Land Bird Conservation Plan Colorado  

Executive Summary
Overview of Colorado
Physiographic Region 36
Physiographic Region 62
Physiographic Region 87
Implementation Strategies
Literature Cited

Overview of Colorado


Colorado is a land of contrasts, a place where rolling grasslands of the Great Plains in the east abruptly give way to a backbone of rugged mountains, which in turn give way to plateaus and canyons in the west. A day's drive can take travelers from semidesert all the way up to alpine tundra. Elevations range from a low of about 975 m (3,200 ft) in Prowers County on the eastern plains, to 4400 m (14,433 ft) on Mt. Elbert, near Leadville. Major rivers include the Yampa, White, Colorado, Gunnison, and Dolores in the west, and the North Platte, South Platte, Cache la Poudre, Arkansas, Arikaree, Republican, Big Sandy, Purgatoire, and Rio Grande in the east. Much of the prairie lands in the east are privately owned, and most of the mountainous western lands are federally owned.

Physiographic Areas

Partners in Flight physiographic areas found in Colorado include the Central Shortgrass Prairie (PA36), Southern Rocky Mountains (PA62), Colorado Plateau (PA87), and Wyoming Basin (PA86). Based on the percentage of the physiographic area within the state boundary, Colorado has the state lead for bird conservation planning in the Central Shortgrass Prairie and Southern Rocky Mountains physiographic areas, but will share responsibility for the Colorado Plateau Physiographic Area with New Mexico, Arizona, and Utah, and will defer responsibility for the Wyoming Basin Physiographic Area to Wyoming. Physiographic areas are discussed in detail later in the plan. Maps of Colorado's physiographic areas are included in Appendix C.


The plan identifies 15 habitat types important to birds in Colorado. The habitat classifications and assignment of bird species to the habitats were developed by Colorado Bird Observatory (CBO) staff along with individuals who contributed to early development of the conservation prioritization scheme. Some adjustments were made by consensus of the BCP team. Bird species were assigned to specific habitats based on their restriction to, or strong representation within, that habitat type. This habitat classification was designed to crosswalk with those of natural resource agencies, or at least be intuitively clear to agency staff. It identifies 13 vegetation-based categories (alpine tundra, aspen, grassland, high elevation riparian, lowland riparian, mixed conifer, mountain shrubland, pinyon-juniper, ponderosa pine, sagebrush shrubland, semidesert shrubland, spruce-fir, and wetlands), and two structural categories (cliff/rock and shore/bank). Because of its high number of priority bird species (14), grassland habitat in Physiographic Area 36 is the highest priority habitat in Colorado. Habitats are discussed in detail within the context of the physiographic areas. A Colorado GAP vegetation classification map is included in Appendix D.

Conservation Issues

Colorado's natural resources are under intense pressure from a burgeoning human population. The human population increased 16% between 1990 and 1997, with an accompanying 261% increase in building permits (from 1990 to 1996). Recent estimates place land development in Colorado at 17,600 ha (43,500 ac) per year (Hobbs and Theobald 1998). Land developed for housing and associated uses is largely unsuitable for birds, save those species that tolerate high levels of human activity and greatly altered habitats. Colorado's rapid growth has led to the decline of some of Colorado's bird species. Burrowing Owl populations, for example, are under intense pressure along the Front Range as urbanization claims suitable habitat.

Colorado's growth has been accompanied by geometric increases in recreational use of public lands where many of Colorado's bird species reside. The impact of recreationists on bird populations is only beginning to be examined, but it appears that even activities thought to be relatively benign, such as hiking on established trails, can negatively affect local bird populations by altering habitat, disrupting breeding activities, attracting native predators, and introducing domestic predators (Miller et al. 1998).

Conservation Opportunities

A list of some current projects that have profound implications for conservation of Colorado's avifauna follows. This list is by no means exhaustive but is intended to highlight innovative and broad-scale initiatives.

