Hummingbirds, creatures typically associated with tropical climates, successfully survive in the far northern reaches of North America. These tiny birds are among the most accomplished long-distance migrants on the planet. Weighing only about as much as a nickel, hummingbirds possess a metabolic engine that allows them to undertake immense seasonal journeys. They are known for their incredible speed and specialized ability to hover, making them highly efficient foragers even in cooler environments.
Which Species Are Found in Alaska and Where
The most common and widespread species seen in Alaska is the Rufous Hummingbird (Selasphorus rufus), which is an aggressive and resilient flier. This species has the northernmost breeding range of any hummingbird in the world. A rare but increasingly frequent visitor is the Anna’s Hummingbird (Calypte anna), which has been found overwintering in coastal communities due to milder conditions.
The geographic range of the Rufous Hummingbird is primarily restricted to the coastal areas. They are commonly found throughout the temperate rainforests of Southeast Alaska, often called the Panhandle. Their range extends north into the Southcentral region, reaching as far as the Prince William Sound and the Kenai Peninsula. This coastal region offers the necessary combination of lush vegetation, abundant insects, and a maritime climate that moderates temperatures. The interior and northern parts of the state are generally unsuitable due to harsh cold and lack of resources.
The Timing of Their Annual Migration
The presence of hummingbirds in Alaska is strictly seasonal, marking them as summer residents. Their spring migration is a biological feat, with the Rufous Hummingbird traveling nearly 4,000 miles from its wintering grounds, which stretch as far south as Mexico. They follow the Pacific Flyway north along the coast, taking advantage of sequential flower blooms along the route.
The first males typically arrive in Southeast Alaska by late April or early May, with females following shortly after. This timing coincides with the brief but intense northern growing season. Males establish breeding territories and perform acrobatic courtship displays for the arriving females.
Their stay is short, with the southern migration beginning relatively early in the summer. Male Rufous Hummingbirds generally start their journey south by July. Females and fledglings remain slightly longer for nesting and rearing young, departing in August or early September. The fall migration often takes them inland through the Rocky Mountains, where they use late-blooming alpine flowers as a fuel source for their flight back to their winter habitat.
Biological Adaptations for the Far North
The survival of hummingbirds in the cooler northern climate is made possible by a physiological adaptation called torpor. This state is a short-term, hibernation-like condition that allows them to conserve energy during cold nights or periods of food scarcity. During torpor, the bird’s metabolism can drop by as much as 95%, and its body temperature may fall significantly from its normal 105°F.
This energy-saving mechanism is important in Alaska, where even summer nights can be quite cool. A hummingbird’s high metabolic rate requires it to consume roughly half its body weight in nectar and insects daily. By entering torpor at night, the bird avoids starvation when it is unable to forage.
The long daylight hours of the Alaskan summer also maximize the available time for feeding. Once the sun rises, the bird must rapidly warm its body by shivering, a process that can take up to an hour. This combination of a daylight-driven feeding schedule and nightly metabolic shutdown allows the Rufous Hummingbird to thrive at the edge of the species’ range.