As we wrote last week, one of the five best things about summer birding in Maine is the interesting rarities that can show up. One of those we briefly mentioned was the fork-tailed flycatcher. One was spotted at one of our favorite places, the Kennebunk Plains, on July 14. It was last spotted there on July 16.

Mid-July is a time when many of the specialty birds of that beautiful grassland/shrubland begin to go quiet. The buzzy song of the grasshopper sparrow. The lilting melody of the vesper sparrow. The whistled “whip-wooo” of the upland sandpiper. They are now less frequently heard. 

All of those species are all still there, it’s just much harder to find them when they are not signaling their presence through song. Birders are, therefore, somewhat less likely to visit. We don’t really know what the person who found the fork-tailed flycatcher was looking for there or if they were just enjoying a pleasant walk in a gorgeous and fragrant place, but it must have been a thrill to suddenly discover this flycatcher with the cool, exceedingly long tail fluttering about.

As you known, many birds breeding in Maine and other parts of the U.S. and Canada build nests and lay eggs in June and July (our summer) and fly south to Central America, the Caribbean, or South America for the November through March period (our winter).

What is less well known is that certain birds from Chile and Argentina raise their young in the November to March period (the southern hemisphere summer) and migrate north to spend April through September in northern South America and Central America (the southern hemisphere winter).

Fork-tailed flycatchers occur from Mexico south through South America. But it’s only the subspecies found in southern South America that engage in this mirror image of the migration pattern we are familiar with that has been called “austral migration.”

That’s why a fork-tailed flycatcher might show up in Maine, five or six thousand miles north of where it was hatched, in the middle of our summer. While we might be in sweltering heat during our hottest month of the year, Chile is experiencing its coldest month of the year.

Of course, most fork-tailed flycatchers from the population that breeds in southern South America) only migrate north to northern South America or Central America. But a few just keep on going. There have even been individuals that have made it as far north in Canda as Akimiski Island in James Bay and Goose Valley in Labrador.

Here in Maine, fork-tailed flycatchers have been recorded perhaps 18-20 times, with one record as early as 1908. Most have been since 1970. In fact, there is a previous record of the species from the Kennebunk Plains from 1994!

This year, there have so far been fork-tailed flycatcher sightings in Quebec and New Jersey in June, though none others recorded in eBird in the U.S.  Birders on the islands of Aruba, Curacao, and Bonaire, off the coast of Venezuela, spotted a number of fork-tailed flycatchers that overshot the mainland in June and July.

There are a few other bird species that engage in this migration north from southern South America from April through September. Most are not as dramatic looking as this bird, with its black head and wings, gray back, white underparts and dramatic and elegant tail that is at least twice as long as the body. Probably more of these less dramatic austral migrants also wander northward to the U.S. and Canada than we know.

Jeffrey V. Wells, Ph.D., is a Fellow of the Cornell Lab of Ornithology and Vice President of Boreal Conservation for National Audubon. Dr. Wells is one of the nation's leading bird experts and conservation biologists. He is a coauthor of the seminal “Birds of Maine” book and author of the “Birder’s Conservation Handbook.” His grandfather, the late John Chase, was a columnist for the Boothbay Register for many years. Allison Childs Wells, formerly of the Cornell Lab of Ornithology, is a senior director at the Natural Resources Council of Maine, a nonprofit membership organization working statewide to protect the nature of Maine. Both are widely published natural history writers and are the authors of the popular books, “Maine’s Favorite Birds” (Down East Books) and “Birds of Aruba, Bonaire, and Curaçao: A Site and Field Guide,” (Cornell University Press).