Naturally Speaking : Staying Connected

Selasphorus rufus hummerDave Hallock, Eldora.  The concept of maintaining “habitat connectivity” has received recent attention. During this past winter the television series NOVA had a program that focused on the Yellowstone to Yukon Conservation Initiative (Y2Y). A goal of the initiative is to link protected wildlife areas so that wildlife species, especially wide-ranging mammals, can move safely between them. More recently, the Conservation Science Partners produced a report called “Disappearing West” that documented the direct loss and fragmentation of natural lands due to such actions as urban expansion, road building, and energy production.  Interior Secretary Sally Jewell has called for a renewed emphasis on large-scale planning to minimize the impacts of a growing human infrastructure that could lead to the isolation of national parks and wildlife refuges.

In the early 1980s a group from the Boulder County Nature Association (BCNA) worked on a plan to address this very issue. The emerging fields of conservation biology and landscape ecology were broadening conservation efforts away from small sites, often based on a single species, towards recognition of landscapes and processes that maintained biodiversity, what ecologists call the “coarse filter”.

The result was the mapping of a countywide system of habitat core areas that were felt to be the “best of what is left” in the county. Riparian and large-mammal movement corridors connected the core areas. It was felt that the relatively natural areas of the landscape should remain as such, and interconnected to allow for the movement of species. The “Ecosystem Plan,” as it was commonly called, was used to influence public land acquisition and management as well as foster private land preservation through the actions of landowners and land trusts.

Some of the core habitats were fairly obvious: Indian Peaks, North St. Vrain Canyon, South St. Vrain, and Central Gulch. The plains and that portion of the mountains that is within the mineral belt – from Jamestown south – were more of a challenge due to existing fragmentation from roads and development. But areas like Walker Mountain, Winiger Gulch, Rabbit Mountain, Walker Ranch, Boulder Mountain Parks, the White Rocks, Boulder Valley Ranch, and the grasslands of south Boulder were felt to have significant ecological value.

During the 1990s, three events occurred that helped achieve much of the envisioned plan. The first was the passing of the County Open Space sales tax in November 1993. This allowed the County to acquire fairly significant chunks of the landscape rather than scattered, isolated parcels. Lands protected around Rabbit Mountain now total over 14,000 acres instead of just the original 2,500, and includes raptor nesting sites and much of their feeding grounds.

The second event was the formal inclusion of the plan into the Boulder County Comprehensive Plan. Representatives from approximately a dozen agencies and organizations reviewed and revised the plan. The core areas were adopted as Environmental Conservation Areas. The County saw them as locations where development rights could be removed through purchase or transfer. The plan provided an ecological framework and rational.

The third event was the update of the Arapaho and Roosevelt National Forest Land and Resource Management Plan in the mid-1990s. District Ranger Bill Anthony used several concepts from the Ecosystem Plan to influence the Forest Plan update. Because of their size and ecological quality, several areas received the Core Habitat designation, which was done in Central Gulch, the Dry St. Vrain, and Coffintop Mountain.  Much of the North St. Vrain Canyon received a Research Natural Area designation.
The primary emphasis in achieving the plan over the past 25 years has been decreasing the development potential within the ECAs and habitat connectors. The acquisition of Heil Valley Ranch between Lefthand Canyon and Lyons as well as lands to the east of North Foothills Highway allowed wildlife to continue movement from the Indian Peaks to the west portion of the plains. Purchase of Reynolds Ranch Open Space along Magnolia Road helped keep open an important wildlife movement corridor. The acquisition by the Forest Service of the “old professor’s ranch” in the North St. Vrain Canyon helped protect habitat for bighorn sheep.

There are some limits as to what can be achieved given the realities of the landscape that Boulder County is a part. The sheer volume of people now living in the urban Front Range, the continual advancement of nonnative plants and animals, air pollution, acid rain, increased nitrogen brought to the mountains from upslope storms, global warming, the growing web of trails, and altered disturbance regimes all provide a sobering reality. The core areas are still relatively small. Wide-ranging mammals, such as pronghorn and buffalo, will never be a viable part of the plains and most elk will be primarily restricted to the mountains. Bighorn sheep have never expanded into their historic range in western Boulder County since being reintroduced into the North St. Vrain Canyon.

The geography of where we live is interesting. We are caught between two major landscape influencers: In our southeast corner, weighing in at 3 million people, is the Denver Metropolitan Area, while in our northwest corner, weighing in at 415 square miles, is Rocky Mountain National Park. We are on the edge of a metropolitan area that is part of the ecosystem of a national park. Many animals that summer in the park spend winter lower in the foothills of Boulder County. Much of western Boulder County was within the original proposal for the park.

Looking ahead, July is one of the best months to observe nature in the Nederland area. It can be a good month for wildflowers. June has already been spectacular. The yellows of sulphur flower and rose-purples of Lambert’s locoweed can dominate montane meadows in early July. Alpine meadows are at their peak; the showy yellow sunflower old-man-of-the-mountain is the most conspicuous. The native cool season grasses Parry’s oatgrass and Thurber fescue are green, tall and full of seeds in montane and subalpine meadows.

With the flowers come the butterflies. This June was one of the best butterfly months in several years. Look for the large Weidemeyer’s admiral (mostly black with white markings) around willows and aspen, Parnassians (mostly white with black and red markings) around stonecrops, and Meade’s sulphurs (burnt-orange and green) in the alpine meadows. Many different types of diminutive “blues” will be found around mud puddles.

Mammals show a mixture of activity. Elk have mostly completed calving and the herds regroup at higher elevations. Pine squirrels and chipmunks are having their young. Pikas are already getting ready for winter in the alpine talus slopes as they begin cutting plants and building their hay piles. Long-tailed weasels breed (July/August).

Birds are quieter this month than in June, as they spend more time incubating and feeding young. Male rufous hummingbirds arrive from the north (a few may make it back by the end of June) and begin competing with our local broad-tailed hummers for feeders.