Spatial assignment of winter migration of Magellanic Penguin using isoscapes

GONZALES JULIANA; MELINA BARRIONUEVO; ESTEBAN FRERE; PABLO YORIO; NOELA SANCHEZ-CARNERO; JAVIER CIANCIO

reñaca

Conferencia; 11 penguin conference; 2023

Penguin society

Studying animal movement can provide valuable insightsinto migration habits and space utilization, which are crucial for developingaccurate conservation policies. Techniques based on electronic devices such as deadreckoning or telemetry (like GPS and GLS), have been used to track the movementof migratory Magellanic penguins (Spheniscus magellanicus). Thesemethods have generated extensive individual tracking data, but they havelimitations when it comes to following long distance migrations: while self-recordingGPS batteries do not last long, solar rechargeable tags or satellitetransmitter service are expensive and the GLS tag geographic accuracy is low. Inrecent years, the use of isotopic landscapes for retrospective geolocation hasemerged as complementary method, and has proven useful in elucidating migrationhabits of pelagic sea birds. In this work, d15N and d13C isoscapes of the AtlanticPatagonian Shelf were used to infer location of Magellanic penguins feeding attheir wintering grounds. The isoscapes used were based on blood samples ofbreeding Magellanic penguin, and showed a strong latitudinal gradient withminimal error, which is requisite for their use to assign location.Subsequently, blood from just arrived individuals were sampled in one colonyand maps of probability of spatial use were developed from the isoscapes andcontrasted with same individual GLS data to evaluate the assignment accuracy. Ourstudy provides valuable information for the understanding of penguin use ofspace in non-breeding season.