The Rufous Hummingbird (Selasphorus rufus). There are only three species of hummingbird in British Columbia, but this one wins the title. These feisty little birds are a measly 3.0 grams of sass. Hummingbirds are solitary and aggressive; they are constantly in dispute with other birds over territory around feeders and flowers (Sibley, 2003) and will attack intruders sometimes many times their size. The Rufous Hummingbird is known as the most aggressive of all Western North American species. They are long distance migrants, but in the summer months they can be found throughout the Pacific Coast of Canada and the Pacific Northwest of the U.S. buzzing around feeders and flower gardens.

Hummingbirds are unmistakable in the field: aside from being ridiculously cute, they are tiny birds with long bills and a distinctly unique hovering flight. They have exceptionally long primary feathers to facilitate hovering (Sibley, 2003).

The male Rufous Hummingbird has brilliant orange and green feathers and a bright pink bib of iridescent structural feathers, also called a ‘gorget’. The gorget is used to show off to female hummingbirds and hopefully attract a mate. The male has a rufous tail with dark green and white tips, and both sexes share a white spot behind the eye. The female is orange and green with a patchy distribution of iridescent feathers on the throat. The female has many more green feathers compared to the male’s mostly rufous colouration (Sibley, 2003; Sakai and Ralph, 2007). Immature Rufous Hummingbirds are impossible to tell apart from adult females in the field, but can be distinguished in the hand by looking for bill corrugation. Hummingbirds are born with tiny grooves along their bills, which wear away and become smooth during their first summer; a smooth bill would indicate an older bird (Sakai and Ralph, 2007).

In British Columbia, the most likely other species of hummingbird that could be confused with a Rufous Hummingbird is the Anna’s Hummingbird (Calypte anna). These species can be distinguished by the presence of any rufous feathers; Anna’s Hummingbirds have no rufous colouration and are larger in size. The hummingbird with most similar colouration to the Rufous Hummingbird is the Allen’s Hummingbird (Selaphorus sasin), which can be distinguished by the presence of green feathers on the back. However, some Rufous Hummingbirds have green feathers on their back, which can make these birds very difficult to tell apart on their wintering grounds in Mexico and coastal California.

Rufous Hummingbirds make many different calls, the main noise they make being a high, hard chip. They also make a buzzing noise with their wings while in flight (Sibley, 2003). When dive-bombing an intruder to their territory, Rufous Hummingbirds make a distinctive vi vi vi virrr sound with their wings (Sibley, 2003). Since describing sounds with text never works, here a couple recordings of noises Rufous hummingbirds typically make:

This is a Rufous Hummingbird call. Retrieved from: [link].

These are sounds made by a Rufous Hummingbirds wings and tail during display, while hovering, or while diving. Retrieved from: [link].

You can also check out Cornell University’s page on Rufous Hummingbird sounds here.

Rufous Hummingbirds build tiny cup-shaped nests out of lichen and spidersilk. They lay two eggs per clutch, and nestlings take from 15 to 17 days to fledge (Calder and Healy, 2006). Check out this narrated PBS Nature video of an Anna’s Hummingbird building her nest.

Also, below is some footage recorded of a Rufous Hummingbird mom raising her chicks (Bonus: watch for giant visitor at 0:59, and a cute head scratch at 1:59).

They collect the soft materials needed for their nests from surrounding trees and shrubs in woodlands.

Rufous Hummingbirds are wide ranging and survive in a variety of habitats, but prefer open woodlands (Sibley, 2003; Calder and Healy, 2006). They breed as far north as Anchorage, Alaska; farther north than any other hummingbird (Calder and Healy, 2006; eBird, 2012). They typically breed in open or shrubby areas, forest openings, yards, parks, and sometimes can be found in forests, thickets, swamps, or meadows (Sibley, 2003; Calder and Healy, 2006). They winter in Mexico, and have been seen as far south as Puerto Angel, near the Mexican-Guatemalan border (eBird, 2012). You can find these hummingbirds wherever there are flowers or hummingbird feeders.

