A Longpoint Bird Observatory article I had handy(amazing how one can find a small newsletter in a stack of papers),says the TVs "breeding range started to expand dramatically northward in the 1920s" Further,though not noting where the northern expansion has occured to it does say that in Ontario according to the breeding bird atlas(article is from fall 2005 so most recent survey results will differ),the range has expanded 200kms in the past 20 years. They attribute this to several factors including,increased road network(more road kills),climate moderation and more open habitat as a result of agricultural expansion. Trends from breeding bird surveys from 1966-2004 show an increase in Canada of 15%. Intersting I think even if it doesnt answer your question. Would the recently released Breeding Bird Survey contain the information? Surely someone who posts here must have the book.
