Introduction to the Update to the Oregon Breeding Bird Atlas
Excerpted from Adamus, P.R. and R. Scalf. 2021. Possible Changes in Breeding Ranges of Oregon Birds, 1990s through 2019. Oregon Birds [47.1, page numbers TBD]
The following maps are intended as a partial update to the Oregon Breeding Bird Atlas, using only non-systematic data from eBird and other digital sources. The OBBA provided the first systematic statewide baseline for our state’s avifauna. Sponsored by the Oregon Birding Association (OBA, previously called Oregon Field Ornithologists), the project involved hundreds of volunteers from 1995 to 1999, and is documented with species maps elsewhere on this website.
The purpose for this update was to produce a set of species maps that depict more recent distribution of each species using the same coarse-scale hexagonal grid used by the OBBA. The OBBA used a hexagonal grid because it has the least distortion when covering a spherical surface such as the earth. Each of the 432 hexagons covering all or part of the state has an area of 250 square miles and a diameter of approximately 20 miles.
In each grid unit, we applied one of three colors:
- [Pink]: Found only during 1995–1999 OBBA (“BBA only”)
- [Tan]: Found during 1995-1999 OBBA and again during a 2000-2019 breeding season (“Replicated”)
- [Green]: Found only during a 2000-2019 breeding season (“New”)
- [Blank]: No reports of presence during the normal breeding period of the species
Where evidence of confirmed breeding was reported, we applied these codes:
- A: Breeding confirmed during 1995-1999 OBBA
- N: Breeding confirmed during a 2000-2019 breeding season
- AN: Breeding confirmed at least once during both periods
Also, we used the letter Q to denote records in which habitat suitable for the species is unlikely to exist in the hexagon and the hexagon is believed to be outside of the species’ normal Oregon breeding range. It is not possible to tell if these occurrences represent vagrants, early or late migrants, non-breeding individuals, or individuals pioneering new territory. Note that while the OBBA assigned various breeding behaviors to one of three levels (possible, probable, or confirmed), data indicating probable breeding could not be parsed from possible breeding in the data used in this analysis and so are represented simply by the absence of any letter code in the grid unit.
Data Sources
The largest source of post-OBBA digital data was eBird. We obtained all reports from Oregon spanning the period of January 2000 through December 2019 that eBird classifies as “vetted.” The download included all records from the Oregon 2020 Project (Robinson 2020). Extensive digital records were also obtained from 1) the Avian Knowledge Network (AKN), which archives many surveys of birds by government agencies; 2) the Point Observation Database (PODS) database maintained by the Oregon Institute for Natural Resources; and (3) the Central Oregon Bird Database compiled by Chuck Gates. In addition, we manually searched all issues of Oregon Birds from 2000 to 2019 for reports of confirmed breeding but not for reports during the breeding season that did not mention breeding.
Nonetheless, we could not include all relevant data sources. Digital data from major sources such as BirdNotes, the North American Breeding Bird Survey (BBS), and the OBOL and COBOL listservs were not included. In some cases that was due to the locational uncertainty of much of those data. We did not include non-digital sources such as Audubon chapter newsletters and notes kept by individual birders due to the considerable effort required to extract and digitize that information.
Methods
To allow comparison with the original OBBA data, a geographic information system (GIS) was used to determine the hexagon associated with the geographic coordinates of each downloaded record. It is known that coordinates of some records had been inaccurately recorded, but it is assumed this proportion is small enough relative to the scale of this analysis to not significantly affect the overall purpose of this analysis. For eBird data, reports of “traveling counts” longer than 15 kilometers (the length of one of an OBBA hexagon’s six sides) were excluded from the analysis due to their potential to span multiple hexagons. Where a record from a non-eBird data source lacked coordinates but contained a named location, searching the location in Google Earth with the hexagon grid overlay in place in most instances allowed its hexagon number to be assigned with confidence. Some popular eBird locations had thousands of records. To avoid overwhelming database and GIS software, each unique set of coordinates was found and assigned an identifier. All unique coordinates were then overlaid with the atlas grid and linked back to the millions of eBird records using a one-to-many database relate.
Like other breeding bird atlases, the OBBA volunteers categorized each breeding season observation as either a) confirmed breeding, b) probable breeding, or c) possible breeding. Standardized criteria for these are described in Smith (1991) and in eBird metadata. However, for the comparison described herein, we categorized records simply as “confirmed breeding” or “all other reports from a species’ usual breeding season in Oregon.” To identify confirmed breeding, we selected reports noting strong evidence of breeding (in the eBird download they were coded C4, or coded C3 with a nest reported) as well as records in which the Comments for that record contained these keywords: nest*, fledg*, baby, babies, young*. We then reviewed keyword-selected records individually and placed the ones wrongly selected by the automated search in the “all others” category. Those records were mapped but no breeding was denoted by application of our “N” code. A surprising proportion of eBird records document breeding in the Comments section without also applying the relevant breeding code.
We excluded records if 1) the observation was far outside of a species’ known range and habitat suitable for the species is unlikely to exist at those locations, or 2) the observation date did not fall within the species’ known breeding period in Oregon (Adamus 2020; Marshall et al. 2003) unless a nest or other strong evidence of breeding was reported. For both 1 and 2, some judgment calls were necessary. These were based on the author’s years of experience birding in all Oregon counties and were complemented by that of two individuals of similar experience (Paul Sullivan and Craig Miller) as well as by Joel Geier who commented specifically on records from Wheeler County and for Willamette Valley prairie species. These individuals reviewed the maps and recommended, for mapping purposes, the exclusion or qualification (by using the Q code) of a small number of records that they believed were likely to represent misidentifications, vagrants, or transient migrants rather than likely breeders. None of the original OBBA records depicted in the maps were second-guessed at this time because they had been reviewed and edited by regional bird experts prior to publication of the OBBA.
