Monday, Dec. 9, 2024 under mostly cloudy skies, light wind, 52F; sunrise 6:39AM

During a family visit in San Diego had a nice opportunity to go out on Crow Patrol with many thanks to San Diego locals, Phil Unitt, Nancy Christensen, Justyn Stahl, and Mel Senac. Phil had been kind to host me for a visit at The San Diego Museum of Natural History a few years back, As the curator of the Department of Birds and Mammals, he oversees the museum’s impressive bird specimen collection. Phil also serves as Editor for Western Birds. Nancy, Justyn and Mel are all involved in counting the Crows for the annual Christmas Bird Count in San Diego. They were kind enough to provide very helpful advance background information on the this long standing roost near the Bonita Plaza Mall in Chula Vista.

Well before sunrise, small numbers of Crows were seen arriving in flight and vocalizing to the general area around SW corner of Plaza Bonita Mall. This was followed by a torrent of incoming flight streams. Most of the flight streams were coming in and descending from the NW by the Sweetwater River. Overcast skies made it seem a bit darker. This image shows arriving Crows at 16 minutes before sunrise.

The incoming Crows were vocalizing loudly and swarming in huge flight swirls between the Plaza and Interstate 805. There were numerous flight groups both close to the SW corner of the mall by the AMC Theater and farther off to the SW over the Sweetwater River Park next to I-805. Each group engaged in swirling flight action with a mix of synchronized and chaotic flight movements. This image below looking SW, was captured  at 15 minutes before sunrise.

The Crows at times are anchored to the SW corner of the building by the AMC Theater complex, both in nearby trees and on roof edges. The vocalizations are constant and this all seems part of stretching flight muscles and perhaps setting up foraging groups for the day ahead. The image below at 14 minutes before sunrise time, looking NNW, provides a view of the action near the AMC corner.

At the 19 winter crow roosts I’ve been blessed to visit, the morning routine is a bit different. The one constant are the Crows moving around in flight bursts and flight swirls before heading out for the day to known foraging grounds. This is part of their wake up and “get ready for the day ahead” routine and it always includes energetic and  boisterous vocalizations. These early flight clusters are always mesmerizing to behold. This image below at 13 minutes before sunrise time. Another outing with dazzling flight action!

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! Craig is the designated sector leader for the roost count.

The counts and methods meticulously developed by the Crow Patrol for the Lawrence roost were reviewed and approved in January 2021. This took place after a full review of all field notes and images, followed by group discussion with the New England Regional Editor for the CBC, full support from the National Director of the CBC, and Donna Cooper as the local CBC Count Circle compiler. After this comprehensive review process, the final count for American Crows for the 2020 CBC was set at 15,200. This final count reflected the detailed field reports and imaging provided by members of the Crow Patrol. This count number was also in total alignment with a long list of experienced local birders who have made prior counting visits to this winter roost in Lawrence, MA!

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 direct block count approach, while standing outside (not sitting in a car after dark) around the roost, to carefully document our observations and to significantly increase reliability and accuracy of our well documented numbers. Please refer to our newly published Winter Crow Roost counting guide PDF on the main page.

The Canon R6 mirrorless cameras excels in low-light photography due to its 24 MP sensor with fewer and larger pixels, allowing for better light collection and signal-to-noise ratio. It offers high dynamic range for detail retention, low digital noise even at high ISOs (up to 102,400), effective image stabilization for sharper images, and advanced image processing to minimize noise in dark areas.

The Canon mirrorless cameras with the RF 50mm f/1.2 lens and the RF 28-70mm F2 lens 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, 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 any 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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