  • In cooperation with the agencies charged with protecting and managing Colorado's birds, Colorado Bird Observatory has developed a program of bird monitoring for the state, Monitoring Colorado's Birds (hereafter referred to as MCB). MCB is designed to monitor all regularly-occurring breeding bird species in the state with annual habitat-based population surveys. Most species will be monitored through count-based techniques; species for which conventional count transects are inappropriate will be monitored through the use a variety of special, species- or group-specific techniques. A second phase of the program will gather demographic information to determine the possible reasons for known declines and to develop management information. Three agencies--Colorado Division of Wildlife, U.S. Forest Service, and Bureau of Land Management--are embarking on a five-year Memorandum of Understanding to institutionalize this program. Two other agencies--National Park Service and U.S. Fish and Wildlife Service--are evaluating possible roles in the program. The Monitoring Colorado's Birds program plan is included in Appendix E.
  • The Colorado Important Bird Areas (IBA) program began in March 1999 as a cooperative effort between the National Audubon Society and Colorado Bird Observatory, with support from Colorado Partners in Flight and Audubon of Colorado. A coordinator was appointed at Colorado Bird Observatory to head the program for the first year, and an 8-member technical committee comprised of some of the state's top bird experts was organized. This committee, using standardized categories for all state programs, identified specific criteria for each category based on the avifauna and habitat types representative of Colorado. The program is currently in the nomination phase and has received nominations for 57 sites (Jan 2000). These site nominations are being reviewed by the technical committee. Official IBA site recognition will occur in March 2000. An overview of the IBA program, with criteria for site selection in Colorado, is included in Appendix F.
  • Colorado Bird Observatory has developed a cooperative program, Prairie Partners, to work with landowners, leaseholders, and land managers in the U.S. and Mexico to conserve shortgrass prairie and the birds that depend upon it. Participants draw upon information gathered in a Best Management Practices manual to facilitate their contributions to bird conservation. All participants receive a certificate of participation and an annual report detailing the contributions of all partners.
  • The Nature Conservancy has adopted an ecoregional planning effort to identify and preserve important natural communities and species within the TNC ecoregions that include Colorado. The basis of the effort is the protection and management of suites of sites that include community types and species that are representative of the ecoregion.
  • The Colorado Natural Heritage Program gathers and compiles data on the distribution and status of "rare and imperiled" organisms in the state, including birds, and provides the data to interested parties as a proactive land-planning and research tool.
  • The Colorado Natural Areas Program identifies lands possessing significant elements of natural diversity in the state, negotiates with the landowners or custodians, and designates State Natural Areas. State Natural Area designation typically carries fraternal rather than legal protections for the highlighted natural elements.
  • The Ponderosa Pine Forest Partnership in southwestern Colorado aims to restore ponderosa pine forests to presettlement conditions by thinning small trees, preserving large trees and snags, and applying prescribed burns to open the understory. Agencies and organizations involved in the undertaking include the San Juan National Forest, Montezuma County, Colorado Division of Wildlife, Fort Lewis College, and the Colorado Timber Industry Association. This collaborative effort aims to develop a sound restoration prescription via adaptive management--attempting new management methods, analyzing the outcome, and modifying subsequent efforts so as to develop a restoration prescription that accomplishes the goals of the Partnership. After an experimentation and evaluation period, ponderosa restoration activities are scheduled to occur on 1620-2020 ha (4,000-5,000 ac) per year in Colorado, and restoration methods may be adopted by resource managers for implementation elsewhere in the West.

Avifaunal Analysis

Colorado's habitat diversity promotes avian diversity--in the last 100 years, 464 species have been seen in the state. Only California, Texas, Arizona, and Florida have higher state species counts. Of the 464 species that have visited Colorado, 278 have bred at some point; the Colorado Breeding Bird Atlas documented 264 breeding in the state during the period of the Atlas (1987-1995). Many of these species reach their highest abundance in the state; 22 reach or exceed 50% of their maximum abundance in any state (based on BBS data through 1996).