Another, albeit smaller, source of error is the misapplication of breeding codes by eBird users. For example, one Tufted Duck report from Oregon contained a FL code (for fledgling), indicating a likely misunderstanding of that code, given the fact that the known breeding range for the species is thousands of miles from Oregon. We attempted to flag such reports and exclude them unless a detailed and credible explanation had been provided.
Acknowledgments
We thank John Alexander and Ellie Armstrong (Klamath Bird Observatory) for facilitating access to selected data in their Avian Knowledge Network; Elizabeth Gaines (Oregon Biodiversity Information Center) for sharing data from their PODS database; and Chuck Gates (East Cascades Audubon Society) for sharing the database of central Oregon bird observations. For the eBird data, we thank the Cornell Laboratory of Ornithology and all the birders who contribute their observations to it.
Literature Cited
- Adamus, P.R. 2020. A compilation of breeding dates for Oregon species. Oregon Birds 46(2):101–108.
- Adamus, P.R., K. Larsen, G. Gillson, and C.R. Miller. 2001. Oregon Breeding Bird Atlas. Oregon Field Ornithologists, P.O. Box 10373, Eugene, OR 97440. Available at: https://oregonbirding.org/wp-content/uploads/2020/bbs/
- eBird Basic Dataset. Version: EBD_relJan2020. Cornell Lab of Ornithology, Ithaca, New York. January 2020.
- Marshall, D.B., M.G. Hunter, and A. Contreras. 2003. Birds of Oregon: a general reference. Corvallis, Oregon: Oregon State University Press.
- Smith, C. 1991. Handbook for Atlasing North American Breeding Birds. North American Ornithological Atlas Committee. Available at: https://www.bsc-eoc.org/norac/index.jsp?targetpg=atlascont
Maps in Alphabetical Order
Maps in Phylogenetic Order
- Loons and Grebes
- Storm-Petrels
- Pelicans
- Cormorants
- Wading Birds
- Hawks and Vultures
- Ducks, Geese, and Swans
- Falcons
- Upland Game Birds
- Rails, Coots, and Cranes
- Shorebirds
- Gulls
- Terns
- Alcids
- Pigeons and Doves
- Parrots
- Owls
- Nightjars
- Swifts
- Hummingbirds
- Kingfishers
- Woodpeckers
- Flycatchers
- Shrikes
- Vireos
- Crows and Jays
- Larks
- Swallows
- Gnatcatchers, Kinglets, and Others
- Cardinals
- Chickadees and Allies
- Nuthatches and Creeper
- Wrens
- Thrushes
- Mockingbirds, Thrashers, Starlings, and Pipits
- Waxwings
- Warblers
- Sparrows
- Orioles and Blackbirds
- Finches and Allies
- Cuckoos
Table 1. Number of hexagons in which species was found only during 1995–1999 OBBA (“BBA only”), found only during a 2000-2019 breeding season (“New”), and found during 1995-1999 OBBA and again during a 2000-2019 breeding season (“Replicated”)
Table 2. Average abundance index from Oregon BBS routes during the 5 BBA years compared to BBS routes during a more recent 5 year period. Sorted from smallest to largest ratio, potentially suggesting the greatest to least declines. Number and location of BBS routes varies somewhat annually with unknown influence on trends analysis.
Table 1
Number of hexagons in which species was found only during 1995–1999 OBBA (“BBA only”), found only during a 2000-2019 breeding season (“New”), and found during 1995-1999 OBBA and again during a 2000-2019 breeding season (“Replicated”)
Species | BBA only | New | Replicated | Total |
Acorn Woodpecker | 4 | 33 | 48 | 85 |
Allen’s Hummingbird | 9 | 4 | 10 | 23 |
American Avocet | 20 | 60 | 83 | 163 |
American Bittern | 20 | 61 | 52 | 133 |
American Coot | 29 | 83 | 195 | 307 |
American Crow | 15 | 74 | 299 | 388 |
American Dipper | 37 | 66 | 152 | 255 |
American Goldfinch | 29 | 76 | 268 | 373 |
American Kestrel | 31 | 32 | 354 | 417 |
American Pipit | 5 | 8 | 4 | 17 |
American Redstart | 5 | 5 | 1 | 11 |
