Bear Creek Watershed Breeding Bird Atlas

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					Bear Creek Watershed Breeding Bird Atlas
   The Evergreen Naturalists Audubon Society

        Leader and Participant Manual
                  April 2008
                   Version 1
Cordilleran Flycatcher photograph by Kay Niyo
                                                            Table of Contents

Authors: Bear Creek Watershed Breeding Bird Atlas Steering Committee (Brad Andres, Mike
Foster, Kay Niyo, Heather Johnson).

Scope............................................................................................................................................... 2

Organization.................................................................................................................................. 2

Site Description and Coverage..................................................................................................... 4

Survey Time Frame ...................................................................................................................... 4

Field Data Collection .................................................................................................................... 4

   Species......................................................................................................................................... 5

   Abundance................................................................................................................................... 5

   Evidence of Breeding .................................................................................................................. 6

   Habitat ........................................................................................................................................ 6

Web-based Data Entry ................................................................................................................. 6

Steering Committee Contacts ...................................................................................................... 7

Literature Cited ............................................................................................................................ 8


The purpose of the Bear Creek Watershed Breeding Bird Atlas (hereafter Bear Creek Atlas) is to
provide information on the distribution, abundance, breeding status and habitat use of birds on
public lands within the Bear Creek Watershed. Information from these surveys will be provided
to the appropriate federal, state, county, and local agencies that manage these public lands. Data
collected in this project will also help inform conservation decisions considered by The
Evergreen Naturalists Audubon Society (Evergreen Audubon) and will be used for educational
purposes in the newly developed Evergreen Nature Center.

We are enlisting your help in meeting our purpose for the Bear Creek Atlas. Although the
instructions may seem lengthy, we believe a little practice in the field will alleviate any fears you
have about participating. Training sessions will be held before each season to provide
information on how to collect field data. We hope you will find this project fun, fulfilling, and


A set of public lands has been designated for surveys over the next five years (2008-2012). After
the initial five-year survey period, sites will be surveyed every five years. These repeated
surveys will provide some information on how bird populations are changing within the
watershed. In general, methods follow state breeding bird atlas projects, such as the Colorado
Breeding Bird Atlas (Kingery 1998, Kingery and Leukering 2007). Much of the material
presented here is modeled after Field Worker’s Handbook, which is available on the Bear Creek
Atlas website ( For information on the Colorado Breeding Bird Atlas II, please

Based on Evergreen Audubon’s membership and area of interest, we have designated the Bear
Creek Watershed as an appropriate area to survey breeding birds (Figure 1). Within the
watershed, there are more than 58,000 acres of public lands that are managed by Jefferson
County Open Space, Denver Mountain Parks, the City of Lakewood, the Colorado Division of
Wildlife, and the USDA Forest Service. We have targeted about 30,500 acres of relatively
natural lands for breeding bird surveys (Table 1). Although we tried to determine the full
complement of sites we will survey over the first five years, access and observer effort may
cause some changes to the site list as project is implemented.


The Bear Creek Atlas is endorsed by Evergreen Audubon and draws on its membership for
participation. A Steering Committee developed the general approach for the atlas, recruited
participants, and provided training sessions and assistance in the field. Each site will be assigned
a Leader who will coordinate visits to the site with participants, provide a liaison to the Steering
Committee, be responsible for collecting information following the protocol described here,

ensure coverage targets are met, and ensure observations are entered into the web-based database
( We are also recruiting Assistant Leaders who may substitute for the Leader to
ensure that the annual survey coverage target is met. Leaders and Assistant Leaders should be
able to identify Bear Creek Watershed breeding birds by sight and sound. We suggest that the
Leader and Assistant Leader visit the site together either on the initial visit or before the start of
data collection. Participants can visit the site with the Leader or Assistant Leader or can visit the
site on their own, provided they follow the protocol presented here and are capable of bird
identification. Leaders, Assistant Leaders, and Participants can all enter data on the website (see
below). Participants can visit any of the sites on the annual schedule as often as they like, can
enter their results on the website, and should let site Leaders know about the effort they have
expended at the site. The Steering Committee will be available to assist Leaders in surveying
any site. Interest in volunteering to be a site Leader, Assistant Leader, or Participant, should be
directed to Mike Foster. We will post contacts for Leaders in the Site Descriptions on the
website. Annual site Leaders will also be announced in the April Dipper each year. The
Steering Committee, Leaders, Assistant Leaders, and Participants are all volunteer positions.
Mileage and out-of-pocket expenses may be tax deductible. We encourage all observers to
survey sites in pairs to minimize safety risks.

Figure 1. Delineation of the Bear Creek Watershed study area (gray area).

Site Description and Coverage

Description of sites surveyed in each year will be provided on the website (
These descriptions will include maps of the site, general habitats found there, and access points.
Please send any corrections or comments to the Steering Committee. We realize that many sites
will be surveyed from existing trails and that complete coverage of a site will be difficult. We
divided the Arapahoe National Forest into sections that have accessible trails or are along the
Squaw Pass or Mount Evans roads. However, it will be important to record the actual areas you
cover during each site visit (see effort). It would be useful to scout your site before beginning
formal surveys. We will add new site descriptions each year so that by the end of the first five-
year period (2012), all site descriptions will be posted on the website. The tentative schedule for
site surveys, from 2008 to 2017, is provided in Table 2.

