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 by
~63%. The potential cause(s) of the species’ decline
are complex and interrelated, yet understanding the timing of migration
and seasonal routes used by this species will aid in direct conservation
actions to address threats. During 2018–2021, we tracked 118 adult
Lesser Yellowlegs using GPS satellite tags deployed on birds from seven
breeding sites spanning the boreal forest of North America from
southcentral Alaska to eastern Canada. Our objective was to provide the
first comprehensive overview of Lesser Yellowlegs migratory patterns,
including routes and timing, use of stopover and non-breeding sites,
habitat associations, and migratory connectivity. 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 mixed, resulting in weak migratory
connectivity. Lastly, agricultural and wetland habitats of the North
American Prairie Potholes, the salt marshes of the Texas Gulf Coast, and
the rangelands of the Argentine Pampas supported the highest proportion
of Lesser Yellowlegs during southbound migration, northbound migration,
and the non-breeding period, respectively. Our findings suggest that
while Lesser Yellowlegs are exposed to a variety of threats throughout
the annual cycle, the breeding population from which an individual
originates influences which threats it experiences over its lifetime.
Further, the species’ dependence on mixed agricultural and wetland
landscapes during migration may make them vulnerable to threats related
to agricultural practices (e.g., pesticides and habitat loss).