"Connected with the raven's function as messenger is its ability to speak or understand the language of men, and of men to acquire understanding of its speech. When a Siberian shaman conjures up a spirit it talks in its own language unless it is a wolf, fox or raven, which have human speech. In an Icelandic tale we hear of a bishop who understood raven language. The German legend of Faithful John who overhears three crows talking and is thereby forewarned of three dangers is paralleled in India by the story of Rama and Luxman. The Buriats relate that a man learned how to cure a Khan's daughter by overhearing the conversation of two ravens." E.A. Armstrong, The Folklore of Birds. New York, 1970.
"A
Preliminary Study of Raven Language Among the Eskimos."
J. Whitestone, Anthopological Studies of the North (1939).

The ravens
of Alaska sounded their Kwakiutl tok different
from the language
of the territorial groups,
so that
the traditional and observed beliefs have divisions characteristic
of Haida dialects. Kwakiutl
spoken from the coast appeared between
Tsimshian southeast
of these human correspondences and represent
a distinct world between
ravens and humans.
Tlingit sounded
though ravens spoke of divisions
between the Kwakiutl tok and tlik populations in territory indigenous
to Haida dialects. Coevolution proves that humans and ravens corresponded
and appeared during the division especially when observed,
and characteristically would tok dialects with traditional Alaskans while
the human is represented from another correspondence, and that
Tsimshian languages are from the ravens.
Characteristically,
the coevolution of Kwakiutl
language
and other dialects of human language along geographically traditional
Haida
are difficult, especially as indigenous ravens
for many years
spoke as humans.
Distinct populations would appear between these groups,
and their
tok
proves that other representative dialects
sound
like that of ravens.
Concordance: “During the years I spent kayaking along the coast of British Columbia and Southeast Alaska, I observed that the local raven populations spoke in distinct dialects. The divisions between these dialects appeared to correspond to the traditional geographic divisions between the indigenous human language groups. Ravens from Kwakiutl, Tsimshian, Haida, and Tlingit territory sounded different from one another, especially in their characteristic ‘tok’ and ‘tlik.’ I believe that this correspondence between human language and raven language represents coevolution rather than coincidence, though this would be difficult to prove.” G. Dyson. In, J. Brockman, Editor, What We Believe But Cannot Prove. New York, 2006.