Little Auk

Fascinating facts about the Little Auk

• At just 19-21 cm long with a 34-38 cm wingspan and weighing only 130-200 g, the little auk is half the size of an Atlantic puffin yet packs a dense, insulated body. Its short, stiff wings beat rapidly for fast, direct flight and underwater "swimming". The bird's small surface area is wrapped in thick layers of fat that insulate vital organs, while a basal metabolic rate of 2.29-2.55 cm³ O₂ hr⁻¹ keeps its body heat humming in icy waters. This compact design lets it thrive where few birds can survive.
• Little auks nest in massive cliff-side colonies, each pair returning to the same rock crevice year after year. Both parents share incubation for 28-31 days, then brood the 21 g hatchling for about five days until it can regulate its temperature. The chick grows fast, fledging after 26-29 days, usually at night, in perfect synchrony.
• When fierce November gales sweep the North Atlantic, little auks can be blown far south. On the Farne Islands in 2007, 18,381 birds were counted on 9 Nov and a surge to 28,803 on 11 Nov, showing how weather can temporarily concentrate tens of thousands of individuals far beyond their normal Arctic range.
• With colonies numbering up to several million, little auks shape Arctic ecosystems. Their guano dumps flood the soil with nitrogen, killing most plants but allowing hardy lichens to dominate, while the birds themselves act as a key food source for glaucous gulls, Arctic foxes and even polar bears. This dual role as predator of zooplankton and prey for higher trophic levels makes them a keystone species of the high north.
• A 150 g little auk must gobble roughly 60,000 tiny copepods each day, about 30 g of dry food, to stay alive. Recent studies show it doesn't filter plankton but uses visual, suction-feeding to snap prey from the water.

Sources

Every fact above was checked against these pages, and kept only where one of them states it.

• Wikipedia

At a glance

About the Little Auk

In the blue-white vastness of the Arctic summer, little auks darken the sky in flocks so vast they look like smoke. These stubby, sparrow-sized seabirds are the vital link between the ocean's microscopic plankton blooms and every larger predator in the Arctic food chain. Small in stature but staggering in number, they are one of the ocean's great invisible engines.

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