Buteo swainsoni - Bonaparte, 1838
Swainson's Hawk
Other Common Names: Gavião-Papa-Gafanhoto
Taxonomic Status: Accepted
Related ITIS Name(s): Buteo swainsoni Bonaparte, 1838 (TSN 175367)
French Common Names: buse de Swainson
Spanish Common Names: Aguililla de Swainson, Aguilucho Langostero
Unique Identifier: ELEMENT_GLOBAL.2.105571
Element Code: ABNKC19070
Informal Taxonomy: Animals, Vertebrates - Birds - Other Birds
Image 10667

© Dick Cannings

 
Kingdom Phylum Class Order Family Genus
Animalia Craniata Aves Accipitriformes Accipitridae Buteo
Genus Size: D - Medium to large genus (21+ species)
Check this box to expand all report sections:
Concept Reference
Help
Concept Reference: American Ornithologists' Union (AOU). 1998. Check-list of North American birds. Seventh edition. American Ornithologists' Union, Washington, D.C. [as modified by subsequent supplements and corrections published in The Auk]. Also available online: http://www.aou.org/.
Concept Reference Code: B98AOU01NAUS
Name Used in Concept Reference: Buteo swainsoni
Conservation Status
Help

NatureServe Status

Global Status: G5
Global Status Last Reviewed: 06Apr2016
Global Status Last Changed: 22Nov1996
Ranking Methodology Used: Ranked by inspection
Rounded Global Status: G5 - Secure
Reasons: Large breeding range in western and central North America; winters mainly in southern South America; relatively common in some areas, but pesticide use and habitat loss in breeding and nonbreeding range have resulted in declines; recently experienced severe mortality associated with pesticide use in Argentina.
Nation: United States
National Status: N5B (19Mar1997)
Nation: Canada
National Status: N4N5B,N4N5M (08Jan2018)

U.S. & Canada State/Province Status
Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.
United States Alabama (S2N), Alaska (S2S3B), Arizona (S3), Arkansas (S1B), California (S3), Colorado (S5B), Idaho (S5B), Illinois (S1), Iowa (S3B,S3N), Kansas (S4B), Minnesota (SNRB), Missouri (S2), Montana (S4B), Navajo Nation (S1B), Nebraska (S4), Nevada (S2B), New Jersey (SNA), New Mexico (S4B,S4N), North Dakota (SU), Oklahoma (S3B), Oregon (S3B), South Dakota (S4B), Texas (S4B), Utah (S3B), Washington (S3S4B), Wyoming (S4B)
Canada Alberta (S4B), British Columbia (S2B), Manitoba (S3B), Northwest Territories (SU), Ontario (SNA), Saskatchewan (S4B), Yukon Territory (S1B)

Other Statuses

IUCN Red List Category: LC - Least concern
Convention on International Trade in Endangered Species Protection Status (CITES): Appendix II

NatureServe Global Conservation Status Factors

Range Extent: >2,500,000 square km (greater than 1,000,000 square miles)
Range Extent Comments: BREEDS: known to have bred in east-central Alaska east into Yukon Territory and extreme northwestern Mackenzie; central Alberta, central Saskatchewan, southern Manitoba, western and southern Minnesota, and western Illinois south (mainly east of Cascades and Sierra Nevada) to southern California (rarely), Baja California (formerly), Sonora, Durango, Chihuahua, central and southern Texas and western Missouri; eastern breeding limits unstable. WINTERS: according to AOU (1983), primarily on pampas of southern South America (south to Uruguay and Argentina), irregularly north to Costa Rica and Panama, casually or irregularly north to the southwestern U.S. (especially Texas) and southern Florida.

Number of Occurrences: 21 to >300
Number of Occurrences Comments: No exact figures.

Population Size: 10,000 to >1,000,000 individuals
Population Size Comments: Guesstimated number of breeding pairs in Canada in the early 1990s was 20,000-50,000 (Kirk et al. 1995). Total population may be 350,000-400,000 individuals.

