English: Northwestern crow (Corvus brachyrhynchos caurinus - hybrid intergrades between Corvus brachyrhynchos and Corvus caurinus species of the American crow), adult, at Steveston Harbor, British Columbia, Canada on April 29, 2014.
The original proposal of the Northwestern crow (Corvus brachyrhynchos caurinus) as a separate hybrid intergrade species was proposed in 2018.
"Crows over a wide area in the west of British Columbia, Canada and the far northwest of Washington, USA, are hybrid intergrades between Corvus brachyrhynchos and Corvus caurinus (ref: Slager, D. L., et al. 2018. Cryptic and extensive hybridization between ancient lineages of American crows. BioRxiv preprint).
However, current 2021 taxonomy considers the northwestern crow as a geographic variation of the western crow (C. b. hesperis).
“C. b. caurinus (Baird, 1858) – northwestern crow: of the Pacific temperate rain forests was formerly considered a distinct species as C. caurinus, averaging smaller in size than other American crows with a distinctly hoarser call. It forms a hybrid swarm with American crow (sensu stricto) in coastal Washington and British Columbia. The American Ornithological Society lumped the northwestern crow with the American crow in 2020. It is now considered a geographic variation within C. b. hesperis.” –
American crow - Wikipedia