Researchers for the Massachusetts Turnpike Authority found over 200 dead crows near Boston recently, and there was concern that they may have died from Avian Flu.
They had a Bird Pathologist examine the remains of all the crows, and, to everyone's relief, he confirmed the problem was definitely NOT Avian Flu. However, he determined that 98% of the crows had been killed by impact with trucks, & only 2% were killed by an impact with a car. Massachusetts then hired an Ornithological Behaviorist to determine the cause of the disproportionate percentages for truck kills versus car kills.
The Ornithological Behaviorist determined the cause in short order:
When crows eat road kill, they always have a look-out crow in a nearby tree, to warn of impending danger. His conclusion was that, while all the lookout crows could say "Cah", none could say "Truck."