Studies help guide North Star management

June 1, 2020

The 2020 North Star Nature Preserve Management Plan, under consideration for adoption in June 2020, calls for science-based decisions in managing the unique property.

To that end, nine studies or assessments have been done since a management plan for the Preserve was adopted in 2015. This data helps guide ongoing habitat restoration and management of recreation.

The studies include assessments of the fen, an old-growth wetland in the northwest corner of the property; monitoring of North Star’s hydrology; assessments of the great blue heron colony and beaver population at the Preserve; floristic inventories related to the distribution of plants on the open space; and a 2017 wildlife study. All of these reports are available HERE on Pitkin County’s website.

Only one federally protected species of wildlife may occur on or near North Star – Canada lynx – though it has not been documented there. Seven species on Colorado’s State Endangered and Threatened Species list (including Species of Concern) are known to or could potentially occur at North Star. One, the bald eagle, has been sighted there more than once this spring. The others include the boreal toad, Colorado River cutthroat trout, northern leopard frog, river otter and Townsend’s big-eared bat.

An additional three species were documented for the first time in the most recent wildlife study! The American marten, North American moose and a loggerhead shrike (a predatory songbird) were photo-documented for the first time in 2017, according to the 2017 North Star Nature Preserve Annual Wildlife Monitoring Report.


North Star is heavily used by elk throughout the year, according to the report. Elk cows use North Star in the summer for rearing habitat and as part of their general summer range, and in autumn for mating activities. Although spotted calves were documented at North Star, the birthing of calves at the Preserve has not been confirmed. The report also confirmed the presence of a large number of mule deer at North Star. The Preserve provides excellent moose habitat and moose are now seen regularly by visitors to North Star, as their range and populations in Colorado increase. American black bears are also abundant; North Star is used heavily used by sows with cubs and solitary males, according to the wildlife study.

At least 11 mammalian predator species are known to use North Star as part of their home range. American marten, black bears, coyotes and martens were formally recorded in the 2017 surveys. American mink, bobcats, short-tailed weasel, long-tailed weasel, mountain lions, red fox and striped skunk have been documented by a biologist via direct observation or indirectly by means of tracks, scat or other sign.

Abundant small mammals provide an excellent prey base for these mammalian predators, as well as avian predators. At least six small mammal species (American red squirrel, deer mouse, golden-mantled ground squirrel, least chipmunk, northern pocket gopher, voles.) were recorded during the 2017 surveys. Past small-mammal surveys have found bushy-tailed woodrat, long-tailed vole, montane vole, mountain cottontail, muskrat, snowshoe hare, southern red-backed vole, western jumping mouse, and Wyoming ground-squirrel occurring at or on the periphery of North Star.

Beavers at North Star were studied in 2018, and seem to be increasing in numbers. Two lodges exist on the property, and beavers play an important role in sustaining wetland vegetation and habitat. Find out more HERE.


At least 86 bird species have been documented at North Star during the breeding season, including 22 species of conservation concern that were documented at North Star in 2017. A single loggerhead shrike was captured by a wildlife camera, making it the first shrike formally documented at North Star.

Four species of raptor that are active in daytime (American kestrel, Cooper’s hawk, osprey, red-tailed hawk) were documented at North Star during the breeding season in the 2017 study. In addition, at least two owl species have been confirmed at North Star during the breeding season: great-horned owls and northern saw-whet owls. Bald eagles and golden eagles have also been documented at North Star.

Five wetland/wading birds (great blue heron, sora, spotted sandpiper, Virginia rail, Wilson’s snipe) were identified at North Star in 2017. Great blue herons were the focus of a 2018 targeted study, which confirmed the herons had moved on from their previous nesting site, identified alternate nesting stands, mapped foraging habitat and included biological information about these birds. Find out more HERE.

Killdeers have been observed in the past as well. At least seven species of waterfowl (American coot, Canada goose, cinnamon teal, gadwall, green-winged teal, mallard and pied-billed grebe) likely breed at North Star. Of these, American coot, Canada goose, mallard and gadwall, were documented during the 2017 surveys.

Open Space and Trails is committed to continuing natural resource studies, including bird and wildlife surveys, at North Star. Only with monitoring at regular intervals can we track changes over time and use place-based science to inform management decisions. The 2020 Management Plan contains a monitoring schedule that will direct wildlife studies to continue every three to five years.

The 2020 Management Plan for North Star continues to prohibit all public access to the majority of the Preserve – everything on the west side of the Roaring Fork River – for the benefit of wildlife. This area, 188 acres or 77 percent of North Star’s total 245 acres, contains multiple habitat types, including significant wetland and riparian habitat that is critical to wildlife activities such as mating, fawning/calving, rearing young, migration, cover and foraging.

– By Pitkin County Open Space and Trails