Hooded merganser

Hooded mergansers have increased significantly in Boulder County since the 1950 Christmas Bird County. They live on insects, small fish and crustaceans from shallow ponds. For more information, see the 2012 March Nature Almanac.
Photo 12/17/2013 near Hygiene by CC VanWie

BCNA research and results

Wintering Raptor Survey

Since 1983 Boulder County Nature Association (BCNA) volunteers have counted wintering raptors along survey routes scattered throughout the plains of Boulder County, Colorado. We initiated the surveys during a time when intensified poisoning efforts by private landowners and government agencies appeared to threaten prairie dog populations in parts of Boulder County. Some of these poisonings were occurring in the Boulder Reservoir area, where Ferruginous Hawks, Red-Tailed Hawks, and Bald Eagles gathered each winter. We wanted to observe the effects of fluctuating prairie dog populations on these and other species. We also hoped to locate wintering raptor concentration areas, such as Bald Eagle roosts, Northern Harrier roosts and large prairie dog colonies, so that these areas could be protected.

Links to wintering raptor survey results, raptor survey maps and forms, and the wintering raptor survey protocol

Boulder County Avian Species of Special Concern

The Avian Species of Special Concern list attempts to red-flag those species in Boulder County that are of interest due to their rareness, probable decline, and habitat or locational restrictions. Hence, they are more vulnerable and less adaptable to change. It is based on a comparison of historic and current records, studies, and lists that are felt to represent the best available information. The list primarily focuses on breeding status. In addition, the list utilizes regional, state and local assessments.

Butterflies in Boulder County

BCNA funded the 2007 continuation of a research program to survey Boulder County butterflies and preparation of a 74-page report. Surveys in 2004-06 were funded by the Boulder County Parks and Open Space Small Grants Program. Since then, monitoring of the butterflies in Boulder County has been funded by both the Boulder County Parks and Open Space Small Grants Program and BCNA. Links to later reports (PDF) on the Boulder County Web site are also given below.

Butterfly counts have been held at the Cal-Wood Education Center every July 4 for 29 years, 1984-2012. A 29 page report covering those 29 years is now available as a PDF (3.8 MB)

Both the Butterflies of the Northern Colorado Front Range website and the book, Butterflies of the Colorado Front Range by Janet Chu and Stephen Jones stem from research partially supported by BCNA.

Indian Peaks Bird Counts

The Indian Peaks Four Season Bird Counts started in 1982 in order to inventory the avifauna of western Boulder and northwestern Gilpin counties in Colorado.  These counts provide information about species presence and relative abundance as well as documenting trends and composition changes occurring in the mountain landscape.

History and summary of results of the Indian Peaks Bird Count

Indian Peaks Checklist of Birds (PDF)

Newsletters with Indian Peaks Bird Counts data (in PDF format):
Allegra Collister Bird Banding Project

Allegra Collister, a co-author of A List of Birds of Rocky Mountain National Park, began banding birds in a small gulch north of Boulder in 1950. Since then, a small group of volunteers have continued the effort; over 10,000 birds and over 180 species have been banded.  or sighted in this small gulch measuring a quarter mile long and 300 yards wide. In 1992, James Guercio donated a Conservation Easement covering the area historically used for bird banding by Allegra Collister and BCNA volunteers to BCNA. The Allegra Collister Nature Preserve came into being at this time. In 2011, the Conservation Easement was transferred to Boulder County Parks and Open Space. BCNA, however, retains one-half of all mineral rights within the Allegra Collister Nature Preserve and pays a small tax assessment on them each year. Bird banding is continuing each spring with Maggie Boswell, a licensed bird bander, and volunteers. This banding is under the aegis of the national Bird Banding Laboratory in Laurel, MD and the Rocky Mountain Bird Observatory.

Data reports for this project