American Robin | 26 | 7 | 397 | 430 |
American Three-toed Woodpecker | 19 | 28 | 28 | 75 |
American White Pelican | 9 | 95 | 44 | 148 |
American Wigeon | 42 | 71 | 93 | 206 |
Anna’s Hummingbird | 7 | 108 | 70 | 185 |
Ash-throated Flycatcher | 36 | 67 | 108 | 211 |
Bald Eagle | 9 | 128 | 221 | 358 |
Band-tailed Pigeon | 1 | 42 | 122 | 165 |
Bank Swallow | 26 | 112 | 116 | 254 |
Barn Owl | 56 | 70 | 109 | 235 |
Barn Swallow | 25 | 30 | 352 | 407 |
Barred Owl | 25 | 60 | 93 | 178 |
Barrow’s Goldeneye | 5 | 22 | 25 | 52 |
Belted Kingfisher | 62 | 29 | 283 | 374 |
Bewick’s Wren | 7 | 96 | 136 | 239 |
Black Oystercatcher | 1 | 4 | 19 | 24 |
Black Phoebe | 0 | 89 | 22 | 111 |
Black Rosy-Finch | 0 | 2 | 1 | 3 |
Black Swift | 9 | 14 | 2 | 25 |
Black Tern | 8 | 52 | 40 | 100 |
Black-backed Woodpecker | 21 | 40 | 90 | 151 |
Black-billed Magpie | 18 | 40 | 222 | 280 |
Black-capped Chickadee | 46 | 48 | 213 | 307 |
Black-chinned Hummingbird | 29 | 100 | 49 | 178 |
Black-chinned Sparrow | 3 | 0 | 0 | 3 |
Black-crowned Night-Heron | 33 | 51 | 68 | 152 |
Black-headed Grosbeak | 29 | 45 | 300 | 374 |
Black-necked Stilt | 8 | 65 | 47 | 120 |
Black-throated Gray Warbler | 40 | 71 | 178 | 289 |
Black-throated Sparrow | 26 | 26 | 36 | 88 |
Blue Grosbeak | 1 | 0 | 0 | 1 |
Blue-gray Gnatcatcher | 7 | 63 | 23 | 93 |
Blue-winged Teal | 37 | 96 | 77 | 210 |
Bobolink | 10 | 12 | 21 | 43 |
Boreal Owl | 4 | 5 | 1 | 10 |
Brandt’s Cormorant | 4 | 3 | 19 | 26 |
Brewer’s Blackbird | 27 | 18 | 371 | 416 |
Brewer’s Sparrow | 31 | 65 | 187 | 283 |
Broad-tailed Hummingbird | 22 | 9 | 1 | 32 |
Brown Creeper | 20 | 46 | 236 | 302 |
Brown-headed Cowbird | 48 | 11 | 360 | 419 |
Bufflehead | 28 | 107 | 79 | 214 |
Bullock’s Oriole | 33 | 73 | 249 | 355 |
Burrowing Owl | 38 | 23 | 56 | 117 |
Bushtit | 24 | 98 | 187 | 309 |
California Gull | 23 | 41 | 75 | 139 |
California Quail | 53 | 40 | 301 | 394 |
California Scrub-Jay | 7 | 112 | 133 | 252 |
California Towhee | 1 | 15 | 12 | 28 |
Calliope Hummingbird | 53 | 52 | 96 | 201 |
Canada Goose | 30 | 59 | 299 | 388 |
Canada Jay | 30 | 48 | 157 | 235 |
Canvasback | 21 | 30 | 35 | 86 |
Canyon Wren | 36 | 58 | 89 | 183 |
Caspian Tern | 19 | 32 | 79 | 130 |
Cassin’s Auklet | 1 | 18 | 4 | 23 |
Cassin’s Finch | 36 | 51 | 181 | 268 |
Cassin’s Vireo | 22 | 56 | 255 | 333 |
Cattle Egret | 2 | 10 | 2 | 14 |
Cedar Waxwing | 20 | 87 | 252 | 359 |
Chestnut-backed Chickadee | 9 | 28 | 151 | 188 |
Chipping Sparrow | 52 | 38 | 294 | 384 |
Chukar | 43 | 25 | 119 | 187 |
Cinnamon Teal | 58 | 44 | 184 | 286 |
Clark’s Grebe | 10 | 91 | 35 | 136 |
Clark’s Nutcracker | 24 | 49 | 128 | 201 |
Clay-colored Sparrow | 0 | 4 | 0 | 4 |
Cliff Swallow | 34 | 28 | 346 | 408 |
Common Goldeneye | 5 | 4 | 2 | 11 |
Common Loon | 9 | 11 | 8 | 28 |
Common Merganser | 38 | 77 | 209 | 324 |
Common Murre | 1 | 3 | 21 | 25 |
Common Nighthawk | 38 | 31 | 345 | 414 |
Common Poorwill | 60 | 89 | 75 | 224 |
Common Raven | 8 | 14 | 410 | 432 |
Common Yellowthroat | 20 | 107 | 206 | 333 |
Cooper’s Hawk | 54 | 93 | 204 | 351 |
Costa’s Hummingbird | 0 | 2 | 0 | 2 |
Dark-eyed Junco | 22 | 26 | 315 | 363 |
Double-crested Cormorant | 18 | 108 | 127 | 253 |
Downy Woodpecker | 47 | 51 | 240 | 338 |
Dusky Flycatcher | 45 | 71 | 216 | 332 |
Dusky Grouse | 19 | 17 | 40 | 76 |
Eared Grebe | 17 | 64 | 56 | 137 |
Eastern Kingbird | 30 | 64 | 89 | 183 |
Eastern Phoebe | 1 | 0 | 0 | 1 |
Eurasian Collared-Dove | 0 | 338 | 0 | 338 |
European Starling | 24 | 34 | 350 | 408 |
Evening Grosbeak | 52 | 48 | 171 | 271 |
Ferruginous Hawk | 33 | 62 | 85 | 180 |
Flammulated Owl | 47 | 38 | 37 | 122 |
Fork-tailed Storm-Petrel | 3 | 0 | 3 | 6 |
Forster’s Tern | 11 | 52 | 49 | 112 |
Fox Sparrow | 43 | 55 | 107 | 205 |
