More than 500 dead penguins have washed up on beaches in southern Brazil in the last week, and experts are not yet sure why.
The Daily Mail reports that biologists and veterinarians are now investigating what killed the birds, which appeared to be healthy and unhurt.
Scientists counted a total of 512 penguins washed up on beaches on the southern state of Rio Grande de Sul, between the towns of Tramandai and Cidreira.
The Magellanic Penguins were migrating north from Argentina in search of food. They normally make the journey between March and September. Their diet consists mostly of small fish and crustaceans and their main enemy is the sea lion.
The BBC reports that early findings indicate that the penguins could have starved to death, as their stomachs were completely empty.
Thiago do Nascimento of the Peruibe Aquarium says that cooler temperatures off the coast could have driven away the fish and squid that the penguins feed on.
He also said that overfishing could have decimated their food sources.
He added that between 100 and 150 penguins arrived on the beaches each year, but they were usually alive with an average of around ten per year found dead.
Scientists are examining the bodies of 30 of the dead penguins, and expect to get the results of the autopsies within the next month.
This isn't the first time this type of incident has occurred and it has previously been blamed on shifting ocean currents and colder temperatures.
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