Overall Threat Impact Comments: In California, threats include expansion of cropland unsuitable for foraging (see GHABCOM) and residential and commercial development in former agricultural and grassland areas. In California, Risebrough et al. (1989) concluded that organochlorine contamination of eggs, mortality during migration, and toxic contamination and habitat loss on wintering grounds did not account for a decline of more than 90%. However, widespread use of pesticides and rodenticides throughout the range is cause for concern (California Department of Fish and Game 1990, Kirk and Houston 1995). For example, in early 1996, thousands (perhaps well over 20,000) died as a result of pesticide (Monocrotophos and others) spraying for grasshopper control in croplands in Argentina; those dead were predominantly adults (subadult winter range is unknown); among the dead were hawks banded in Alberta, Saskatchewan, Colorado, Idaho, and California (Geoff Holroyd, Canadian Wildlife Service). Reduced prey populations and shooting possibly are significant threats in Central and South America (Kirk and Houston 1995). See Bednarz and Hoffman (1988) for threats in New Mexico.
Easily disturbed during nesting; often abandons nest if disturbed before the eggs hatch (Biosystems Analysis 1989).

Short-term Trend Comments: Numbers have declined in the western U.S. (Terres 1980); about half of the former breeding range in California is now vacant (Palmer 1988). See Bednarz (1988) for information on status in the southwestern U.S., Bednarz and Hoffman (1988) for status in New Mexico. Recent declines in productivity have been noted in Canada (Kirk and Houston 1995). Remains common in some areas of the Great Plains.

Other NatureServe Conservation Status Information

Protection Needs: Ensure availability of nesting sites in conjunction with suitable foraging habitat.

Distribution
Help
Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) BREEDS: known to have bred in east-central Alaska east into Yukon Territory and extreme northwestern Mackenzie; central Alberta, central Saskatchewan, southern Manitoba, western and southern Minnesota, and western Illinois south (mainly east of Cascades and Sierra Nevada) to southern California (rarely), Baja California (formerly), Sonora, Durango, Chihuahua, central and southern Texas and western Missouri; eastern breeding limits unstable. WINTERS: according to AOU (1983), primarily on pampas of southern South America (south to Uruguay and Argentina), irregularly north to Costa Rica and Panama, casually or irregularly north to the southwestern U.S. (especially Texas) and southern Florida.

U.S. States and Canadian Provinces

Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.
Color legend for Distribution Map
NOTE: The maps for birds represent the breeding status by state and province. In some jurisdictions, the subnational statuses for common species have not been assessed and the status is shown as not-assessed (SNR). In some jurisdictions, the subnational status refers to the status as a non-breeder; these errors will be corrected in future versions of these maps. A species is not shown in a jurisdiction if it is not known to breed in the jurisdiction or if it occurs only accidentally or casually in the jurisdiction. Thus, the species may occur in a jurisdiction as a seasonal non-breeding resident or as a migratory transient but this will not be indicated on these maps. See other maps on this web site that depict the Western Hemisphere ranges of these species at all seasons of the year.
Endemism: occurs (regularly, as a native taxon) in multiple nations

U.S. & Canada State/Province Distribution
United States AK, AL, AR, AZ, CA, CO, IA, ID, IL, KS, MN, MO, MT, ND, NE, NJ, NM, NN, NV, OK, OR, SD, TX, UT, WA, WY
Canada AB, BC, MB, NT, ON, SK, YT

Range Map
Note: Range depicted for New World only. The scale of the maps may cause narrow coastal ranges or ranges on small islands not to appear. Not all vagrant or small disjunct occurrences are depicted. For migratory birds, some individuals occur outside of the passage migrant range depicted. For information on how to obtain shapefiles of species ranges see our Species Mapping pages at www.natureserve.org/conservation-tools/data-maps-tools.

