Cormorants Are On The Move
October 08, 2021
By Steve Grinley

     In October we see large flocks of birds moving in broken lines across the skies that don’t keep the strict formation of geese. These are the cormorants, our summer resident double-crested cormorants, that are migrating in flocks that number fifty, or a hundred or more birds at a time. If you are near the coast and you can sit and watch these birds flying by, they would easily number in the thousands on any given day.

     Margo and I counted 1291 cormorants in a short period of time moving south across the sky from Plum Island one evening this week. There were likely more that went by before we started counting.

     Cormorants are fish eaters and are most often seen in the water diving for fish. Their long, thin necks give them a loon-like appearance, but they sit lower in the water and have a distinct hooked bill, used to catch fish. Their feathers lack the oil to shed water, unlike loons and diving ducks, so you often see cormorants on land with their wings spread to dry.

     Years ago, I wrote about the “cormorant tree” on the Amesbury side of the Merrimack River near the Chain Bridge. That dead tree is gone, but the double-crested cormorants still use the nearby trees as a night roost during the summer months. Other cormorants roost on the wires over the Plum Island bridge. These roosts are shrinking, as more double-crested cormorants head South for the winter. Soon, however, the larger great cormorant, will begin arriving for the winter to fish the waters vacated by the double-crested.

     Doug Chickering of Newbury shared his experience watching the migrating cormorants:

     “There are times when the very ordinary becomes quite extraordinary. Double-crested Cormorants are very common sights on Plum Island from spring to late fall. Some would even say they are too common. They fish the pools, sun themselves on the power lines over the Plum Island bridge, and dry themselves on points of land at Hellcat, Stage Island and in the marshes. They are colorless and numerous, and eventually tend to vanish into the background. When we decide to count the birds we find Cormorants are a pain and because we see them constantly fishing the shallow pools, we worry that they are pushing out other, more attractive species.

     “Usually Cormorants are little more than a nuisance, but this morning at Plum Island they provided a spectacular scene. It is difficult to fully and adequately describe the sight of thousands of Double-crested Cormorants spread in long ragged formations above the western horizon on a Plum Island dawn. The sun has not yet pushed above the dunes; the sky is a pale but bright blue and the land below is just starting to take on definition.

     “It takes a little bit to notice them at first; amorphous strings, moving south not in perfect symmetry but in long fluid strings with occasional clusters of birds in the forefront. The sheer number of them is impressive and they nearly spread the entire horizon. A soundless, relentless movement, an antique ritual as emblematic of the changing seasons as the scarlet leaves on the hillsides.

     “Summer is gone and the winter moves in on the wings of migrating Cormorants.”