BCAS Articles
September Nature Almanac: Aspen Leaves Glow and Glimmer, Whisper and—Maybe—Whimper as the World Gets Hotter
Early in September an occasional aspen tree turns into a lone golden candle, and by the fourth week entire hillsides glow in luminous tones of yellow, sometimes shading into salmon and red. Although members of a clone share the same genes and flaunt the same color...
August Nature Almanac: Skippers Flit through Mountain Meadows
The tiny skippers seem particularly at home in these sun-dappled clearings, where the males dart back and forth while trying to impress potential mates. Females perch calmly on logs…
July Nature Almanac: Ovenbirds Fill Foothills Canyons with Exotic Song
Beginning about 15 years ago, we began to hear Ovenbirds singing in most of our moist foothills canyons containing ponderosa pine and Rocky Mountain maple. What brought them here, and could the maple leaves be providing a suitable substitute for oak leaves in their nests?
June Nature Almanac: Non-Native Smooth Brome May Crowd Out Native Wildflowers
Smooth brome was introduced into North America in grass seed imported from Eurasia. An early maturing species, smooth brome can form dense stands long before many native grasses have initiated spring growth.
May Nature Almanac: Listen, It’s Spring
All birds have a wide repertoire of sounds ranging from sweet melodies to raucous cries and soft chips and chirps.
April Nature Almanac: March Snows Nourish Fields of Wildflowers
When 2-5 feet of snow fell on Boulder County's foothills and mountains during the second week of March, local wildflower-lovers jumped with joy.
March Nature Almanac: Soaring Into Spring on a Turkey Vulture’s Wing
A hulking black bird associated with carrion is not what most people think of as a harbinger of spring. Nevertheless, the return of Turkey Vultures brings excitement to winter-weary Colorado birders.
February Nature Almanac: Cavity-Nesting Ducks Take to Front Range Woodlands
Fifty years ago, some of us would have driven miles to see courting mergansers, and Wood Ducks were considered uncommon in Boulder County. What has changed?
January Nature Almanac: It’s a Mouse, It’s a Bird, It’s a BROWN CREEPER!
The herky-jerky climbing actions of this bird makes us think of a little mouse scrambling up a tree. A glance in the field guide confirms its identity as the appropriately named Brown Creeper.
December Nature Almanac: Sage—A Symbol for the Season but not for Seasoning
All the various sage species (Artemisia sp.) emit a mouth-watering scent, but they are not the herb for seasoning meats.
November Nature Almanac: Courtship!
“Why are Great Horned Owls hooting so much”. Courtship is the simple answer, even if it seems premature during these first cold days and nights of the winter season.
Nature Almanac: Tiny Divers. . . Buffleheads!
Leaving the cold northland behind, Buffleheads find favorable wintering grounds near open water and in sheltered bays along both coasts.
September Nature Almanac: Limpkins Lurk Where They Are Not Supposed to Be
A Limpkin—the tropical wetland bird whose usual home is Florida and Central and South America—visited Colorado this summer for the first time in recorded history.
August Nature Almanac: Polyphemus Moths Spin Summer Magic
What really captured Cindy's attention were the blue-ringed, transparent eyespots, reminiscent of distant planets, on the moth's wings. This striking feature inspired the name Saturnidae for a family of silk moths found on every continent except Antarctica.
June Nature Almanac: What’s Up on the Tundra?
It’s a paradox that forget-me-nots, moss campions, and other alpine flowers usually bloom in June while snowdrifts still cover marsh marigolds and globeflowers in the spruce-fir forest at lower elevations.
May Nature Almanac: Black-headed Grosbeaks arrive in full song from Mexico
As spring migration reaches a climax, many birders in Front Range towns have the opportunity to see transient bird species that stop over in the plains for a day or two before heading to the foothills and mountains of the Rockies. One colorful songbird that we are happy to catch on its migration travels is the Black-headed Grosbeak.
April Nature Almanac: Early Easter Daisies Finally Emerge from their Winter Blanket
As we stood on one sun-warmed limestone slope in a foothills canyon, we could see dozens of fist-sized plants blooming all around us.
March Nature Almanac: Marching to a Different Drummer
Different drummers are pounding on trees, metal railings, and the sides of our houses proclaim that it’s spring. Flickers and other woodpeckers are beating out a fanfare—the noisier the better—hoping to ignite romance and deter rivals.
February Nature Almanac: Wandering Waxwings
Our frigid early morning bird walk began just after sunrise, as we looked for some rare visitors to the Colorado Front Range.
January Nature Almanac: A Confusion of Warblers
Popular English collective nouns for warblers include a “bouquet,” a “fall,” or a “wrench” of warblers. Or—most apt for Colorado this past autumn—a confusion of warblers. What were those tiny bits of fluff thinking when they settled down here in November instead of migrating south?