Hummingbirds are nectar feeders, they lap nectar from flowers and from hummingbird feeders with their long tongues (Roberts, 1996). For protein and fat, Rufous Hummingbirds feed on small insects like gnats and aphids (Calder and Healy, 2006). They are important pollinators since they transfer pollen with their bills as they move from flower to flower. Being able to build up food reserves is particularly important for these birds because they need the energy to migrate south for the winter.

Rufous Hummingbirds are long distance neotropical migrants; a particularly amazing behaviour for such a small bird. They have the longest migratory distance compared to body length then any other migratory bird (Calder and Healy, 2006). Its migration path is about 6,200 kilometres from Alaska to Mexico one-way is equivalent to 78,470,000 body lengths. In comparison, the bird with the longest distance migration in the world, the Arctic Tern’s one-way flight of around 18,000 kilometres is only 51,430,000 body lengths (Calder and Healy, 2006). Flying is a costly activity, and hummingbirds are the only birds that not only migrate long distances but spend most of their lives in the air, hovering.

Hummingbirds beat their wings in a figure-eight pattern to produce lift with both the downstroke and upstroke of the wings to facilitate hovering (Warrick, et al., 2005). Rufous Hummingbirds beat their wings 52-60 times per second to stay airborne (Calder and Healy, 2006). The ability to hover allows hummingbirds to feed from flowers without the need of a perch (Suarez, 2013).

Hummingbirds are the smallest of all birds in North America; Rufous Hummingbirds weigh, on average about 3.0 grams (Sibley, 2003). On top of having the longest migration in relation to body length, they also have the fastest metabolism of all vertebrates, with the ability to convert sugars to energy in as little as 30 minutes (Suarez, 1992; Suarez, 2013). Their heart rate can reach as high as 1,260 beats per minute while in flight (Suarez, 1992). During flight, the oxygen consumption per gram of muscle tissue in a hummingbird is about ten times higher than what is seen in human elite athletes (Hargrove, 2005). At night, hummingbirds slow their metabolism and lower their core body temperature in order to enter a state called ‘torpor’ to conserve energy reserves overnight when the temperature drops (Hiebert, 1993). During this state hummingbirds are very susceptible to predation, since it will take them over an hour to wake out of this state.

Rufous Hummingbirds are tiny, fascinating birds with enough power and energy to fly from Alaska to Mexico and back, every single year. Their high speed lives make for a fascinating example of the world’s smallest neotropical migrant. Stay tuned for a blog post on some current research involving Rufous Hummingbirds.

 

Literature Cited

Calder, W. A., and Healy, S. 2006. Rufous Hummingbird. The Birds of North America Online (A. Poole, Ed.) Ithaca: Cornell Laboratory of Ornithology; Retrieved from The Birds of North America Online database: [link]

eBird. 2012. eBird: An online database of bird distribution and abundance [web application]. eBird, Ithaca, New York. Available: http://www.ebird.org. (Accessed: October 29, 2015). [link]

Hargrove, J., L. 2005. Adipose energy stores, physical work, and the metabolic syndrome: lessons from hummingbirds. Nutrition Journal 4: 36-41. [link]

Hubert, S. 1993. Seasonal changes in body mass and use of torpor in a migratory hummingbird. The Auk 110: 787-797. [link]

Roberts, W. M. 1996. Hummingbirds’ nectar concentration preferences at low volume: the importance of time scale. Animal Behaviour 52: 361-370. [link]

Sakai, W., H. and Ralph, C. J.  2007.  A Tabular Format of Pyle’s Ageing and Sexing Methods for Land Birds.  North American Bird Bander 27: 77-90.

Sibley, D. A. 2003. The Sibley Field Guide to Birds of Western North America. Alfred A. Knopf, New York. 472 p.

Suarez, R. K. 1992. Hummingbird flight: sustaining the highest mass-specific metabolic rates among vertebrates. Experiential 48: 565-570. [link]

Suarez, R. K. 2013. Pre migratory fat metabolism in hummingbirds: a rumsfeldian approach. Current Zoology 59: 371-380. [link]

Warrick, D. R., Tobalske, B. W., and Powers, D. R. 2005. Aerodynamics of the hovering hummingbird. Nature 435: 1094-1097. [link]