A review of wildlife lost to vehicle collisions in three iconic national parks shows the National Park Service is struggling, and sometimes failing, to reverse the trend, according to Public Employees for Environmental Responsibility.

But at Yellowstone National Park, where PEER charged officials "take no preventative measures" to reduce wildlife roadkill, spokesman Al Nash took strong exception to that allegation.

"Yellowstone National Park takes the issue of road-killed wildlife very seriously," Mr. Nash said in an email to the Traveler. "One only has to check out the front page of the newspaper handed to every visitor who enters the park, attend an interpretive ranger program, or check out the park web site to see how Yellowstone reaches out to current and prospective visitors regarding this serious issue."

Highways Can Be Blamed

Now, it can be argued that speeding motorists are more responsible for roadkills than is the Park Service's approach to averting them. Drive down U.S. 191 through Yellowstone, along U.S. 89/191 through Grand Teton National Park, or the Tioga Road through Yosemite National Park, and you'll see many motorists exceeding the speed limit and running the risk of encountering an animal darting across the pavement.

These highways, just like park boundaries, show no consideration for migratory corridors, a problem specifically in Grand Teton where the pavement rolls quickly through a landscape crisscrossed by elk, pronghorn, bison, and moose, just to name some of the highly mobile residents of the park's wild kingdom. Back in 2009, a pronghorn darting across U.S. 89 in the early afternoon actually knocked over a motorcycle that was attempting to pass an RV.

At PEER, however, officials maintain Park Service engineers in Yellowstone, at least, have created a roadkill problem by designing roads that encourage faster driving.

“Yellowstone views roadkill as inevitable as the sunrise, while Grand Teton regards it as a behavioral issue which can be managed,” said Jeff Ruch, PEER's executive director, in a press release. “The problem of roadkill merits greater park management attention because, besides the needless wildlife carnage, these collisions endanger the people involved and account for a lot of property damage.”

According to the group, "Yellowstone has taken no steps to minimize road kill. In fact, it has made road improvements which have led to higher vehicle speeds, such as widening roads and increasing the number of pull-outs for slower traffic. The park had no record of any study or planning on the issue, aside from reviews required under the Endangered Species Act."

But Mr. Nash said some mitigation efforts taken in the park, "such as increasing the number of traffic pullouts when reconstructing road segments, have reduced traffic congestion, a contributing factor in some accidents involving wildlife."

"However," he continued, "our in-depth analysis of vehicle/wildlife accidents has not indicated there is any one particular road segment where more aggressive re-engineering such as the installation of overpasses or long stretches of fencing would significantly improve the situation. ... Experiments with flashing light signs had no significant impacts on vehicle speed, which is a major contributor to vehicle-animal collisions."

According to documents PEER obtained through a Freedom of Information request, roughly 95 animals -- elk, moose, bears, wolves, bison -- are killed in vehicle collisions each year, on average, in Yellowstone. However, after 1995, when the park's wolf recovery program began, the number of elk, mule deer, moose, and white-tail deer involved in roadkill accidents dropped, while those collisions involving bison, grizzly bears and wolves have increased.

"The average number of WVCs (wildlife vehicle collisions) involving bison increased from 10.5 per year from 1989-1999 to 15.5 per year from 2000-2012, almost a 50 percent increase. The situation is even more grim if large carnivores are considered," a PEER document notes. "Black bear vehicle strike mortalities increased 41 percent over that time period, while grizzly bear fatalities rose 196 percent. Wolves themselves averaged 1.4 vehicle caused fatalities from re-introduction until 2002, and almost 1.6 vehicle fatalities per year from 2003-2011, a 13 percent increase, with 5 wolves killed in 2011 alone.

"These trends suggest that carnivores tend to be proportionately more affected by road mortality than other species, due to generally lower population densities, larger home ranges, and longer reproductive cycles than herbivores."

Grand Teton Works, And Struggles, To Reduce Roadkills

At Grand Teton, PEER applauded the park's efforts to "proactively implement and test an array of mitigation measures, including reducing nighttime speed limits (when most collisions occur) and variable message signs."

But at the same time, the park has struggled with roadkill incidents, and actually averages more per year than does Yellowstone. Since 2008 the park has averaged 115-120 animals lost to vehicle collisions, said park spokeswoman Jackie Skaggs. In 2010 the number spiked at 162 before dropping to 102 in 2011, and then 110 last year, she said.

“We are proactively looking at different ways to bring the number down even more," said Ms. Skaggs. "It’s definitely a concern, an annual concern that we’re addressing and trying to see what other ways that we might be able to redude that number even more.”

Currently, Grand Teton officials put on a big public education push in the spring and fall during migrations, and also utilize flashing lights and signage in a bid to get motorists to slow down.

And yet, the park's own figures show that collisions between wildlife and vehicles has been on an upward trend since 1981. While that trend might be due in part to better efforts to track WVCs, the park staff notes, studies also show that the collisions rise in summer when visitation to the park peaks.

While there have been suggestions that wildlife overpasses and tunnels be built along U.S. 89 with hopes of mitigating the problem, Ms. Skaggs called that suggest impractical because of the widespread animal movements in Grand Teton.

"There are 101 locations that are areas where wildlife cross. So targeting a spot where we could effectively put an overpass or underpass is impractical," she said.

At Yosemite National Park, PEER noted that there have been 300 collisions with black bears since 1995, but that the park lacks data on other species involved in vehicle collisions.

While Yosemite officials have a visitor education campaign called “Red Bear, Dead Bear," which places red signs along roadways where bears have recently been hit, PEER said officials have "not studied its effectiveness." At the same time, "bear deaths continued to rise after 2005 – as have the number of red bear signs stolen," the group said.

Reviewing roadkill data from just three of the more than 400 units of the National Park System make it difficult, if not impossible, to gain a clear picture of just how serious vehicle collisions with wildlife are across the system. At the same time, the PEER report noted, "The National Park Service has no policies or guidance addressing road-kill. Thus, individual parks are left on their own."

“Road-kill in national parks is a growing conservation failure,” said Mr. Ruch, acknowledging that the causes of roadkill, other than cars themselves, are varied and complex.

“In some cases, vegetation in the median strip functions like a salad bar drawing animals into harm’s way," he said. "Once hit, the resulting carcass attracts scavengers who, in turn, get hit by passing cars.”