Bonjour,
Par pure curiosité, ne connaissant pas du tout ces régions lointaines, je suis allé voir ce qu'en dit le HBW...
Pour la Corneille d'Amérique Corvus brachyrhinchos :
:Distinguished from C. ossifragus by slightly larger size, less iridescent plumage, also by voice, habitat and timing of breeding.
et
:Common in human-dominated landscapes from core of large cities (where may nest on buildings) to parks, suburbs, golf courses, woodlands, some forests (especially deciduous and riverine ones, but also forest edges and open or fragmented coniferous forests), farms, orchards, ranches, and wildland recreation areas.
Pour la Corneille de rivage on peut lire :
:Distinguished from similar C. brachyrhynchos by substantially smaller size, relatively longer legs, and voice.
:Usually found close to water in coastal or riverine settings; exploits human settlements and, to lesser extent, agriculture.
Si cela peut vous aider ...
Amicalement
Dominique