Partial migration in Magellanic penguins

We study the migration of Magellanic penguins at the southern tip of the breeding distribution. We found for the first time for this species evidence of partial migration within the same colony. Forty-three percent of the penguins studied stayed within ~290 km from the colony (residents), while others went northwards as far as 2000 km. All penguins spent the same amount of time at sea and traveled similar total distances, but residents experienced colder waters (2 °C less) and lower chlorophyll-a habitats than migrants. The two habitats are inhabited by different prey items, consequently giving the penguins different possibilities of prey items. We have shown individual strategies with high variability in the non-breeding dispersion behavior of Magellanic penguins, nonetheless, further research is required to understand the proximate and ultimate causes and the consequences of this behavior.

Methods
We tracked 14 Magellanic penguins from the colony Cabo Vírgenes in 2020 and 2021. We used geolocators that were analyzed following the methods in Lisovski et al. (2020) and Barrionuevo et al. (2023).