Range Map Compilers: NatureServe, 2002; WILDSPACETM 2002


U.S. Distribution by County Help
State County Name (FIPS Code)
AZ Cochise (04003), Coconino (04005), Graham (04009), Maricopa (04013), Mohave (04015), Navajo (04017), Pima (04019), Pinal (04021), Yavapai (04025)
CA Alameda (06001), Butte (06007), Colusa (06011), Contra Costa (06013), Fresno (06019), Glenn (06021), Inyo (06027), Kern (06029), Kings (06031), Lassen (06035), Los Angeles (06037), Madera (06039), Marin (06041)*, Merced (06047), Modoc (06049), Mono (06051), Monterey (06053)*, Napa (06055), Orange (06059)*, Placer (06061), Plumas (06063), Riverside (06065)*, Sacramento (06067), San Benito (06069)*, San Bernardino (06071)*, San Diego (06073)*, San Joaquin (06077), San Luis Obispo (06079), Santa Barbara (06083)*, Santa Clara (06085), Sierra (06091), Siskiyou (06093), Solano (06095), Sonoma (06097)*, Stanislaus (06099), Sutter (06101), Tehama (06103), Tulare (06107), Yolo (06113), Yuba (06115)
IA Black Hawk (19013), Fayette (19065)*, Osceola (19143)
ID Ada (16001), Adams (16003), Bannock (16005), Bear Lake (16007), Bingham (16011), Blaine (16013), Boise (16015), Bonneville (16019), Boundary (16021), Butte (16023), Camas (16025), Canyon (16027), Caribou (16029), Cassia (16031), Clark (16033), Custer (16037), Elmore (16039), Franklin (16041), Fremont (16043), Gem (16045), Gooding (16047), Idaho (16049), Jefferson (16051), Jerome (16053), Latah (16057), Lemhi (16059), Lincoln (16063), Madison (16065), Minidoka (16067), Nez Perce (16069), Oneida (16071), Owyhee (16073), Payette (16075), Power (16077), Teton (16081), Twin Falls (16083), Valley (16085), Washington (16087)
IL Kane (17089), Mchenry (17111)
MO Bates (29013), Greene (29077)
ND Grand Forks (38035), Stark (38089), Walsh (38099)*
NE Adams (31001), Arthur (31005), Banner (31007), Blaine (31009), Box Butte (31013), Chase (31029), Cherry (31031), Cheyenne (31033), Dawes (31045), Deuel (31049), Dixon (31051), Dundy (31057), Garden (31069), Grant (31075), Hamilton (31081), Holt (31089), Kearney (31099)*, Keith (31101), Kimball (31105), Lincoln (31111), Madison (31119), Morrill (31123), Perkins (31135), Pierce (31139), Platte (31141), Sheridan (31161), Sioux (31165), York (31185)
NM Dona Ana (35013), Lincoln (35027), Otero (35035), Sierra (35051), Socorro (35053)
NV Churchill (32001), Elko (32007), Eureka (32011), Humboldt (32013), Lander (32015)
OK Cimarron (40025), Jackson (40065), Murray (40099), Texas (40139), Tillman (40141)
OR Baker (41001), Crook (41013), Gilliam (41021), Harney (41025), Jefferson (41031), Lake (41037)*, Morrow (41049), Sherman (41055), Umatilla (41059), Union (41061), Wallowa (41063), Wasco (41065)
SD Bennett (46007), Brule (46015), Butte (46019), Campbell (46021), Corson (46031), Custer (46033), Davison (46035), Day (46037), Deuel (46039), Dewey (46041), Douglas (46043), Edmunds (46045), Fall River (46047), Faulk (46049), Hamlin (46057), Harding (46063), Hughes (46065), Hyde (46069), Jackson (46071), Jones (46075), Lake (46079), Lyman (46085), Marshall (46091), McPherson (46089), Meade (46093), Pennington (46103), Perkins (46105), Potter (46107), Roberts (46109), Spink (46115), Stanley (46117), Sully (46119), Tripp (46123)
UT Beaver (49001)*, Box Elder (49003), Cache (49005), Carbon (49007), Duchesne (49013), Grand (49019), Iron (49021), Juab (49023), Millard (49027), Piute (49031)*, Rich (49033), Salt Lake (49035), San Juan (49037), Sanpete (49039), Sevier (49041), Summit (49043)*, Tooele (49045), Uintah (49047), Utah (49049), Wasatch (49051), Washington (49053), Weber (49057)
WA Adams (53001), Benton (53005), Columbia (53013), Douglas (53017), Franklin (53021), Garfield (53023), Grant (53025), Kittitas (53037), Klickitat (53039), Lincoln (53043), Walla Walla (53071), Whitman (53075), Yakima (53077)
