March 9, 2026: clear skies, wind SW 8MPH, temp 63F; sunset time 6:43PM

It took a while to locate the major flight lines of Crows this evening. Early on there were scattered groups passing overhead, but the dominant flight lines were not immediately obvious. After watching the skyline carefully for a period of time, the incoming streams finally began to reveal themselves, small groups and loose lines of American and Fish Crows moving steadily downriver. Compared with peak winter numbers, the overall volume has clearly diminished as spring approaches, but the remaining flights were still impressive. By tracking these flight paths, it eventually became clear that most birds were continuing downriver and dropping into trees along the south side of the river.

As dusk deepened, the organized chaos of roosting behavior unfolded. Groups circled, shifted, and repositioned before committing to the trees, with constant calling and bursts of aerial maneuvering as later arrivals negotiated space. Even with reduced numbers this late in the season, the settling process was lively and dynamic, with Crows sweeping in, peeling off, and circling out over the river and back into the canopy. Gradually the movement slowed, the calling softened, and the last late arrivals slipped into the roost trees. Within minutes the frenetic activity gave way to stillness as the communal roost quieted 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.