Blue, a 21-year-old harbor seal, is believed to have contracted the virus through contact with a wild bird, zoo officials said.

Tests show bird flu caused the death of a 21-year-old harbor seal at a zoo in New Bedford, Massachusetts earlier this month. The Buttonwood Park Zoo said in a social media post that the "beloved" seal named Blue likely got the avian flu by coming into contact with an infected wild bird.

Bird flu has killed at least four snowy owls in Massachusetts in recent weeks, adding the graceful white and black-patterned predators to its victims as it sweeps through the wild bird population.