Middle America isn’t what it used to be. It used to be that we could count on the Rockies, the Great Plains and the Mississippi River to keep western birds on their own side of the country. But then again, this has been an especially weird winter.
Of all the weirdness, the weirdest is the arrival of a black-throated sparrow in Winter Harbor. It was discovered during the Schoodic area Christmas Bird Count by Chuck Whitney, Ed Hawkes and Debbie Hawkes. Since then, it has been re-located multiple times.
This small sparrow is confined to arid areas of the southwest. Its range reaches through Colorado into Oregon, but most of the population is located between western Texas and eastern California. I saw my first in Phoenix on June 23, 1985.
It never flies east. Heck, not many of them fly anywhere at all. Only those in the northern states move south for the winter, and not very far. Maine Audubon naturalist Doug Hitchcox looked up the records and found that only one unverified sighting of this species has ever occurred in Maine. One showed up in Massachusetts in 1959, another in 1963, and one in 2012. Those are the only New England records, so this little fella in Winter Harbor is rare indeed.
How did it get here? Some birds are prone to wandering abnormally. It even helps some species to colonize new places and extend ranges. The rufous hummingbird looks like a copper-colored variation of our own ruby-throated hummingbird. It’s a notorious vagrant. Like all other western hummingbirds, it is unlikely to be found east of Texas. But over the last few decades, enough of them have wandered east that they have established wintering grounds along much of the Gulf Coast. One turns up in Maine just about every fall.
But the black-throated sparrow is a homebody, not inclined to meander. It’s happiest in the desert, and it tends to stay there. Still, individual birds can have a genetic defect that throws off their internal compass. A genetically disoriented sparrow could leave Colorado thinking it was heading to Mexico, only to find itself confronting the Atlantic Ocean.
Storms can blow birds off course. Maine’s weather has not been severe, but other parts of the country have gotten socked. Our guy may have been heading south to Albuquerque, only to get caught up in an eastbound tempest.
I like this last theory, because it also would explain why a western tanager has been haunting a hillside in Saco for the last month. It would explain how a white-winged dove turned up in Frankfort. That bird is the subject of next week’s column, but suffice to say that it came a long way from the southwest, too.
Several southern birds also have been hanging around. A yellow-breasted chat in Rockland and a couple of yellow-throated warblers elsewhere have been seen and re-seen by countless birders this season. A painted bunting is in Mount Vernon. New Jersey is the northern limit of the chat’s nesting range. Ditto for the warbler. The bunting doesn’t breed any farther north than the Carolinas. Yet it’s not abnormal for these birds to show up in Maine. Though rare, it’s an annual event. Even a normal storm sweeping up the coast can carry southern birds up here. But it would take a whopper of a storm to carry birds across the continent from the southwest.
Whoppers happen. The northern lapwing is a European bird that migrates long-distance to Africa. A couple of years ago, a freak storm crossed the Atlantic and rained lapwings on the east coast of America. Sightings were scattered from Maine to New Jersey. The cattle egret is a common bird from Florida to Connecticut. It is often seen in pastures and along roadways. In 1877, a storm likely helped a bunch of them to cross the ocean from their native territory in Africa to South America. They’ve been working their way north ever since, arriving in the United States in 1953, and now reaching parts of Canada.
Or maybe all of these vagrants turn up every year, and it is just our own weather pattern that is abnormal. The life expectancy of a bird out-of-range is not long. A normal Maine winter might kill off wandering birds before they’ve been discovered. But milder weather may have kept more vagrants alive longer than usual, giving us a chance to find more of them. I will end this column now, before you realize that I’m just guessing.
Bob Duchesne serves as vice president of Maine Audubon’s Penobscot Valley Chapter. He developed the Maine Birding Trail, with information at mainebirdingtrail.com. He can be reached at duchesne@midmaine.com.