Meet the Pacific Brant

Every November, flocks of one of North America’s smallest geese leave Alaska’s Izembek Lagoon and begin an epic migration of up to 3,000 miles. On flights that can last up to 60 hours, Pacific seabass head to seagrass grasslands stretching from British Columbia to Baja.

Many people consider these distinctive birds—black, with mottled flanks and a necklace of winding white stripes—to be the “best goose” in North America. They are unusual and beautiful and popular with bird watchers. Hobby and recreational hunters also appreciate them: they are particularly tasty.

However, much of their habitat is compromised, and their size and habits make them more difficult to study than other geese. But as technology advances—from smaller trackers to more powerful computing tools—researchers are learning more and more about what this species needs to survive and thrive.

Pacific terns breed along arctic and subarctic coastal mudflats, But climate change and fossil fuel development are causing many of these areas to shrink. In 2023, U.S. officials estimated that there were 108,000 Brant in the West – less than half their historical number.

Brant wanders in flocks, instead of Vs or lines and behave similarly on land, moving together in tight knots.

Brant weighs about 3 pounds, This makes them more similar to mallards than Canada geese, which can weigh up to 20 pounds.

Waterfowl population estimates are often based on ripening and harvest dates, but since almost every Pacific Brant spends the fall in Izembek, it is only possible to count them. Scientists have been doing this from the air since the 1970s, but low-level flights often disturb birds and manual counts are difficult to do properly. In 2017, USGS scientists tested a new, safer and more precise method: They captured images of high-flying aircraft and then trained the AI ​​to count birds.

Some populations face greater threats than others. and genetic research helps biologists target protective measures. For example, birds from several breeding sites overwinter in Washington. Most are black shads, many of which breed in Alaska, where some colonies actually grow. A rarer group, the so-called grey-bellied birds, nests at much higher latitudes in Canada. Identifying subpopulations has allowed Washington authorities to restrict hunting in years when just one group’s numbers are low.

Researchers once tracked Brant migrations via telegram, how Arctic scientists notified their southern colleagues when the swarms left Izembek. Newer bird tracking devices have long been limited by battery life and weight. And brants pose an additional challenge: Scientists use tracking collars on other geese, but brants who wear them are often socially ostracized. So researchers have developed other methods, such as implanted trackers and devices worn on a backpack-like strap. Some even use tiny solar panels, allowing for lighter, longer-lasting batteries.

These birds rely almost exclusively on seagrass. This development, reduced water quality and rising sea levels have led to a deterioration of the situation along the entire coast.

Brant needs to eat enough seaweed every winter to fuel their flight back to the Arctic and provide the stored energy they need to lay eggs.

Illustrations by Alex Boersma/High Country News

This article appeared in the December 2024 print edition of the magazine with the headline “Get to Know the Pacific Brant.”