Speaking of dead crows... I did some Googling and came up with an interesting story from Nova Scotia:
The story read that they recently found about 200 dead crows near Halifax, and there was concern that they may have died from Avian Flu.
In doing the research, a Bird Pathologist examined the remains of all the crows, and he confirmed the problem was definitely NOT Avian Flu, to everyone's relief. However, he determined that 98% of the crows had been killed by impact with trucks, and only 2% were killed by an impact with a car.
The Province then hired an Ornithological Behaviourist to determine the disproportionate percentages for truck versus car kills.
The Ornithological Behaviourist determined the cause, the conclusion in short order was:
When crows eat road kill, they always set-up a look-out Crow in a nearby tree to warn of impending danger.
His conclusion was that the lookout crow could say "Cah", but he could not say "Truck."