AUGUSTA, Maine — A large number of finches have been reported sick or dead at feeders across the southern and central parts of the state, and Maine may not be the only state where this is happening, wildlife officials say.
Mortality at feeders is not uncommon this time of the year. But it can be alarming to people who have been calling the state Inland Fisheries and Wildlife Department and Maine Audubon and taking sick birds to wildlife rehabilitators, DIF&W officials said.
No Maine specimens had been tested as of late last week, but state wildlife biologist Tom Hodgman said he suspects the cause of death is a gastrointestinal disease caused by the bacteria salmonella. It leads to death most commonly in gulls and songbirds. Pine siskins, American goldfinches and common redpolls have been affected in Maine.
Salmonellosis is commonly seen in late winter and early spring when a combination of factors increases risk to birds at feeders.
First, a winter’s worth of seed waste and bird droppings accumulate on the ground under feeders. As weather warms up and snow melts, seed and bird waste are exposed. Temperatures in the debris under feeders can reach levels favorable for bacterial — including salmonella — growth.
Wintering finches often arrive at Northern feeders in great numbers, and many end up sifting through the seed waste under feeders looking for bits of food that have fallen from above.
Birds affected by salmonellosis appear puffed out, with their head down and eyes closed, and many seem to have no fear of humans and remain at the feeder even as someone approaches. That can leave affected birds more vulnerable to predators. In recent cases, cats known to have eaten infected birds have become seriously ill and required veterinary care, DIF&W said.
Dogs and humans, especially children, can become exposed if they handle sick or dead birds.
To minimize exposure, homeowners can wash feeders in a solution of 10 percent bleach and 90 percent water, scrubbing tight spaces with an old toothbrush. Allow the feeder to sit in the sun and thoroughly dry before reusing it.
Wildlife officials said it’s also important to remove seed waste under the feeder and dispose of it in trash or bury it.