Resightings of Magellanic penguins ( Spheniscus magellanicus ) rehabilitated and released in eastern Brazil, with remarks on injuries and feather damage caused by flipper bands

Magellanic penguins ( Spheniscus magellanicus ) are frequent winter visitors of the coastal waters of Brazil. During this migration, they may experience a number of health problems (e.g. malnutrition, trauma, bycatch in fisheries, interaction with marine debris, oiling) which lead them to wash ashore, where they are rescued and brought to rehabilitation facilities to receive veterinary care. From 2012 to 2014, a total of 226 Magellanic penguins, mostly juveniles (98%), were successfully rehabilitated and released with flipper bands in coastal waters of Espírito Santo state, Brazil, by the Institute of Research and Rehabilitation of Marine Animals. Of these, 28 (12.3%) were resighted along the coast of Brazil and Uruguay on the months following their release. The spatial and temporal distribution of resightings suggests that rehabilitated penguins were able to reorient themselves and engage in normal migratory movements after release, but the data also reveals that they experienced gradual body mass loss in the post-release period. The proportion of individuals resighted was significantly higher in penguins released during the non-breeding season of 2012 (16.3%) than in 2013 (1.8%), which may be linked to decreased prey availability in southeast Brazil due to the oceanoclimatic conditions related to the 2011–2012 El Niño event. Nearly one-third of resighted penguins had injuries or feather damage associated with flipper bands, and similar problems were also seen in penguins that were admitted after having been rehabilitated and released months earlier by other rehabilitation facilities. Subcutaneous transponders, temporary plumage dyes and satellite transmitters are discussed as alternatives to monitor the post-release movements and survival of rehabilitated Magellanic penguins.