Franklin’s Gull | 3 | 35 | 15 | 53 |
Gadwall | 36 | 93 | 133 | 262 |
Glaucous-winged Gull | 1 | 24 | 19 | 44 |
Golden Eagle | 57 | 45 | 238 | 340 |
Golden-crowned Kinglet | 23 | 41 | 234 | 298 |
Golden-crowned Sparrow | 2 | 3 | 1 | 6 |
Grasshopper Sparrow | 19 | 54 | 31 | 104 |
Gray Catbird | 19 | 52 | 19 | 90 |
Gray Flycatcher | 30 | 58 | 144 | 232 |
Gray Partridge | 22 | 26 | 45 | 93 |
Gray-crowned Rosy-Finch | 1 | 9 | 7 | 17 |
Great Blue Heron | 34 | 63 | 262 | 359 |
Great Egret | 6 | 159 | 61 | 226 |
Great Gray Owl | 73 | 8 | 7 | 88 |
Great Horned Owl | 70 | 44 | 287 | 401 |
Greater Sage-Grouse | 83 | 11 | 33 | 127 |
Greater Scaup | 2 | 0 | 0 | 2 |
Greater Yellowlegs | 2 | 1 | 0 | 3 |
Great-tailed Grackle | 0 | 25 | 3 | 28 |
Green Heron | 13 | 50 | 81 | 144 |
Green-tailed Towhee | 45 | 60 | 119 | 224 |
Green-winged Teal | 67 | 80 | 155 | 302 |
Hairy Woodpecker | 11 | 27 | 301 | 339 |
Hammond’s Flycatcher | 10 | 82 | 197 | 289 |
Harlequin Duck | 10 | 22 | 10 | 42 |
Hermit Thrush | 25 | 58 | 227 | 310 |
Hermit Warbler | 7 | 30 | 146 | 183 |
Hooded Merganser | 26 | 83 | 80 | 189 |
Horned Grebe | 10 | 35 | 10 | 55 |
Horned Lark | 26 | 45 | 215 | 286 |
House Finch | 45 | 60 | 288 | 393 |
House Sparrow | 27 | 57 | 250 | 334 |
House Wren | 41 | 34 | 319 | 394 |
Hutton’s Vireo | 4 | 19 | 122 | 145 |
Indigo Bunting | 0 | 15 | 1 | 16 |
Juniper Titmouse | 1 | 17 | 1 | 19 |
Killdeer | 45 | 23 | 344 | 412 |
Lark Bunting | 0 | 1 | 0 | 1 |
Lark Sparrow | 22 | 93 | 164 | 279 |
Lawrence’s Goldfinch | 0 | 1 | 0 | 1 |
Lazuli Bunting | 33 | 90 | 264 | 387 |
Leach’s Storm-Petrel | 5 | 1 | 2 | 8 |
Least Bittern | 1 | 0 | 0 | 1 |
Least Flycatcher | 8 | 27 | 2 | 37 |
Lesser Goldfinch | 8 | 169 | 95 | 272 |
Lesser Scaup | 35 | 49 | 84 | 168 |
Lewis’s Woodpecker | 36 | 87 | 95 | 218 |
Lincoln’s Sparrow | 17 | 116 | 99 | 232 |
Loggerhead Shrike | 26 | 54 | 151 | 231 |
Long-billed Curlew | 21 | 63 | 114 | 198 |
Long-eared Owl | 69 | 63 | 38 | 170 |
MacGillivray’s Warbler | 38 | 50 | 249 | 337 |
Mallard | 35 | 24 | 363 | 422 |
Marbled Murrelet | 12 | 8 | 27 | 47 |
Marsh Wren | 20 | 86 | 118 | 224 |
Merlin | 27 | 25 | 3 | 55 |
Monk Parakeet | 1 | 2 | 1 | 4 |
Mountain Bluebird | 32 | 36 | 217 | 285 |
Mountain Chickadee | 29 | 39 | 200 | 268 |
Mountain Quail | 42 | 55 | 148 | 245 |
Mourning Dove | 28 | 30 | 365 | 423 |
Mute Swan | 0 | 7 | 1 | 8 |
Nashville Warbler | 37 | 73 | 116 | 226 |
Northern Bobwhite | 9 | 5 | 0 | 14 |
Northern Flicker | 32 | 3 | 385 | 420 |
Northern Goshawk | 65 | 59 | 112 | 236 |
Northern Harrier | 32 | 54 | 266 | 352 |
Northern Mockingbird | 8 | 67 | 9 | 84 |
Northern Pintail | 45 | 68 | 91 | 204 |
Northern Pygmy-Owl | 63 | 28 | 185 | 276 |
Northern Rough-winged Swallow | 37 | 58 | 282 | 377 |
Northern Saw-whet Owl | 81 | 64 | 75 | 220 |
Northern Shoveler | 27 | 100 | 122 | 249 |
Northern Waterthrush | 5 | 12 | 5 | 22 |
Oak Titmouse | 6 | 6 | 16 | 28 |
Olive-sided Flycatcher | 24 | 62 | 229 | 315 |
Orange-crowned Warbler | 36 | 72 | 250 | 358 |
Osprey | 27 | 76 | 250 | 353 |
Pacific Wren | 22 | 48 | 190 | 260 |
Pacific-slope Flycatcher | 28 | 34 | 256 | 318 |
Pelagic Cormorant | 1 | 3 | 21 | 25 |
Peregrine Falcon | 34 | 152 | 75 | 261 |
Pied-billed Grebe | 21 | 98 | 126 | 245 |
Pigeon Guillemot | 1 | 2 | 22 | 25 |
Pileated Woodpecker | 22 | 26 | 235 | 283 |
Pine Grosbeak | 4 | 19 | 2 | 25 |
Pine Siskin | 32 | 65 | 260 | 357 |
Pinyon Jay | 8 | 20 | 23 | 51 |
Plumbeous Vireo | 3 | 1 | 1 | 5 |
Prairie Falcon | 59 | 43 | 177 | 279 |
Purple Finch | 35 | 55 | 155 | 245 |
Purple Martin | 3 | 53 | 57 | 113 |
Pygmy Nuthatch | 23 | 48 | 99 | 170 |
Red Crossbill | 31 | 54 | 225 | 310 |
Red-breasted Nuthatch | 14 | 43 | 287 | 344 |
Red-breasted Sapsucker | 9 | 52 | 161 | 222 |
