David Bird is an ornithologist, an expert on birds. He has written a number of popular bird watching guides, including the recently published "Pocket Birds of Canada": https://www.amazon.ca/Pocket-Birds-Canada-DK/dp/1553632672
You can find Professor David Bird at the following links.
Website: https://www.askprofessorbird.com
Brome Bird News: https://bromebirdcare.com/bbn-video-post/