Survey Time Frame

We have designated the period from 1 May to 15 July as the core time to survey breeding birds
in the Bear Creek Watershed. For elevations above 10,000 feet, we will likely need to start on
16 May, at the earliest, and continue until 31 July. During this time frame, we encourage you to
visit the sites five times, once every two weeks during the following intervals: 1–15 May, 16–31
May, 1–15 June, 16–30 June, 1–15 July (and 16–31 July for high elevations). The goal is to
spend 10–15 hours surveying birds at your site each year, which is somewhat dependent on the
size of the site. If Leaders suspect that they will not reach the survey effort target for their site,
due to vacations or other unforeseen circumstances, please work with your Assistant Leader to
substitute for the period. If this is not possible, please contact one of the Steering Committee
members to help fill in. Site surveys outside of the core period to confirm breeding are
encouraged. If brief trips are made only to confirm a certain species (e.g., a Great Horned Owl
on a nest), record the observer, date, site, species, number, and breeding evidence but do not
record effort (see below). Participants should relay any such observations to the site Leader. See
Table 3 for the breeding season of species suspected of breeding in the Bear Creek Watershed. If
possible, a nocturnal trip to the site to record owls and nightjars is suggested.

For observations not related to breeding birds, we encourage you to record your observations on
eBird ( We have entered all the sites designated for the Bear Creek Atlas
as “hotspots” in eBird. Also use eBird to record birds observed at other sites within the

Field Data Collection

Field forms are available on the web, but surveyors can also use notebooks or any other media as
long as the pieces of information described below are recorded. After reading the sections
below, please see the field data sheet example in Figure 3.


An important component of the Bear Creek Atlas is to record the amount of EFFORT spent by
observers on each visit. Names of observers should be recorded as should start and end times.
For most visits, Leaders and Participants will likely remain in one group during the survey and
the hours of effort would be calculated as the end time minus the start time. If the group happens
to split during any visit, each separate group should record their hours of effort and the two
groups should combine their total hours for the visit. For example, the Leader, Assistant Leader,
and two other Participants meet at Elk Meadow and split into two groups who take different
trails through the meadow and agree to meet at the parking lot in 2 hours. Total effort for this
visit would be 4 hours (2 groups x 2 hours). If only the Leader and 1 Participants surveyed Elk
Meadow from 8:00 to 10:00 am, the effort would be 2 hours. Of course, it would be best to
survey early in the morning. We would also like you to map the general area you cover on each
visit (see Figure 2), which will allow us to ascertain the coverage of a site and plan the re-survey
effort after five years. Using polygons, you should delineate “buffers” around the trails you walk
to the extent where you can visually detect birds or hear them sing. At some sites, it will be
possible to cover areas beyond the trail system. The length of trails covered at some sites in the
Arapahoe National Forest is up to the ability of the observer. We envision observers covering
about a three-mile stretch of trail. The important thing will be to map the area covered and
record the amount of time spent surveying. The drawn polygons will be plotted in Google
Earth® to determine general habitats surveyed at the site, which may be useful in tracking
vegetation changes and resultant changes in breeding bird composition and abundance.


All species observed at a site should be recorded, but special attention should be paid to the
SPECIES SUSPECTED OF BREEDING in the Bear Creek Watershed (Table 3). Observers can
use full species names or the American Ornithologists’ Union (AOU) codes (provided in Table
3) to record information. Distinguishing migrants from potential breeders can be tricky,
especially because breeding locations of species do change and documenting those changes is
one of the purposes or the Bear Creek Atlas project. Careful observation of behavior in the field
and consultation with Table 3 and the references provided in the Literature Cited should help
identify the species that historically bred near your site. As noted above, some species will
initiate breeding before our official 1 May start date; breeding seasons for species nesting in the
Bear Creek Watershed are provided in Table 3. Species groups that initiate breeding well before
1 May include waterfowl, raptors, owls, jays and crows, and the Red Crossbill.


Observers should COUNT ALL ADULTS of every species they encounter. We realize it may be
difficult to identify adults and fledged young as the season progresses, but observers should try
to distinguish adults. Numbers per the amount of effort (birds/hour) will be converted into

categorical measures of abundance (e.g., common, rare, uncommon) after the completion of the
season. Because of changes in singing rate and the appearance of young as the season
progresses, we may restrict estimates of abundance to the June surveys. Inspection of the data
collected in 2008 will help us decide on an analytical strategy.

Evidence of Breeding

A central element of a breeding bird atlas is to DETERMINE THE LEVEL OF BREEDING
EVIDENCE exhibited by each species at each site. Evidence, in order of increasing confidence
that the species is breeding at the site, follows four general categories: observed, possible,
probable, or confirmed. The goal is to confirm as many species breeding at a site as possible.
Descriptions and codes to use in the field are provided in Table 4. Observers should record all
levels of evidence in the field, but only the strongest evidence observed on a specific visit should
be entered into the web database. Observers should study the criteria before going into the field.
Nelson and Leukering (2007), available on the Bear Creek Atlas website, provide detailed
descriptions of acceptable codes for all species breeding in Colorado, and a summary of codes
judged to be inappropriate for species breeding in the Bear Creek Watershed is presented in
Table 3. Determining the occupant of a “Used Nest (UN)” is difficult for many species, and this
code should be used carefully. When using breeding evidence code “Pair (P)”, study the
behavior of the birds to be sure they represent an interaction between a male and female.


