Flyway-scale GPS tracking reveals migratory routes, stopovers, and
habitat associations of Lesser Yellowlegs
Abstract
Many populations of long-distance migrant shorebirds are declining
rapidly. Since the 1970s, the Lesser Yellowlegs (Tringa flavipes) has
experienced a pronounced reduction in abundance of
~63%. The potential causes of the species’ decline are
complex and interrelated yet understanding the timing of migration and
seasonal routes used by this species will aid in directing conservation
planning to address potential threats. During 2018–2021, we tracked 118
adult Lesser Yellowlegs using GPS satellite tags deployed on birds from
five breeding and two migratory stopover locations spanning the boreal
forest of North America from Alaska to eastern Canada. Our objectives
were to quantify migratory connectivity and identify key stopover and
non-breeding locations. Individuals tagged in Alaska and central Canada
followed similar southbound migratory routes through the Prairie Pothole
Region of North America, whereas birds tagged in eastern Canada
completed multi-day transoceanic flights covering distances of
>4,000 km across the Atlantic between North and South
America. Upon reaching their non-breeding locations, Lesser Yellowlegs
populations overlapped, resulting in weak migratory connectivity.
Lastly, freshwater and agricultural habitats of the Prairie Pothole
region supported the highest proportion of Lesser Yellowlegs during
southbound migration. Our findings suggest that while Lesser Yellowlegs
travel long distances and traverse numerous political boundaries each
year, the breeding population from which an individual originates likely
has the greatest influence on which threats birds experience during
migration. Further, the species’ dependence on wetlands in agricultural
landscapes during migration may make them vulnerable to threats related
to agricultural practices, such as pesticide exposure.