Bird Migration

A Year in the Life of a Lesser Yellowlegs

The story of endurance, perseverance and defeat

U.S.Fish&Wildlife Alaska
7 min readDec 5, 2021


A brown and white bird with long yellow legs standing on a lily pad.
Lesser Yellowlegs weigh no more than two decks of playing cards, which allows them to easily walk through wetlands to forage on Joint Base Elmendorf-Richardson, Alaska. 📷 USFWS/Laura McDuffie

Small Knights

The Lesser Yellowlegs stands just 8 inches tall and weighs no more than a tangerine, yet this species of shorebird completes one of the longest bird migrations in the Western Hemisphere a round trip of up to 20,000 miles. Know in French as the Petit chevalier, these “small knights” breed within the boreal forest of Alaska and Canada and spend the winter months in southern North America, Central and South America, and the Caribbean. Unlike the typical shorebirds that can be seen zipping up and down coastal white sand beaches, Lesser Yellowlegs are commonly observed calling from the tops of spruce trees. In fact, their calls can carry for more than a half mile — have you ever heard one?

“ …they will be perched there as though the safety of the entire universe depended on the amount of noise they made” — William Rowan 1929

A brown and white bird with long yellow legs standing on a tree snag and singing.
A Lesser Yellowlegs alarm calling from a snag at Otter Lake, Joint Base Elmendorf-Richardson, Alaska. 📷 USFWS/Laura McDuffie

A Species in Decline

Since the 1970s, the species has experienced a steep decline in abundance. Data from North American bird surveys suggest a statistically significant population decline of 60–80%. Additionally, aerial surveys at non-breeding sites in the Caribbean and South America indicate a decline of up to 90%!

What is the cause?

Unclear because there are many potential threats that Lesser Yellowlegs encounter across their breeding and non-breeding range, such as:

1. Habitat alteration — The loss of habitat through logging, energy-sector related development and agricultural expansion.

2. Urbanization — The conversion of wetland habitats to residential and commercial developments.

3. Agrochemical exposure — The application of insecticides, herbicides and fungicides to protect crops.

4. Harvest — The unregulated harvest of Lesser Yellowlegs in the Caribbean and northeastern South America.

5. Climate Change — The drying of wetlands in the boreal forest due to increasing temperatures and changes in annual precipitation.

A aerial view of agriculture fields.
Agriculture in Calgary, Alberta, Canada–a common feeding area for migrating Lesser Yellowlegs. 📷 USFWS/Laura McDuffie

Finding the Answer

Understanding where, when, and how birds migrate is fundamental for identifying which threats have the greatest impact on the Lesser Yellowlegs population. Since 2018, ornithologists have worked to identify the cause(s) of the decline by tracking the annual movements of 115 adult Lesser Yellowlegs. The tracked birds originated from seven breeding populations dispersed across Alaska and Canada.

A map showing markers of each Lesser Yellowlegs population tracked.
Locations of 7 Lesser Yellowlegs breeding populations tracked between 2018–2021. (1) Anchorage, Alaska, (2) Eielson Air Force Base, Alaska, (3) Kanuti National Wildlife Refuge, Alaska, (4) Yellowknife, Northwest Territories, (5) Churchill, Manitoba, (6) James Bay, Ontario, and (7) Mingan Archipelago, Quebec. Source: ArcGIS Online.
A white and black bird with yellow legs standing on a stump.
Lesser Yellowlegs wearing a GPS transmitter near Anchorage, Alaska. 📷 USFWS/Zak Pohlen

Tracking Technology

Ornithologists tracked Lesser Yellowlegs by attaching miniaturized GPS transmitters to birds. Each transmitter is 4-grams (about the weight of a U.S. Nickle) and has two unique capabilities. First, the transmitters are programmable such that data can be collected anywhere at any time. Second, data is collected in real-time and can be accessed remotely without the requirement of recapturing the bird each year. In using GPS transmitters, the once mysterious life of the Lesser Yellowlegs has been reveled and with that, some unexpected findings.

A person holding a brown and white bird that is wearing a GPS transmitter.
A leg-loop backpack style methods was used to attached GPS transmitters to Lesser Yellowlegs. Each transmitter weighs 4.0-grams or no more than 5% of the bird’s total body mass. 📷 USFWS/Callie Gesmundo

World Travelers

Imagine that you decide to walk around the circumference of the moon (i.e. 6,700mi). You begin walking at a brisk pace of 3 miles per hour. Minutes, hours and weeks go by. At the 3-month mark, you finally complete the journey. Now imagine doing that another 1.5 times and not eating anything for a 1,000 mile stretch. It would be impossible, right? Well not for the Lesser Yellowlegs!

A brown and white bird flying.
Lesser Yellowlegs female “JE” departs the Anchorage Coastal Wildlife Refuge on 22 June, beginning a 2-month long migration that will take her to the heart of Buenos Aires Province, Argentina — 8,400 miles from her breeding location in Alaska. 📷 USFWS/Zak Pohlen

Lesser Yellowlegs have the extraordinary ability to fly thousands of miles to and from breeding and non-breeding locations each year. But migration does not look the same among all individuals. GPS tracking efforts clearly indicate that each Lesser Yellowlegs is unique.