In general, monitoring information from the BBS is poor, with only 63 (23%) species being well monitored. Data for 216 (77%) species are so sparse that those species are virtually unmonitored in the state. Of those that are well monitored, eight are declining and 55 are increasing or stable. (It should be noted, however, that common species are more easily monitored, and declines are statistically more difficult to detect.) The main message regarding bird monitoring within the state is that many species may be falling through the cracks due to inadequate monitoring, and declining populations may be going unnoticed.

A number of Colorado species have small distributions (occupying <5% of North America) on either their breeding (n = 16; 6%) or wintering (n = 16; 6%) grounds. The number of species threatened by impacts to breeding or winter grounds is moderate; sixteen species (16%) score 4 or 5 for Threats on Winter grounds in the PIF Priority System, and 23 (8%) score 4 or 5 for Threats on Breeding grounds.

Together, these statistics indicate that Colorado has a unique and important avifauna. The populations of a few species show documented declines and many show documented increases, but the vast majority are unmonitored. While individual threats are probably extensive, the number of species documented to be suffering from any single threat or from combinations of threats is moderate, both in the breeding and non-breeding seasons. Many species inhabit very small ranges and may be at risk from events occurring within these small ranges. Only one of the state's species has gone extinct in recorded history (Carolina Parakeet), but others may have been extirpated and many are currently listed by natural resource agencies as either endangered, threatened, of concern, or sensitive. The generally positive picture is compromised by the known declines and the fact that some species exhibit small ranges, others are experiencing habitat loss on their breeding and/or wintering grounds, and most are virtually unmonitored.

State of Knowledge of Colorado's Birds

Colorado's history of ornithological study extends back to the days of frontier exploration. A fine recounting of that history can be found in Bailey and Niedrach (1965), but several landmark accomplishments deserve mention. One of the first zoologists afield in Colorado was Thomas Say, who collected bird specimens while accompanying the Long Expedition in the early 1820s. Later ornithologists added to the species list and expanded our knowledge of natural history through the collecting of specimens and eggs, and careful recording of observations. Cooke (1897) published the first extensive collection of information on Colorado's birds, followed later by Sclater (1912) and Bergtold (1928). The two-volume set by Bailey and Niedrach (1965) was, for many years, the standard reference to Colorado ornithology, and is still widely used. The Colorado Bird Distribution Latilong Study (Chase et al. 1982, Kingery 1988) included schematic distribution maps, and estimates of abundance. Andrews and Righter (1992) has replaced Bailey and Niedrach as the standard reference on distribution and abundance of birds in Colorado. The Colorado Breeding Bird Atlas (Kingery 1998) provides more extensive information on the natural history and distribution of the state's breeding birds. Yanishevsky and Petring-Rupp (1998) offers detailed life history information and management recommendations for some Colorado species.

Recently completed projects have collected extensive data on distribution and abundance of Colorado birds. The CDOW's COVERS project compiled information on population status, ecology, and management for all vertebrate species in Colorado, including birds. The Colorado Breeding Bird Atlas project collected data from nearly 1300 field workers over eight years (1987-1994), compiling over 80,000 records (Kingery 1998). Those data have been deposited with several agencies and organizations in Colorado, with the raw data on file at the Denver Museum of Natural History.

Several bird monitoring programs in the state are ongoing. The Audubon Society's Christmas Bird Count inventories wintering birds, currently in 35 locations. The Hawkwatch, conducted under the direction of the Denver Museum of Natural History and the Colorado Bird Observatory, counts raptors during their spring migration along the Dakota Hogback west of the Denver metropolitan area. The Colorado Natural Heritage Program compiles information on the distribution of rare species in Colorado for use in setting conservation priorities and assisting in land-use planning activities. The Breeding Bird Survey initiated in 1966 and jointly coordinated by the USGS Patuxent Wildlife Research Center and the Canadian Wildlife Service, conducts roadside surveys each spring. The BBS data have been basic to determining priority species in this plan. Colorado Bird Observatory's MCB project is conducting count-based surveys in a large number of habitats, surveying nesting colonies, and conducting species-specific surveys to document habitat associations, distributions, and population trends. This project will greatly increase the data available on Colorado's bird populations.

