March 10, 2026 under clear skies, wind SW at 8MPH, temp 71F; sunset time 6:45PM

Out on Crow Patrol along the south side of the Merrimack River just downriver from the Route 495 bridge, arriving shortly before sunset. At first the area was unexpectedly calm. Small groups of crows passed overhead at higher altitude, suggesting they were still some distance from landing. A few hundred birds perched in trees farther downriver along the south bank, while most of the distant treetops remained quiet. Then, about twenty minutes after sunset, everything changed! From the east, several massive flight streams suddenly charged upriver, converging toward the bridge area in powerful waves. Hundreds of birds filled the fading sky before funneling down into the roost trees along the north side of the river near the Route 495 bridge and adjacent exit ramp.

Within minutes the riverside canopy erupted with sound as the birds packed tightly into the trees. The active roost stretched roughly 200 yards east from the bridge, covering about two acres along the riverbank. Loud vocalizations carried across the water as wave after wave of arriving crows located perches and settled in. Even this late in the winter season, when numbers begin to taper as spring approaches, the spectacle was dazzling. For a few remarkable minutes the sky above the Merrimack became a swirling cloud of wings before the roost finally absorbed the last arrivals for the night.

For the 2025 National Audubon Christmas Bird Count (CBC) for the Andover Circle (MAAN), the dedicated crow roost count totaled 14,025 crows, including both American Crows and Fish Crows. By comparison, the Andover Circle crow count was 12,550 in 2024 and 11,600 in 2023. Many thanks to Mark Morroni and Donna Cooper, who coordinated and compiled the Andover Circle CBC this year. Craig serves as the designated sector leader for the Lawrence winter crow roost count.

The counting methods developed by the Crow Patrol for the Lawrence roost were formally reviewed and approved in January 2021 following a detailed evaluation of field notes, images, and group discussion with Wayne Petersen, New England Regional Editor for the CBC, with full support from Geoff LeBaron, National Director of the CBC, and Donna Cooper as local compiler. After this comprehensive review, the 2020 CBC American Crow count was finalized at 15,200, a figure fully supported by field documentation and consistent with long-term observations by experienced local birders.

Building on guidance from the National CBC leadership, we now use enhanced, field-based counting methods tailored to large winter crow roosts. These include multiple direct block counts of birds in flight, during staging, and once perched, conducted entirely on foot around the roost. Counts are later cross-checked using still images and video, supported by modified open-source counting software. This multi-layered approach significantly improves accuracy and repeatability. A detailed overview of these methods is available in the Winter Crow Roost Counting Guide (PDF) on the main page.

All images are captured using professional low-light mirrorless camera systems and fast-aperture lenses, allowing for reliable documentation under the very challenging lighting conditions at dusk and after dark typical of winter crow roosts.