Two hundred dead crows were recently found near LittleRock Ark. There was concern that they may have died from Avian Flu. A Bird Pathologist examined the remains of all the crows and 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 2% were killed by impact with a car. The State then hired an Ornithological Behaviourist to determine the disproportionate percentages for truck versus car kills. The Ornithological Behaviourist determined the cause in short order. It seems that, 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 all of the lookout crows could say "Cah", but none of them could say "Truck."