Crows loudly converging and bursting!

Nov. 18, 2024: clear skies, wind NW 15, 55F; sunset 4:18PM

Out on Crow Patrol with first stop to observe staging area along the Merrimack River east of Rt. 495. The Crows were arriving from downriver and perching in trees on south side of the river. A Boston bound train whistle sent them into a number of flight outbursts. Image below at 4 minutes before sunset time.

Moved on to lower Marston Street and the lack of incoming flight streams prompted thoughts that the roost may have shifted a bit over the last few days. Discovered Crows vocalizing and converging in flight into trees at the east end and south side of nearby Island Street. Image below at 32 minutes after sunset time.

At close to 50 minutes after sunset, many of the Crows moved north in flight over Canal Street towards the tall trees around the south side of the hospital upper and lower parking lots. Image below at 44 minutes post sunset time.

Found lots of Crows in the trees along the Spicket River, alongside the well-lit hospital parking lots, and behind the red brick building at One Canal Street. Image below at just over an hour after sunset time.

After noticing that the total numbers didn’t seem add up compared to last visit, made a final check at the south end of the Duck Bridge, looking east along the Merrimack River. Discovered Crows perched in the trees along the south side of the river from the Duck Bridge all the way down near The Pavilion parking garage. Only on rare occasions do we find the roost spilt into two nearby locations. In past years, split roost locations have always been temporary and the Crows quickly reset into one roost location. Image below at almost 90 minutes post sunset. Quite a show tonight!

For the 2023 Audubon Christmas Bird Count (CBC) for the Andover Circle (MAAN), this separate Crow Count was 11,600 total Crows, including American Crows and Fish Crows. In 2022, the CBC Andover Circle Crow Count was 13,750. Many thanks to Donna Cooper who coordinates and compiles the CBC Andover Circle each year!

The counts and methods meticulously developed by the Crow Patrol for the Lawrence roost were reviewed and validated at the highest levels in January 2021. This took place after review and a group discussion with the New England Regional Editor for the CBC, with full support from the National Director of the CBC, and Donna Cooper as the local compiler. This discussion was prompted after an outspoken female birder, with little prior large roost counting experience, submitted highly unusual and very questionable numbers (24,300). She had recorded her sightings after dark, from her car, with obstructed views! The final count for American Crows for the 2020 CBC was set at 15,200 and reflected the extensive written data and field reports along with detailed imaging provided by members of the Crow Patrol. These final numbers are in total agreement with a long list of experienced local birders who have made counting visits to this winter roost in Lawrence.

As a result of meaningful input from the National CBC Director, we are now using improved methods for counting the large number of Crows while streaming, staging, and settling into the roost. For all images, we use both a modified open source counting software program, as well as a hand count approach, while standing outside (not sitting in a car) around the roost, to carefully document our observations and to significantly increase reliability and accuracy of the our well documented numbers. Please refer to our newly published Winter Crow Roost counting guide on the main page.

The Canon mirrorless cameras with the RF 50mm f/1.2 lens and the RF 28-70mm F2 excel in low-light conditions, blending versatile focal lengths with an ultra-wide aperture. Both focal lengths work extremely well in very low light conditions, while the f/1.2  and F2 aperture settings ensure exceptional performance in low light conditions, offering stunning clear, and aesthetically pleasing images, making them ideal for the challenging very low light conditions around the overnight winter crow roost.

Remember to check out the latest Crow Patrol Podcast with John Macone (Merrimack River Watershed Council): wintercrowroost.com/podcast/

Photo gear used for most outings:

Canon EOS 80D with Canon EF-S 18-135mm f/3.5-5.6 IS 

Canon EOS 80D with Canon EF-S 18-135mm f/3.5-5.6 IS (Infrared)     

Canon EOS R6 Mirrorless with Canon RF 28-70 f/2 L IS USM 

Canon EOS R6 II Mirrorless with Canon RF 50 f/1.2 L USM 

Sony AX700 4K HDR Camcorder

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