The raven’s most obvious field mark, other than size, is the extremely large bill which has a massive base attachment to the head. The crow’s bill is petite in comparison.

A raven’s call, meanwhile, is a lower, more guttural croak. A handy mnemonic device to help you remember this is that caw and crow both start with the letter c .

Columbia University School of Engineering and Applied Science. "Crow or raven? New birdsnap app can help." ScienceDaily. www.sciencedaily.com / releases / 2014 / 05 / 140528163635.htm (accessed ...

Crow or raven? Twitcher app ... Website includes 50,000 images as well as bird calls for each species; By SARAH GRIFFITHS . Published: 11:14 EDT, 29 May 2014 | Updated: 12:16 EDT, 29 May 2014 . e ...

The free app, which enables users to identify bird species through uploaded photos, accompanies a visually beautiful, comprehensive website that includes some 50,000 images.