Observers are also asked to RECORD THE GENERAL HABITAT where they find breeding
birds. Coarse habitat descriptions, which represent vegetation cover types, are provided in Table
5; some special natural and human-made structures are also included. As you work through the
site, note each of the habitats where you find breeding species. You do not need to record every
observation, but you should indicate where you are generally finding birds. At most sites, there
will only be a few choices for habitats. For an American Dipper at Lair O’ the Bear Park, you
might indicate OWS (open water streams) and nesting under a bridge as MSB (bridge/culvert).
As an example of the use of forest types, you might code Mountain Chickadee as FUCL, Pine
Grosbeak as FUCE, and Pygmy Nuthatch as FUCP (see Table 5).

Web-based Data Entry

With the help of Ann Johnson of Norwalk, Iowa, we have created a website ( to
enter, store, and retrieve data, and pose questions. Data entry screens have drop-down menus to
ease data entry. You will need to create an account with a specific login username and your own
password. By entering data on this website, you accept responsibility for adhering to the
protocol described here. Only Leaders, Assistant Leaders, and Participants should create
accounts and enter data. We encourage you to enter data soon after completing a survey, so we
can track progress in a timely way.

Remember that the value of conducting surveys outside of the project’s time frame is to confirm
breeding of a particular species at a site. Observations of bird species only migrating through the
watershed (those not exhibiting breeding behaviors and not listed in Table 3) can be entered into
the BCA database, but these species should also be entered into eBird. To enter observations in
eBird, go to You will need to create an account if you do not already have
one. Choose Submit Observations from the top of the homepage. From the Submit Observations
screen, click on the link for Select an entire city, county, or state. At that screen, enter
“Jefferson” or “Clear Creek” in the COUNTY box and “CO” in STATE/PROVINCE box and
click in the “Show me Birding Hot Spots in the area”. At the next screen, you can Select a
Birding Hot Spot from the dropdown menu. At the Step2: Date and Effort screen, you need
select only the Casual Observation for migrants. You will find all the sites we are surveying in
the Bear Creek Watershed listed as Hot Spots for Jefferson and Clear Creek Counties. Please
use this hotspot list to enter data from these named sites. Do not enter data using the My eBird
portal. If you make observations from sites we are not surveying, they can still be added as a
Hot Spot for the Watershed. We plan to upload the data from our database into eBird, so there is
no need to enter breeding season records into eBird if they are in the Bear Creek Atlas database.
Please inform the Steering Committee if you find a species breeding in the Bear Creek
Watershed that is not listed in Table 3.

Steering Committee Contacts

Brad Andres, 7663 St. Moritz Rd., Evergreen, CO, 80439; 303-670-0101 (h); 720-226-7614 (c);

Mike Foster, 12871 W. Jewell Circle, Lakewood, CO, 80228; 303-456-2647;

Heather Johnson, 7663 St. Moritz Rd., Evergreen, CO, 80439; 303-670-0101 (h);

Kay Niyo, 25100 Sunset Lane, Evergreen, CO, 80439; 303-679-6646;

Literature Cited

Andrews, R., and R. Righter. 1992. Colorado Birds: A Reference to Their Distribution and
      Habitat. Denver Museum of Natural History, Denver, CO.

Kingery, H. E. (ed.). 1998. Colorado Breeding Bird Atlas. Colorado Bird Atlas Partnership and
      Colorado Division of Wildlife, Denver, CO.

Kingery, H. E., and T. Leukering. 2007. Atlas II – The Second Colorado Breeding Bird Atlas,
      Field Worker’s Handbook. Colorado Bird Atlas Partnership, Colorado Division of
      Wildlife, Denver, CO. Available at <>.

Nelson, D., and T. Leukering. 2007. Atlas II – The Second Colorado Breeding Bird Atlas,
       Manual on Use of Breeding Codes, Version 1.0. Colorado Bird Atlas Partnership,
       Colorado Division of Wildlife, Denver, CO. Available at

Figure 2. An example of mapping survey coverage at Elk Meadow Park. Hatched regions show
the areas covered on each of five visits. Mapped area indicates the extent to where observers can
detect birds by sight and sound.

Figure 3. An example of a field data form with codes from Tables 4 and 5. Circled numbers
indicate the total for the visit.

Table 1. Public lands designated for breeding bird surveys in the Bear Creek Watershed.

