There's a steep embankment along Clear Creek where we often see a muskrat munching on a leaf or a clump of pond weed. The muskrat seems unperturbed, nibbling away, while we sit on the opposite bank watching. Then, with hardly a sound, she eases into the water and vanishes below the surface. Her den entrance is located underwater, and she swims unseen from there up to the den floor deep within the embankment.

When Coloradans talk about our "midsummer monsoon," visitors from India must shake their heads. After all, two or three inches of precipitation over a six-week period hardly compares to the torrents of life-sustaining rain that wash over the Indian subcontinent each summer.

The common name variegated fritillary describes the complex pattern of orange, brown, and buff scaling on the underwings.

Standing just 5.5 inches tall and weighing less than 4 ounces, Northern Saw-whet Owls need to consume close to 20% of their body weight each winter day to keep body temperatures from plunging.

When we first settled in Boulder more than a half-century ago, we would have been startled and thrilled to see a Cedar Waxwing in our backyard. Now we see or hear them throughout the year -- flocking to junipers, dangling from berry-laden mountain ashes, or visiting our backyard bird feeders.

When out looking for butterflies in the foothills, we typically scan wildflowers blooming along either side of the trail, alert for flashes of orange or yellow. But during September, if you look straight overhead, you're likely to see a striking butterfly flitting through the conifers.