WY Albany (56001), Big Horn (56003), Campbell (56005), Carbon (56007), Converse (56009), Crook (56011), Fremont (56013), Goshen (56015), Hot Springs (56017), Johnson (56019), Laramie (56021), Lincoln (56023), Natrona (56025), Niobrara (56027), Park (56029), Platte (56031), Sheridan (56033), Sublette (56035), Sweetwater (56037), Teton (56039), Uinta (56041), Washakie (56043), Weston (56045)
* Extirpated/possibly extirpated
U.S. Distribution by Watershed Help
Watershed Region Help Watershed Name (Watershed Code)
07 Upper Minnesota (07020001)+, Lac Qui Parle (07020003)+, Turkey (07060004)+*, Middle Cedar (07080205)+, Kishwaukee (07090006)+, Upper Fox (07120006)+, Lower Fox (07120007)+*
09 Turtle (09020307)+, Park (09020310)+*
10 Yellowstone Headwaters (10070001)+, Clarks Fork Yellowstone (10070006)+, Upper Wind (10080001)+, Little Wind (10080002)+, Popo Agie (10080003)+, Muskrat (10080004)+, Lower Wind (10080005)+, Badwater (10080006)+, Upper Bighorn (10080007)+, Nowood (10080008)+, Greybull (10080009)+, Big Horn Lake (10080010)+, Dry (10080011)+, North Fork Shoshone (10080012)+, South Fork Shoshone (10080013)+, Shoshone (10080014)+, Little Bighorn (10080016)+, Upper Tongue (10090101)+, Middle Fork Powder (10090201)+, Upper Powder (10090202)+, South Fork Powder (10090203)+, Salt (10090204)+, Crazy Woman (10090205)+, Clear (10090206)+, Middle Powder (10090207)+, Little Powder (10090208)+, Upper Little Missouri (10110201)+, Antelope (10120101)+, Dry Fork Cheyenne (10120102)+, Upper Cheyenne (10120103)+, Lance (10120104)+, Lightning (10120105)+, Angostura Reservoir (10120106)+, Beaver (10120107)+, Hat (10120108)+, Middle Cheyenne-Spring (10120109)+, Rapid (10120110)+, Middle Cheyenne-Elk (10120111)+, Cherry (10120113)+, Upper Belle Fourche (10120201)+, Lower Belle Fourche (10120202)+, Redwater (10120203)+, Upper Lake Oahe (10130102)+, Lower Lake Oahe (10130105)+, West Missouri Coteau (10130106)+, Upper Heart (10130202)+, Cedar (10130205)+, North Fork Grand (10130301)+, South Fork Grand (10130302)+, Grand (10130303)+, South Fork Moreau (10130304)+, Upper Moreau (10130305)+, Lower Moreau (10130306)+, Fort Randall Reservoir (10140101)+, Bad (10140102)+, Medicine Knoll (10140103)+, Medicine (10140104)+, Upper White (10140201)+, Middle White (10140202)+, Little White (10140203)+, Lower White (10140204)+, Niobrara Headwaters (10150002)+, Upper Niobrara (10150003)+, Middle Niobrara (10150004)+, Snake (10150005)+, Upper James (10160003)+, Elm (10160004)+, East Missouri Coteau (10160007)+, Snake (10160008)+, Turtle (10160009)+, Lower James (10160011)+, Lewis and Clark Lake (10170101)+, Vermillion (10170102)+, Middle Big Sioux Coteau (10170201)+, Upper Big Sioux (10170202)+, Rock (10170204)+, Upper North Platte (10180002)+, Pathfinder-Seminoe Reservoirs (10180003)+, Medicine Bow (10180004)+, Little Medicine Bow (10180005)+, Sweetwater (10180006)+, Middle North Platte-Casper (10180007)+, Glendo Reservoir (10180008)+, Middle North Platte-Scotts Bluff (10180009)+, Upper Laramie (10180010)+, Lower Laramie (10180011)+, Horse (10180012)+, Pumpkin (10180013)+, Lower North Platte (10180014)+, Cache La Poudre (10190007)+, Lone Tree-Owl (10190008)+, Crow (10190009)+, Upper Lodgepole (10190015)+, Lower Lodgepole (10190016)+, Sidney Draw (10190017)+, Lower South Platte (10190018)+, Middle Platte-Buffalo (10200101)+, Lower Platte-Shell (10200201)+, Upper Middle Loup (10210001)+, Dismal (10210002)+, Upper North Loup (10210006)+, Calamus (10210008)+, Loup (10210009)+, Upper Elkhorn (10220001)+, North Fork Elkhorn (10220002)+, Logan (10220004)+, Little Sioux (10230003)+, North Fork Republican (10250002)+, Frenchman (10250005)+, Stinking Water (10250006)+, Upper Big Blue (10270201)+, West Fork Big Blue (10270203)+, Upper Little Blue (10270206)+*, Lower Marais Des Cygnes (10290102)+
11 James (11010002)+, Upper Cimarron (11040002)+, Upper Beaver (11100101)+, Middle Beaver (11100102)+, Coldwater (11100103)+, Lower Salt Fork Red (11120202)+, Blue-China (11130102)+, West Cache (11130203)+, Middle Washita (11130303)+
