BCNA CITIZEN SCIENCE RESEARCH AND RESULTS

Currently Active Projects

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.

For the Winter Raptor Protocol and Survey Routes, click here.

• Populations and Prey Selection of Wintering Raptors in Boulder County,Colorado. 1989. Stephen R. Jones. North American Prairie Conference
• Wintering Raptor Population Totals in Boulder County, 1990-2011 (pdf)
• Raptor population trends for Boulder County by species combining survey data from all locations, 1990-2011 (pdf)
• Population trends of common raptors (red-tailed hawk, ferruginous hawk and rough-legged hawk) for each of the three survey transects with longterm data, 1990-2011 (pdf)
• Population trends of uncommon raptors (bald eagle, golden eagle and northern harrier) for each of the three survey transects with longterm data, 1990-2011 (pdf)
• Spreadsheet with full 1990-2011 data set (.xls file)
• Wintering Raptor Populations in Boulder County, 1983 – 1996 (pdf)
• 2018-2019 wintering raptor survey results and summary data from 1990-2019 (pdf)
• Wintering Raptor Spreadsheets: Summary data for all routes, 1990-2012,2014-2016 and data for individual routes, 1990-2012 (.xls file)
• 2019/2020 Wintering Raptor Survey data by observer for all routes  (.xsls file)
• 2020 Wintering Raptor Survey summary data with graphs of routes and species for prior years (pdf)
• 2021-22 Boulder County Wintering Raptor Survey Summary
• 2024-25 Wintering Raptor Survey summary data

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, information, and summary of results of the Indian Peaks Bird Count

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 the 1950’s. Since then, a small group of volunteers have continued the effort; over 10,000 birds and over 140 species have been captured or banded in this small gulch measuring a quarter-mile long and 300 yards wide. In 1992, James Guercio donated a Conservation Easement to BCNA 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. Bird banding continues during spring (May) and fall (mid-August to mid-October) migratory season. Megan Jones Patterson and John Malenich, licensed bird banders, lead a team of volunteers who operate and maintain the banding program.  This banding is under the aegis of the national Bird Banding Laboratory in Laurel, MD, and the Bird Conservancy of the Rockies.

More information and data reports

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.

• Report for 2004-2007
• Summary of 2007-2011 butterfly data
• Summary report of butterfly observations on the Ann U. White trail before the September 2013 floods
• Other butterfly reports and inventories from 2002-2022 are published on the Boulder County website.

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)

• Fourth of July Butterfly Counts 1984-2012

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