March 23, 2011

Humans and dogs have spent time together in the woods for as long as, well, for as long as humans and dogs have spent time together. So when a University of Kentucky College of Agriculture conservation biologist collects gray fox, bobcat and coyote population data, he doesn't depend entirely on the latest high tech gizmo. He relies, instead, on a canine's tried-and-true olfactory talents and the joy every dog experiences when it discovers... poo. Or scat, to use the more scientific term.

John Cox, adjunct assistant professor in the UK Department of Forestry, UK forestry graduate student Bryan Tom and Lucas Epperson of Auburn University spent four weeks this winter in the Morehead ranger district of the Daniel Boone National Forest working with scat dogs, a non-invasive way to track and count the number of a given species in a predetermined area.

Cox said there's been some speculation that fox numbers have declined over the past 20 or 30 years, so he wanted to come up with a way to monitor gray foxes over long periods of time so population trends can be determined.

"Our original plan was to focus only on gray foxes and figure out a good way to monitor the species over long periods of time. However, we later decided to try out the technique on bobcats and coyotes, since these are potential competitors to foxes," Cox said.

"Sometimes, it takes decades to really understand how those population patterns wax and wane and understand what may influence it," he said. "Without long term data sets, it can be difficult to tease those data out."

To accomplish this, Cox and Tom used two noninvasive survey methods: hair snares and scat dogs. A hair snare uses a scent attractant as a lure, which often encourages the animal to rub against something, leaving a few hairs behind that can be identified using DNA. But Cox said many furbearing animals are suspicious of such snares, so using scat dogs has the potential to provide more data that may indicate better where animals occur.

Labrador retrievers Kasey and Nitro accompanied Epperson, their handler, from their home base in Auburn, Ala. They are part of the Eco-Dog program at the Animal Health and Performance Program in Auburn University's College of Veterinary Medicine. The program trains dogs to sniff out a variety of targets, including scat.

Epperson said they look for dogs who enjoy working and being out in the woods, as well as having a lot of independence-a dog that can think for itself. The reward for a job well done? A favorite toy.

"It's a game for them, the whole thing is just a game," Epperson said. "The way we do their training is we'll associate the odor that we're training them for with their ball. Then it becomes a fun thing for them. The dog enjoys it a lot."

If Kasey's and Nitro's enthusiasm for the job is any indication, Epperson is right. Both dogs came out of the truck ready to hit the ground running-tails wagging, big canine grins spread across their faces, eyes bright, ears relaxed. Kasey's job that day was to demonstrate how they do it. Within seconds she had found the scat Epperson and Tom had placed alongside the road. Looking expectantly at her handler, she immediately sat next to the scat, little waves of excitement moving from her tail up through her torso. Epperson tossed her the ball and the game ensued.

"All she thinks about is that ball. She lives and breathes that ball," he said.Cox and Tom had divided the study area in Bath County into triangular transects or survey paths, 500 meters to a side. Nitro was scheduled to walk the transect that day with Tom and Epperson.

"We'll try to walk on the line, as best we can," Tom said, indicating the direction on a map. "But the dog will judge the wind and work a pattern based on that, and they'll cover much more ground than we will."

The dog wears a GPS collar that records its movements and gives the researchers the exact location of the scat. Using both scat dogs and hair snares placed in the center of each triangle has proven to be very successful in gathering data, Tom said.

"I think if this study were longer, you'd get really good numbers here," he said. "The dogs are averaging, between them, something like 15 (scats) a day, which adds up quickly. Some days they'll find as many as 25."

With Nitro leading the way, bounding out in front or side to side, the men set off, climbing steep terrain, far off any manmade trail. Occasionally Nitro will hit on something that isn't visible to the men-the scent can linger long after scat decays. When that happens, there is no toy reward and the search continues. But when he does find visible droppings, Tom collects two genetic samples and the scat itself. He records the location using the GPS data. Back in the lab, they'll run a genetics test to identify the animal species and have a unique DNA profile of each individual.

Cox said the method is an effective way for collecting certain population components, particularly for presence/absence studies or rare or elusive species, where the researcher wants to know whether the species is present and then can estimate its numbers.

"You can take those data and say, ‘OK, the animal was present here, and it was absent here. Why?' Then you can do models to try and understand," he said. "Was it because of the forest cover? Is it because of some other environmental variables?"

Serious research for humans, but just another game in the woods for dogs.

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