Selasphorus rufus

Geographic Range

Rufous hummingbirds ( Selasphorus rufus ) are migratory birds that inhabit the Nearctic region. Migratory distances average 2,700 km, but can be as long as 4,000 km. Rufous hummingbirds travel in a loop pattern when migrating, rather than a linear pathway.

The breeding season lasts from April to July. The hummingbirds’ range includes Washington state in the United States northward to British Columbia, Canada. This range is roughly 200 km along the Pacific northwestern coast of North America.

During winter migration (July-early September), the hummingbirds travel southward through the western US to reach southern California and nearly all Mexico (except the southern peninsula). These birds remain there until late February or early March. By March, they travel northward along the coast of California to reach Washington again by the end of April.

• Biogeographic Regions
• nearctic nearctic
  • native native

Habitat

In the breeding season, rufous hummingbirds inhabit terrestrial habitats such as meadows, parks, orchards, coniferous forests, chaparral and gardens. Typical areas for these hummingbirds are plentiful with an abundance of green plants. The urban areas of Washington state and British Columbia offer include suitable habitats at high elevations and seasonally cool environments.

During the winter, rufous hummingbirds migrate to warmer locales in Mexico’s and southern California’s mountainous and woodland regions.

Throughout their range, rufous hummingbirds live at elevations of 1830m to 3000m.

In their migratory journey, these hummingbirds spend most of their time in the southwest of the US. Because these areas are more desert-like, they are dryer and therefore do not provide adequate food supply.

• Habitat Regions
• terrestrial terrestrial

• Terrestrial Biomes
• chaparral chaparral
• forest forest
• mountains mountains

• Other Habitat Features
• urban urban
• suburban suburban
• agricultural agricultural

Physical Description

Rufous hummingbirds weigh 2.6-5.7 g (average 3.4 g). On average, they are 9.5 cm long with a wingspan of 11.4 cm. There are insufficient data on birth size of these hummingbirds. They can have spots of color, but overall are dull in appearance. Males appear to be more colorful than females.

Rufous hummingbirds have black bills that become smoother in adults.

Young birds start with darker skin without feathers, but have grey striping down either side of the back. As they grow from hatchlings to nearly a month old, the feathers of the throat region begin to get green with bronze spotting. The head begins to appear more red or burnt orange in color. The females’ throat appear to have more bronze spotting and the males’ throat appear orange. The females’ throat appear wider than those of males.

In adults, the top of the head down to the nape of the neck is metallic bronze-green. This appears duller in females than males. The bronze-green feather color is a theme for most of the body in adults. The face and throat appear more bright red in males and bronze-green in females. Females’ bodies have more hints of purple than males.

Subadult hummingbirds become more rusty red in color, especially near the posterior end of the bird. Feathers become larger in number on the entirety of the bird. Males' tails show metallic spotting with hints of bronze and green.

Basal metabolic rate has been reported as 0.0685 W, or 0.018034 W/g.

• Other Physical Features
• endothermic endothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• sexes colored or patterned differently
• male more colorful

Reproduction

Rufous hummingbirds have a breeding season from April to July. Males dive in a “J” motion to attract females. After the initial attraction, mating ensues on the ground. These actions continue throughout the breeding season. These hummingbirds are considered polygynous.

• Mating System
• polygynous polygynous

These birds have one clutch per year. Eggs are laid beginning in April with the majority from mid-May until the mid-July. Eggs are laid in nests that are close to the ground and well hidden in plants and lower branches of trees. These nests, made by females, are made of soft plants and supported by bark, moss and spider webs. In general, the average clutch size is 2 eggs yearly with an incubation period of 15-17 days. Young hummingbirds fledge when they are around 15 days old. If the fledging is successful, the hummingbirds will not return to the nest and live independently. There are no data on age of sexual maturity for rufous hummingbirds.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• fertilization fertilization
• oviparous oviparous

Incubation is performed by females only. During warm weather the female can leave the nest when necessary for as long as an hour. Females are responsible for their young for as long as they are in the nest. Both parents are responsible for feeding their offspring. It’s likely that parental involvement ceases when the birds reach the fledgling stage at 15 days old.

