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OSMP Nature Almanac and Favorite Hikes - January

OSMP Nature Almanac and Favorite Hikes - January


Hike of the Month – Sawhill Ponds

January is a time for peaceful reflection and contemplation. Sawhill Ponds, located on 75th Street near its junction with Valmont Road, is an extraordinary place to savor winter's calm. The trails are flat and smooth, providing a respite from the steep icy trails of the mountains. Snow covers the ground and blankets the icy ponds. Wind rustles through the cattails. Wildlife proceeds with the subdued rhythms of winter. Gone are the raucous Red-winged Blackbirds of summer, but many animals remain for the careful observer. Canada Geese pad about on the dikes, and Bald Eagles frequent the leafless trees. Song Sparrows lurk in the brush. Cottontail Rabbits, Muskrats and Red Foxes are also about but you may just see their footprints in fresh snow. With luck, you may notice a sleeping Great-horned Owl doing its wonderful imitation of a dead gray tree branch. Don't forget to visit Sawhill Ponds again in May, to contrast the wild frenzy of breeding and feeding with January's sedate pace.

OSMP maintains an up-to-date web page with current trail conditions across our system, so you can avoid trails that are particularly muddy, wet or icy. 

Those Fat Brown Caterpillars

Sometimes during the late winter, you may notice chubby little black and brown caterpillars strolling about on trails or sidewalks. These are Banded Woolly Bears, the larvae of the tan-colored  Isabella moth Pyrrharctia isabella. The adults lay eggs in the fall, which hatch into the familiar caterpillars. The larvae feed on a variety of foods, including dandelions, maples, asters and clovers. When the weather gets cold, the caterpillars find a snug spot to spend the winter under logs or rocks, in wood piles or tree cavities. They may emerge on warm days in January and February and wander about. In spring, the caterpillars make a silken cocoon and become a pupa. Inside the cocoon, the caterpillar changes into an adult moth. Its chewing mouthparts are replaced with a long, thin tube called a proboscis, which the adult uses to sip nectar from flowers. Wings and antennae develop, and the spiny bristles are replaced with fine scales. In spring, look for the adult moths around your porch light, and remember the fat little brown caterpillars you saw in January.

Birds: Staying Warm in Winter

Many of Boulder's birds fly south during the cold months to find more plentiful food in warmer climates. Birds that stay must be able to survive chilly conditions, including the coldest nights of the year. They manage through a fascinating array of adaptations.

Have you ever seen a bird fluff up its feathers, so that it looks like a tiny little puff ball? Fluffing creates small dead air spaces between the feathers, which serve to trap body heat. Tiny birds have a tough time when it gets cold since they have a very large surface area to radiate heat compared to their body size. Large birds like Canada Geese and eagles have it easier: because their body is large, its surface area for heat loss is proportionately smaller. Fluffing fur or feathers is a common way to stay warm. When you get goose bumps, you body is desperately trying to fluff up the small bit of fur you have!

To stay warm, most birds shiver constantly. Shivering results from very rapid muscle contractions. These contractions create friction between muscle fibers, which generates body heat. Shivering requires a great deal of energy, so birds must work extra hard to find food in winter. When nights get very cold, some small birds like chickadees and nuthatches will pack into an old woodpecker hole. In such a communal roost, all the birds share body heat and can survive sub-zero temperatures.

You may see ducks and geese standing on ice or swimming in icy water. To retain their body heat, they have evolved a clever heat exchange mechanism. Warm blood from the bird's body core moves through arteries toward the feet. Cold blood in the feet returns to the heart through veins. The arteries and veins run next to each other, allowing the warm arterial blood to transfer its heat to the cool returning blood. The warmth thus returns to the body core, while the now chilled arterial blood continues on to the goose's toes.

How Now, Brown Cloud?

In winter, residents of the Front Range often notice a brownish smoggy cloud fouling the air over the plains. The cloud results from a cocktail of trapped air pollutants that interact with sunlight to create the dull haze.

As cool air sinks, it pools at low levels in the atmosphere near the ground. A cap of warm air may sit on top, forming a temperature inversion - a lid that traps the cooler air beneath. Exhaust fumes from city automobiles, homes and factories spill into the cool air, but are unable to rise above the lid of warm air and disperse. The smog cloud may persist until strong winds break up the inversion and blow the pollutants away.

What's in the stew? A host of chemicals we'd be better off without. Oxides of nitrogen interact with sunlight and volatile organic pollutants to create the haze. Sulfur dioxide (SO2) is present as well, and lots of tiny particles of dust and grit. Carbon monoxide (CO), ozone (O3) and methane gases (CH4) are invisible but toxic and can cause respiratory problems.

From Boulder, you can easily hike above the brown cloud by climbing higher than the temperature inversion. Pick a trail that climbs into the mountain backdrop, such as Green Mountain, Bear Peak or even Flagstaff Mountain. From up above, you may enjoy a crystal clear view of distant mountains and the satisfaction of looking down on the layer of yellowish murk.

You can help combat the brown cloud by driving less and choosing fuel-efficient vehicles to reduce exhaust; and by using less electricity, which may have been generated by coal-fired power plants. Observe air quality restrictions on wood burning stoves and fire places: never burn on a RED (low air quality) day, or switch to an approved clean-burning stove.

The Last Word

Whenever man comes up with a better mousetrap, nature immediately comes up with a better mouse.

- James Carswell