Walking on the wild side: Pitkin County Open Space asseses wildlife on its properties

Pitkin County Open Space and Trails is conducting an in-depth survey of wildlife on its trails and properties, including use of cameras, but the staff is interested in more than pretty pictures of critters.

The open space program is using 10 infrared, motion-detecting cameras to capture images of wildlife day and night on its properties. In addition, it hired wildlife biologist Jonathan Lowsky to conduct its latest wildlife survey, which is performed about every three years. The data will be compared with baseline information to determine how the properties are faring as habitat.

“We’re trying to protect biodiversity,” said Gary Tennenbaum, executive director of the open space program. “You can see trends that are occurring.”

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For the first time ever, the data for properties will be shared on a property-by-property basis with the public on the open space program’s website later this year or early next year.

“We’ve been doing this (surveying) all the time but the public probably isn’t aware of it,” Tennenbaum said. “We need to show them.”

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The open space program has used past surveys and consultations with Colorado Parks and Wildlife officers to determine the proper length of seasonal closures on some of its properties.

For example, the surveys established that Sky Mountain Park in the upper valley and the Glassier Open Space in the midvalley are heavily used by elk for winter range and migration routes. Based on that information, those properties are closed from Dec. 1 through May 15.

Wheatley Open Space along Lower River Road isn’t used as a migration route, so its closure is lifted earlier, on May 1.

The mid-May closure for Sky Mountain Park and Glassier comes at the chagrin of some mountain bikers who want to hit the trails when spring has sprung. Tennenbaum feels that releasing the data about when elk use the property will convince skeptics that the timing is based on science rather than random dates. People will be able to see that elk really do use those properties into May.

Lowsky, former wildlife biologist for Pitkin County, has also been hired as a consultant by the Roaring Fork Transportation Authority to monitor winter use of a portion of the Rio Grande Trail corridor in the past. He uses images from strategically placed cameras, personal observations and examination of tracks to assess wildlife presence.

Although Lowsky’s work for the open space program isn’t completed, preliminary data show rich diversity of wildlife at places such as North Star Nature Preserve and Sky Mountain Park.

“All the species that should be on those properties are on those properties,” Tennenbaum said. That includes predators such as mountain lions and bobcats.

Anecdotally there is information that there are more deer now on Sky Mountain Park then when it was in private hands, even though its trails are popular with mountain bikers and hikers, Tennenbaum said. The surveys will be an important tool to use to make sure recreational use isn’t affecting habitat.

Lowsky’s survey is complemented by the use of the motion-detection cameras, which are used at alternating locations as well as fixed sites on open space property.

Some of the more striking images captured recently include a ghostly looking marten peering into the night along the Ditchline Trail; a huge bear stopping for a snack along the trail at Red Wind Point in the Crystal Valley; a fox bounding along the snow-covered Ditchline Trail, apparently trying to flush a mouse that had burrowed underneath; and a mountain blue bird improbably looking like it’s posing for the camera mid-flight.

Then there are multiple shots of deer and elk on the Sky Mountain Park in the upper valley and the Glassier property in the midvalley. The cameras also confirm that humans do a pretty good of complying with the winter closures, Tennenbaum said.

One camera set up Nov. 25 through May 15 last winter and spring in Sky Mountain Park recorded 72 elk sightings, 46 deer sightings, 12 fox, six coyotes, five birds, four rabbits, one mountain lion and one grouse, according to open space and trails staff. Those weren’t necessarily different animals, but they were sightings of animals at different times.

A picture tells a thousand words, the cliché goes, but the open space program feels the broader wildlife surveys will tell the whole story about its properties.

scondon@aspentimes.com