13 Jornada Del Muerto (13020210)+, Tularosa Valley (13050003)+
14 Westwater Canyon (14030001)+, Upper Green (14040101)+, New Fork (14040102)+, Upper Green-Slate (14040103)+, Big Sandy (14040104)+, Bitter (14040105)+, Upper Green-Flaming Gorge Reservoir (14040106)+, Blacks Fork (14040107)+, Muddy (14040108)+, Vermilion (14040109)+, Great Divide closed basin (14040200)+, Little Snake (14050003)+, Muddy (14050004)+, Lower White (14050007)+, Lower Green-Diamond (14060001)+, Ashley-Brush (14060002)+*, Duchesne (14060003)+, Strawberry (14060004)+, Willow (14060006)+*, Price (14060007)+, Lower San Juan-Four Corners (14080201)+
15 Havasu Canyon (15010004)+, Hualapai Wash (15010007)+, Upper Virgin (15010008)+, Lower Virgin (15010010)+, Detrital Wash (15010014)+, Middle Little Colorado (15020008)+, Cottonwood Wash (15020011)+, Polacca Wash (15020013)+*, Piute Wash (15030102)+*, Sacramento Wash (15030103)+, Upper Gila-San Carlos Reservoir (15040005)+, San Simon (15040006)+, Willcox Playa (15050201)+, Upper San Pedro (15050202)+, Lower San Pedro (15050203)+, Upper Santa Cruz (15050301)+, Lower Santa Cruz (15050303)+, Brawley Wash (15050304)+, Upper Verde (15060202)+, Agua Fria (15070102)+, Rio De La Concepcion (15080200)+, Whitewater Draw (15080301)+, San Bernardino Valley (15080302)+
16 Upper Bear (16010101)+, Central Bear (16010102)+, Bear Lake (16010201)+, Middle Bear (16010202)+, Little Bear-Logan (16010203)+, Lower Bear-Malad (16010204)+, Upper Weber (16020101)+, Lower Weber (16020102)+, Utah Lake (16020201)+, Spanish Fork (16020202)+, Provo (16020203)+, Jordan (16020204)+, Hamlin-Snake Valleys (16020301)+*, Pine Valley (16020302)+*, Rush-Tooele Valleys (16020304)+, Skull Valley (16020305)+, Southern Great Salt Lake Desert (16020306)+, Northern Great Salt Lake Desert (16020308)+, Curlew Valley (16020309)+, Middle Sevier (16030003)+, San Pitch (16030004)+, Lower Sevier (16030005)+, Escalante Desert (16030006)+, Beaver Bottoms-Upper Beaver (16030007)+*, Lower Beaver (16030008)+, Middle Humboldt (16040105)+, Little Humboldt (16040109)+, Smoke Creek Desert (16040203)+*, Carson Desert (16050203)+, East Walker (16050301)+*, Fish Lake-Soda Spring Valleys (16060010)+*, Ivanpah-Pahrump Valleys (16060015)+*
17 Lower Kootenai (17010104)+, Moyie (17010105)+, Franklin D. Roosevelt Lake (17020001)+, Chief Joseph (17020005)+, Upper Columbia-Entiat (17020010)+, Moses Coulee (17020012)+, Upper Crab (17020013)+, Banks Lake (17020014)+, Lower Crab (17020015)+, Upper Columbia-Priest Rapids (17020016)+, Upper Yakima (17030001)+, Lower Yakima, Washington (17030003)+, Snake headwaters (17040101)+, Gros Ventre (17040102)+, Greys-Hobock (17040103)+, Palisades (17040104)+, Salt (17040105)+, Idaho Falls (17040201)+, Upper Henrys (17040202)+, Lower Henrys (17040203)+, Teton (17040204)+, Willow (17040205)+, American Falls (17040206)+, Blackfoot (17040207)+, Portneuf (17040208)+, Lake Walcott (17040209)+, Raft (17040210)+, Goose (17040211)+, Upper Snake-Rock (17040212)+, Salmon Falls (17040213)+, Beaver-Camas (17040214)+, Medicine Lodge (17040215)+, Little Lost (17040217)+, Big Lost (17040218)+, Big Wood (17040219)+, Camas (17040220)+, Little Wood (17040221)+, C. J. Idaho (17050101)+, Bruneau (17050102)+, Middle Snake-Succor (17050103)+, Upper Owyhee (17050104)+, Middle Owyhee (17050107)+, Jordan (17050108)+, Boise-Mores (17050112)+, South Fork Boise (17050113)+, Lower Boise (17050114)+, Middle Snake-Payette (17050115)+, South Fork Payette (17050120)+, Payette (17050122)+, North Fork Payette (17050123)+, Weiser (17050124)+, Brownlee Reservoir (17050201)+, Burnt (17050202)+, Powder (17050203)+, Hells Canyon (17060101)+, Imnaha (17060102)+, Upper Grande Ronde (17060104)+, Wallowa (17060105)+, Lower Grande Ronde (17060106)+, Lower Snake-Tucannon (17060107)+, Palouse (17060108)+, Rock (17060109)+, Lower Snake (17060110)+, Upper Salmon (17060201)+, Middle Salmon-Panther (17060203)+, Lemhi (17060204)+, Upper Middle Fork Salmon (17060205)+, South Fork Salmon (17060208)+, Lower Salmon (17060209)+, Little Salmon (17060210)+, Clearwater (17060306)+, Middle Columbia-Lake Wallula (17070101)+, Walla Walla (17070102)+, Umatilla (17070103)+, Willow (17070104)+, Middle Columbia-Hood (17070105)+*, Klickitat (17070106)+, Lower John Day (17070204)+, Upper Deschutes (17070301)+*, Beaver-South Fork (17070303)+*, Upper Crooked (17070304)+, Lower Deschutes (17070306)+, Trout (17070307)+, Harney-Malheur Lakes (17120001)+, Silvies (17120002)+, Silver (17120004)+, Summer Lake (17120005)+*, Alvord Lake (17120009)+
