State wildlife officials and the Mass Audubon bird conservation group are advising residents to bring in their bird feeders and birdbaths until more is known about a mysterious ailment that has been killing birds in the southeast and mid-Atlantic area.

While there have been no confirmed cases of the disease closer to the Vineyard than New Jersey, Island wildlife biologist Rob Culbert said there have been reports of dead birds in Connecticut — an easy flight from the Vineyard for many species.

Pine siskins. — Lanny McDowell

“Don’t pay attention to artificial lines we draw on a map,” said Mr. Culbert, who writes the Gazette’s weekly Bird News column. “Especially now that migration is underway.”

Mr. Culbert urged Martha’s Vineyard bird lovers to bring in their songbird feeders and birdbaths as a precaution against the disease, which is being studied by veterinary toxicologists.

“I would encourage everyone with bird feeders to do it, even though it means there will be fewer birds close to their house,” he said. “We don’t want to be responsible for spreading mortality,” he added. “The birds have enough problems already.”

Since 1990, three billion birds worldwide have died from causes including diseases, predation by cats and collisions with motor vehicles and glass windows, said Mr. Culbert, who said he sets his own feeders out only in colder months when natural food is limited for birds.

Hummingbird feeders currently are considered safe by wildlife officials, but Mr. Culbert has some caveats for protecting the tiny, gleaming pollinators.

“For hummingbird feeders, I recommend — especially in this hot and humid weather — that they be cleaned every couple of days and the sugar water replaced,” he said.

“Don’t wait for the sugar water to be consumed,” before making a fresh batch, he said, because warm summer temperatures encourage the growth of harmful bacteria.

Mr. Culbert takes issue with the widely-shared advice to clean bird feeders with a 10 per cent bleach solution.

“I’m opposed to bleach, because it breaks down into something close to a hazardous material,” he said. “Any number of household products will sanitize that don’t have bleach in them.”

Once washed — according to the cleaner manufacturer’s instructions — and rinsed, the feeders should be sun-dried, Mr. Culbert said.

Meanwhile, anyone who spots a dead bird that doesn’t appear to be the victim of an accident or predation is asked to email the state at mass.wildlife@mass.gov with details, Mr. Culbert said.

Mr. Culbert receives reports of live bird sightings on the Vineyard at birds@mvgazette.com.