Studying wildlife ecology through road-killed animals

Hilary Turner works for the Idaho Fish and Game Department as a roadside carcass surveyor in the Upper Snake Region. She drives U.S. Highway 20 from Idaho Falls to the Montana border searching for carcasses and collecting data.

“Why?” you may ask.

Ecology is the study of interactions and relationships between organisms and their environments. Road ecology is an emerging science in which scientists study the ecological effects of roads, which Turner does by collecting data on road kills.

From two-tracks to interstates, most people use some kind of road in their daily lives. The United States alone contains 4.12 million miles of road (2.68 million paved miles) and the ecological effects (direct and indirect) of this transportation system are vast.

The ecological effects of roads have been studied in Idaho since at least the late 1960s, when Fish and Game documented the effects of the completion and opening of Interstate 84 in southern Idaho on the migratory Sublett mule deer herd. The freeway opened in November 1969, and in the next six weeks, 18 mule deer were killed by vehicles.

For a herd that historically migrated southwest from summer range in the Sublett Mountains to winter range in the Black Pine Mountains, I-84 became an impediment to migration. Some animals were unable, or unwilling, to cross the freeway, and many were killed as they attempted to cross it.

The interstate altered their migration route, and many deer remained on the east side of the freeway and spent winters near Snowville, Utah. That winter range had insufficient forage for deer, and during the following winters, an estimated 40 percent of the herd died of malnutrition.

In an attempt to pass cattle safely across the road, as well as restore this important migration route, crossing structures in the form of underpass culverts were eventually installed. Without wildlife-proof fencing to help funnel deer to the culverts, the project was ineffective at restoring the migration route.

Improvements were made to the culverts since then, and some deer now cross under the road successfully. But some biologists estimate the deer herd is currently less than half of what it was in the 1960s because of the freeway, which still acts as an impediment to migration. The story of the Sublett mule deer herd demonstrates both the direct and indirect effects of roads on wildlife.

Often, the indirect effects of roads can be as severe, or more, than the direct wildlife mortality. Habitat is lost and fragmented when roads are built. Animals have a harder time accessing resources and moving throughout their home ranges. Migrations are lost or changed due to the barrier effect of roads.

To further complicate things, deer, elk, pronghorn and other animals’ migrations depend on learned and socially transmitted information, which if lost, can take decades to restore.

Noise, light, and chemicals also pollute roadside habitat for up to several hundred feet beyond the side of the road. Disturbed roadsides provide ideal habitat for invasive plant and animal species. Litter, intended or not, finds its way into ecosystems throughout the year via roads.

Beyond big game

People often think of the large animals that are directly killed on roads because we can see the evidence that deer and elk are hit, even skunks, raccoons, and owls are commonly observed. But the direct effects of roads are much farther reaching than what typically meets the eye.

Billions of insects, birds, reptiles, amphibians, and small mammals are killed annually on roads. Some studies estimate that up to one million animals are killed each day on roads in the U.S. Using the work done in Idaho as an example, since December 2017, Turner has documented over 700 unique dead organisms on a 63-mile stretch of US-20 in Southeast Idaho. Because carcasses do not persist long on roadways, Turner said she may be missing up to 14 times the number of small animals that are found.

Before getting a negative feeling about roads, not all is lost. Fish and Game has a memorandum of understanding with Idaho Transportation Department, and the agencies work together toward solutions for some of the ecological problems associated with Idaho’s roads.

Not just a wildlife problem

Because wildlife/vehicle collisions are also safety risks for drivers, ITD has an interest in projects that reduce them, and the agency works with Fish and Game to implement them. It is through this agency collaboration that the road-kill carcass survey is possible. Carcass surveys provide valuable information about mortality hotspots, which can be used to determine appropriate wildlife/vehicle collision mitigation siting and what methods to use.

ITD and Fish and Game have already collaborated on mitigation projects, including the wildlife underpass and fencing that was installed on US-21 near the Boise River Wildlife Management Area. Trail cameras have documented wildlife using the underpass. A wildlife overpass with fencing is also planned for the near future on US-21 to reduce wildlife-vehicle collisions and improve habitat connectivity.

Other projects include wildlife underpasses and fencing in the Coeur d’Alene region, and barn owl collision mitigation in the Twin Falls area.

You can help save animals, and prevent vehicle repairs

Remember, as a driver, you can also do your part to make a difference for animals. Fall and spring are the peak seasons for deer and elk movement. During fall, herds are migrating from summer to winter range and beginning their mating season. Add daylight savings time (a one hour shift in predictable traffic patterns) into the mix and fall is usually the worst time of year for collisions.

Here are tips to avoid them:

n Keep a watchful eye for animals near the road

n If you see one animal cross the road, it is likely that others are near

n Animals are more active at dawn and dusk

n Avoid nighttime driving when possible

Idaho Fish and Game implements fire restrictions

Because of the current fire risk condition throughout Idaho, the Idaho Department of Fish and Game (IDFG) is imposing a Stage I Fire Restriction on IDFG-owned and managed lands statewide, effective immediately.

Until further notice, the following restriction applies to all Wildlife Management Areas and fishing access areas owned or managed by IDFG.

