Deer-in-the-headlights

Deadlier Than Sharks: The Science of Deer in the Headlights by Ross Pomeroy

Why are deer the poster children for animal-automotive collisions in the United States? The simplest explanation is that they are large in size, abundant, and widespread. As many as 30 million of the 100 to 300-pound mammals reside in the U.S., ranging from Maine in the Northeast, to Florida and Texas in the South, to Idaho in the West.

For a more nuanced explanation, we can look to their behavior. According to Purdue University ecologist Esteban Fernandez-Juricic, when confronted with oncoming vehicles, deer rely on anti-predator instincts. First and foremost, that means freezing -- the stereotypical "deer-in-the-headlights" response. In a normal predatory situation, this would allow them to avoid detection and gauge the situation. But while such a reaction is well suited to a gun-toting human or a lurking wolf, it is not at all useful when confronted with a one-ton hunk of metal traveling at 60 miles per hour. Often, a deer's decision to flee comes too late, if at all. The consequences to animal, car, and driver can be dire.