Thanks for the info everyone.
I heard a radio piece about the coy-wolf thing in eastern Canada and north eastern US. I think the piece was in response to that woman being killed by Coyotes. It substantiates everything Sjemac says with genetic proof of interbreeding. It was a while ago now so a little tough to recall but it sounded to me like massive population expansion in those areas from the time of the original US colonies wiped out the eastern wolf. It was an area where coyotes did not occur. The result was a hybrid critter.
The interesting thing now is the clash of populations now happening in the north eastern US. The researcher said the well established coy-wolf (his term) is now comming into contact with the eastward expanding western coyote with the area of contact being NY state and there-abouts.
To the original poster: I doubt the pack behaviour is new. I think it was a feature of both species since time began.
Question: What is the size difference? The radio guy said that it was not uncommon for eastern coy-wolves to go to 50 lbs. I don't think many western coyotes go beyond about 35. Sjemac, your expertise on the western version would be welcome here.
The biggest (out of a few hundred) that I worked on a decade ago on PEI was 55 lbs (estimated weight since the hide was off when it was submitted and hide weight and water loss weight due to drying can be significant -- our formula was designed to estimate on the low side) and we had many in the mid to high 40's. Our average was about 35 lbs which is higher than the average for western yotes (about 25lbs). One thing to factor into that, is that the majority of trapper/hunter killed and submitted coyotes are young of the year and considerably smaller than fully adult yotes. Adult yotes averaged in the low 40's. They are noticeably bigger and thicker animals than the western animals. I have the skull of a big Alberta yote, the 55 lb PEI yote and a Alberta wolf skull. The Eastern yote is intermediate in size and robustness to that of the western yote and wolf.
My buddy who is a taxidermist on PEI has had a couple of yotes in the 60's come onto his scales in the years since then.


















































