Two years ago, Ellen Martinsen, was collecting mosquitoes at the Smithsonian’s National Zoo, looking for malaria that might infect birds–when she discovered something strange: a DNA profile, from parasites in the mosquitoes, that she couldn’t identify. By chance, she had discovered a malaria parasite, Plasmodium odocoilei–that infects white-tailed deer. It’s the first-ever malaria parasite known to live in a deer species …