Aspergillosis in free-ranging Magellanic penguins.

We evaluated the mortality due to aspergillosis in free-ranging Magellanic penguins during their migration and the reproductive season. Ninety-eight carcasses of penguins were collected along 370 km of coastline in Southern Brazil, between June 2017 and October 2019, and from reproductive colonies at Patagonian Argentina, in January 2019. All animals were necropsied, and only proven cases were computed. Aspergillosis was diagnosed in 2.5% of the penguins evaluated during their migration route. Our study, of the Southern coast of Brazil, is the first to demonstrate that aspergillosis is an important cause of mortality in free-ranging penguins. The implications of these findings in the One Health context are discussed.