Allen’s Hummingbird Guide (Selasphorus Sasin)

As a birdwatcher living in Colorado, I have always had to be satisfied with seeing the few species of hummingbird that can be found here–primarily the Black-chinned Hummingbird and the Broad-tailed Hummingbird. Occasionally I might be able to spot a Rufous Hummingbird as they are migrating through our fair state, headed either to the Pacific Northwest in the spring or back down to Mexico for the winter. However, we recently took a trip to Los Angeles to drop off our oldest daughter at college. While she was attending an event for incoming freshmen, and my wife and younger daughter were sightseeing in Hollywood, I took the opportunity to sit on the patio of our hotel room and take in the warm California sun. As I sat there, I became aware of a whirring noise, and I spied a small object darting amongst the flowers of the bush right outside the patio. That’s when I saw it… my first Allen’s Hummingbird! Shockingly, the rest of my family was not nearly as excited as I was about this sighting.

The Allen’s Hummingbird is named after Charles Andrew Allen, a taxidermist, and collector who was an early identifier of the species, distinguishing it from the similar Rufous Hummingbird. However, the bird had been formally identified decades earlier by French naturalist Rene Lesson. The taxonomic classification for Allen’s Hummingbird is Selasphorus sasin. Unlike most North American hummingbirds, which only have one subspecies, Allen’s Hummingbird has two identified subspecies:

  • Selasphorus sasin sasin – This subspecies migrates between breeding grounds along the coasts of California and Oregon and winter locations in south-central Mexico.
  • Selasphorus sasin sedentarius – This subspecies does not migrate, living year-round on channel islands off the coast of southern California. In recent decades this subspecies has expanded its range to include mainland areas of California in and around Los Angeles.

Physically, there are very few differences between the two subspecies of Allen’s Hummingbird, with the Selasphorus sasin sedentarius being slightly larger than its counterpart. The primary difference in the subspecies is in their migratory behavior, with the S. s. sasin subspecies migrating between the United States and Mexico, while the S. s. sedentarius subspecies remains in their local range year-round.

Taxonomy at a Glance

  • Domain:
  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Aves
  • Order: Caprimulgiformes
  • Family: Trochilidae
  • Genus: Selasphorus
  • Species: Selasphorus sasin
  • Sub-species:
    • Selasphorus sasin sasin
    • Selasphorus sasin sedentarius

How to Identify the Allen’s Hummingbird

The Allen’s Hummingbird, like other hummingbird species, can sometimes be tricky to identify. Not only are they small, fast, and always on the go, but they also bear some similarities to other common North American hummingbird species. Allen’s Hummingbirds are small, measuring less than 4 inches in length. Their build is compact and chunky, stockier than some other hummingbird types. They have a straight black bill that is about the same length as their head.

The coloring of adult male Allen’s Hummingbirds consists primarily of greens and rusty or coppery orange tones. Their backs and caps are metallic green. Lower on their back, towards their tail, they have rusty orange coloring. Their bellies are mostly rust-colored, with patches of white higher on their chest (just under their throat) and further down, near their legs. They have a rusty orange ‘mask’ around their eyes. The most prominent color feature for adult males is the shiny metallic reddish-orange coloring on their throats. This patch of colored plumage on their throat is called a gorget.

Allen's Hummingbird

Female and juvenile male Allen’s Hummingbirds have less prominent coloring. While they also have a greenish back and cap, is it less uniform, with speckles of darker brown interspersed with the green. They also have rusty orange coloring further down on their back, near the tail. Their bellies are pale, rust and white in color. Females and juvenile males are lacking prominent rust-colored masks around their eyes. They are also lacking the gorget–the shiny metallic patch of color on their throats. Instead, their throats are more white in color with brown or orange speckles. Female Allen’s Hummingbirds are slightly larger than the males.

When out in nature, your first clue to any hummingbird being nearby may be auditory, and Allen’s Hummingbirds are no exception. Male and female Allen’s Hummingbirds both emit single staccato pick sounds while they fly around and feed. They may also string together several pick sounds in a row; males especially may do this while perched, if they see another male intruding on their territory, or to call out to any females who may be in the area looking for a potential mate. In flight, the rapidly moving wings and feathers of the adult male Allen’s Hummingbird produce a high trill or buzzing sound, not unlike the sound of a bumblebee (or a very small weed whacker!). This sound helps the male to establish and communicate his territory. He will also use and modulate these nonvocal sounds as part of his displays, either to chase off intruders or to put on a show for potential female mates in his territory.

