Tracking the epic migrations of American and Pacific golden-plovers: from neighbors on the tundra to oceans apart

If you drive along any road out of Nome in June and July, you are likely to catch sight of our most elegant and eye-catching breeding shorebirds, golden-plovers.

Decked out in striking black, white and glinting-gold plumage, these conspicuous birds run across their tundra breeding grounds in short bursts, stopping abruptly to scan for insects with an erect, regal stance.

If you hadn’t noticed that there are actually two species of golden-plovers in our midst, you aren’t alone. In 1995 when I moved to Nome, I was surprised to learn that the “lesser golden plover,” a bird I had long known, had recently been split into two species: the American golden-plover, and the Pacific golden-plover. How does one tell them apart, I wondered?

Looking at these plovers with a more critical eye, they are in fact usually not so hard to distinguish, at least when in breeding plumage. The extent of the white band on the males and the coloration of the females usually differs enough between these two golden-plovers to set them apart.

But it was not until 1993 that the American Ornithological Union was convinced that their differences warranted separation into distinct species. It was here, along Nome’s road system, that much of the field work leading to the species split occurred.

Both golden-plover species are fairly common and widespread breeders in suitable habitat across the Seward Peninsula. Their abundance along the road system gave researchers easy access to study the bird’s differing habitat preferences, breeding behavior and vocalizations.

Both species are tundra nesters. American golden-plovers typically nest at higher elevations where the vegetation is shorter and more sparce, often on rocky ground.

Pacific golden-plovers tend to select nesting sites at lower elevations, often on moist ground where higher, denser vegetation grows.

However, there can be considerable overlap, and both species may use areas of relatively dry upland tundra. Occasionally a pair will even use a nest cup made by the other species in a previous year.

While breeding behavior of the two species is generally quite similar, vocalizations are not. The males’ songs during breeding display flights are vastly different. Other calls used when establishing or defending territories or nests and when communicating with a mate are also unique to each species.

It is thought that these differences in vocalizations may be a factor that discourages interbreeding. Despite breeding in very close proximity to each other, there is no documented evidence of hybridization in Alaska.

American and Pacific golden-plovers are among the greatest long-distance fliers of the bird world. Their long, slender wings are designed for fast and efficient nonstop flight.

During the last two summers, graduate student Rozy Bathrick from the University of Massachusetts, Amherst, placed satellite tags on American and Pacific golden-plovers in the Nome area. When these neighbors on the breeding ground part ways at the end of the breeding season, they are destined for distant and vastly different parts of the globe. With maps and her own words, Rozy will tell us about her research and give us a picture of the remarkable journeys these birds undertake:

Long-distance bird migration is hard to observe. Most of it happens outside our range of vision. Many birds migrate at night, up to 15,000 feet above sea level, and in small flocks that are hard to detect. For people living at high latitudes, as on the Seward Peninsula, migration is most visible in the seasons sandwiching summer, when large numbers of birds arrive and depart.

In spring, as the snow melts on the tundra and the willows leaf out, the riparian shrubs and wet tundra quiver with the arrival of long-distance migrants. The clear whistles of golden-plovers carry over the tundra as males identify and defend their territories. It is a special time to arrive from Western Massachusetts as a visiting biology student and join the ranks of avian migrants that return to Nome every year to raise their young.

Shorebirds are among the longest distance migrants on earth. My doctorate research at UMass Amherst focuses on the incredible diversity of strategies that they use during migration. I use GPS technology to track six species of shorebirds from different sites in Alaska during their fall migration to understand what factors shape the differences we see in migratory route, timing, stopover sites, and non-breeding destinations. Understanding this diversity can help us identify threats and protect vulnerable species and habitat.

The Seward Peninsula is a great place to study these birds; while many species share breeding habitat in Nome, they spread across the globe and use different migratory corridors to arrive at their non-breeding sites.

Unlike seabirds, which can soar or sit on the water to rest their wings, shorebirds cannot stop flapping, nor can they touch down to rest on open water.

To track the spectacularity of these migrations, we attach a tiny GPS satellite transmitter that weighs less than a nickel to a bird’s lower back. The model we use on golden-plovers turns on as the bird leaves Nome and sends locations throughout fall migration to its non-breeding site before the battery dies.

In 2022, transmitters on American golden-plovers revealed an astonishing route. While we typically think of fall migration as southbound, Americans that left Nome flew northeast into the Canadian arctic.

There, they stopped to forage before they finally turned south and flew nonstop flights along the entire Atlantic seaboard. In early fall, after 3,100-mile direct flights, they touched down in Venezuela, coastal French Guiana, Suriname and Guyana. Many stopped in the Amazon Basin to forage in shallow mudflats and open agricultural fields before moving even farther south to wintering sites in Argentina and Uruguay.

In 2024, when Pacific golden-plovers were tagged, fewer tracks of their entire migratory routes were recorded.  While many of them flew over the Bering Sea to Russia’s Kamchatka Peninsula, just one bird transmitted data from farther south.

That individual left Nome on August 8 and flew 310 miles in a single day to Nunivak Island, where it stayed for a month. Then a 4,200-mile nonstop flight brought it to Taiwan, where it hopped between agricultural fields on the outskirts of the township of Luodong. Finally, on October 15 the golden-plover flew another 2,800 miles from Taiwan to the northern coast of Australia, touching down on October 19, over 6,200 miles from Nome. These tracks add to those of other researchers, like Wally Johnson’s in Hawaii, who have tracked them to wintering sites in Indonesia, Japan and French Polynesia.

The cause for the incomplete tracks isn’t clear. The transmitters either failed or slipped off the birds, or the birds died before completing migration. This, unfortunately, is a common challenge in animal tracking studies where lightweight technology and a small sample size pose limitations.

The migrations of these two species, while almost exactly opposite in direction, are mirrors of each other in distance and extremity, demonstrating the impressive extent of migratory diversity.

Just three decades ago, we considered these two species to be the same—a single species with an expansive range that spanned from Utqiagvik down to the Alaska Peninsula. We now know that Nome is one of the few places these two species overlap, and that they are genetically and geographically distinct from each other.

With the help of tracking data, we have learned they travel separate oceans to spend their winters on entirely different continents. These different routes come with their own suite of risks: tailwind regimes and timing of food availability differ, as well as human development on the landscapes they depend upon.

Both species are facing precipitous population declines for reasons not entirely clear. With the help of tracking data, we can find where specifically—from Taiwanese farm fields to the bank of the Amazon River—to direct conservation efforts and protect habitat. In the meantime, the people and the tundra of the Seward Peninsula continue to welcome these species back from their epic journeys each spring. 

American golden-plover flight song  https://macaulaylibrary.org/asset/31729531

Pacific golden-plover flight song https://macaulaylibrary.org/asset/31730301