The Arctic regions present one of the most demanding environments on the planet, characterized by extreme cold and dramatic seasonal shifts in daylight. For the birds that inhabit this vast, treeless landscape, survival hinges entirely on specialized and flexible feeding strategies. The short, intense summer offers a brief period of abundance, but the long winter plunges the ecosystem into scarcity, forcing avian life to exploit every available resource.
Marine and Coastal Food Sources
The ocean is the primary food source supporting massive colonies of Arctic seabirds, which rely on the marine food web’s dense concentration of life. Birds like the Little Auk, Murres, and Puffins exploit these rich waters for nourishment.
Plankton-feeding birds, such as the Little Auk, consume vast quantities of minute crustaceans, primarily copepods like the energy-rich Calanus species. These zooplankton are abundant in cold Arctic waters, providing the high-fat diet necessary for survival in a harsh climate. The Little Auk forages by diving up to 35 meters, using its wings for underwater propulsion to catch swarms of these tiny invertebrates.
Other seabirds, including Guillemots (Murres) and Puffins, focus on small schooling fish like capelin and sand lance. Capelin are cold-water forage fish prized for their high caloric value, and their availability impacts the breeding success of many bird populations. These species employ pursuit-diving techniques, often reaching considerable depths to capture fish for their chicks.
Gulls and Terns also frequent coastal areas, often engaging in surface feeding or plunge-diving to catch fish or marine invertebrates closer to the surface. The diet of many marine species reflects the underlying oceanographic conditions, favoring plankton-eaters or shifting the food chain toward fish-eating birds.
Tundra and Terrestrial Vegetation
Away from the sea, a different set of birds focuses on the low-growing plant life and brief insect bloom of the tundra. The summer provides a temporary but rich source of food.
Birds like the Snow Bunting rely on a combination of seeds and invertebrates during the breeding season. Their summer diet includes abundant ground-dwelling insects such as flies, beetles, and spiders, which provide essential protein for growing chicks. As summer wanes, their focus shifts heavily toward seeds from grasses and weeds, which they forage from the ground or low-hanging stems.
The Willow Ptarmigan, a type of grouse, is a primarily herbivorous consumer of the tundra’s woody plants and berries. In the summer, they eat leaves, flowers, and berries, including crowberry and blueberry. These resources, along with seeds and buds, are high in energy.
Ptarmigan adults eat tough plant material, including moss and lichens, but their most important staple is the buds and twigs of willow and birch. Their powerful digestive systems, which include a muscular gizzard, are adapted to process this fibrous, low-nutrient food source, a necessity when other food is covered by snow.
Apex Predators and Scavengers
Some Arctic birds occupy the top tiers of the food web, relying on hunting small mammals or scavenging larger carcasses. These strategies allow them to utilize prey unavailable to smaller species.
The Snowy Owl is a specialized hunter whose diet is dominated by small rodents, particularly lemmings and voles. These rodents are the cornerstone of the owl’s existence, and their population cycles directly influence the owl’s reproductive rates. The owls hunt using exceptional sight and hearing to locate prey moving beneath the snow, capturing them with powerful talons.
Other aerial predators, such as Jaegers (Skuas), are known for their aggressive feeding style called kleptoparasitism. They relentlessly chase smaller seabirds, like Terns or Auks, until the victim drops its captured fish, which the Jaeger snatches in mid-air. Jaegers also hunt small rodents, birds’ eggs, and chicks on the tundra during the breeding season.
The Common Raven, a highly intelligent and adaptable bird, is an important scavenger on the Arctic slope. Ravens obtain energy by consuming carrion, such as the carcasses of caribou or other animals killed by larger predators. They are also opportunistic hunters, preying on small mammals, eggs, and vulnerable chicks, demonstrating a flexible diet that allows them to thrive in unpredictable conditions.
Adapting to Seasonal Food Scarcity
The seasonal contrast in the Arctic requires avian life to cope with periods of extreme food scarcity. The short summer offers peak food availability, which is when most species must breed and accumulate fat reserves.
The most common strategy is migration, with species like the Arctic Tern undertaking the longest known migration of any animal to escape the winter freeze. Migratory waterfowl and shorebirds must time their arrival precisely to coincide with the brief emergence of plant shoots and insect blooms.
For species that remain year-round, such as the Ptarmigan, survival depends on a complete shift in diet and foraging behavior. The Ptarmigan transitions from a varied summer diet to one consisting almost entirely of tough, low-nutrition willow buds and twigs, which remain accessible above the snow. This specialization, combined with energy conservation, is the primary means of enduring the long winter months.