Allen’s Hummingbirds are quite similar in appearance to several other hummingbird species, namely the Rufous Hummingbird, Broad-tailed Hummingbird, and the Calliope Hummingbird. Some ways to distinguish between these breeds are listed below:

  • vs. Rufous Hummingbirds: Male Rufous Hummingbirds typically have more of an orange back, with less (or no) green, compared to an Allen’s Hummingbird. One other difference (though very hard to see) is that the outer tail feather of an Allen’s Hummingbird is narrow, while the outer tail feather of a Rufous Hummingbird is broader. Females of these two species can be very difficult to differentiate, with the only difference being the width of the outermost tail feather.
  • vs. Broad-tailed Hummingbird: Broad-tailed Hummingbirds are larger than Allen’s Hummingbirds, and typically do not have the rusty orange coloring around their tails, eyes, and bellies.
  • vs. Calliope Hummingbirds: Calliope Hummingbirds are smaller than Allen’s Hummingbirds, and are also lacking the coppery colors found on the Allen’s Hummingbird. Also, the tail feathers of the Calliope Hummingbird do not stick out past their wings, while the tails of the Allen’s Hummingbird do jut out past their folded wings.

Where Does the Allen’s Hummingbird Live: Habitat

Allen's Hummingbird

As previously mentioned, the Allen’s Hummingbird breeding grounds range extends along a narrow band of land along the coast of California and up into Oregon, as well as on some of the channel islands off the coast of southern California. The S. s. sasin subspecies winters in south-central Mexico, migrating between there and their breeding grounds annually. In their breeding grounds, Allen’s Hummingbirds can be found in wooded or brushy areas along the coast, often in or near canyons, parks, or woodlands. Males will establish a breeding territory and patrol this territory–they can often be seen perched on a high branch, surveying their territory for intruders or possible mates. Female Allen’s Hummingbirds set up nests in brushy areas, preferring denser vegetation that may provide cover for the nests that they build.

During migration, and in their wintering grounds in Mexico, Allen’s Hummingbirds are attracted to meadows and pastures in mountains or highlands, where they can find enough flowers and plants to provide much-needed nectar for food.

The Allen’s Hummingbird subspecies S. s. sedentarius does not migrate, instead living primarily on a few islands off the coast of southern California (and in recent years expanding their range to include mainland California, in some small pockets around the Los Angeles area).

Allen’s Hummingbird Diet and Feeding

Like other hummingbirds, the Allen’s Hummingbird has no trouble keeping the weight off (I wish I were so lucky!). They have an extremely high metabolism which, coupled with their near-constant motion and activity, means they must feed often to ensure they are taking in enough calories to stay alive and healthy. Their primary food source is nectar that they collect from flowers and plants such as Columbine, Currant, Gooseberry, Sage, and Eucalyptus. Allen’s Hummingbirds will also happily visit hummingbird feeders for a much easier (and higher capacity) source of sugary liquid. The Allen’s Hummingbird laps up this nectar from these various sources using its long tongue.

They supplement this high-sugar diet with very small insects that they catch. They may catch these tiny bugs in mid-air while flying, or grab them from the surfaces of flowers or plants while they are hovering. These insects provide them with some nutrients and protein that they would not get from the sugary nectar that makes up their primary food source.

Allen’s Hummingbird Breeding

Allen's Hummingbird

Allen’s Hummingbird males will set up a breeding territory when they arrive at their spring/summer grounds. Males will establish this territory and zealously patrol it, warning away any other males that dare to intrude onto their turf. Once they have this territory, they will patrol it, and perch in conspicuous places, both to be seen and also to be able to survey the area. Allen’s Hummingbirds are not monogamous–males may mate with multiple females in their territory in a breeding season, and females will have multiple broods in one season (two to three generally, but as many as five). The only real interaction between the males and females is the courtship and mating–after that, they go their separate ways.

The male Allen’s Hummingbird puts on a very elaborate courtship display when he spots an available female in his territory. This display takes the form of an intricate series of flight patterns and stunts that he performs in front of the female. In what is called a shuttle display, he may fly back and forth in front of the object of his attention, making sharp noises with his rapidly moving wings. In a pendulum display, the male flies back and forth in longer arcs, just over or in front of the desired audience. Finally, males will also perform dives, in which they fly upward, as high as fifty feet or more, then dive quickly at the target, pulling up at the last second. Displaying males will combine these different elements (shuttlespendulums, and dives), creating an elaborate display, accompanied by sharp noises, all to impress and woo the intended female target.

