Winter movements and sedentariness in the high Andes by an extremophilic shorebird

EBERHART-HERTEL, LUKE; DIAZ, FERNANDO; PIETREK, ALEJANDRO G.; PINTO, CRISTIAN; CONTRERAS, ANDREA; SCHMITT, FABRICE; SENTEMA, PETER; TELTSCHER, KIM; VALCU, MIHA; JOHNSON, JIM; LYON, BRUCE; KEMPENAERS , BART

Sylt

Conferencia; International Wader Study Group Conference; 2023

International Wader Study Group

The Diademed Sandpiper Plover (Phegornis mitchellii, hereafter “DSP”) is a charismatic shorebird inhabiting the high Andes of South America. Despite the species’ iconic status for ecotourists and ornithologists worldwide, surprisingly little is known about the annual movements of DSP throughout the continent. Current understanding of DSP life history suggests that breeding activities are limited to high elevation (>2500 m) wetlands often fed by thermal springs. Although these wetlands experience freezing temperatures, high winds, and snowfall over the winter, no DSP have been observed at lower elevations on the Andean Pacific slope: suggesting that DSP remain sedentary around thermal springs or migrate to unidentified regions of the continent. To solve this ornithological mystery, we deployed a combination of GPS- and Argos-based tags on DSP at two breeding sites spanning the central core and southern limit of the species’ range: Lagunas de Vilama, Argentina, and the El Yeso Valley, Chile, respectively. Data are currently being collated during the austral winter, but preliminary evidence suggests that DSP do not exhibit concerted latitudinal or elevational migrations. Rather, DSP remain sedentary around thermal springs used during the breeding season, or move to adjacent thermal springs up to 150 km away, presumably where local carrying capacity allows for over-wintering. Our results demonstrate that DSP are a unique extremophilic shorebird whose range may be restricted, in part, by geothermal activity. Future work is needed to document the social cohesion and foraging ecology of DSP flocks residing at these winter oases.