Red-eyed Vireo | 18 | 47 | 21 | 86 |
Redhead | 28 | 58 | 69 | 155 |
Red-naped Sapsucker | 55 | 39 | 93 | 187 |
Red-necked Grebe | 2 | 17 | 2 | 21 |
Red-shouldered Hawk | 2 | 137 | 29 | 168 |
Red-tailed Hawk | 24 | 9 | 400 | 433 |
Red-winged Blackbird | 30 | 21 | 353 | 404 |
Rhinoceros Auklet | 0 | 10 | 14 | 24 |
Ring-billed Gull | 20 | 105 | 87 | 212 |
Ring-necked Duck | 28 | 90 | 104 | 222 |
Ring-necked Pheasant | 43 | 40 | 157 | 240 |
Rock Pigeon | 26 | 84 | 207 | 317 |
Rock Wren | 34 | 70 | 249 | 353 |
Rose-breasted Grosbeak | 0 | 25 | 0 | 25 |
Ruby-crowned Kinglet | 57 | 53 | 103 | 213 |
Ruddy Duck | 25 | 74 | 80 | 179 |
Ruffed Grouse | 33 | 41 | 182 | 256 |
Rufous Hummingbird | 31 | 51 | 256 | 338 |
Sage Thrasher | 27 | 47 | 145 | 219 |
Sagebrush Sparrow | 36 | 25 | 86 | 147 |
Sandhill Crane | 23 | 56 | 112 | 191 |
Savannah Sparrow | 46 | 67 | 250 | 363 |
Say’s Phoebe | 30 | 91 | 174 | 295 |
Semipalmated Plover | 2 | 9 | 1 | 12 |
Sharp-shinned Hawk | 48 | 98 | 186 | 332 |
Sharp-tailed Grouse | 0 | 0 | 1 | 1 |
Short-eared Owl | 43 | 45 | 59 | 147 |
Snowy Egret | 6 | 27 | 14 | 47 |
Snowy Plover | 3 | 17 | 16 | 36 |
Solitary Sandpiper | 3 | 3 | 0 | 6 |
Song Sparrow | 24 | 22 | 363 | 409 |
Sooty Grouse | 19 | 27 | 119 | 165 |
Sora | 47 | 65 | 117 | 229 |
Spotted Owl | 121 | 3 | 1 | 125 |
Spotted Sandpiper | 49 | 56 | 283 | 388 |
Spotted Towhee | 28 | 51 | 301 | 380 |
Spruce Grouse | 3 | 2 | 6 | 11 |
Steller’s Jay | 12 | 33 | 290 | 335 |
Swainson’s Hawk | 24 | 93 | 130 | 247 |
Swainson’s Thrush | 12 | 61 | 215 | 288 |
Townsend’s Solitaire | 38 | 51 | 202 | 291 |
Townsend’s Warbler | 22 | 97 | 124 | 243 |
Tree Swallow | 19 | 55 | 316 | 390 |
Tricolored Blackbird | 6 | 46 | 14 | 66 |
Trumpeter Swan | 13 | 35 | 9 | 57 |
Tufted Puffin | 2 | 8 | 14 | 24 |
Turkey Vulture | 20 | 24 | 383 | 427 |
Upland Sandpiper | 5 | 0 | 2 | 7 |
Varied Thrush | 33 | 45 | 137 | 215 |
Vaux’s Swift | 19 | 79 | 228 | 326 |
Veery | 11 | 17 | 21 | 49 |
Vesper Sparrow | 31 | 46 | 254 | 331 |
Violet-green Swallow | 41 | 36 | 335 | 412 |
Virginia Rail | 36 | 96 | 111 | 243 |
Virginia’s Warbler | 5 | 2 | 0 | 7 |
Warbling Vireo | 35 | 59 | 288 | 382 |
Western Bluebird | 34 | 74 | 228 | 336 |
Western Grebe | 10 | 72 | 70 | 152 |
Western Gull | 1 | 0 | 25 | 26 |
Western Kingbird | 29 | 66 | 261 | 356 |
Western Meadowlark | 20 | 43 | 309 | 372 |
Western Screech-Owl | 70 | 71 | 136 | 277 |
Western Tanager | 17 | 51 | 320 | 388 |
Western Wood-Pewee | 19 | 39 | 339 | 397 |
White-breasted Nuthatch | 22 | 54 | 188 | 264 |
White-crowned Sparrow | 26 | 120 | 210 | 356 |
White-faced Ibis | 8 | 65 | 42 | 115 |
White-headed Woodpecker | 25 | 33 | 90 | 148 |
White-tailed Kite | 7 | 26 | 25 | 58 |
White-throated Swift | 16 | 67 | 41 | 124 |
White-winged Crossbill | 8 | 6 | 3 | 17 |
Wild Turkey | 13 | 139 | 92 | 244 |
Willet | 8 | 52 | 67 | 127 |
Williamson’s Sapsucker | 15 | 26 | 122 | 163 |
Willow Flycatcher | 43 | 97 | 196 | 336 |
Wilson’s Phalarope | 46 | 68 | 107 | 221 |
Wilson’s Snipe | 36 | 59 | 216 | 311 |
Wilson’s Warbler | 31 | 74 | 233 | 338 |
Wood Duck | 46 | 69 | 164 | 279 |
Wrentit | 4 | 36 | 80 | 120 |
Yellow Rail | 4 | 6 | 4 | 14 |
Yellow Warbler | 30 | 57 | 302 | 389 |
Yellow-billed Cuckoo | 1 | 6 | 0 | 7 |
Yellow-breasted Chat | 28 | 102 | 153 | 283 |
Yellow-headed Blackbird | 31 | 61 | 138 | 230 |
Yellow-rumped Warbler | 20 | 41 | 288 | 349 |
Table 2
Average abundance index from Oregon BBS routes during the 5 BBA years compared to BBS routes during a more recent 5 year period. Sorted from smallest to largest ratio, potentially suggesting the greatest to least declines. Number and location of BBS routes varies somewhat annually with unknown influence on trends analysis.