If the courtship display is successful, it will result in the male and female mating. Immediately afterward, they part ways. The male goes back to patrolling his territory (and possibly finding other mates), while the female is faced with the hard work of building a nest, laying and hatching the eggs, and feeding the young until they are ready to go out on their own.

Allen’s Hummingbird Nesting

Allen's Hummingbird

While the male Allen’s Hummingbird aggressively tends to his territory after mating, the female now begins the work of building a nest in which to hatch and raise the young. Females will find a new location (which may or may not be in the male’s territory) to build this nest. They typically seek out areas with denser brush and tree cover, where the nest will not be easily spotted. The nest is usually built in an elevated spot, anywhere from a couple of feet to as high as fifty feet off the ground, on a suitable plant stalk or tree branch.

It takes the female, working by herself, one to two weeks to build the nest. The nest is typically constructed from plant fibers, down, and even spiderwebs that the female collects. She may even re-use a previous nest, either building on top of it or taking parts of it to use for her new nest. The finished nest will be in the shape of a small cup, a little over an inch wide across the top. The inside is lined with lichen and spiderwebs to form a comfortable surface. She may also place webs and lichen on the outside of the nest to make it harder to see (and thus safer from predators). Once completed, this nest is where the female will spend the next few weeks incubating her eggs and caring for her young ones.

Allen’s Hummingbird Eggs

As the nest is being completed or just afterward, the female Allen’s Hummingbird will lay her eggs. Allen’s Hummingbird females lay one or two eggs (almost always two, as much as a day apart). The eggs are white, and less than .5 inches long. She will incubate these eggs for about two weeks, only occasionally leaving the nest for some quick power-feeding sessions. After about two weeks, the eggs will hatch. The mother does not help the hatchlings get out of their shells–they must do this themselves. She may occasionally remove some larger shell fragments from the nest to clear some space.

When the baby Allen’s Hummingbirds first emerge from their shells, they are helpless. Their eyes are closed, and they have almost no feathers. The hatchlings will remain in the nest for about three weeks, relying on their mother for feeding and continuing to keep them warm while they grow and develop. At the end of this stage (about three weeks), the small Allen’s Hummingbirds will leave the nest, but even then the mother may continue to feed and watch over them for a while longer while they figure out how to live outside the nest. Finally, after a few more weeks, the young hummingbirds are on their own.

Once this process is completed, the female may repeat it all–courtship, mating, nest-building, egg-laying, incubation, hatching and feeding. In a single breeding season, female Allen’s Hummingbirds may raise as many as five broods!

Allen’s Hummingbird Population

Allen's Hummingbird

Recent studies and calculations have estimated the total population of Allen’s Hummingbirds to be roughly 1.5 million. Accurate numbers can be difficult to come by–Allen’s Hummingbirds migrate early, which makes it harder to get accurate counts. Additionally, because they do not have a recognizable birdsong, it is difficult to identify or count them in the wild apart from actually spotting them.

Is the Allen’s Hummingbird Endangered?

The short answer seems to be no–Allen’s Hummingbird is not considered especially endangered or at risk. However, there is some contradictory data on this question. Birding surveys seemed to show an overall Allen’s Hummingbird population decline of about 80% from 1968 to 2019, which would be a cause for concern. The Audubon Society placed the Allen’s Hummingbird on their watch list as a species to monitor against further decline. However, the difficulty of identifying and counting Allen’s Hummingbirds using standard birding survey practices does call into question the severity (or even existence) of this population decline. For this reason, the Allen’s Hummingbird continues to have an official Conservation Status of Least Concerned.

Allen’s Hummingbirds are also not as threatened by human encroachment and development in their natural habitat as some other species might be. While construction and development may reduce some natural food sources that the Allen’s Hummingbird might utilize, the appearance of humans brings with it new food sources, such as feeders or ornamental plant types like Eucalyptus, which helps offset the natural food sources that might be lost. Allen’s Hummingbirds have shown a willingness and readiness to incorporate these new food sources into their foraging and dietary habits.

Allen’s Hummingbird Habits

The Allen’s Hummingbird, like other hummingbirds, is a fascinating bird to observe and has many interesting habits and characteristics. Despite having the shortest wings and wing surface area relative to the body size of the North American hummingbirds, Allen’s Hummingbirds are fast and maneuverable in the air. They can easily hover in place, and fly sideways or even backward. In level flight, they can fly at speeds approaching 30 mph. In their downward dives, their speeds can exceed 50 mph!

