101 Ways to Help Birds includes this:
#60: Drive at the slowest speed that is safe, courteous, and convenient.
During the winter of 2004-05, the largest irruption of northern owls ever recorded brought thousands of Great Gray, Northern Hawk and Boreal Owls into northern Minnesota, Wisconsin, and North Dakota. Birds that had spent their entire lives in northern wilderness suddenly found themselves on country roads and even major thoroughfares and interstate highways. As many as 10 owls could be found on the 20-mile drive along the highway between Duluth and Two Harbors, Minnesota, some right on signs and telephone poles at the edge of the road. And over the season, a great many of these inexperienced birds were killed by cars. Virtually every day in December and January I received phone calls—some days as many as five or six—from distraught people who had collided with an owl or come across one dead on the road. These collisions were a topic of conversation throughout the area, in grocery stores and doctor’s offices. I asked many people whether they thought it would be better for these owls if we all slowed down a bit. Almost without exception, people said yes. But then they added that they thought it would be too dangerous to slow down unless everyone else did. No one wanted to be first to start the new trend.
Great Gray Owls are huge and conspicuous. But just a few months before their winter invasion, there was a fall migration fallout of Yellow-rumped Warblers in Duluth when cool air and warmer land temperatures grounded them all over the city, especially on sun-warmed areas such as roads. So many were being run over that I discovered that several crows and jays had actually learned to sit atop traffic lights in wait, and would swoop down on the dead and dying little birds during red light cycles. There were so many dead birds that the jays and crows I saw weren’t even eating the ones they retrieved—they were stashing them in conifers and under leaves as they do when caching seeds. I found that driving 25 mph was the fastest speed I could go and manage to avoid hitting any of the tiny warblers. It’s easy to drive 25 when we have the road to ourselves; far trickier in traffic. But again, the “I’d drive slower if everyone else did” mindset was at work. Interestingly, when I did slow down to a bird-safe speed during this time, no other drivers showed impatience. Perhaps during migration phenomena of this magnitude, radio and television news commentators could remind their listeners to slow down a bit. Such events are very rare, and usually last only a few days. Couldn’t we humans accommodate birds during such a brief period?
Of course, birds gather on roadsides throughout the year. The United States is crisscrossed by over 8 million lane miles of roads, and 6.3 million of them—over 75 percent—are in rural areas. Early in the morning, many sparrows and thrushes gather on roadsides to pick up grit or insects and worms illuminated by streetlights. So many are killed by cars that many crows, ravens, and jays have learned to take early morning excursions above highways to capitalize on the carnage—some even migrate above highways where they can spot these flattened fast food opportunities as they go. There is evidence that Red-headed Woodpecker numbers have been especially affected by highways because of their habit of swooping at lower heights than other woodpeckers across clearings.
Collisions with automobiles kill 60 to 80 million birds a year, and from thousands to millions more die each year from oil spills, oil field waste pits, and other causes directly related to fueling our cars. According to EPA figures, the optimal highway speed for fuel efficiency in the average car is 55 miles per hour, and fuel efficiency drops dramatically above 60 miles per hour. That’s why the Nixon Administration lowered the speed limit to 55 on interstate highways in the 1970s during a time of severe gas shortages. My hybrid car’s optimal speed for the best mileage is about 40; I consistently average over 60 miles per gallon at that speed. As a finite natural resource, gas we burn up today will simply not be available for our children and grandchildren, and the more gas we use, the more we contribute to the many problems associated with oil extraction, transport, and refining. When we’re in a hurry for a good reason, driving the speed limit is certainly justifiable. But when we drive the slowest speed that’s convenient for us and safe and courteous for other drivers, we protect our air and water, and save gas, money, lives, and wildlife.
Of course, even driving slowly we can’t avoid all collisions with birds and other wildlife, but speed is definitely a major factor in the magnitude of the problem. And when we slow down, not only can we more easily detect and react to animals in the road ahead; we can also notice and enjoy wildlife along roadsides. On a country road, slowing down from 60 to 45 mph makes our drive time 33 percent longer, but can increase both our enjoyment of the trip and the safety of ourselves and wildlife by far greater margins.
Minimizing road kills helps in other ways, as well. Many people who complain about excessively high crow populations never even think about the huge subsidies road killed animals provide crows and other scavengers. And with the extremely tight city, county, and state budgets in many areas, even high crow populations aren’t enough to quickly clear away decaying animals. Pathogens build up quickly in carcasses and can be carried from roadsides to our homes and yards on the feet or bodies of scavengers, including house flies. Preventing roadkills in the first place is in the best interests of all of us.
Other driving habits will also help avoid collisions with deer, birds, and other wildlife. Any time a car is following closely behind you, do what you can to allow it to pass as soon as possible to avoid problems during the critical moments after you spot an animal ahead. Of course, when any car approaches rapidly from behind, it’s safest and most courteous to speed up until you reach a safe place for the car to pass you, or to find a place where you can pull over. And of course, always wear your seat belt: according to several insurance websites, most people injured in car/animal crashes were not wearing their seat belt. Be extra vigilant in early morning and evening hours, the most active time for wildlife on roads. In low light and at night when there is no oncoming traffic, use your high-beam headlights to pick up eye shine at a distance, and as soon as you detect a deer or other animal, slow down and turn on your low-beams so the animal doesn’t “freeze” in the headlights.
If you spot a bird, deer, or other animal in the road ahead of you, what’s the best response? The first thing is to be completely aware of the traffic around you. If you’re on a quiet country road with no cars or motorcycles behind you, brake and stop as far from the animal as possible and beep your horn. .If there is a distant car behind you, pump your brake a few times to alert him to slow down. If you see an oncoming vehicle, flash your lights to alert him that the animal might cross into his lane. Never swerve—you may confuse the animal and you have a bigger chance of losing control of your vehicle or colliding with another vehicle. Look for other animals after one has crossed the road. Deer and many ground-feeding or gallinaceous birds are usually found in pairs or groups.