However, during the detailed analysis it was noted that varying colors of paints appeared on the bird's beaks and claws. By analyzing these 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 then hired an Ornithological Behaviorist to determine if there was a cause for the disproportionate percentages of truck kills versus car kills.
The Ornithological Behaviorist 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." Absolutely amazing!