Species | 1995-1999 mean | 2013-2017 mean | Change | Ratio |
Black Tern | 1.40 | 0.34 | -1.06 | 0.24 |
Evening Grosbeak | 2.20 | 0.69 | -1.51 | 0.31 |
Pine Siskin | 3.80 | 1.25 | -2.54 | 0.33 |
Western Gull | 17.80 | 6.92 | -10.88 | 0.39 |
California Gull | 2.79 | 1.12 | -1.66 | 0.40 |
Glaucous-winged Gull | 0.99 | 0.42 | -0.57 | 0.42 |
Green Heron | 0.13 | 0.06 | -0.08 | 0.44 |
Cinnamon Teal | 1.01 | 0.45 | -0.57 | 0.44 |
Lesser Scaup | 0.52 | 0.23 | -0.28 | 0.45 |
Veery | 0.05 | 0.02 | -0.02 | 0.47 |
Spotted Owl | 0.00 | 0.00 | 0.00 | 0.47 |
Forster’s Tern | 1.66 | 0.79 | -0.86 | 0.48 |
Black-crowned Night-Heron | 0.23 | 0.11 | -0.12 | 0.49 |
American Wigeon | 0.29 | 0.14 | -0.15 | 0.50 |
Northern Pintail | 0.32 | 0.16 | -0.16 | 0.50 |
Horned Lark | 20.67 | 10.42 | -10.25 | 0.50 |
Rufous Hummingbird | 1.17 | 0.60 | -0.57 | 0.51 |
Trumpeter Swan | 0.08 | 0.04 | -0.04 | 0.53 |
Golden-crowned Kinglet | 3.04 | 1.65 | -1.40 | 0.54 |
Pine Grosbeak | 0.02 | 0.01 | -0.01 | 0.55 |
American Bittern | 0.15 | 0.08 | -0.07 | 0.55 |
Vesper Sparrow | 7.12 | 3.90 | -3.22 | 0.55 |
Bushtit | 1.43 | 0.80 | -0.63 | 0.56 |
Red-eyed Vireo | 0.06 | 0.04 | -0.03 | 0.56 |
Marbled Murrelet | 0.02 | 0.01 | -0.01 | 0.57 |
Rock Wren | 4.31 | 2.51 | -1.80 | 0.58 |
Orange-crowned Warbler | 2.98 | 1.74 | -1.24 | 0.58 |
Cassin’s Finch | 6.76 | 3.97 | -2.79 | 0.59 |
Barn Swallow | 5.34 | 3.15 | -2.19 | 0.59 |
Ring-necked Pheasant | 4.82 | 2.88 | -1.94 | 0.60 |
White-crowned Sparrow | 8.71 | 5.21 | -3.50 | 0.60 |
Pinyon Jay | 0.81 | 0.49 | -0.33 | 0.60 |
House Finch | 3.87 | 2.35 | -1.52 | 0.61 |
Brown-headed Cowbird | 7.44 | 4.54 | -2.91 | 0.61 |
Savannah Sparrow | 3.16 | 1.97 | -1.20 | 0.62 |
Black-throated Gray Warbler | 2.86 | 1.80 | -1.06 | 0.63 |
American Coot | 2.06 | 1.29 | -0.76 | 0.63 |
Wilson’s Phalarope | 0.60 | 0.39 | -0.22 | 0.64 |
Yellow Warbler | 2.45 | 1.58 | -0.87 | 0.64 |
Redhead | 1.72 | 1.12 | -0.60 | 0.65 |
Chipping Sparrow | 9.44 | 6.23 | -3.21 | 0.66 |
Ruby-crowned Kinglet | 1.52 | 1.01 | -0.51 | 0.66 |
Northern Saw-whet Owl | 0.00 | 0.00 | 0.00 | 0.67 |
Snowy Egret | 0.05 | 0.03 | -0.02 | 0.67 |
Brewer’s Blackbird | 42.28 | 28.56 | -13.72 | 0.68 |
Mountain Chickadee | 12.08 | 8.22 | -3.86 | 0.68 |
Gray Partridge | 0.04 | 0.03 | -0.01 | 0.69 |
Cedar Waxwing | 1.76 | 1.22 | -0.54 | 0.69 |
Lark Sparrow | 1.49 | 1.04 | -0.46 | 0.69 |
Brewer’s Sparrow | 42.06 | 29.20 | -12.86 | 0.69 |
Western Meadowlark | 50.60 | 35.22 | -15.39 | 0.70 |
Red-naped Sapsucker | 0.17 | 0.12 | -0.05 | 0.70 |
European Starling | 19.82 | 13.88 | -5.94 | 0.70 |
Violet-green Swallow | 11.52 | 8.11 | -3.42 | 0.70 |
Spotted Sandpiper | 0.54 | 0.38 | -0.16 | 0.71 |
American Robin | 32.08 | 22.69 | -9.40 | 0.71 |
Lewis’s Woodpecker | 0.09 | 0.06 | -0.03 | 0.71 |
Grasshopper Sparrow | 0.07 | 0.05 | -0.02 | 0.71 |
Sage Thrasher | 42.80 | 30.99 | -11.81 | 0.72 |
Olive-sided Flycatcher | 2.67 | 1.94 | -0.73 | 0.73 |
Bufflehead | 0.16 | 0.12 | -0.04 | 0.74 |
Ring-billed Gull | 9.32 | 6.96 | -2.36 | 0.75 |
Sora | 0.19 | 0.14 | -0.05 | 0.75 |
Red-winged Blackbird | 13.70 | 10.28 | -3.42 | 0.75 |
Song Sparrow | 8.54 | 6.43 | -2.11 | 0.75 |
Greater Sage-Grouse | 0.26 | 0.20 | -0.06 | 0.76 |
Killdeer | 2.74 | 2.08 | -0.66 | 0.76 |
Short-eared Owl | 0.17 | 0.13 | -0.04 | 0.76 |
Eared Grebe | 1.82 | 1.40 | -0.43 | 0.77 |
Northern Rough-winged Swallow | 1.17 | 0.90 | -0.27 | 0.77 |
MacGillivray’s Warbler | 4.43 | 3.42 | -1.01 | 0.77 |
