BCAS Articles
2021 Was Not a Good Year for Bluebirds
2021 was a disappointing year for Mountain and Western Bluebirds in Colorado. The data from our Boulder County Open Space and Boulder County Audubon bluebird monitoring combined with the data from the entire state of Colorado bluebird box surveys shows fewer bluebirds fledged in 2021 than in 2020.
Winter finch news you can use
New research says your bird list may have just gotten shorter (but not officially yet).
December Nature Almanac: Cedar Waxwings Embrace Suburban Life
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.
Conservation Corner: Gross Reservoir and the Colorado River
For this issue of Conservation Corner, it seems appropriate to consider new developments regarding the proposed expansion of Gross Reservoir, and the associated problems affecting the Colorado River.
November Nature Almanac: Defective compass may send disoriented migrants our way
In the autumn and early winter of 2018 local birders became excited by birds that should not have been here. Winds probably helped push these out-of-place birds north that year, but another cause may be a phenomenon called “reverse migration” that happens when a bird flies in the opposite direction from their usual route.
October Nature Almanac: Irascible Mud Hens
They've been here all summer, and they'll probably be here all fall and winter too—those noisy little dark, duck-like birds that like to dabble around in the wetlands of eastern Colorado.
Insects and Kin of the Colorado Front Range
Insects and Kin, in 1104 pages, is a comprehensive guide to the major orders of insects that you are likely to observe throughout Colorado’s seven Front Range life zones.
September Nature Almanac: Pine Whites Float on Late Summer Breezes
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.
Conservation Corner
Locally, the most important issues that have arisen are those connected with the property known as CU-South and with management of the Boulder Reservoir and the adjacent wetlands.
2020-2021 Year in Review: A Message from Our President
It’s been quite a year of ever-adapting public health guidelines but that hasn’t stopped us from having a busy year of online and in-person activities! September is the beginning of our new year, so let’s look back at what we’ve accomplished as a group in 2020 and 2021. Much thanks to you, our members, and to our dedicated volunteers for making this a successful year.
Fall Bird Migration in Colorado
Fall bird migration is underway across the state with Colorado's peak migratory activity happening during September nights. However, bright lights around homes and cities can disrupt this important annual phenomenon.
August Nature Almanac: Ebony Jewelwings Dash and Flash Above Languid Streams
Like turquoise and emerald wands with ebony wings, jewelwing damselflies (Calopteryx maculata) make us catch our breath in wonder.
July Nature Almanac: AcroBats Over Boulder
Ten species of bats breed in Boulder County! Learn more about their activities throughout the year and where you can see them in July.
June Nature Almanac: Bobcats Emerge from the Shadows
During our first few decades living in Boulder, we hardly ever saw a bobcat. Now friends and neighbors seem to report encounters with these mostly nocturnal felines almost daily.
May Nature Almanac: Enticing Avocets
Each spring flocks of shorebirds traveling through eastern portions of Boulder County search for places to stop over to refuel before continuing northward to breeding areas on the arctic tundra. Other shorebirds remain here for the summer, setting up territories in the few suitable habitats that remain. One such species is the appealing American Avocet.
Conservation Corner
New conservation easement on ag property in the city of Boulder and more on the CU South ongoing annexation activity.
Conservation Corner
In February, the County Public Works department made an ill-conceived and disastrously prepared application for a special use permit for an industrial-scale composting facility on county open space at the site of the former Rainbow Tree Nursery Site, east of US 287 and north of Lookout Road.
April Nature Almanac: Bluebirds Make Our Hearts Sing
How did bluebirds acquire their dazzling color? Once upon a time, according to folklore, all the birds and animals were painted but one. The forgotten bird flew up into the sky to protest its drab coat, and bits of sky stuck to its feathers. Today, we still thrill to see that dazzling color whenever we see a bluebird.
March Nature Almanac: Pampas Hawks Arrive on Schedule but Find Fewer Vacancies
For millennia, pampas hawks (Buteo swainsoni) have lived geographically symmetrical lives, wintering in mid-latitude grasslands of Argentina and nesting in mid-latitude grasslands and desert shrublands of western North America.
Conservation Corner
Many of the issues that have been important in 2020 continue to require attention in 2021.