Zoos all around the world love penguins. They’re cute, they don’t require much space, they never eat zookeepers. And children adore watching them, especially at feeding time.
But as carefree as they might look, torpedoing through the water or rocketing into the air like a Poseidon missile, zoo penguins are stalked by an unrelenting killer: malaria.
“It’s probably the top cause of mortality for penguins exposed outdoors,” said Dr. Allison N. Wack, a veterinarian at the Maryland Zoo in Baltimore, which is building a new exhibit that will double its flock to a hundred birds. If left untreated, the disease would probably kill at least half the birds it infected, though outbreaks vary widely in intensity.
The avian version is not a threat to humans because mosquitoes carrying malaria and the parasites are species-specific; mosquitoes that bite birds or reptiles tend not to bite mammals, said Dr. Paul P. Calle, chief veterinarian for the Wildlife Conservation Society, which runs New York City’s zoos. And avian malaria is caused by strains of the Plasmodium parasite that do not infect humans.
But for penguins in captivity, the threat is so great that many zoos dose their birds in summer with pills for malaria, said Dr. Richard Feachem, director of global health at the University of California, San Francisco.
Most of the penguin exhibits I have seen (the Central Park Zoo penguin exhibit comes to mind) are crowded, dirty, and sad. Maybe we’ll feel differently about keeping penguins in zoos if the avian malaria virus mutates into a strain that infects humans.