A penguin died Aug. 25 at the Woodland Park Zoo. This is the second bird from the zoo's new penguin exhibit that has died in the past two weeks.

According to a zoo press release, the penguin appears to have died from complications related to a suspected case of avian malaria, a parasitic blood disease transmitted by mosquitoes.

The 21-year-old bird had been undergoing intensive medical treatment, including a blood transfusion, for avian malaria since it began presenting symptoms last week, according to the press release.

The first penguin's death was attributed to ingestion of a sealant material from a pipe in the exhibit.

Subsequent tests of tissue samples revealed the presence of avian malaria in the first bird, which may have contributed as a secondary factor to his death, according to the press release.

As standard procedure, Woodland Park Zoo animal health staff will perform a postmortem examination and order diagnostic testing to determine the exact cause of death of the second bird; it can take up to two weeks to receive complete test results, according to the zoo.

According to the press release, there was no evidence of foreign material in the second bird; the sealant was removed from the penguin pool in the exhibit.

“Penguins are known to be especially prone to avian malaria," Dr. Darin Collins, the zoo's director of animal health, said in a press release. "However, like other diseases spread by mosquitoes, avian malaria is not typically a major concern in the Pacific Northwest because of our relatively small mosquito population."

Three other penguins are currently showing symptoms consistent with avian malaria, including partial loss of appetite, though their symptoms are less severe than those seen in the now deceased bird.

The three birds are receiving anti-malarial treatment and supportive care behind the scenes at the zoo’s penguin exhibit.

“Penguins cannot transmit avian malaria to other penguins,” Collins said. “However, as a preventative measure against mosquito vectors, penguins in our colony that are 15 years of age or older are being put on prophylaxis treatment, since older penguins are more susceptible to the disease.”

“It’s important to stress that zoo visitors are not at risk," Collins said. "Neither birds nor mosquitoes can transmit avian malaria to humans."

The Woodland Park Zoo's Humboldt penguin exhibit opened this past spring.