Site                          General location   Manager1   Acres    Elevation      Elevation zone

Alderfer/Three Sisters Park       Alderfer         JCOS       660     7,200-8,500      Montane

Bear Creek Lake Park          Bear Creek Lake      LAK      1,500     5,700-5,800   Plains/Foothills

Beaver Meadows Trail             Arapahoe          NF         640     9,400-9,600   Subalpine/Alpine

Bell Park                        Cub Creek         DMP        480     7,200-7,800      Montane

Bergen Park                       Bergen           DMP         25          7,600       Montane

Bergen Peak (DMP)               Elk Meadow         DMP        520     8,200-9,700      Montane

Bergen Peak SWA                 Elk Meadow         SWA        500     8,000-9,400      Montane

Berrian Mountain              Berrian Mountain     DMP       520      8,400-9,100      Montane

Birch Hill                      Mount Lindo        DMP       160      7,400-8,000   Plains/Foothills
Captain Mountain/Lincoln
Lake Trails                      Arapahoe          NF         640    9,200-10,600   Subalpine/Alpine
Chief Mountain
Trail/Forest Road 192            Arapahoe          NF        160    10,600-11,700   Subalpine/Alpine

Corwina Park                      O'Fallon         DMP       298      7,000-7,200   Plains/Foothills

Cub Creek Park                   Cub Creek         DMP        550     7,200-7,400      Montane

Cub Creek Trail                  Arapahoe          NF         960    8,800-10,400   Subalpine/Alpine

Dedisse Park                      Alderfer         DMP        420     7,000-7,400      Montane

Dinosaur Ridge North          Dinosaur Ridge       JCOS        40     6,000-6,400   Plains/Foothills

Dinosaur Ridge South          Dinosaur Ridge       JCOS        25     6,000-6,300   Plains/Foothills

Elephant Butte                    Alderfer         DMP        665     7,600-8,400      Montane

Elk Meadow Park                 Elk Meadow         JCOS     1,754     7,800-8,400      Montane

Fillius Park                      Bergen           DMP       106      7,600-7,800      Montane

Flying J Ranch Park               Flying J       JCOS/DMP     484     8,000-8,400      Montane

Genesee Park                      Genesee          DMP      1,000     7,800-8,300      Montane

Grass Creek Trail                Arapahoe          NF         960    9,200-10,000   Subalpine/Alpine
Hayden Green Mountain
Park                          Green Mountain       LAK      1,540     6,200-6,800   Plains/Foothills

Hicks Mountain                Hicks Mountain       DMP        840    8,400-10,000   Subalpine/Alpine

Lair O' the Bear Park         Lair O' the Bear     JCOS      392      6,600-7,200   Plains/Foothills

Legault Mountain               Meyer Ranch         DMP        120     8,000-8,400      Montane

    Site                         General location   Manager1   Acres     Elevation      Elevation zone

    Little Park                  Lair O' the Bear     DMP        400      6,600-7,700   Plains/Foothills

    Lost Creek Trail                Arapahoe          NF         960    9,000-10,800    Subalpine/Alpine

    Matthews/Winters Park           Red Rocks         JCOS     1,724      6,200-7,200   Plains/Foothills

    Maxwell Falls Trail             Arapahoe          NF         960      7,800-9,400      Montane

    Meyer Ranch Park              Meyer Ranch       JCOS/DMP     567      7,800-8,800      Montane

    Mount Evans SWA              Elk Management       SWA      3,438      8,200-9,000      Montane

    Mount Falcon Park             Mount Falcon        JCOS     1,782      6,000-7,800   Plains/Foothills

    Mount Glennon                Dinosaur Ridge       JCOS        39      5,800-6,400   Plains/Foothills

    Mount Goliath Trail             Arapahoe          NF         320   11,200-12,200    Subalpine/Alpine

    Mount Judge                  Hicks Mountain       DMP        360    9,000-10,300    Subalpine/Alpine

    Mount Lindo                    Mount Lindo      JCOS/DMP     985      6,000-7,800   Plains/Foothills

    O'Fallon Park                    O'Fallon         DMP        860      7,000-7,400   Plains/Foothills

    Pence Park                       O'Fallon         DMP        320      7,400-8,000   Plains/Foothills

    Red Rocks Park                  Red Rocks         DMP        640      6,100-7,800   Plains/Foothills

    Snyder Mountain              Hicks Mountain       DMP        240      8,400-9,600   Subalpine/Alpine

    Squaw Mountain Road             Arapahoe          NF         480   10,200-11,500    Subalpine/Alpine
    Squaw Pass Road Picnic
    Areas (Eagles Aerie,
    Cloudland, Juniper Pass,
    Warrior Mountain)               Arapahoe          NF         320   11,200-11,400    Subalpine/Alpine

    Summit Lake                     Arapahoe        NF/DMP       640   12,600-13,000    Subalpine/Alpine

    Truesdell Creek Area Trail      Arapahoe          NF         960    9,800-10,200    Subalpine/Alpine

 Yankee Creek Road               Arapahoe               NF           640      8,400-9,800  Montane
 DMP = Denver Mountain Parks; JCOS = Jefferson County Open Space; LAK = City of Lakewood; NF = National
Forest, USDA Forest Service; SWA = State Wildlife Area, Colorado Division of Wildlife.

Table 2. Schedule of sites to be surveyed for the Bear Creek Watershed Breeding Bird Atlas.

