Lesser Yellowlegs

Lessons of Patience and Resilience

A backlit shorebird with a geolocator tag perches in a spruce tree
A backlit shorebird with a geolocator tag perches in a spruce tree
A banded Lesser Yellowlegs atop a black spruce on Joint Base Elmendorf-Richardson (JBER). A metal band, a dark green color band, an alpha character leg flag and in some instances, a 4g Argos PinPoint satellite-GPS unit are deployed on captured adults. 📷 USFWS/Alec Blair
wood frog in someone’s hand
Top: Wood Frog (Lithobates sylvaticus; right) are common across boreal wetlands in Southcentral Alaska. Bottom: One of 35 species of mosquito found in Alaska.📷:USFWS

The Bird

The Lesser Yellowlegs (Tringa flavipes) is a shorebird (sandpiper, specifically) with long yellow legs and a relatively long neck. It’s an elegant bird that people describe as both “dainty” and “slender”; certainly not a species you would expect to migrate tens-of-thousands of kilometers a year from the northern boreal forests of Alaska and Canada to the wetlands and coastlines of Central and South America and the Caribbean.

A lesser yellowlegs with leg bands perches on a branch
A nesting adult Lesser Yellowlegs perched on top of a mossy black spruce snag on JBER. Parents will take turns foraging and incubating. Incubation lasts 22–23 days and precocial young (hatched in an advanced state and able to feed themselves) are defended by the male parent until fledge.

The Plight of Lesser Yellowlegs

Since the 1970s, the Lesser Yellowlegs has experienced a precipitous population decline. In Alaska alone, the population has seen a 5.3% to 9.2% decline per year since 2003 (Handel and Sauer 2017). The factors contributing to this decline are complex and include wetland conversion, agricultural pollution, climate change, and the most recently identified threat — harvest. The movement data collected by the GPS units provide conservationists an understanding of the proportion and timing of Lesser Yellowlegs traveling through regions where shorebird harvest is practiced, in turn leading to the development of conservation strategies for the species.

“This is a frequently harvested shorebird species for both subsistence and sport hunting on their wintering grounds; we want to understand how different breeding populations may be disproportionately influenced.” — Laura McDuffie

A range map for the lesser yellowlegs
A range map for the lesser yellowlegs
Map represents the breeding, non-breeding, and migratory range of the Lesser Yellowlegs. Occupancy data derived from Cornell Lab of Ornithology eBird data.

The Research

The goal of fieldwork this season was to understand the species annual migratory movements by deploying 4g Argos PinPoint satellite-GPS units on a small sample of breeding adults. Birds were trapped using mist nets, which consist of a fine mesh meant for entangling a bird without harm. Upon capture, morphometrics (i.e. wing, head and tarsus length) and biological samples (i.e. blood, feather, and nail clippings) were collected from each captured bird.

A biologist takes measurements of a lesser yellowlegs in her hand
A biologist takes measurements of a lesser yellowlegs in her hand
Laura reads the tarsus measurement of a Lesser Yellowlegs captured on the Anchorage Coastal Wildlife Refuge.
Two biologists affix a geolocator tag to a lesser yellowlegs
Two biologists affix a geolocator tag to a lesser yellowlegs
Laura adjusting a leg-loop harness prior to releasing the bird.

“GPS units are accurate to about 10 meters in optimal conditions, because of this, I can determine where Lesser Yellowlegs are stopping to refuel during migration, the types of habitats they prefer, and their probability of occurrence within shorebird harvest regions.” — Laura McDuffie

The Crew

I was fortunate to spend a week studying Lesser Yellowlegs with two young, but very seasoned ornithologists: Laura McDuffie and Will Britton.

Biologist Laura McDuffie
Biologists Laura McDuffie and Will Britton
Laura McDuffie (top), a previous UAA graduate student and current USFWS term biologist and Will (bottom) a USFWS seasonal avian technician.

The Trials and Tribulations

Perhaps a poorly made soap opera could have served better than a written story to speak towards the week of fieldwork I experienced.

Lesser yellowlegs nest and eggs
Lesser yellowlegs nest and eggs
A Lesser Yellowlegs nest lies among the Labrador Tea (Rhododendron tomentosum) and Dwarf Birch (Betula nana) at a bog on JBER.
Biologists remove a lesser yellowlegs from a mist net
Biologists remove a lesser yellowlegs from a mist net
Will and Laura untangle a Lesser Yellowlegs carrying a GPS unit deployed in 2018. The old unit was removed and replaced in hopes that the consistency of individual birds’ migratory movements can be revealed.
Dowitcher chicks at the edge of a tundra pond
Moose foraging on green vegetation
Bonaparte’s gull and chicks
Short-billed Dowitcher chicks (top) huddle together in the short grasses of the Boreal. Moose run-ins (left) can be frequent on JBER. A Bonaparte’s Gull (right) protects its chicks as they forage around Otter Lake, JBER.
Lesser yellowlegs chasing a red-necked phalarope
A Lesser Yellowlegs (right) chases off a Red-necked Phalarope (left) while foraging at a lake on Joint Base Elmendorf-Richardson in Anchorage, Alaska. Lesser Yellowlegs can be territorial, especially during the breeding and incubation periods.

Stories from Alaska by the U.S. Fish & Wildlife Service