Order: Apodiformes
Family: Trochilidae
Genus: Selasphorus
Species: Selasphorus rufus
Introduction:
The Rufous Hummingbird (Selasphorus rufus) is one of 20 species in the United States (Gleisner et al., n.d.). They are small in size, extremely territorial and migrate almost 8,000 miles a year (Cornell Lab of Ornithology, n.d.). The males are easily identified by their rufous (reddish brown) color, long narrow bill, and iridescent throat patch (Cornell Lab of Ornithology, n.d.). The females and immature typically have green iridescence on the throat and back with some rufous on their sides (Cornell Lab of Ornithology, n.d.). It is typical to start seeing Rufous Hummingbirds in Olympia, WA in late February to early March (Healy & Calder, 2006).
Rufous Hummingbirds are well known for their iridescence and feisty mannerisms. They are small in size, about 7-9.5 cm with an 11 cm wingspan, weigh between 2-5 g, and have a long bill with a slight curve (Cornell Lab of Ornithology, n.d., Healy & Calder, 2006).
Males are a bright copper color on their backs, crown, auriculars, and upper wing and tail coverts (Healy & Calder, 2006). Their forehead is iridescent green and occasionally the back and crown will have green iridescent feathers (Healy & Calder, 2006). Their throat, which can appear red, copper, or green, is very iridescent and changes color depending on the angle it is viewed from (Healy & Calder, 2006). Their chest is white and belly and under tail coverts are rufous (Healy & Calder, 2006, Cornell Lab of Ornithology, n.d.).
Females have green iridescence on its head, back and throat. They have a slight rufous color on their sides and a white belly (Cornell Lab of Ornithology, n.d.). Immature Rufous Hummingbirds are similar is color to the females but may have a bright iridescent patch on their throat (Cornell Lab of Ornithology, n.d.).
Juveniles are typically seen between June through November (Healy & Calder, 2006). They look similar to females with additional rufous on the rectrices and can be identified from creases on their upper mandible (Healy & Calder, 2006).
Hummingbirds have unique flight capabilities and the Rufous Hummingbird is no exception. They are able to hover in place, move in all directions (even backwards), all due to the unique rotation of their wings from the shoulders (Gleisner et al., n.d.). They are able to beat their wings up to 80 times in one second (Gleisner et al., n.d.). According to Healy & Calder (2006), Rufous Hummingbirds have a high wing load and are capable of forward and backwards wing strokes, which generate lift. Achache et al. (2017), researched wing aerodynamics of both Rufous and Anna’s Hummingbirds in an attempt to better understand the functions and limitations of flight in Anna’s Hummingbirds. Achache et al. (2017), found a “leading-edge bubble”, which generates a low-pressure area and “vortex shedding”, which essentially adds frequencies from the flow of air over the wings. Achache et al. (2017), found that this process creates a high lift to torque ratio during the revolution of the wings. Rufous Hummingbirds make a humming noise during flight and its pitch and frequency changes based on the rate of wing movement (Cornell Lab of Ornithology, n.d.). Clark et al. (2011), found that male Rufous Hummingbirds can create “aeroelastic flutter” with rectrix feathers 2, 3 and possibly 4, 5, which often creates more than one frequency at a given time.
Rufous Hummingbird species is found in western North America (Healy & Calder, 2006, Cornell Lab of Ornithology, n.d.). All About Birds, Birds of North America, and BirdLife International provide range maps. The range for Rufous Hummingbirds are from Southern Mexico to Southern Alaska and from the west coast of Canada and the United States to western Alberta, and the western portions of Montana, Wyoming, Colorado, and Texas in the United States (Healy & Calder, 2006, Cornell Lab of Ornithology, n.d.). Rufous Hummingbird migration patterns follow flower blooms (Healy, and Calder, 2006, Cornell Lab of Ornithology, n.d.). In late winter and early spring they migrate north up the west coast of the United States, British Columbia, and Alaska and in the late summer they begin southbound migration down the Rocky Mountains to wintering grounds in Mexico, and more recently along the gulf coast of the United States (Healy, and Calder, 2006). Courter (2016) used historical data to determine arrival dates of Rufous Hummingbirds in Tacoma Washington and found that warmer springs are associated with earlier arrival dates. Courter (2016), research indicates a small change in migration patterns in Oregon and Washington state.
Baily and Segelbacher (2013), researched genotypes of Rufous Hummingbirds to understand the structure within Rufous Hummingbird populations. Baily and Segelbacher (2013), didn’t find a significant genetic structure but instead their research indicated that there are Rufous Hummingbirds moving and breeding between populations.
Rufous Hummingbirds have a wide range of habitats including: forests, forest meadows, bushy areas, and urban parks and yards (Cornell Lab of Ornithology, n.d.). They are typically found in elevations from sea level to 6,000 ft but have been documented in elevations as high as 12,600 ft (Cornell Lab of Ornithology, n.d.).
