Nature Column: Birds of a Feather…

On a neighborhood walk in the city, it is a cool and dreary day, fat raindrops starting to fall. Out of the sky comes an unexpected crow, which grabs a small rodent to carry off to a tree to devour. It could have been carrion or living, as this species are omnivores, opportunistic feeders. It continues to eat voraciously, as its mate in their nesting tree across the busy street screams incessantly and raucously, almost as if indignant at being left out of the feast. It returns to that tree, empty-beaked!

A few years ago, I went several times to Lawrence with my late partner, to try to find the huge numbers of crows which gather to roost for the night late October to March. Most are birds which migrated from the north during the cold months. Just 20% are local, mostly American crows, with a few fish crows scattered in.

They gather at ‘staging areas’ just before dusk, moving from place to place, until they “stream towards the roost like a black river,” as biologists McFarland and Zahendra describe it. This constant shifting may confuse predators. These birds often change their roost areas for the same reason. It succeeds in confusing birders as well, in this shifting landscape.

The phenomenon was noted as early as the 1980’s, with their arrival at dusk, departure at dawn, and return again in the evening. The group roost behavior may be for warmth, gaining information on locating food and mates, and warding off predators such as Great horned owls, which swoop through roosts at night. A Crow Patrol was formed in 2017 by Craig Gibson, crow enthusiast, and an older couple, the Foxes, who were documenting the event nightly.

We see a few crows heading in one direction, and follow them to a small mall. We have dinner, and come out to find dozens on wires and rooftops, a Hitchcockian event. Luckily, we drive to a random empty parking lot, and there are the Foxes, taking notes. They offer to drive in front of us to find the staging areas of that evening, and we make various stops along the way, as smaller groups of birds, possibly family and known others, move from one copse of trees to another. The air is filled with black swirling shapes and a deafening cacophany of  caws. We are open-mouthed, stunned, at this spectacle, and finally end up at a tiny lot behind a small building, to see them streaming in over the water. We are told the count for this evening is 14,000!  Persistence has certainly paid off in our quest to witness this unforgettable event.

At Salisbury Beach, and at Crane’s Beach, in season, one can see thousands of tree swallows heading south for the winter. We stand in an open marshy area, the salt flats, and see wave after wave of these birds, flying low in large groups. The come in spurts, and their stunning iridescent blue backs and white breasts shine in the late afternoon sun.

At our local cemetery, the mourning doves have mostly departed, but in December there are still some small groups of 20 or 30 feasting and foraging, to fatten up for their long migration. Juncos, our winter birds, have arrived from the north. They appear chubby, small, gray, black and white, with white stripes on underwings dazzling in the sun. They travel in groups to feed on this flat grassy area, then fly up in unison to trees when disturbed, before returning en masse to feed. Their flight is lilting, and they seem happily ensconced in their winter retreat.

Our resident starlings also travel in large groups at this season, sometimes in the hundreds. Some are in winter plumage, some still in breeding coloration, and others are in transition from glossy black to a dark background topped with thousands of crisp white dots, Even on the heads, and around the beaks, there are countless tiny pale dots. Amazingly, they do not molt, but grow a white tip at the end of each feather, which wears away in the spring!

Originally from Europe, 100 were released in Central Park in the 1800’s , as part of a project to introduce birds mentioned in Shakespeare to these shores. There are now hundreds of millions in the U.S., and  they can destroy crops and compete with native species. So much for poetry.

In Europe, they form murmurations, named after the whoosh of wings, where large groups of thousands can be seen , flying, changing direction, forming ethereal clouds of shapes, shifting on a dime. They have mastered the art of evasion, while creating an almost unbelievably diaphonous and outstanding series of shapes and movements, to evade predators, and one wonders if also for pure joy. There is no leader. Each bird follows the seven or so birds adjacent to it on the sides, where their vision rests.

Here, over a hilltop, we witness hundreds of these birds in a mini-murmuration. They swoop up, backlit by the sun, their wings glowing, This is a mere hint of the mind-boggling displays in Europe, yet one still catches one’s breath at this more intimate display, a spontaneous natural show, admired by just the few humans who notice.