Site                                   Location         08   09   10   11   12   13   14   15   16   17
Bear Creek Lake Park                Bear Creek Lake     X                        X
Beaver Meadows Trail                   Arapahoe         X                        X
Bergen Peak (DMP)                    Elk Meadow         X                        X
Bergen Peak SWA                      Elk Meadow         X                        X
Captain Mountain/Lincoln Lake
Trail                                  Arapahoe         X                        X
Dinosaur Ridge North                Dinosaur Ridge      X                        X
Dinosaur Ridge South                Dinosaur Ridge      X                        X
Elk Meadow Park                      Elk Meadow         X                        X
Lair O' the Bear Park               Lair O' the Bear    X                        X
Little Park                         Lair O' the Bear    X                        X
Mount Glennon                       Dinosaur Ridge      X                        X
Summit Lake                            Arapahoe         X                        X
Bell Park                             Cub Creek              X                        X
Cub Creek Park                        Cub Creek              X                        X
Flying J Ranch Park                    Flying J              X                        X
Genesee Park                           Genesee               X                        X
Hayden Green Mountain Park          Green Mountain           X                        X
Mount Goliath Trail                    Arapahoe              X                        X
Mount Judge                         Hicks Mountain           X                        X
Red Rocks Park                        Red Rocks              X                        X
Snyder Mountain                     Hicks Mountain           X                        X
Truesdell Creek Area Trail             Arapahoe              X                        X
Chief Mountain Trail/Forest Road
192                                    Arapahoe                   X                        X
Hicks Mountain                      Hicks Mountain                X                        X
Mount Evans SWA                     Elk Management                X                        X
Mount Falcon Park                    Mount Falcon                 X                        X
Squaw Mountain Trail                   Arapahoe                   X                        X
Squaw Pass Road Picnic Areas
(Eagles Aerie, Cloudland, Juniper
Pass, Warrior Mountain)                Arapahoe                   X                        X
Alderfer/Three Sisters Park            Alderfer                        X                        X
Birch Hill                           Mount Lindo                       X                        X
Corwina Park                           O'Fallon                        X                        X
Cub Creek Trail                        Arapahoe                        X                        X
Dedisse Park                           Alderfer                        X                        X
Elephant Butte                         Alderfer                        X                        X
Grass Creek Trail                      Arapahoe                        X                        X

Site                     Location      08   09   10   11   12   13   14   15   16   17
Maxwell Falls Trail      Arapahoe                     X                        X
Mount Lindo             Mount Lindo                   X                        X
O'Fallon Park            O'Fallon                     X                        X
Pence Park               O'Fallon                     X                        X
Bergen Park               Bergen                           X                        X
Berrian Mountain         Mountain                          X                        X
Fillius Park              Bergen                           X                        X
Legault Mountain        Meyer Ranch                        X                        X
Lost Creek Trail         Arapahoe                          X                        X
Matthews/Winters Park    Red Rocks                         X                        X
Meyer Ranch Park        Meyer Ranch                        X                        X
Yankee Creek Road        Arapahoe                          X                        X

Table 3. Potential breeding bird species found in the Bear Creek Watershed, with species codes.
Breeding season indicates most likely time to confirm breeding in Colorado and is taken from
Nelson and Leukering (2007), as are codes that are not accepted, for a given species, by the
Colorado Breeding Bird Atlas Partnership. Details on reasons for not using specific codes are
provided in Nelson and Leukering (2007). For most species, the code “Used Nest (UN)” should
always be noted carefully and use behavioral cues when coding “Pair (P)” and “Courtship (C)”.
 Family/Species                     AOU code Breeding season Evidence codes to avoid1
   Canada Goose                       CAGO        11 Mar – 31 Aug            X, M, CF, FF
   Wood Duck                          WODU          1 May – 31 Jul         X, M, NB, CF, FF
   Gadwall                            GADW         21 Apr – 31 Aug           X, M, CF, FF
   Mallard                            MALL        11 Mar – 10 Aug            X, M, CF, FF
   Blue-winged Teal                   BWTE         1 May – 20 Aug            X, M, CF, FF
   Green-winged Teal                  AGWT         11 May – 10 Sep           X, M, CF, FF
   Ring-necked Pheasant                RINP         1 Apr – 10 Sep           X, M, CF, FF
   White-tailed Ptarmigan             WTPT         11 Jun – 20 Sep           X, M, CF, FF
   Dusky Grouse                       DUGR         21 Mar – 10 Sep          X, M, P, CF, FF
   Wild Turkey                        WITU        15 Mar – 31 Aug               CF, FF
 Pelicans to Vultures
   Great Blue Heron                   GBHE          15 Mar – 20 Jul    H, T, V, A, X, M, DD, CF
   Black-crowned Night-Heron          BCNH         15 Apr – 20 Aug H, T, V, A, X, M, DD, CF
   Turkey Vulture                     TUVU          21 Apr – 5 Aug       X, M, A, DD, NB, CF
   Bald Eagle                         BAEA          1 Jan – 10 Aug           X, M, DD, CF
   Sharp-shinned Hawk                 SSHA         20 Apr – 31 Aug             X, M, CF
   Cooper's Hawk                      COHA          1 Apr – 31 Aug             X, M, CF
   Northern Goshawk                   NOGO          1 Apr – 11 Sep             X, M, CF
   Swainson's Hawk                    SWHA         14 Apr – 20 Aug           X, M, DD, CF
   Red-tailed Hawk                    RTHA         1 Mar – 25 Aug            X, M, DD, CF
   Golden Eagle                       GOEA          1 Feb – 15 Aug           X, M, DD, CF
   American Kestrel                   AMKE          1 Apr – 15 Aug        X, M, NB, DD, CF
   Prairie Falcon                      PRFA       20 Mar – 15 Aug            X, M, DD, CF
   Virginia Rail                       VIRA       25 Mar – 20 Aug              X, CF, FF
   Sora                               SORA         20 Apr – 20 Aug             X, CF, FF
   American Coot                      AMCO         15 Apr – 25 Aug             X, CF, FF
   Killdeer                            KILL         1 Apr – 10 Sep           X, M, CF, FF
   Spotted Sandpiper                   SPSA        21 Apr – 10 Sep           X, M, CF, FF
   Wilson's Snipe                     WISN          11 Apr – 31 Jul          X, M, CF, FF
   Rock Pigeon                        RODO          1 Jan – 31 Dec         X, M, A, DD, CF
   Band-tailed Pigeon                  BTPI        21 Apr – 30 Sep           X, A, DD, CF
   Eurasian Collared-Dove             EUCD          1 Feb – 31 Oct           X, A, DD, CF