Allen’s Hummingbirds are not very social–they are among the more aggressive of the North American hummingbird species. Allen’s Hummingbird males will not hesitate to threaten (via their flight displays and sounds), chase, or strafe intruders in their territories. This aggressive behavior is not limited to other males of their species… they will also take offense at other hummingbirds or even larger birds. Allen’s hummingbirds have even been seen harassing and chasing hawks that were trespassing in their territories! Allen’s Hummingbirds will also chase other hummingbirds away from food sources such as feeders.

Allen's Hummingbird

The feet and legs of the Allen’s Hummingbird are too small to be useful for walking. With their tiny legs and feet, they are only able to perch or shift slightly on their perch. However, their legs and feet do play an important role in temperature regulation. In cooler weather, the hummingbird will fly with its feet tucked up against its body to conserve body heat. In warmer weather, they will fly with their feet extended away from the body to help shed excess body heat and stay cooler.

Speaking of heat and energy regulation–the Allen’s Hummingbird, like other hummingbirds, can enter a state called torpor, in which its metabolism and bodily function enter a greatly reduced state. Think of it as a miniature shortened state of hibernation. This allows the hummingbird to conserve energy and body fat during the times of the day when they are not active or able to take in nourishment (such as at night).

Allen’s Hummingbirds are very early migrators relative to other species. The migrating subspecies S. s. sasin leave their winter grounds in Mexico and begin heading north to California in late fall or early winter, arriving in their breeding grounds in California and Oregon as early as January. The exact timing may vary year to year, to coincide with the optimal rainfall periods and patterns, which bring with them flowering plants that provide much-needed nectar. The males seem to arrive in the breeding grounds slightly ahead of the females, to establish their breeding territories for the season.

Allen’s Hummingbird Predators

Adult Allen’s Hummingbirds are at relatively low risk from predators in the wild. While larger birds of prey might be interested in hunting them, their small size, fast speed, and high maneuverability make them a difficult target for hungry predators. They are more at risk as eggs or hatchlings in the nest. Some Allen’s Hummingbird eggs might be eaten by larger birds such as American Crows. Additionally, the small and delicate nature of the nest itself makes it vulnerable to the elements–a strong wind or rain could topple a nest or knock the eggs out of it.

The biggest mortality risk for Allen’s Hummingbirds is simply starvation. Their high metabolism and active nature mean they must keep very busy taking in food and nourishment. They are constantly on the go in their waking hours, foraging and finding the all-important nectar, in competition with other hummingbirds in the vicinity.

Allen's Hummingbird

Allen’s Hummingbird Lifespan

The oldest recorded Allen’s Hummingbird was over five years old, as determined by being captured, banded, and then recaptured years later. This is quite a bit less than the oldest recorded ages for other hummingbird species in North America (which have maximum recorded ages as high as twelve years). However, there is little reason to think the Allen’s Hummingbird has a shorter lifespan than other similar species. This shorter documented maximum age is more likely due to the relatively lower frequency of capturing and banding of the Allen’s Hummingbird compared to other hummingbird species.


Question: What is the best way to see an Allen’s Hummingbird?

Answer: First, you need to make sure you are in their range, which is very limited. In their breeding season, they are only found in the costal lands of California and up into Oregon, as well as on some of the channel islands of the coast of southern California (for the non-migrating subspecies). If you are lucky enough to be in these areas during their breeding season, you may see them as they flit about the bushes and flowers, collecting nectar. Males may also be spotted perched in conspicuous places (often on high branches) overlooking their territories. Finally, feeders are a great way to attract and spot hummingbird (including Allen’s Hummingbirds) that are in the area.

Question: Are Allen’s Hummingbirds aggressive or dangerous to people?

Answer: Male Allen’s Hummingbirds are plenty aggressive to intruders of their territory of feeding sites. They are not hesitant to zip around the unwelcome visitor, hovering and displaying in front of them to get them to leave. They will do this with humans as well, especially around a feeder. However, while these “fly-bys” can give you a jump scare, the hummingbirds are not dangerous and will not harm people.

Question: How can I tell an Allen’s Hummingbird from other North American hummingbird types?

Answer: The first clue is location–make sure to check and see what types of hummingbirds are likely to be found in the area in which you are looking. This can help narrow down the list of suspects from the very start. If you see a male hummingbird, you can typically identify the species by the color patterns, as described in the previous How to Identify the Allen’s Hummingbird section above. If you are spotting a female or juvenile, it can be much more difficult to make an identification with confidence, as the visible variations among the species can be very slight or nonexistent for female or juvenile hummingbirds.

Research Citations


  • Peterson, Roger Tory. (2010). Peterson Field Guide to Birds (4th Edition). Houghton Mifflin Harcourt Publishing Company.


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