Wildlife Crossing Sign in Canada – ©gripso_banana_prune/Flickr CC
It’s estimated that 400 million animals die each year on roads in the United States, struck by vehicles. It’s impossible to know precise numbers, particularly since mortally wounded animals will crawl away from road shoulders (where the dead can be counted). That 400 million figure is extrapolated from various local surveys and collision statistics.
A Road Kill Diary
This topic is on my mind because of a Photostream I came upon at Flickr this morning. Jon Sullivan, a photographer in New Zealand, has a short, pictorial tally of dead animals he’s found along New Zealand roads. It’s a gruesome subject. But it’s also a poignant diary showing just a fraction of the carnage that’s heaped alongside the world’s byways . It’s the death often brushed aside as “road kill” — a significant contribution to animal suffering and population reduction, especially among threatened species. Car-animal collisions are also a source of human injury. The U.S. Department of Transportation says more than 200 people die each year in accidents involving animals.
Not All Roads Are Created Equal
In the Winter 2004 issue of Conservation, David Havlick published a piece on road kill “hotspots” using Florida as a case study. Not surprisingly, road ecologists discovered that more animals were killed on roads that bisected important habitat and migration corridors. It’s a problem known as habitat fragmentation, where roads and roadside development essentially split historical wildlife terrain, forcing animals onto human thoroughfares — to get where they are going. Computer models effectively predicted where these crossings were most likely to occur in Florida. Transportation officials then began constructing passageways in these areas to help animals link more safely to their natural corridors.
Building Wildlife Crossings
The planned wildlife crossing is a relatively new consideration in transportation, but one that’s being implemented to good effect around the world. The U.S. Department of Transportation has a table of contents showing the various types of wildlife crossings being built, including ideas as diverse as large-mammal passages, tortoise underpasses, and amphibian-and-reptile culverts.
Wildlife Crossing Between Banff and Lake Louise – ©Sangudo/Flickr CC
These solutions work. On one section of the Trans-Canada Highway, for instance, an erected fence reduced ungulate deaths (hooved animals) by 96 percent (USDOT). In Florida, a bear-friendly underpass proved appealing for at least twelve other species that now use the passage, in addition to the targeted black bears. In San Bernardino County (Southern California), fences guiding desert tortoises to culverts, reduced tortoise deaths by 93 percent on that section of Route 58.
Engineering a perfect wildlife crossing is complex in terms of getting animals to actually use the crossing — and taking into account predators and other dangers inherent in the crossing itself. It’s an evolving endeavor.
Turtle Crossing Culvert – Photo Courtesy of Caltrans
A comprehensive plan for wildlife crossings has been a long time in coming. If you drive roads like Highway 1 along the Sonoma Coast with any regularity, you know that such habitat realignment is much needed along many of our most traveled corridors. On one trip to Mendocino, we stopped every few miles to allow the passage of deer with fawns, bobcats, opossums, birds and other wild animals simply trying to navigate the treacherous two-lane speedway.
Avoiding Road Kill: What Drivers Can Do
In an earlier post on secondary road kill, I mentioned an article on Road Kill Avoidance Tips. The best thing any one of us can do ecologically speaking, is reduce our reliance on cars. Ironically, that’s tougher to do in rural areas where many of the road kill hot spots occur. When in the car, however, there are things you can do to reduce the probability of hitting an animal. The most significant measure is to slow down. Always drive at speed limit, or even below, if conditions warrant. Avoid driving at dawn and dusk, when animal activity is at its highest. Know the seasons as they pertain to animals. Spring brings fawns and animals just getting their bearings around human technology. In Road Kill Avoidance Tips, Merritt Clifton takes the advice a bit further by explaining how different species react when on the road. Understanding species behavior can help you adjust for the unexpected when an animal crosses your path.
Stopping for Injured Animals
As difficult or inconvenient as it may be to stop for an injured animal, H. and I try — where stopping doesn’t endanger us or other drivers. There are obviously places where it’s impossible to pull over in a car — or leap into traffic to wrangle a deer. Or attempt a transport if you’re on foot or bike. So any rescue effort takes into consideration a lot of factors, including human safety, the probability of further injuring the animal or scaring it back into the road, and also the type of animal in question. Only qualified individuals should attempt to handle a rabies-vector species, for instance (bat, skunk). An adult deer can kill you, writhing in panic, so wildlife personnel should be called in those instances.
If you find any injured animal and are not comfortable handling it, at least give the local animal control a call. I realize not everyone carries a list of wildlife rescue facilities in their car, but it’s something I’ve gotten in the habit of doing. Animals that languish with automobile injuries can sometimes be transported and rehabilitated by a qualified person. It’s really my only solace when faced with the countless dead animals I see along any stretch of road — to know that when I could, I helped.
(I posted these general What to do with injured wildlife guidelines when I worked at About.com. It includes a list of Bay Area wildlife hospitals as well.)
Related post: Avoiding Secondary Road Kill