Flyway‐scale GPS tracking reveals migratory routes and key stopover and non‐breeding locations 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. Understanding the timing of migration, seasonal routes, and important stopover and non‐breeding locations used by this species will aid in directing conservation planning to address potential threats. During 2018–2022, 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 identify migratory routes, quantify migratory connectivity, and describe key stopover and non‐breeding locations. We also evaluated predictors of southbound migratory departure date and migration distance. Individuals tagged in Alaska and Central Canada followed similar southbound migratory routes, stopping to refuel in the Prairie Pothole Region of North America, whereas birds tagged in Eastern Canada completed multi‐day transoceanic flights covering distances of >4000 km across the Atlantic between North and South America. Upon reaching their non‐breeding locations, lesser yellowlegs populations overlapped, resulting in weak migratory connectivity. Sex and population origin were significantly associated with the timing of migratory departure from breeding locations, and body mass at the time of GPS‐tag deployment was the best predictor of southbound migratory distance. Our findings suggest that lesser yellowlegs travel long distances and traverse numerous political boundaries each year, and breeding location likely has the greatest influence on migratory routes and therefore the threats birds experience during migration. Further, the species' dependence on wetlands in agricultural landscapes during migration and the non‐breeding period may make them vulnerable to threats related to agricultural practices, such as pesticide exposure.

Movement and Genomic Methods Reveal Mechanisms Promoting Connectivity in a Declining Shorebird: The Lesser Yellowlegs

“…Tracking devices (Lotek Pinpoint Argos GPS-75, 4 g) were attached to birds via leg-loop harness [33]. Transmitters were programmed to transmit for approximately 1 year and record locations at 1-to 4-day intervals during southward migration and 4-day intervals during northward migration [27]. For birds that returned to breeding areas with active transmitters during the subsequent breeding season, the mean arrival date was calculated for each site and sex [34].…”

“…This does not appear to be the case for lesser yellowlegs, even though migration and breeding schedules differ between eastern and western populations [34]. Genomic connectivity through natal dispersal is likely facilitated by the amount of geographical and temporal overlap during migration and the boreal winter [27]. However, genomic connectivity could be disrupted as breeding and boreal wintering areas continue to become fragmented [72][73][74][75].…”

“…Recent evidence based on satellite tracking data showed that individuals breeding in central and eastern Canada had substantially greater probabilities of occurring in the harvest zone during hunting season than individuals originating in western Canada and Alaska [26]. The migration tracking data also indicated that individuals from geographically disparate breeding locations used different flyways during migration but overlapped in the non-breeding area, resulting in weak migratory connectivity overall [27]. These conclusions indicate that breeding birds using the Atlantic Americas Flyway are disproportionately affected by harvest, but it is unknown whether these birds represent a genetically distinct breeding population segment warranting special attention.…”

Where did my dog go? A pilot study exploring the movement ecology of farm dogs

“…GPS has been successfully used in studies involving a diverse range of animals, from birds ( 8 ) to mammals ( 9 ). By harnessing this technology, we can analyze various aspects of animal movement on a fine-scale including migration routes ( 10 , 11 ), foraging behavior ( 12 , 13 ), and habitat selection ( 14 , 15 ). In the context of farming, GPS collars have become widely and commercially available and have been used effectively to track livestock to inform herd management, including regrouping and pasture rotation ( 16–18 ).…”