Many “birds of a feather flock together,” but not all, and those that do, indulge in different degrees of flocking. “Birds of a feather” means one species, but sometimes a flock can contain several species. Then it can be said that birds of different feathers are flocking together.
Almost all ducks and shorebirds form flocks, and they waste little time getting together after breeding season ends. Geese usually gather in uniform flocks, but ducks can often mix and mingle, especially closely related species like greater and lesser scaup.
Swallows, blackbirds and starlings are examples of land bird species that will join ranks very quickly. They can consist of a single or several species, and their numbers can reach thousands or even tens of thousands. These monster flocks begin to form as early as late July and remain together until spring.
Open country land birds such as horned larks, snow buntings, and some sparrow species also form large flocks. All these species spend most of their lives away from the protection of forests and thickets. Flocking is a device that provides both an early warning and a “confusion” effect.
Most raptor species do not flock at all, notable exceptions being vultures and broad-winged hawks. The latter are legendary for their daytime migration, swirling “kettles” and streams of hundreds as they begin their north to south migration each fall. By the time they reach the Mexican border, they number in the thousands.
Finches almost always are found in flocks, especially the siskins and redpolls, both of which have wandered south this winter. At feeders, the siskins have dwindled to a few lost leftovers, and only a handful of stray redpolls have even found feeders.
Finding a flock of 150 redpolls in Agawam on the Christmas Count was something special. They chattered wildly as they flew into the single tree that stood in the center of a huge field. Many quickly flew off, but about two dozen remained, allowing a close approach.
Starling flocks can blacken the sky and even a small flock can overwhelm the feeders. A modest group of 35 starlings has haunted my suet feeders for weeks, driving away the woodpeckers. For two weeks a mass of cowbirds hung out in my neighborhood. More than 75 of them would stand shoulder to shoulder on the ground and wolf down the millet seed.
Colder days and snow flurries drove the cowbirds south, but not the sparrows. Mixed groups of juncos, or tree, song and white-throated sparrows can reach 60 individuals when clouds threaten snow or rain. Add in a dozen cardinals, and they keep me busy casting millet on the ground.
On the Westfield Count there were flocks of 50-75 juncos enjoying the fields where wild seeds still are plentiful. They twittered constantly to each other and flushed from weeds to nearby shrubs and trees when approached. Stand still and they quickly return, to scatter on the bare ground or disappear in the tall stems.
Woodland birds rarely gather in such numbers, though sometimes small groups of mixed species join together and work their way through the branches and treetops, gleaning insects and seeds. Chickadees, nuthatches, titmice and woodpeckers can be encountered anytime on a walk through the wintery woods.
These birds relish sunflower or suet in hanging feeders. A handful of chickadees and titmice seem to stick together, but woodpeckers are strictly loners, often chasing each other, or waiting for a turn when a dominant bird is feeding.
I have to leave home to find water birds, unless a flock of geese flies overhead. On nearby Congamond Ponds, a small group of common mergansers were swimming and diving for a week, but on count day the number had grown to a raft of 70-80 birds. It was a beautiful flock, but the biggest surprise of the day was a flock not seen at all, but heard.
Listening for owls well before dawn, I suddenly heard the raucous, resounding calls of snow geese. On a clear night they fly very high, but strong northwest winds and an overcast sky forced these birds to descend closer to ground. Whether a species flocks together or not, birds of any feather are always fascinating.
Seth Kellogg can be contacted at email@example.com
The Allen Bird Club website can be found at massbird.org/allen