18 Lost (18010204)+, Butte (18010205)+, Shasta (18010207)+, Upper Pit (18020002)+, Sacramento-Stone Corral (18020104)+, Lower American (18020111)+, Upper Stony (18020115)+, Upper Cache (18020116)+, Middle Fork Feather (18020123)+, Upper Yuba (18020125)+, Upper Bear (18020126)+, Thomes Creek-Sacramento River (18020156)+, Big Chico Creek-Sacramento River (18020157)+, Butte Creek (18020158)+, Honcut Headwaters-Lower Feather (18020159)+, Upper Coon-Upper Auburn (18020161)+, Upper Putah (18020162)+, Lower Sacramento (18020163)+, Upper Kern (18030001)+, Middle Kern-Upper Tehachapi- (18030003)+, Upper Poso (18030004)+*, Upper Deer-Upper White (18030005)+, Upper Tule (18030006)+, Upper Kaweah (18030007)+, Upper Dry (18030009)+, Tulare-Buena Vista Lakes (18030012)+, Middle San Joaquin-Lower (18040001)+, Middle San Joaquin-Lower (18040002)+, San Joaquin Delta (18040003)+, Upper Chowchilla-Upper Fresno (18040007)+, Upper Merced (18040008)+, Upper Tuolumne (18040009)+, Upper Stanislaus (18040010)+, Upper Calaveras (18040011)+, Upper Mokelumne (18040012)+, Upper Cosumnes (18040013)+, Panoche-San Luis Reservoir (18040014)+*, Rock Creek-French Camp Slough (18040051)+, Suisun Bay (18050001)+, San Pablo Bay (18050002)+, Coyote (18050003)+, Pajaro (18060002)+*, Estrella (18060004)+, Salinas (18060005)+*, Cuyama (18060007)+, Santa Maria (18060008)+*, Santa Clara (18070102)+*, Santa Monica Bay (18070104)+*, Los Angeles (18070105)+*, San Gabriel (18070106)+*, Seal Beach (18070201)+*, Santa Ana (18070203)+*, Santa Margarita (18070302)+*, San Luis Rey-Escondido (18070303)+*, San Diego (18070304)+*, Surprise Valley (18080001)+, Madeline Plains (18080002)+, Honey-Eagle Lakes (18080003)+, Mono Lake (18090101)+*, Crowley Lake (18090102)+, Owens Lake (18090103)+, Antelope-Fremont Valleys (18090206)+, Mojave (18090208)+*
+ Natural heritage record(s) exist for this watershed
* Extirpated/possibly extirpated
Ecology & Life History
Help
Basic Description: A large soaring bird (hawk).
Reproduction Comments: Egg dates: mainly April-May in southwestern U.S., California, and Oregon; mainly May-June in central plains states and Canada. Clutch size usually is 2-3. Incubation lasts 34-35 days per egg, almost exclusively by female (male provides food). Young are tended by both adults, leave nest in about 30 days, attain flight at 42-44 days (around 3rd week in July in southwestern U.S.), dependent on parents for 4-4.5 weeks after fledging. First breeds at 2 years. Usually 0.1-0.2 pairs per sq km; average of 1.4-2.4 km between nests. See Bednarz (1988) for information on reproduction in New Mexico. Reported nest density throughout range varies from 0.08-1.61 nests per sq km.
Ecology Comments: May form premigratory aggregations in summer. Nesting density in suitable habitat varies throughout range from 0.1-1.6 nests per 10 sq km (Bednarz and Hoffman 1988); nests average 1.4-2.4 km apart (see Rothfels and Lein 1983). At one site in California, five nests typically found along a 1 km riparian strip, the nearest nests only 60 meters apart (England et al. 1997). Home ranges during breeding season vary greatly--from 69 to 8718 hectares (reviewed in England et al. 1997). Interspecific territoriality with Red-tailed Hawk in some areas; in other areas may compete with Ferruginous Hawk or be limited by presence of and predation by Great Horned Owl (Palmer 1988).