Stage I Fire Restrictions

Building, maintaining, attending, or using a fire, campfire, or stove fire except within a designated recreation site, within a fire structure provided by the administrative agency, or on their own land and only within an owner-provided fire structure (see definition below)

Smoking, except within an enclosed vehicle or building, a developed recreation site, or while stopped in an area at least three feet in diameter that is barren or cleared of all flammable materials.


Persons with a written permit that specifically authorizes the otherwise prohibited act.

Persons using fire fueled solely by liquid petroleum or LPG fuels.

Persons conducting activities in those designated areas where the activity is specifically authorized by written posted notice.

Any Federal, State, or local officer, or member of an organized rescue or firefighting force in the performance of an official duty.

All land within a city boundary is exempted.

Other exemptions unique to each agency.

The wildlife management areas covered by this announcement include: Tex Creek, Sand Creek, Mud Lake, Market Lake, Deer Parks, Cartier Slough, Sterling, Portneuf, Blackfoot, Georgetown, Montpelier, Hagerman, Niagara Springs, CJ Strike, Camas Prairie Centennial, Billingsley Creek, Big Cottonwood, Carey Lake, Cecil D. Andrus, Payette, Montour, Boise River, Fort Boise, Craig Mountain, Red River, Boundary Creek, McArthur Lake, Pend Oreille, Farragut, Coeur d’Alene, Snow Peak. Signs are being posted at many of these areas, but the restrictions are in effect whether or not signs are present.

According to Upper Snake Regional Habitat Manager Rob Cavallaro, “Dry conditions around the State have made the potential for wildfires extremely high. As a result, IDFG has implemented a restriction on all open fires on IDFG- managed lands and access sites in the Upper Snake, Southeast, Southwest, Magic Valley, Clearwater, Panhandle, and Salmon regions. The use of exploding targets and fireworks are always prohibited on IDFG owned lands.”

IDFG is also asking visitors to these lands to be cautious of the potential for fires caused by other sources as well.

Fire restrictions will remain in place until fire conditions change and the public will be notified at that time. Anyone with questions should contact:

Upper Snake Regional Office at 208-525-7290

Southeast Regional Office at 208-232-4703

Southwest Regional Office at 208-465-8465

Magic Valley Regional Office at 208-324-4359

Panhandle Regional Office at 208-769-1414

Clearwater Regional Office at 208-799-5010

Salmon Regional Office at 208-756-2271

Big game application period extended until June 7

In recognition of current licensing system issues, the Idaho Department Fish and Game has extended the big game application period to midnight on June 7. Fish and Game continues to work with its license system contractor to solve the problem so it can get the licensing system back online as soon as possible.

“We don’t have an estimated time yet, but we will inform people as soon as it’s live again,” said Michael Pearson, Fish and Game’s Chief of Administration.

In the meantime, Fish and Game is trying to ensure customers are treated fairly and have an opportunity to apply for controlled hunts. The department will be updating people on the website and through other means as more information becomes available.

“We value you as a customer and always want you to have a good experience with us,” Pearson said. “We realize we are not currently living up to those expectations, but we are doing our best to make it right.”

The deer, elk, antelope and fall black bear controlled hunt deadline is among the busiest days of the year for the licensing system. Last year, there were 166,000 applications for those controlled hunts, and Pearson said traditionally about 20 percent come on the final day of the application period, which opened on May 1.

It is not yet known whether extending the application deadline will affect the drawing and notification dates.

June 5 is last day to apply for fall controlled hunts

Hunters have until midnight Monday, June 5 to apply for this fall’s deer, elk, pronghorn, black bear and turkey controlled hunts.

Hunters with a valid 2017 Idaho hunting license may apply for controlled hunts at any hunting and fishing license vendor, Fish and Game office; with a credit card by calling 1-800-554-8685, online at, or by mail to Fish and Game’s License Section, P.O. Box 25, Boise, ID 83707. Mailed applications must be postmarked no later than June 5.

Hunters purchasing a license online before applying for a controlled hunt are reminded that Fish and Game has added security measures, which require the buyer to establish a unique account with a user name and password.

Hunters can make informed decisions on what controlled hunts to apply for by using the Hunt Planner on Fish and Game’s website that lists the drawing odds and statistics for all controlled hunts. The search tool is available at

New home found for orphaned Idaho mountain lion kittens

Two orphaned mountain lion kittens recently took refuge behind hay bales in a barn in Meadows near McCall, much to the surprise of the property owners and their horses, according to a Fish and Game press release.

Too small to make it on their own, and after several weeks of becoming habituated to and fed by humans, Fish and Game decided that a captive facility would be the best option for these naïve youngsters.

It took some time to find a facility that would take them both, but space was ultimately secured at Elmwood Park Zoo in Pennsylvania.

With a new home waiting, Fish and Game wildlife biologists and conservation officers from McCall put in motion a two-step plan.

First, baited live-traps were set in the barn overnight in hopes the kittens would investigate the food and catch themselves. This approach succeeded on the second night.

Then the kittens were transferred from the live-traps to large crates for safe transport. After a stop at the Wildlife Health Lab in Nampa for a full physical exam, the brother-sister kittens were Pennsylvania-bound.