Family/Species                AOU code        Breeding season    Evidence codes to avoid1
  Mourning Dove                MODO            1 Apr – 10 Sep            X, CF

  Flammulated Owl              FLOW       11 May – 10 Aug              NB, DD, CF
  Eastern Screech-Owl          EASO       10 Feb – 31 Aug              NB, DD, CF
  Great Horned Owl             GHOW        15 Jan – 31 Jul              NB, CF
  Northern Pygmy-Owl           NOPO        15 Feb – 31 Jul             NB, DD, CF
  Long-eared Owl               LEOW        10 Feb – 15 Jul             NB, DD, CF
  Northern Saw-whet Owl        NSWO       10 Feb – 15 Aug              NB, DD, CF
Nightjars to Kingfisher
  Common Nighthawk             CONI       20 May – 20 Aug             X, M, NB, CF
  Common Poorwill              COPO       1 May – 15 Aug                 NB, CF
  White-throated Swift         WTSW        1 May – 25 Aug          X, M, T, A, DD, CF
  Broad-tailed Hummingbird     BTLH       1 May – 20 Aug            X, M, P, DD, CF
  Belted Kingfisher            BEKI       1 May – 15 Aug            X, M, A, DD, CF
  Williamson's Sapsucker       WISA       1 May – 15 Aug            X, M, T, NB, DD
  Red-naped Sapsucker          RNSA       10 May – 25 Aug           X, M, T, NB, DD
  Downy Woodpecker             DOWO       1 May – 15 Aug            X, M, T, NB, DD
  Hairy Woodpecker             HAWO       25 Apr – 10 Aug           X, M, T, NB, DD
  Am. Three-toed Woodpecker    TTWO       1 May – 15 Aug            X, M, T, NB, DD
  Northern Flicker             NOFL       10 Apr – 15 Aug           X, M, T, NB, DD
  Olive-sided Flycatcher       OSFL         1 Jun – 31 Jul                 DD
  Western Wood-Pewee           WWPE       25 May – 10 Aug                  DD
  Hammond's Flycatcher         HAFL       30 May – 5 Aug                   DD
  Dusky Flycatcher             DUFL       20 May – 5 Aug                   DD
  Cordilleran Flycatcher       COFL       20 May – 10 Aug                  DD
  Say's Phoebe                 SAPH       10 Apr – 10 Aug                  DD
  Western Kingbird             WEKI        5 May – 20 Aug                  DD
  Eastern Kingbird             EAKI       5 May – 20 Aug                   DD
  Plumbeous Vireo              PLVI        15 May – 31 Jul                 DD
  Warbling Vireo               WAVI       20 May – 20 Aug                  DD
  Red-eyed Vireo               REVI        1 Jun – 10 Aug                  DD
Jays to Swallows
  Gray Jay                     GRAJ            21 Feb – 10 Jul          DD,CF
  Steller's Jay                STJA           1 Apr – 25 Aug           A, DD, CF
  Blue Jay                     BLJA           10 Apr – 10 Aug          A, DD, CF
  Western Scrub-Jay            WESJ            5 Apr – 25 Aug          A, DD, CF
  Clark's Nutcracker           CLNU           1 Mar – 20 Aug           A, DD, CF
  Black-billed Magpie          BBMA           1 Mar – 20 Aug           A, DD, CF
  American Crow                AMCR            1 Mar – 1 Aug           A, DD, CF
  Common Raven                 CORA            1 Mar – 1 Aug           A, DD, CF