Male Rufous Hummingbirds have been documented preforming courtship flights, where they will dive in oval, J or in figure-eight forms and use their feathers to make a whining noise at the bottom of the dive (Cornell Lab of Ornithology, n.d., Seattle Audubon Society, n.d.). About the time males start making feather noise they also vocalize (Hurly et al., 2001). Females build nests and raise altricial young without the aid of a male (Betchelder et al., 2012, Cornell Lab of Ornithology, n.d.). In Washington, females, who build nests early choose coniferous trees, bushes, and drooping branches and are typically low in the canopy due to the cold and rainy environment, while nests built later in the season are usually higher to protect against the heat (Seattle Audubon Society, (n.d.). Females build the nest, which is 2 inches across, using moss and soft plant material on the inside and bark and lichen to camouflage the outside and this is all held together by spider silk (Seattle Audubon Society, n.d., Cornell Lab of Ornithology, n.d.). Two eggs, which are incubated for about two weeks, are typically laid in a nest and nestlings spend about three weeks in the nest before fledging (Seattle Audubon Society, (n.d.). When nestling hatch, they have little down on their backs, closed eyes, and require extensive parental care (Cornell Lab of Ornithology, n.d.). In a unique case in Montana, Betchelder et al. (2012) observed a case were a female Rufous Hummingbird had two active nests at the same time. The nests were located in close proximity and one nest had a nestling almost ready to fledge while the second nest had eggs incubating (Betchelder et al., 2012).
Rufous Hummingbirds can be seen hovering at flowers using their long bill to reach nectar. To reach nectar, Rufous Hummingbirds are able to insert their bill into flowers and use their forked tongues to extract nectar (Grant & Temeles, 1992). According to Grant & Temeles (1992), Rufous Hummingbirds long tongues allow them to adapt to different sizes of flowers, which increases their overall available food sources. Their diet is Comprised of nectar and small insects to meet protein and fat requirements (Cornell Lab of Ornithology, n.d.). They prefer tubular flowers and visit feeders in backyards (Seattle Audubon Society, n.d.). To catch insects, they snatch them out of the air, referred to as “hawking insects” or from plant “gleaning” (Cornell Lab of Ornithology, n.d., Jelbert et al., 2014, Healy, and Calder, 2006). Hurley et al., (2009), tested how Rufous Hummingbirds are able to relocate flowers/feeders using distant features or local cues; they found that Rufous Hummingbirds use spatial cues to relocate flowers/feeders. Hurley et al., (2009), also found supporting evidence that the color of the flower/feeder does not influence if Rufous Hummingbirds locate flowers/feeders. Therefore, making it unnecessary to put food coloring in hummingbird feeders. In an experiment conducted by Jelbert et al. (2014), they tested Rufous Hummingbirds ability to recognize visual cues and sequences to get rewards, which consisted of high calorie nectar. Jelbert et al. (2014) found that Rufous Hummingbirds were able recognize cues and learn sequences but learning the order of a sequence to attain a reward was difficult for them.
Rufous Hummingbirds are well known for aggressively defends territory and food sources along migration routes and in breeding ranges (Cornell Lab of Ornithology, n.d., Seattle Audubon Society, n.d.). Aggravated individuals will fan their rectrices and sound a warning call and males display their throat patch (Cornell Lab of Ornithology, n.d.). Their flight pattern consists of rapid movement, usually from flower to flower, always in a straight line and they maintain the ability to stop and reverse quickly in smooth fluid motions (Cornell Lab of Ornithology, n.d.).
Torpor is essentially nightly hibernation and a useful tool hummingbirds use. According to Heibert (1991), Rufous Hummingbirds need to carefully manage energy reserves and torpor is a means to reduce energy use. Rufous Hummingbirds enter torpor at night, which reduces their body temperature and metabolic rate (Hiebert, 1990). Hiebert (1991), researched how food restrictions affect Rufous Hummingbirds and found when nutrients are restricted, they increase the time they spend in torpor. Hieberts (1991) findings indicate that Rufous Hummingbirds use torpor to conserve energy when food is scarce.
Rufous Hummingbirds have a raspy call used as a warning for intruders (Cornell Lab of Ornithology, n.d.). During mating, males make a “chu chu chu chu” sound just before the ascent of their mating ritual dive (Andrew et al., 2001, Cornell Lab of Ornithology, n.d.).
All About Birds provides display and call sounds made by Rufous Hummingbirds (Cornell Lab of Ornithology, n.d.).
The best way to attract hummingbirds to your yard is by planting native plants and putting up a hummingbird feeder (Gleisner et al., n.d.). It is important to remember that Washington state is home to five species, although only the Anna’s and Rufous Hummingbirds frequent western Washington (Gleisner et al., n.d.). Washington Department of Fish & Wildlife provides a list of Native plants that attract Hummingbirds (Gleisner et al., n.d.).