American Goldfinch | 2.97 | 2.30 | -0.67 | 0.77 |
Williamson’s Sapsucker | 0.69 | 0.54 | -0.16 | 0.78 |
Belted Kingfisher | 0.25 | 0.19 | -0.05 | 0.79 |
Yellow-headed Blackbird | 8.04 | 6.34 | -1.70 | 0.79 |
Western Screech-Owl | 0.01 | 0.01 | 0.00 | 0.79 |
Wilson’s Warbler | 3.48 | 2.76 | -0.73 | 0.79 |
Calliope Hummingbird | 0.10 | 0.08 | -0.02 | 0.79 |
Bullock’s Oriole | 1.70 | 1.36 | -0.34 | 0.80 |
Red-breasted Nuthatch | 6.11 | 4.89 | -1.22 | 0.80 |
Wilson’s Snipe | 2.84 | 2.27 | -0.57 | 0.80 |
Black-capped Chickadee | 2.20 | 1.77 | -0.43 | 0.80 |
American White Pelican | 13.17 | 10.58 | -2.59 | 0.80 |
Burrowing Owl | 0.22 | 0.18 | -0.04 | 0.81 |
Willet | 1.73 | 1.41 | -0.32 | 0.81 |
Great Horned Owl | 0.19 | 0.15 | -0.04 | 0.81 |
Dusky Flycatcher | 7.25 | 5.94 | -1.31 | 0.82 |
Hermit Thrush | 7.66 | 6.31 | -1.35 | 0.82 |
Pygmy Nuthatch | 0.97 | 0.80 | -0.16 | 0.83 |
Green-tailed Towhee | 3.78 | 3.14 | -0.64 | 0.83 |
Gadwall | 1.18 | 0.98 | -0.20 | 0.83 |
House Sparrow | 5.27 | 4.39 | -0.88 | 0.83 |
Red Crossbill | 24.32 | 20.29 | -4.04 | 0.83 |
Wrentit | 5.08 | 4.24 | -0.84 | 0.83 |
Clark’s Nutcracker | 1.14 | 0.96 | -0.18 | 0.85 |
California Quail | 5.49 | 4.65 | -0.85 | 0.85 |
Blue-winged Teal | 0.05 | 0.04 | -0.01 | 0.85 |
Caspian Tern | 0.17 | 0.14 | -0.03 | 0.85 |
Pacific Wren | 3.90 | 3.32 | -0.58 | 0.85 |
American Kestrel | 1.26 | 1.08 | -0.19 | 0.85 |
Chestnut-backed Chickadee | 4.19 | 3.58 | -0.61 | 0.85 |
Long-eared Owl | 0.00 | 0.00 | 0.00 | 0.86 |
Varied Thrush | 1.81 | 1.56 | -0.24 | 0.86 |
Western Wood-Pewee | 10.73 | 9.31 | -1.42 | 0.87 |
Spotted Towhee | 11.88 | 10.33 | -1.55 | 0.87 |
Tree Swallow | 3.03 | 2.64 | -0.39 | 0.87 |
Vaux’s Swift | 1.07 | 0.94 | -0.13 | 0.88 |
Steller’s Jay | 7.85 | 6.92 | -0.93 | 0.88 |
American Avocet | 1.29 | 1.14 | -0.14 | 0.89 |
Virginia Rail | 0.03 | 0.03 | 0.00 | 0.89 |
House Wren | 2.91 | 2.59 | -0.31 | 0.89 |
Marsh Wren | 1.26 | 1.15 | -0.11 | 0.91 |
Oak Titmouse | 0.39 | 0.36 | -0.03 | 0.91 |
Mountain Quail | 0.97 | 0.89 | -0.08 | 0.92 |
Bewick’s Wren | 1.17 | 1.07 | -0.09 | 0.92 |
Nashville Warbler | 1.04 | 0.96 | -0.08 | 0.92 |
Purple Finch | 1.25 | 1.15 | -0.09 | 0.92 |
Common Yellowthroat | 1.14 | 1.06 | -0.08 | 0.93 |
Downy Woodpecker | 0.26 | 0.24 | -0.02 | 0.93 |
White-throated Swift | 0.67 | 0.63 | -0.04 | 0.95 |
Common Nighthawk | 3.13 | 2.98 | -0.15 | 0.95 |
Swainson’s Thrush | 14.71 | 14.01 | -0.70 | 0.95 |
Western Kingbird | 2.34 | 2.23 | -0.11 | 0.95 |
Ruffed Grouse | 0.07 | 0.06 | 0.00 | 0.95 |
Townsend’s Warbler | 2.90 | 2.78 | -0.12 | 0.96 |
Brown Creeper | 0.86 | 0.83 | -0.03 | 0.96 |
Mountain Bluebird | 3.34 | 3.21 | -0.13 | 0.96 |
Hermit Warbler | 14.43 | 13.89 | -0.54 | 0.96 |
Hairy Woodpecker | 1.13 | 1.10 | -0.03 | 0.97 |
Wood Duck | 0.15 | 0.14 | 0.00 | 0.97 |
American Crow | 6.72 | 6.62 | -0.10 | 0.99 |
Chukar | 3.08 | 3.07 | -0.02 | 0.99 |
Cassin’s Vireo | 1.34 | 1.34 | 0.00 | 1.00 |
Cliff Swallow | 137.65 | 137.16 | -0.50 | 1.00 |
Bank Swallow | 4.22 | 4.26 | 0.03 | 1.01 |
Black-headed Grosbeak | 9.75 | 9.89 | 0.13 | 1.01 |
Northern Goshawk | 0.02 | 0.02 | 0.00 | 1.02 |
Hutton’s Vireo | 1.35 | 1.37 | 0.02 | 1.02 |
Mourning Dove | 6.14 | 6.24 | 0.11 | 1.02 |
American Dipper | 0.05 | 0.05 | 0.00 | 1.02 |
Gray Jay | 0.61 | 0.62 | 0.02 | 1.03 |
Warbling Vireo | 4.49 | 4.65 | 0.16 | 1.03 |
Bobolink | 0.11 | 0.11 | 0.00 | 1.04 |
Pied-billed Grebe | 0.29 | 0.30 | 0.01 | 1.05 |
Green-winged Teal | 0.09 | 0.10 | 0.00 | 1.05 |