Family/Species               AOU code        Breeding season    Evidence codes to avoid1
  Horned Lark                 HOLA           1 Mar – 20 Aug           A, DD, CF
  Tree Swallow                TRES           1 May – 10 Aug             T, DD
  Violet-green Swallow        VGSW           5 May – 20 Aug             T, DD
  No. Rough-winged Swallow    NRWS            15 Apr – 25 Jul           T, DD
  Bank Swallow                BANS            5 May – 31 Jul            T, DD
  Cliff Swallow               CLSW           5 May – 25 Aug             T, DD
  Barn Swallow                BARS           20 Apr – 31 Aug            T, DD
Chickadees to Gnatcatchers
  Black-capped Chickadee      BCCH       20 Apr – 10 Aug                  DD
  Mountain Chickadee          MOCH        1 May – 20 Aug                  DD
  Bushtit                     BUSH        10 Apr – 5 Aug                  DD
  Red-breasted Nuthatch       RBNU       10 May – 20 Aug                  DD
  White-breasted Nuthatch     WBNU       10 Apr – 10 Aug                  DD
  Pygmy Nuthatch              PYNU       1 May – 25 Aug                   DD
  Brown Creeper               BRCR       10 May – 15 Aug                  DD
  Rock Wren                   ROWR       20 Apr – 10 Aug                   N
  Canyon Wren                 CANW       15 Mar – 10 Aug                   N
  House Wren                  HOWR        1 May – 20 Aug                  NB
  Marsh Wren                  MAWR       15 May – 15 Aug                  NB
  American Dipper             AMDI       21 Feb – 15 Aug                  DD
  Golden-crowned Kinglet      GCKI        1 May – 21 Aug                  DD
  Ruby-crowned Kinglet        RCKI       10 May – 15 Aug                  DD
  Blue-gray Gnatcatcher       BGGN       5 May – 10 Aug                   DD
Thrushes to Waxwings
  Western Bluebird            WEBL        1 May – 10 Aug                  DD
  Mountain Bluebird           MOBL        5 Apr – 10 Aug                  DD
  Townsend's Solitaire        TOSO        1 Apr – 20 Aug                  DD
  Veery                       VEER        11 Jun – 5 Aug                  DD
  Swainson’s Thrush           SWTH        5 Jun – 10 Aug                  DD
  Hermit Thrush               HETH       20 May – 25 Aug                  DD
  American Robin              AMRO       20 Mar – 25 Aug                  DD
  Gray Catbird                GRCA       15 May – 10 Aug                  DD
  European Starling           EUST         1 Mar – 1 Aug                 T, DD
  American Pipit              AMPI       10 Jun – 20 Aug                  DD
  Cedar Waxwing               CEDW        15 Jun – 15 Sep                T, DD
Wood Warblers
  Virginia's Warbler          VIWA       25 May – 15 Aug
  Yellow Warbler              YWAR        5 May – 15 Aug
  Yellow-rumped Warbler       YRWA       15 May – 15 Aug
  American Redstart           AMRE       25 May – 10 Aug
  Ovenbird                    OVEN        15 May – 5 Aug
  MacGillivray's Warbler      MGWA        25 May – 5 Aug
  Common Yellowthroat         COYE       15 May – 20 Aug                  DD
  Wilson's Warbler            WIWA       20 May – 25 Aug

Family/Species                    AOU code         Breeding season   Evidence codes to avoid1
  Yellow-breasted Chat             YBCH            20 May – 25 Jul
  Western Tanager                  WATA        15 May – 10 Aug                 DD
  Green-tailed Towhee              GTTO         1 May – 20 Aug
  Spotted Towhee                   SPTO         5 May – 25 Aug
  Chipping Sparrow                 CHSP         1 May – 20 Aug
  Vesper Sparrow                   VESP        11 May – 10 Aug
  Lark Sparrow                     LASP        15 Apr – 15 Aug
  Savannah Sparrow                 SAVS         20 May – 5 Aug
  Fox Sparrow                      FOSP          5 May – 5 Aug
  Song Sparrow                     SOSP        11 May – 15 Aug
  Lincoln's Sparrow                LISP        25 May – 20 Aug
  White-crowned Sparrow            WCSP        15 May – 20 Aug
  Dark-eyed Junco (Gray-
  headed)                           GHJU           5 May – 20 Aug
Cardinals to House Sparrow
  Black-headed Grosbeak            BHGR        15 May – 25 Aug                 DD
  Lazuli Bunting                   LABU         5 May – 15 Aug                 DD
  Indigo Bunting                   INBU        5 May – 15 Aug                  DD
  Red-winged Blackbird             RWBL        11 Apr – 20 Aug
  Western Meadowlark               WEME        15 Apr – 10 Aug
  Yellow-headed Blackbird          YHBL         15 Apr – 5 Aug
  Brewer's Blackbird               BRBL        25 Apr – 20 Aug
  Common Grackle                   COGR         10 Apr – 31 Jul                 T
                                                                        A, P, N, NB, DD,
    Brown-headed Cowbird              BHCO     25 Apr – 20 Aug             ON, CF, FF
    Bullock's Oriole                  BUOR       5 May – 25 Jul                DD
    Brown-capped Rosy-Finch           BCRF     10 Jun – 20 Aug                 DD
    Pine Grosbeak                     PIGR      5 May – 10 Aug                 DD
    Cassin's Finch                    CAFI     10 Apr – 20 Aug                 DD
    House Finch                       HOFI      5 Mar – 15 Aug                 DD
    Red Crossbill                     RECR       1 Jan – 31 Dec                DD
    Evening Grosbeak                  EVGR     20 May – 31 Aug                T, DD
    Pine Siskin                        PISI    25 Apr – 20 Aug                 DD
    Lesser Goldfinch                  LEGO      1 Jun – 31 Aug                 DD
    American Goldfinch               AMGO       25 May – 5 Sep                 DD
    House Sparrow                     HOSP      1 Apr – 25 Aug                T, DD
  See Table 4 for breeding evidence codes.

