Researchers for the Massachusetts turnpike authority found over 200 dead crows near Greater Boston recently and there was concern that they had died from Avian flu.
A bird pathologist examined the remains of all the crows and, to everyone's relief, confirmed the problem was definitely NOT Avian flu. The cause of death appeared to be vehicular impacts.
However, during the detailed analysis it was noted that various colours of paints appeared on the birds beaks and claws.
By analysing the paint residues it was determined that 98% of the crows had been killed by impact with trucks, while only 2% were killed by an impact with a car.
MTA than hired an Ornithological Behaviourist to determine if there was a cause for the disproportionate percentage of truck kills versus car kills.
He very quickly concluded the cause:
When Crows eat road kill, they always have a look-out Crow in a nearby tree to warn of impending danger.
They discovered that while all the lookout Crows could shout "Cah", not a single one could shout "Truck".