Statewide Implementation Goals and Objectives

Based on the key concepts identified by the Colorado Partners in Flight bird conservation planning team, we have identified the following statewide goals and objectives which must be met to achieve our overall goals of "keeping common birds common" and "reversing the downward trends of declining species" in Colorado. These statewide goals and objectives will be fleshed out and expanded within the habitat writeups.

l. Bird Monitoring

Goal: All breeding birds in Colorado will be monitored or tracked to document distribution, population trends, and abundance in a statistically acceptable manner.

Objective: All species with an area importance (AI) score > 2 will be monitored with count-based methods. We will continue to use BBS data, but will incorporate Monitoring Colorado's Birds data as they become available.

Objective: Species with AI scores 2 will be tracked through count-based methods or their presence or absence noted in the state.

Objective: Some species such as colonial nesters and nocturnally-active species will be monitored or tracked using special techniques such as colony counts and nocturnal transects.

Objective: All species with a population trend (PT) score of 4 or 5 will be tracked with demographic monitoring methods.

2. Habitat Monitoring

Goal: To monitor all major habitats in Colorado in order to document amount, condition, and ownership. This goal is crucial to the implementation of all parts of the bird conservation plan since it will allow us to determine the current state of things and the potential partners available to implement activities on any particular habitat.

Objective: Develop collaborative efforts (potential partners include Colorado DOW, Colorado Natural Heritage Program, Colorado Bird Observatory, The Nature Conservancy, USGS) to use GIS in mapping all major habitat types in the state, documenting amount, condition, ownership, etc.

3. Habitat Core Areas

Goal: To conserve unique representatives and/or core areas in each major habitat in Colorado. Specific candidates or foci may be identified in the habitat writeups. This goal considers the importance of such areas to birds during breeding, migration, and winter.

Objective: Identify unique representatives and/or core areas in each major habitat type in Colorado that should be conserved.

Objective: Identify any of these core areas that are appropriate for designation as IBAs, nominate them, and promote involvement of local groups in conserving these areas once they are designated.

Objective: Identify additional means of designating and conserving unique representatives and/or core areas in each major habitat type in Colorado.

Objective: Identify agency- or organization-specific means of designating and conserving unique representatives and/or core areas (e.g., state management areas, refuges, wilderness areas, and possible purchase by private or public entities, etc.). Identify areas that are appropriate for such designations, work with the appropriate agency or organization to designate them, and promote conservation activities.

Objective: Promote collaboration/cooperation between agencies, organizations, and individuals in conserving unique representatives and/or core areas with multiple ownership.

4. Site-based Conservation

Goal: To conserve local sites that are important for the conservation of priority species. These sites may include key nesting spots (e.g., cliffs, nest colonies, individual nest sites for rare species, etc.), lek sites, migration staging or stopover spots, or concentration sites. This goal considers the importance of such areas to birds during breeding, migration, and winter.

Objective: Identify key local sites that are appropriate for designation as IBAs, nominate them, and promote involvement of local groups in conserving these areas once they are designated.

Objective: Identify additional means of designating and conserving key local sites.

Objective: Identify agency- or organization-specific means of designating and conserving key local sites (e.g., exclosures, protocols in management plans, exclusion of certain activities during important times of the year, and possible purchase by private or public entities, etc.). Identify areas that are appropriate for such designations, work with the appropriate agency or organization to designate them, and promote conservation activities.

5. Management Practices

Goal: To promote management practices that benefit birds on all lands. This goal is not meant to encourage the impression that someone can manage a single piece of land to benefit all birds, but rather to encourage all land managers to understand that there is something they can do on any piece of land to benefit birds.