• Parental Investment
• female parental care female parental care
• pre-hatching/birth
  • protecting
    • female
• pre-weaning/fledging
  • provisioning
    • female
  • protecting
    • male
    • female

Lifespan/Longevity

Rufous hummingbirds, have an average lifespan of 6 years in the wild. Bird banding data show the longest living rufous hummingbird to be 8 years and 11 months old. Lifespan can be estimated based on mass of the bird. According to Miller and Gass (1985), 3 g hummingbirds would have an average life expectancy of 5.5-5.8 years whereas a 4 g hummingbird would have one of 5.8-6.1 years. There is not sufficient data for lifespan of rufous hummingbirds in captivity.

Behavior

Rufous hummingbirds are known for their quick, figure-eight movement of their wings. This allows them to hover as they forage for food.

These hummingbirds are not a social species. Males are highly territorial, not allowing females to share feeding grounds during breeding seasons. Females feed lower to the ground whereas males hover higher. To keep up with high energy demands, the hummingbirds must feed constantly. To conserve energy, rufous hummingbirds can enter a torpor state. This state is achieved at nighttime as well as during hot days. The bigger, more energy rich their meals are, the longer torpor period they can endure.

• Key Behaviors
• motile motile
• migratory migratory
• daily torpor
• territorial territorial

Home Range

There is no information on a specific home range for rufous hummingbirds.

Communication and Perception

Rufous hummingbirds are not very social, and the majority of sounds they produce are as warning signals. They let out a chipping noise to alert others of danger. In breeding, males visually attract females by a diving motion, and do not rely on acoustic messages.

They view the world in color using the UV spectrum. This is how they make reward associations with flowers. When migrating and foraging, memory and visual cues are important. Specific colors, red and yellow, and locations of flowers allow these hummingbirds to find reliable fuel.

• Communication Channels
• visual visual
• acoustic acoustic

• Perception Channels
• visual visual
• ultraviolet
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

Rufous hummingbirds are primarily nectarivores but also eat small insects. Because they have such a high metabolism, they must eat often, eating about half their body weight each day. When they know they will be using a great amount of energy (i.e. migrating), they will increase their food intake to accommodate those activities. When foraging for nectar, they return where they have had successes before and use color cues for which flowers may supply their next meal.

• Primary Diet
• herbivore herbivore
  • nectarivore nectarivore

• Animal Foods
• insects

• Plant Foods
• nectar
• flowers

Predation

Predators prey on hummingbirds while hummingbirds are hovering over plants to feed. They are in a more vulnerable and unaware state during this period. Predation does not play a significant role in the mortality rate of adult hummingbirds.

Rufous hummingbirds, typically males, are known to chase off predators or intruders to protect their territory. Hummingbirds will also make alert sounds to warn others of imposing threats.

Ecosystem Roles

Rufous hummingbirds are pollinators, which contributes to plant reproduction. Haemoproteus archilochus is a protozoan that uses many vertebrates as hosts, including rufous hummingbirds. This protozoan attacks and destroys erythrocytes. Ornithoica vicina and Microlynchia pusilla are species of Hippoboscid flies that are parasitic to many birds, including rufous hummingbirds. These flies are vectors to many diseases that are harmful to birds and mammals alike, including malaria. Trypanosoma avium is a parasitic protazoan that feeds on the blood and blood marrow of many bird species, including rufous hummingbirds. This parasite often enters the bloodstream of the hummingbird via infected hippoboscid flies.

• Ecosystem Impact
• pollinates

Economic Importance for Humans: Positive

Rufous hummingbirds act as pollinators. Pollination is a vital requirement for the growth of many plants and crops. Humans indirectly benefit from hummingbirds’ economic role when they consume foods that have been pollinated.

• Positive Impacts
• pollinates crops

Economic Importance for Humans: Negative

There are no known adverse economic effects of Selasphorus rufus on humans.

Conservation Status

According to the IUCN Red list, rufous hummingbirds are listed as a species of “Least Concern.” They are protected under the US Migratory Bird Act, which prohibits the trafficking and sale of these birds. There is no species status for the US Federal list or CITES due to large geographical ranges and population sizes. Feeders created by humans ( Homo sapiens ) aid hummingbirds in winter months when food is less readily available for them. In recent years, the populations are declining, possibly due to deforestation. However, the rate of decline does not put the species at risk. Rufous hummingbirds are being monitored but no conservation action plan is currently enacted.

Additional Links

Encyclopedia of Life

Contributors

Carrie Anderson (author), Radford University, Cari Mcgregor (editor), Radford University, Zeb Pike (editor), Radford University, Karen Powers (editor), Radford University, April Tingle (editor), Radford University, Jacob Vaught (editor), Radford University, Genevieve Barnett (editor), Colorado State University.

References

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