Survey data (see link below) indicate a statistically nonsignificant 0.3% per year decline rangewide from 1966-2001 but with significant declines in Montana and Oregon. It is increasingly observed overwintering in southwestern and south-central portions of the United States.

Ecology
Despite its small size and long migration route, this hummingbird does not find comfort in numbers. It makes the roughly 9,000 km round-trip on its own, splitting the trip into smaller segments to refuel. Its fall migration route follows the Rocky Mountain Cordillera and Sierra Madre Occidental. Traveling at an elevation of roughly 3,900 m, they stop in subalpine and alpine meadows to refuel. When they arrive on their wintering grounds, they occupy a range of habitats from dry thorn forest up to the transition between arid and humid pine-oak forests as well as brushy areas. They return in the spring along the Pacific coast at an elevation of roughly 5,400 m. En route they occupy desert washes, low coastal mountains, and coastal riparian habitats, before heading eastward if they breed in the Rockies. Here it is mostly a montane species, breeding at elevations ranging from 1,200 m to timberline. It occupies habitats ranging from riparian forests to shrub-sapling secondary growth to open montane forests.

Males arrive on the breeding grounds before the females in late-April to early-May. Males maintain a territory in which multiple females will nest and take sole responsibility for raising the young. Females construct nests usually in pine or other coniferous tree, but sometimes in apple, or alder, usually with the nest tucked under an overhanging branch to reduce exposure to the elements. The nest is often built on the base of an old pinecone and looks like a pinecone when complete. Two eggs are incubated for 15-16 days. Nests may be used more than once. Calliopes consume floral nectar from flowers of many different colors, as well as small insects that may be captured in flight. It also eats sap from wells in trees created by sapsuckers.

Threats
Many species of pollinators have shown decreases across the continent. Little information is available on the overall issues that are causing these declines but potential threats include habitat loss, increased use of pesticides, and replacement of native plants by invasive plants. The restricted wintering range of Calliope Hummingbird makes the species more susceptible to natural disasters, diseases, or land use changes that could wipe out significant portions of the population.

Conservation
Despite its unique characteristics in the avian world, Calliope Hummingbird has not been well studied, leaving much of its life history unknown. In order for any conservation measures to be taken that would benefit this species, we need to better understand the biology and needs of this species.

Partners in Pollination/Alianza para Polinizacion, a consortium of non-profit organizations, universities, and businesses, was formed in 1995 to increase awareness of the importance of pollinators to ecosystems, encourage research and conservation on plant/pollinator interactions, and influence policy related to plant/pollinator conservation.

The Arizona-Sonora Desert Museum's Migratory Pollinators and Their Corridors project is working to educate, develop community stewardship, and conservation for plant/pollinator systems in the U.S. and Mexico (http://www.desertmuseum.org/conservation/mp/polpart.html).

What Can You Do?
Audubon's Important Bird Areas program is a vital tool for the conservation of Calliope Hummingbirds as well as other species. To learn more about the Important Bird Areas program, and how you can help, visit: http://www.audubon.org/bird/iba/.

Information on where Calliope Hummingbirds occur and in what numbers is vital to conserving the species. Help in monitoring this and other species by reporting your sightings to eBird. A project of Audubon and the Cornell Lab or Ornithology, eBird is the world's first comprehensive online bird monitoring program: http://www.audubon.org/bird/ebird/index.html.

Volunteers are also crucial to the success of long-term monitoring programs such as the Breeding Bird Survey (BBS). The BBS helps determine the distribution of species such as the Calliope Hummingbird and monitors population trends. To find out how you can get involved, log on to: http://www.mp2-pwrc.usgs.gov/bbs/participate/.

The Southeastern Arizona Bird Observatory has a hummingbird banding station on the San Pedro River. Their website not only provides information about hummingbirds, but the station also offers hummingbird workshops for visitors, including one on hummingbird banding and one on hummingbird identification. For more information, visit: http://www.sabo.org/hummers.htm.

References
Calder, W. A. and L. L. Calder. 1994. Calliope Hummingbird (Stellula calliope). In The Birds of North America, No. 135 (A. Poole and F. Gill, eds.). Philadelphia: The Academy of Natural Sciences; Washington, D.C.: The American Ornithologists' Union.

Kaufman, K. 1996. Lives of North American Birds. Houghton Mifflin Company, New York.

Sibley, D. A. 2000. The Sibley Guide to Birds. National Audubon Society. Chanticleer Press, New York.