Early-arriving Eastern phoebes build nests in eaves

I saw my first eastern phoebe of the season last week.

A few days after the snow I was walking alongside a small stream at the edge of a hayfield. The snow was melting, albeit slowly, and temperatures hadn’t yet risen much beyond the 30s.

It must have been warm enough, though, for insects to be present – I spotted an eastern phoebe making little sallying flights to snatch up the unlucky bugs. It flew from fence post to thicket to streamside and back to fence post; each time it alighted it voiced its call note, a short, simple chip, accompanying it with its characteristic tail bobbing.

Eastern phoebes are a familiar bird around human habitations; they often nest under the eaves of porches or sheds, or under bridges.

They have an easily recognizable song – its signature, emphatic “fee-brrreee!” They are also one of the earliest birds to arrive from their wintering grounds in the southeastern United States and South America – a sure sign of spring despite the weather.

This bird’s propensity for nesting under porch eaves has made it an unwelcome visitor to some. People sometimes notice, and are horrified by, the presence of mites around the birds’ nests. I wanted to know more about this myself, so I turned to the “Birds of North America” series, in which Harmon P. Weeks Jr. summarizes the volume of study done on these interesting birds. I found out that the adult birds can carry two types of mites. To find out if these mites would bother people, I turned to a fellow Audubon chapter member, Harold Gibbs.

Gibbs, a retired University of Maine wildlife professor, veterinarian, and parasitologist, said he didn’t think these mites would infest or harm people in the long term. For a more definitive answer, he had me contact Richard Dearborn, a Maine state entomologist.

Dearborn usually handles 15-20 complaints each year from people concerning bird-mite populations. Phoebes are the biggest culprits, followed by starlings and swallows.

“All birds have mites to a certain degree, especially those that return to the same nest year after year,” Dearborn said. The problem arises when mite populations get too high, he said, as this may cause mortality in the nestlings, in which case the mites will leave the dead birds to find another source of food.

That’s when things get ugly. Dearborn says people have had mites entering houses through cracks in walls or window panes. Some people have experienced being bitten, while others haven’t. The mites are adapted to living with their avian hosts, so they don’t last long around people – maybe up to a month, after which they die off, he said.

“As far as I know, these mites do not transmit disease,” he added.

Some people go for years with phoebes nesting under their porch rafters without noticing mite problems; if you do want birds to be around your house, just be aware of this consequence, Dearborn said.

“It’s like Russian Roulette – you never know when you’ll get the loaded cylinder,” he said.

If you don’t want phoebes to nest near your house, the time to do something about it is now. Prevent them from nesting by screening off known nest sites. If you do want the birds to return but want to reduce the chance of mite infestations, knock the nest down after each breeding season, or before the start of this one, and clean the area thoroughly.

If you still end up having a problem with mites, a regular insecticide – used within the home – will quickly eliminate them, Dearborn said.

For additional information, you can call your local Cooperative Extension Service pest management office; the number for Orono is 581-3880.

Chris Corio, a volunteer at Fields Pond Nature Center in Holden, can be reached at fieldspond@juno.com