Currently the Rufous Hummingbird is listed as near threatened (BirdLife International, 2019). With a current population estimated at 19,000,000 and decreasing (BirdLife International, 2019). Another issue facing the rufous hummingbird is estimates of declining habitat in the winter grounds. According to Audubon (2019), their climate report estimates a 15% decrease in summer range and an estimated 100% loss of non-breeding range in Canada and the United States between 2000-2080 (Audubon, 2014).
Achache Y, Sapir N, Elimelech Y. (2017). Hovering hummingbird wing aerodynamics during the annual cycle. I. Complete wing. R. Soc. Open sci. 4: 170183. http://dx.dio.org/10.1098/rsos.170183
Audubon (2014). Climate endangered Rufous Hummingbird. The Climate Report. Retrieved from http://climate.audubon.org/birds/rufhum/rufous-hummingbird
Bailey, I. E., Segelbacher, G., Healy, S. D., Hurly, T. A., & Pemberton, J. M. (2013). Microsatellite variation in Rufous Hummingbirds (Selasphorus rufus) and evidence for a weakly structured population. Journal of Ornithology, 154(4), 1029-1037. doi:10.1007/s10336-013-0971-2
BirdLife International (2019) Species factsheet: Selasphorus rufus. Retrieved from http://datazone.birdlife.org/species/factsheet/22688296
Clark, C., Elias, D., & Prum, R. (2011). Aeroelastic flutter produces Hummingbird feather songs. Science, 333(6048), 1430-1433. Retrieved from http://www.jstor.org/stable/23060233
Cornell Lab of Ornithology. (n.d.). Rufous Hummingbird overview. All About Birds. Retrieved from https://www.allaboutbirds.org/guide/Rufous_Hummingbird
Courter, J. R. (2017). Changes in spring arrival dates of Rufous Hummingbirds (Selasphorus rufus) in western North America in the past century. The Wilson Journal of Ornithology, 129(3), 535-544. doi:10.1676/16-133.1
Donna Gleisner, Stephen Penland, Patricia Thompson and Russell Link (n.d.). Hummingbirds and how to attract them. Washington Department of Fish & Wildlife Retrieved March 3, 2019, from https://wdfw.wa.gov/living/hummingbirds/#plants
Grant, V., & Temeles, E. (1992). Foraging ability of Rufous Hummingbirds on hummingbird flowers and hawkmoth flowers. Proceedings of the National Academy of Sciences of the United States of America, 89(20), 9400-9404. Retrieved from http://www.jstor.org.evergreen.idm.oclc.org/stable/2360408
Healy, S. and W. A. Calder (2006). Rufous Hummingbird (Selasphorus rufus), version 2.0. In The Birds of North America (A. F. Poole, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bna.53
Hiebert, S. (1990). Energy costs and temporal organization of torpor in the Rufous Hummingbird (Selasphorus rufus). Physiological Zoology, 63(6), 1082-1097. Retrieved from http://www.jstor.org.evergreen.idm.oclc.org/stable/30152634
Hiebert, S. M. (1991). Seasonal differences in the response of Rufous Hummingbirds to food restriction: body mass and the use of torpor. The Condor, 93(3), 526-537. doi:10.2307/1368184
Hurly, T. A., Scott, R. D., & Healy, S. D. (2001). The function Of displays of male Rufous Hummingbirds. The Condor, 103(3), 647-651. doi:10.1650/0010-5422(2001)103[0647:tfodom]2.0.co;2
Hurly, T. A., Franz, S., & Healy, S. D. (2009). Do Rufous Hummingbirds (Selasphorus rufus) use visual beacons? Animal Cognition, 13(2), 377-383. doi:10.1007/s10071-009-0280-6
Jelbert, S. A., Hurly, T. A., Marshall, R. E., & Healy, S. D. (2014). Wild, free-living hummingbirds can learn what happened, where and in which context. Animal Behaviour, 89, 185-189. doi:10.1016/j.anbehav.2013.12.028
Koerner T. (2018). Rufous hummingbird at Seedskadee National Wildlife Refuge. United State Fish & Wildlife Services. Retrieved from https://www.flickr.com/photos/usfwsmtnprairie/43282705084
Seattle Audubon Society. (n.d.). Rufous Hummingbird. Bird Web. Retrieved from http://www.birdweb.org/birdweb/bird/rufous_hummingbird
Sieburth, D., & Pyle, P. (2018). Evidence for a prealternate molt-migration in the Rufous Hummingbird and its implications for the evolution of molts in Apodiformes. The Auk, 135(3), 495-505. doi:10.1642/auk-17-231.1
Leave a Reply