Crow Counting Quiz #1!

One aspect of this Crow roosting phenomenon is counting the large number of crows using the roost. By obtaining accurate and reliable numbers, biologists can better track changes in the size of winter crow populations, follow the timing and extent of winter migration, pin down specific roost locations each winter and over time, document responses to changes in the local habitat, and monitor the possible effects of climate change. In addition, this data can help biologists establish priorities for ongoing research and may also allow for comparisons between different counting methods.

With strong encouragement from senior staff at the National Audubon Society, we’re striving to better understand the types of current counting methods that can be most effective in this specialized counting effort, which is a unique challenge due to the very large numbers of crows, low light conditions, and dynamic flight patterns. From the Audubon perspective, this is a compelling opportunity to document and compare different methods for counting large numbers of birds at an overnight roosting site!

Note on counts/estimates: we are now using much improved methods for counting the large number of Crows while streaming, staging, and in the roost. For all images, we use both a modified open source software program, as well as a hand count approach to carefully document our observations and to increase reliability and accuracy of the presented numbers. 

THE 2020 NATIONAL AUDUBON CHRISTMAS BIRD COUNT (CBC) ESTIMATE FOR THIS CROW ROOST: 15,200