Gathering on Rooftops

Oct. 15, 2026: under mostly clear skies, calm, 55F; surveyed along Merrimack Street from Rt. 495 overpass up to Parker St, and many nearby side streets, observing small groupings of Crows before final staging in larger numbers on rooftops and utility wires, along Merrimack Street near the National Grid substation on South Canal St. The aerial image below shows the buildup of 900+ Crows on one section of the former B&D Warehouse building complex.

The final arrival and buildup of Crows took place on multiple rooftop levels on the red brick New Balance factory building. The following aerial image facing the SE direction captures a lot of the action.

As always it was a spectacle of nature watching the Crows converge into the overnight roost trees along the New Balance building on the south side of the Merrimack River, and in trees on both sides of the Union Street Duck Bridge. The aerial image below (fulgurite color palette) shows an angled view of the tree tops with Crows settling in for the night, while looking west from near the Duck Bridge.

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.