Tracking the Dowitchers

Long-billed Dowitchers (Limnodromus scolopaceus) are long-distance migrants that depend on a vast network of shallow-water sites from Alaska to Central America. Unlike the closely related Short-billed Dowitcher which primarily relies on coastal wetlands for important life events like feather replacement and overwintering, the Long-billed Dowitcher frequently uses interior freshwater wetlands to replace feathers and spend their winter. Importantly, Long-billed Dowitchers’ movements connect seemingly separate wetlands. As wetlands across inland portions of North America have been drained and degraded, their populations have declined in lockstep.

Long-billed Dowitchers begin arriving in the Klamath Basin every July after leaving their nesting grounds on the Arctic tundra. Most plan to stay for extended stopovers to take advantage of once-reliable food resources and to replace essential flight feathers. Research by the Migratory Bird Conservation Partnership aims to study how wetlands and agriculture fields of the Klamath Basin are connected to other similar places throughout western North America. These insights will help us highlight the importance of Klamath wetlands and the types of conservation practices that dowitchers rely on throughout their annual migration.

Researchers attach solar-powered tags to dowitchers that are tracked using the Argos satellite network.

Tracking Updates from Winter 2023 and Spring/Summer 2024

A map of the approximate wintering areas of 23 long-billed dowitchers

A total of 18 dowitchers transmitted locations during spring migration! Seven of these birds took flights over the Pacific Ocean, just under 3000km, which has never been described in Long-billed Dowitchers before. Three birds left the San Joaquin Valley in the same flock and made landfall two days later. Most of these birds traversed southern Alaska, crossed the Bering Sea, and set up breeding territories in northeastern Russia! Three birds stopped to refuel for 2-4 days in the Klamath Basin before continuing north.

LBDO 544, a female long-billed dowitcher, spent the winter in the Central Valley of California. On May 10th she left from the San Joaquin Valley in a flock that included two of our other tagged birds and set off over the Pacific Ocean, reaching Alaska two days later. She briefly refueled in Alaska’s Yukon Delta National Wildlife Refuge before a second trans-oceanic flight over the Bering Sea to Siberia. We believe she nested successfully and may have had two attempts before leaving the breeding grounds on July 5th. She returned to the Yukon Delta NWR where she refueled for about a week before returning on a similar path south, making landfall and arriving back in the Klamath Basin on July 24th. As of August 7th, she is still at Tule Lake NWR.

Four birds spent winter outside of California. One on the Gulf Coast of Texas, and three in northwestern Mexico. Check out their movements throughout winter and the habitats they frequented. Notably, all four spent time in and nearby designated Western Hemisphere Shorebird Reserve Network sites.

The Migratory Bird Conservation Partnership has spearheaded habitat incentive programs throughout the Central Valley alongside critical collaborators at the California Department of Fish and Wildlife (CDFW) and the California Rice Commission (CRC). The dowitchers that wintered in the Central Valley were closely associated with winter flooded rice enrolled in the CRC’s California Winter Rice Habitat Incentive Program from October through late February.

Tracking Updates from August and September 2023 in the Klamath Basin

Traversing the Sierra Crest overnight

Detected at 4:26 pm on November 7th in Lassen County, then again at 9:26 am on November 8th at the Salton Sea. 600 miles straight-line distance between locations = 35mph for 17 hours straight!! This bird has been located near Sonny Bono National Wildlife Refuge since its arrival.

From Klamath to Southeast Texas

Another dowitcher that traversed the Sierra Crest overnight, and then short stopovers in Arizona and northern Mexico before settling in for winter in southeast Texas. This area of Texas has a similar mix of farmlands and wetlands to California’s Central Valley.

Reliance on a mosaic of flooded ricelands in California’s Sacramento Valley

Around ⅓ of the tagged dowitchers are wintering in the mosaic of flooded rice fields and wetlands of the Sacramento Valley, a hotspot for wintering and migrating shorebirds. These maps show the tracks of two dowitchers that used the same area north of Sacramento for nearly two months.

Connecting Klamath and Mexico wetlands

Below are maps for two of the four dowitchers overwintering in northwest Mexico. One dowitcher took the nonstop route from Klamath to Baja, while the other hopped through California wetlands before settling in for winter on the Sinaloa coast, just south of the other who prefers Sonora coast wetlands.