FIRST INSIGHTS INTO THE MIGRATION PATTERN OF AN UPLAND GOOSE (CHLOEPHAGA PICTA) BASED ON SATELLITE TRACKING

Detailed knowledge of the migratory strategies is important to understand the ecology and evolution of migration and the conservation of migratory birds The Argentinean federal government declared sheldgeese (Chloephaga spp.) pests in 1930, claiming that they reduce crop yield. Currently sheldgeese have suffered severe reductions in their populations and are the focus of serious conservation concern. From September to April they breed in southern Patagonia (Argentina and Chile) while from May to September they winter mainly in the southern Pampas (central east Argentina). The precise knowledge of their migratory routes is essential to ensure protection of necessary resources and sites needed on their annual journeys. Here, by using a satellite transmitter for the first time we unravel the migration route of an Upland Goose (Chloephaga picta), a species endemic to southern South America with an unknown migration strategy. We received data for 121 days (from September 2014 to January 2015). During this time, the bird migrated 1485 km from the wintering grounds in Buenos Aires Province to the breeding area in Santa Cruz province, Patagonia. Part of the migration route was over the sea. The largest displacement was 817 km in 19 hours, representing a minimum mean speed of 43 km h-1

Spatial and temporal variation in the migration of Ruddy-headed Goose in southern South America using satellite tagging

Ruddy-headed Goose Chloephaga rubidiceps is the smallest of the five South American sheldgeese and has two separate populations: one sedentary, which resides in the Malvinas/Falkland Islands and one migratory that overwinters mainly in the Pampas region, Argentina and breeds in Southern Patagonia. The Ruddy-headed Goose’s continental population has decreased considerably, and recent estimates indicated that the population size is less than 800 individuals. In Argentina and Chile, this population is categorised as endangered. Understanding migration across vast landscapes is essential for the identification of factors affecting the survival of this endangered population and for the application of effective conservation measures. We aim to provide the first documentation of the complete migration cycle of Ruddy-headed Goose, and to analyse their annual migration in detail, including identification of stop-over, breeding and wintering sites, and to compare migration timing during spring and autumn migration. Adults were captured in the southern Pampas and equipped with solar satellite transmitters in 2015 and 2016. We analysed the influence of season (spring vs autumn migration) on the number and duration of stop-overs, distance travelled and overall migration speed using Generalized Linear Mixed Models. Our results showed that tracked geese used the eastern Patagonian route to reach their breeding grounds and take the same route after breeding. Spring migration was significantly faster than autumn migration, at least based on the number of days spent in their stop-overs. Stop-overs were closer to the final destination, either during spring and autumn migrations, though some of them were not used during subsequent migrations. Our migration cartography for Ruddy-headed Geese, together with the timing and location data, should be used to improve conservation efforts directed at this species and might contribute to the modification of the current status of ‘Least Concern’ under the IUCN criteria.EEA BalcarceFil: Pedrana, Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Putz, Klemens. Antarctic Research Trust; AlemaniaFil: Bernad, Lucia. Instituto Nacional de Tecnología agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Muñoz, Sebastián. Instituto Nacional de Tecnología agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Gorosabel, Antonella. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Castresana, Gabriel. Gobierno de la Provincia de Buenos Aires. Organismo Provincial de Desarrollo Sostenible; ArgentinaFil: Leiss, Alejandro. Gobierno de la Provincia de Buenos Aires. Organismo Provincial de Desarrollo Sostenible; ArgentinaFil: Seco Pon, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata; Argentina. Instituto de Investigaciones Marinas y Costeras; Argentin