Objective: Best Management Practices (BMPs) manuals will be produced and distributed for each priority habitat in Colorado. In some cases, existing documents such as Birds in a Sagebrush Sea (Paige and Ritter 1998) will be used to avoid duplication of effort. The focus on priority habitats rather than priority species is meant to promote management using a community approach, recognizing the range of needs expressed by the suite of species using a particular habitat.

Objective: Identify key landowners and/or land managers and ask them to incorporate best management practices to conserve priority species and their habitat in Colorado. Work with land managers to develop practices that meet their needs and those of the birds, and evaluate effectiveness.

Objective: Monitor the quantity and quality of acres managed under each BMP.

6. Interstate/International Wintering Grounds

Goal: To conserve the wintering ground habitat used by Colorado migratory birds outside of the state and the country.

Objective: Identify the wintering distribution and key habitat associations of all priority Colorado species. Some of this information is already available and presented in the habitat and species writeups.

Objective: Monitor all major wintering habitats for priority species in order to document amount, condition, and ownership.

Objective: Develop collaborative efforts with other states and countries to monitor wintering habitats and conserve them for wintering migrants and resident species.

Objective: Develop collaborative efforts with other states and countries on projects (e.g., education, research, fund-raising, donations, etc.) which benefit species on their winter grounds.

7. Migration Concerns

Goal: To conserve the migration habitat used by priority Colorado species, and to conserve those species themselves as they migrate. This goal focuses particularly on migration corridors, concentration areas, and staging areas.

Objective: Identify key migration habitats of priority Colorado species.

Objective: Monitor key migration habitats for priority species in order to document amount, condition, and ownership.

Objective: Develop collaborative efforts with other states and countries to monitor migration habitats and conserve them for migrants and resident species.

Objective: Develop collaborative efforts with other states and countries on projects (e.g., education, research, fund-raising, donations, etc.) which benefit species on their migration grounds.

8. Outreach and Education

Goal: To provide information about priority species (conservation, habitat needs, natural history, etc.) and habitats to the public, resource managers, and other interested parties with emphasis on school children, teachers, naturalists, landowners, and natural resource professionals. The habitat writeups may identify priority species and habitats on which to focus.

Objective: Develop and make educational materials and information booklets about priority species or habitats available to local nature centers and organizations, landowners, natural resource agency offices, and teachers. This might include producing materials for the agricultural extension service, the Natural Resources Conservation Service, or the timber industry.

Objective: Integrate information on priority species or habitats into existing education programs (Project Wild, Balarat, other programs for children and adults).

Objective: Hold workshops and field programs for teachers, natural resource professionals, and landowners.

Objective: Present information at education, natural resource professional, and land manager (timber and ranching) association meetings and conferences.

Objective: Submit manuscripts to popular magazines for children and adults, and also those targeting landowners and managers.

Objective: Use the annual International Migratory Bird Day (IMBD) to supply local media outlets with information on priority species and habitats, organize informational activities for school children and the public, provide guided natural history viewing opportunities, and promote local conservation activities in which people can become involved.

Objective: Collaborate with Mexican and Central American colleagues in translating and/or developing informational and educational materials on priority species and habitats in Spanish.

9. Research Priorities

Goal: To fill the voids in scientific information needed to conserve Colorado's birds.

Objective: Identify the top ten research needs in each major habitat in Colorado. See the habitat writeups for these developing lists.

Objective: Facilitate investigations to answer these questions by providing information about priority needs to universities, and public and private research entities, identifying funding sources, promoting collaboration between management and research agencies, etc.

10. Adaptive Management

Goal: To evaluate the success of the Partners in Flight bird conservation program and to incorporate the lessons learned and the new information produced into an improved program for the conservation of Colorado's birds.

Objective: Convene an annual meeting where progress on the above goals and objectives is presented. This may be accomplished with a sort of "score card" based on the previous nine categories of goals and objectives.

Objective: Based on the results of the score card and annual meeting, redraft objectives to reflect progress or what has been learned in the previous year.

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