A animated map of colored dots showing bird movements.
Migratory routes of Lesser Yellowlegs tracked between 2018–2021. Animation: USFWS/Laura McDuffie

A Year in the Life of the Lesser Yellowlegs

A male Lesser Yellowlegs known as “A65” successfully hatched four downy chicks in Churchill, Manitoba, Canada during June 2019. In the middle of August he departed North America and completed a 5-day non-stop flight across the Atlantic Ocean, prior to making landfall in Venezuela. After multiple stops to feed in South America, A65 settled in Argentina. During his migration, A65 was potentially exposed to numerous threats including pesticides in the Prairie Pothole region, habitat alteration by logging in Venezuela and agriculture expansion in the Pampas of Argentina. However, despite the many threats and physiological challenges endured during a long-distance migration, A65 persevered and return to Churchill to produce a new clutch of chicks.

Migratory route of Lesser Yellowlegs A65. Map produced by Laura McDuffie/USFWS

Just like every year before A65 departed Churchill in late summer with the prospect of enjoying a warmer climate in South America, but 2020 was not like other years. A65 was legally harvested in Martinique (Caribbean) on September 4, 2020.

An aerial view of a shallow swamp.
Port-Louis swamp, Martinique. 📷 Anthony Levesque

Protecting Traditions

The harvesting of shorebirds in Martinique is a cultural practice common among the Caribbean Overseas Departments of France and jurisdictions in northeastern South America. For 205 days between July and February, shorebird species can be legally harvested with minimal restrictions. Until recently, sustainable harvest was overlooked, but today bag limits have been established for large species, such as Whimbrel and Hudsonian Godwit, and hunter logbooks are being used to inform harvest estimates. By beginning to establish harvest regulations, Martinique is doing their part to ensure the wellbeing of migratory shorebirds. However, bird abundances fluctuate through time and therefore, new and evolving regulations are frequently proposed. When a species is properly managed it ensures that birds will be around for future generations and traditional harvest practices will be able to continue.

We All Have A Voice

Ensuring that declining species are protected is the moral responsibility of everyone. Awareness and education through stories like this are critical components in the conservation and management of all species. Awareness is the motivation that leads to action and action among ornithologists and citizens alike is imperative for ensuring the sustainability of an imperiled population — such as the Lesser Yellowlegs. Let’s all do our part in protecting birds!

A graphic describing the 7 actions people can take to protect birds: buy bird-friendly coffee, use less plastic, do citizen science, make windows safer, keep cats indoors, use native plants, and avoid pesticides.
Seven simple actions to protect bird populations. Created by: Cornell Lab of Ornithology
The head of a brown and white bird with a black beak.
Lesser Yellowlegs head profile of a breeding adult in Anchorage, Alaska. 📷 USFWS/Zak Pohlen

Read more: Want an immersive experience? Check out this article in Story Map form!

Created by Laura McDuffie, Communication Specialist for The Great Basin Institute and U.S. Fish and Wildlife Service Alaska External. Data produced by Migratory Bird Management Alaska Region.

Ethics Statement: This research was conducted in compliance with Institutional Animal Care and Use Committee standards (USFWS 2016–07 and 2019–05, ADF&G 0058–2018–2, and UAA 1388604) and the Canadian Animal Care Committee (Trent U 25284, Environment Canada 18CF01, 19CF01, and 19YA01).

Funding Sources: This research is supported by the 673 CES/CEIEC, U.S. Department of the Air Force (project numbers FXSB46058118, FXSB4658119, and FXSBA53216120), U.S. Fish and Wildlife Service, Alaska Department of Fish and Game, Environment and Climate Change Canada, Parks Canada, Bird Studies Canada and Trent University.

Acknowledgements: Thank you Jim Johnson and Christopher Harwood (U.S. Fish and Wildlife Service), Katie Christie (Alaska Department of Fish and Game), Audrey Taylor (University of Alaska Anchorage), Yves Aubry, Jennie Rausch and Christian Friis (Canadian Wildlife Service, Environment and Climate Change Canada), Erin Bayne (University of Alberta) and Erica Nol (Trent University) for assisting with field logistics, hiring field technicians, and providing project funding. We also thank Callie Gesmundo, Zak Pohlen, Will Britton, Casey Weissburg, Charlie Wright, Linnaea Wright, and Amanda Mumford (U.S. Fish and Wildlife Service); Shelby McCahon, Mitch Paisker, Rachel Gingras, Court Brown, Matthew Danihel, Nicole DeLuca, Christina Howell, Adam DuBour, Danielle Eneix, Marian Snively, Jeff Wagner (Alaska Department of Fish and Game); Christophe Buidin and Yann Rochepault (Trent University), Ken Foster and Christine Godwin (Owl Moon Environmental), Lee Tibbitts (USGS Alaska Science Center), Ross Wood (Bird Studies Canada), Jay Wright (The Ohio State University), and Benoit Laliberte (Environment and Climate Change Canada) for successfully conducting capture and banding efforts in remote and challenging conditions.

In Alaska we are shared stewards of world renowned natural resources and our nation’s last true wild places. Our hope is that each generation has the opportunity to live with, live from, discover and enjoy the wildness of this awe-inspiring land and the people who love and depend on it.

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