Northern Harrier | 0.45 | 0.47 | 0.02 | 1.05 |
Canvasback | 0.22 | 0.23 | 0.01 | 1.05 |
California Towhee | 0.17 | 0.18 | 0.01 | 1.06 |
Eastern Kingbird | 0.18 | 0.19 | 0.01 | 1.07 |
Yellow-breasted Chat | 0.79 | 0.84 | 0.06 | 1.08 |
Golden Eagle | 0.32 | 0.34 | 0.03 | 1.08 |
Common Merganser | 0.20 | 0.22 | 0.02 | 1.11 |
Lazuli Bunting | 4.03 | 4.47 | 0.44 | 1.11 |
Band-tailed Pigeon | 3.06 | 3.41 | 0.34 | 1.11 |
Black-throated Sparrow | 0.52 | 0.58 | 0.07 | 1.13 |
Juniper Titmouse | 0.02 | 0.02 | 0.00 | 1.14 |
Blue-gray Gnatcatcher | 0.02 | 0.02 | 0.00 | 1.15 |
Say’s Phoebe | 0.65 | 0.76 | 0.10 | 1.16 |
White-tailed Kite | 0.00 | 0.00 | 0.00 | 1.16 |
Tricolored Blackbird | 1926.64 | 2242.38 | 315.74 | 1.16 |
Fox Sparrow | 0.72 | 0.83 | 0.12 | 1.17 |
Black-billed Magpie | 7.56 | 8.88 | 1.32 | 1.17 |
Northern Shoveler | 0.22 | 0.26 | 0.04 | 1.18 |
Western Tanager | 17.12 | 20.30 | 3.19 | 1.19 |
Double-crested Cormorant | 1.26 | 1.50 | 0.24 | 1.19 |
White-headed Woodpecker | 0.20 | 0.24 | 0.04 | 1.20 |
Hammond’s Flycatcher | 3.50 | 4.19 | 0.68 | 1.20 |
White-breasted Nuthatch | 0.55 | 0.66 | 0.11 | 1.20 |
Sharp-shinned Hawk | 0.02 | 0.03 | 0.00 | 1.20 |
Great Egret | 0.84 | 1.01 | 0.18 | 1.21 |
Gray Flycatcher | 7.61 | 9.51 | 1.90 | 1.25 |
Rock Pigeon | 1.71 | 2.14 | 0.43 | 1.25 |
Canyon Wren | 0.10 | 0.12 | 0.03 | 1.26 |
Swainson’s Hawk | 0.27 | 0.34 | 0.07 | 1.26 |
Sandhill Crane | 2.76 | 3.51 | 0.75 | 1.27 |
Common Poorwill | 0.08 | 0.10 | 0.02 | 1.27 |
American Three-toed Woodpecker | 0.02 | 0.03 | 0.01 | 1.27 |
Lincoln’s Sparrow | 0.23 | 0.30 | 0.07 | 1.29 |
Western Bluebird | 0.50 | 0.64 | 0.15 | 1.29 |
Northern Mockingbird | 0.00 | 0.00 | 0.00 | 1.30 |
Northern Pygmy-Owl | 0.04 | 0.06 | 0.01 | 1.32 |
Pileated Woodpecker | 0.54 | 0.71 | 0.17 | 1.32 |
Ash-throated Flycatcher | 0.92 | 1.26 | 0.34 | 1.37 |
Lesser Goldfinch | 0.81 | 1.11 | 0.30 | 1.37 |
Ruddy Duck | 0.36 | 0.50 | 0.14 | 1.38 |
Red-breasted Sapsucker | 0.58 | 0.81 | 0.23 | 1.39 |
Black-chinned Hummingbird | 0.02 | 0.02 | 0.01 | 1.44 |
Turkey Vulture | 1.28 | 1.88 | 0.60 | 1.47 |
Common Raven | 8.34 | 12.61 | 4.27 | 1.51 |
Pelagic Cormorant | 0.18 | 0.28 | 0.10 | 1.53 |
Black-backed Woodpecker | 0.18 | 0.28 | 0.10 | 1.55 |
Purple Martin | 0.20 | 0.32 | 0.12 | 1.58 |
Townsend’s Solitaire | 0.89 | 1.43 | 0.53 | 1.59 |
Dusky Grouse | 0.04 | 0.06 | 0.02 | 1.61 |
Sooty Grouse | 0.13 | 0.21 | 0.08 | 1.63 |
Loggerhead Shrike | 0.85 | 1.40 | 0.55 | 1.64 |
Cooper’s Hawk | 0.04 | 0.07 | 0.03 | 1.66 |
Long-billed Curlew | 4.10 | 6.89 | 2.79 | 1.68 |
Ferruginous Hawk | 0.14 | 0.24 | 0.10 | 1.69 |
Barn Owl | 0.01 | 0.01 | 0.01 | 1.69 |
Franklin’s Gull | 30.29 | 52.46 | 22.17 | 1.73 |
Prairie Falcon | 0.22 | 0.38 | 0.16 | 1.74 |
Black Phoebe | 0.08 | 0.15 | 0.07 | 1.80 |
Gray Catbird | 0.03 | 0.06 | 0.03 | 1.82 |
Hooded Merganser | 0.01 | 0.02 | 0.01 | 1.84 |
Acorn Woodpecker | 2.04 | 3.83 | 1.79 | 1.88 |
Canada Goose | 11.50 | 22.08 | 10.58 | 1.92 |
Black-necked Stilt | 0.50 | 0.97 | 0.47 | 1.94 |
Barred Owl | 0.01 | 0.03 | 0.01 | 2.01 |
Osprey | 0.27 | 0.65 | 0.38 | 2.39 |
White-faced Ibis | 141.69 | 424.36 | 282.68 | 3.00 |
Bald Eagle | 0.06 | 0.22 | 0.15 | 3.55 |
Peregrine Falcon | 0.01 | 0.03 | 0.02 | 3.70 |
Ring-necked Duck | 0.16 | 0.59 | 0.43 | 3.72 |
Red-shouldered Hawk | 0.02 | 0.12 | 0.09 | 5.16 |
Anna’s Hummingbird | 0.03 | 0.16 | 0.13 | 5.60 |
Wild Turkey | 0.07 | 0.53 | 0.46 | 7.75 |
Eurasian Collared-Dove | 0.00 | 4.37 | 4.37 | 2064.81 |