Table 4. Codes and descriptions for levels of breeding evidence for the Bear Creek Atlas.

General level of evidence
     code      breeding behavior description
Observed (OB)
       O       Migrants, species beyond normal breeding range, or in unlikely breeding habitat, species flying
               over, or those that exhibit no breeding behaviors
Possible Breeders (PO)
       H       Species found or breeding calls heard
       X       Singing male; less than 7 different males
Probable Breeders (PR)
               Multiple males: 7 different singing males heard in one day; this code is meant for song birds
      M        (passerines); don’t use it for birds that don’t sing to proclaim territory (ducks, geese, pheasants,
               grouse, quail, grebes, pelicans, raptors, shorebirds, gulls, terns, swifts, hummingbirds, kingfishers,
       P       Pair: male and female observed in behavior suggesting a pair, not just a male and a female present
               together (except grouse)

       T       Territorial behavior: defense of a territory, chasing other birds, or singing in same location on
               occasions at least a week apart; singing male(s) responding directly to other singing male(s)
       C       Courtship behavior: displaying, exchanging food, copulating; be aware that ducks court while
       A       Agitated behavior or anxiety calls of adult, indicating nest site or young in vicinity. Don’t include
               if the behavior resulted from your “pishing” or playing recorded calls.
       V       Visiting a probable nest site frequently, but showing no confirmed nesting behaviors
       N     Nest building, by Bald Eagles; House and Marsh Wrens may build “dummy” nests; woodpeckers
             dig cavities and nests, so use this code for all of them, but not NB below
Confirmed Breeders (CO)
     NB      Nest building: use for Canyon and Rock Wrens, which do not build dummy nests; and for all other
             species carrying nesting material to a suitable location
     DD      Distraction display, or pretending an injury, and leading you or predators away from a possible
             nest site
     ON      Occupied nest: bird sitting on nest, or flying in and out of a likely nest site that you cannot see into
      NE       Nest with eggs: you see eggs in a nest (otherwise ON); for cowbirds, count them and the host
               species if you find eggs
               Carrying food to a suitable nesting site: you do not see the nestlings or fledglings. Caution:
      CF       raptors, corvids, shrikes, jays, chickadees and nuthatches may carry food some distance before
               eating or caching
      NY       Nest with young: you do see the nestling in the nest, or hear the nestling begging even if you can’t
               locate the nest
      FF       Feeding fledgling: you see an adult feeding a recently fledged bird (one not yet capable of
               sustained flight)
      FL       Fledged recently: you see a young bird incapable of sustained flight (be sure it is not a juvenile
               that may have flown in from a distant location)
      FS       Adult carrying away a fecal sac; they don’t usually fly very far, so this behavior can help locate a
      UN       Used nest, or egg shells (if you can reliably link the nest or eggs to a species)

Table 5. Habitat descriptions and codes for the Bear Creek Atlas.

 Grasslands (dominated by grass and low shrubs)
    TSG – shortgrass prairie (grasses, low shrubs, some yucca)
    TTG - taller grassland in low-elevation areas
    TMG – montane meadow (grasses, some low shrubs)
    TAL - alpine tundra (meadows, grasses, forbs above timberline)
 Shrublands (woody plants <20' in height, trees <10%)
    SOS - Oak Scrub (oak brush, tree-like oak woodlands)
    SMM – montane shrubland (mountain mahogany, snowberry, serviceberry, chokecherry)
    SLE - low-elevation shrubland (taller shrublands not defined above)
    SMC – mid-elevation carr (willow and alders often associated with water or moist ground, often
    with overstory of riparian trees)
    SBC – higher-elevation carr (willow thickets often associated with water or moist ground, usually
    lacking an overstory)
    SKR – krummholz (conifer shrubland: short or even prostrate)
    SSL-# – clear cut areas, # should indicate forest type below
    SBL-# - burned areas; # should indicate forest type below
 Woodland (<30% crown cover by trees)
    WJJ – scattered Rocky Mountain Junipers
    WPP – woodland dominated by Ponderosa Pine
 Forest (>30% crown cover by trees)
    FRD – riparian deciduous (cottonwoods boxelders)
    FRC – riparian coniferous (blue spruce, Douglas fir)
    FAM – mixed aspen-conifer forest, <50% conifer
    FAP – pure aspen, <5% conifer
    FUC – upland (montane) coniferous forest: specify type (ponderosa pine {P}, Douglas fir {D},
    lodgepole pine {L}, Engelmann spruce {E}, subalpine fir {S}, bristlecone {B} or limber pines
    AEM - emergent marshes: saturated soil with annual vegetation, such as cattail, bulrush, sedges
    ASU – submerged or floating mats of vegetation
    ASL - shoreline: open shores of streams or lakes; little vegetation
    OWL – open water: lakes and ponds
    OWS – open water: streams
 Urban and Other
    URB - residential: includes parks and industrial areas
    RRL - rural: scattered farm buildings, with/without plantings
    TSU – barren ground: plowed fields, blowouts, dunes
    MCL - cliffs (but not talus, scree, rock piles, which would be MSC)
    MBK - dirt or clay bank: natural or man made
    MSB - bridges & culverts: use this for nest location only
    MSP - power poles, transmission towers (for nests); not fence posts
    MSC - miscellaneous: anything not above; specify