BCAS Articles
Nature Almanac: Hardy prairie plants thrive in dry conditions and provide critical food for late-summer insects
In many years, when the snow-on-the-mountain plant blooms on dry, gravelly prairies, it’s a sign that snow may soon be falling in the mountains nearby. In this year’s hot, dry summer, some wildflowers, including snow-on-the-mountain, seem to have flowered earlier and more sparsely than usual.
Nature Almanac: Goldfinches Time Nesting to Take Advantage of Ripening Thistles
In our area, bird nesting season begins as early as January, when Great Horned Owls start incubating eggs. By early June, most songbirds are on eggs or tending fledglings. Late to the party are goldfinches, who often don’t begin building nests until July. Why the delay?
July Nature Almanac: Nectar from Summer Wildflowers Helps Ladies and Admirals Achieve Flights of Wonder
It seems appropriate that some of our most striking butterflies, the Ladies and Admirals, adorn some of our showiest summer wildflowers.
June Nature Almanac: Penstemons AKA Beardtongues
About 250 penstemon species flourish throughout the United States, with 62 to 65 species native to Colorado.
May Nature Almanac: Cactus Blossoms Brighten a Dry Spring
During one of our driest late winters and early springs on record, our little ball cacti have been putting on vivid displays on rocky ridge tops in the foothills.
April Nature Almanac: False Flowers Fool Pollinators
It looks like a flower. To insects, it smells and tastes like a flower. But actually, it’s a rust fungus!
March Nature Almanac: Cavity-nesting Ducks Court and Dance
For some of us who have seen colorful Wood Ducks flying into tree cavities or their downy young leaping from woodpecker holes, cavity nesting may seem like an anomaly among waterfowl. Surprisingly, six of Colorado’s nesting ducks lay their eggs in tree cavities or cliff hollows.
February Nature Almanac: Wollemi Pines Give Us Hope For The Future
Wollemi pines were abundant during the Cretaceous Period and may have been browsed on by dinosaurs. Known only from leaf fossils they were thought to have gone extinct two million years ago until, in 1994, park ranger David Noble rappelled into a remote Australian canyon and found a small grove of Wollemi pines!
January Nature Almanac: Warm Early Winter Offers Unique Views of Diving Ducks
This year’s December 22 high of 76° F in Boulder and Denver came close to that record, and temperatures remained warm enough this fall to keep local ponds and lakes ice-free throughout December and into January.
December Nature Almanac: A Least Bittern Pays a Rare Late Fall Visit to Sawhill Ponds
It was tiny, cute, and furtive. And it should have been along the Gulf Coast or in Central or South America. Instead, this Least Bittern was skulking in and out of the cattails at Sawhill Ponds.
November Nature Almanac: “Où sont les neiges d'antan?”
“Où sont les neiges d'antan?” “Where are the snows of bygone years?” Well, I haven’t heard that exact question from local friends and colleagues, but I have heard, “I remember when it used to always snow before Halloween,” or “What happened to the early fall snows that we used to get?”
October Nature Almanac: Don’t Underrate the Understory
Golden aspens steal the show in September, and then in October they decay into spicy-smelling brown humus. But when the aspen show fades, you can revel in the often-overlooked understory plants.
September Nature Almanac: Songbirds of Eastern Deciduous Forests Finding New Nesting Sites in Boulder County
Have you noticed an increase locallly in some of your favorite eastern U.S. songbirds? Species with an affinity for deciduous woodlands have been increasing in Colorado, including Boulder County.
August Nature Almanac: All Hail To The Emperor
Did you know that Colorado has a state mushroom? Commonly known as “The Prince” or “The Emperor,” Agaricus julius became our state mushroom on March 31, 2025, when Governor Polis signed a bill that had been in the works for four years.
July Nature Almanac: Milkweeds Flourish after Wet Spring
With frequent showers and mild conditions, Boulder County’s spring was one of the greenest in recent memory. Moisture-dependent wildflowers emerged early and burst into bloom by the time our first hot summer days arrived in late June. Boulder County supports at least seven native milkweed species.
June Nature Almanac: NCAR Sycamore Soared to the Moon and Back
The American sycamore on the north side of the Fleischmann Building at the National Center for Atmospheric Research is a descendant of one of the original moon trees.
May Nature Almanac: Snake, Awake!
Snakes that have snoozed away the winter in underground hibernacula or, possibly in your crawl space, awake and emerge in April or May.
April Nature Almanac: Outfoxed by Fox Squirrels
In early spring, sparrows, siskins, finches, and other seed-eating birds flock to our backyard feeders, stocking up on calories to fuel nesting activities. Meanwhile, neighborhood fox squirrels are busy providing milk and nuts for their first brood of young, and there’s hardly anything more attractive to fox squirrels than bird feeders.
March Nature Almanac: Frigid Conditions Push Some Hawks Southward
One benefit of these frigid, snowy days is the opportunity to get close to Ferruginous and Rough-legged Hawks. When temperatures are hovering near zero, raptors would rather stay put on their perches than fly away.
February Nature Almanac: Roosting (Not Roasting!) Wild Turkeys
Wild Turkeys by the scores have been coasting down from a cliff to roost in large cottonwoods along the St. Vrain Creek in Lyons this winter. Raymond Davis counted 134 turkeys on evening in late January!