In California, dispersal distances from natal sites to subsequent breeding sites ranged from 0 to 18 kilometers, mean 8.8 kilometers (Woodbridge et al. 1995). In contrast, none of 697 banded nestlings in Saskatchewan returned to the study area; three were found 190, 200 and 310 kilometers away (Houston and Schmutz 1995).

Non-Migrant: N
Locally Migrant: N
Long Distance Migrant: Y
Mobility and Migration Comments: In migration, occurs regularly in most of Middle America, and rarely east along the Gulf Coast to Florida (AOU 1983). In California, migrates March-early May, with a peak in the first half of April, and September-October (Biosystems Analysis, Inc. 1989). Migrants are greatly concentrated as they pass through Panama (mostly March-early April and October-early November; Ridgely and Gwynne 1989). Migrates through Costa Rica late September-November and late February-early May (Stiles and Skutch 1989). In Colombia, flocks of various sizes reported mainly February-March and September-early November (Hilty and Brown 1986). Main northward migration passes through Panama in mid-March, Veracruz in latter half of March and early April, southern Texas and southwstern U.S. chiefly in April (Palmer 1988); fall concentrations and movements occur in August-September in the north, mainly early October in Texas; peak in migration occurs in September in the southwestern U.S.; arrives in Argentina in late November (Palmer 1988). Annual migration flight may be 18,000-27,000 km, encompasses 4 months of the year. See Houston (1990) for information on migrations of Saskatchewan breeders. Migrates in large, often immense, flocks. Migrates over terrain where updrafts provide needed buoyancy for soaring. May roost at night on ground during migration.
Palustrine Habitat(s): Riparian
Terrestrial Habitat(s): Cropland/hedgerow, Desert, Grassland/herbaceous, Savanna, Woodland - Mixed
Habitat Comments: Savanna, open pine-oak woodland and cultivated lands (e.g., alfalfa and other hay crops, and certain grain and row croplands) with scattered trees. Tolerates extensive cultivation in nesting area (Schmutz 1989), though vineyards, orchards, rice, corn, and cotton are not suitable foraging habitat. In migration and winter also in grasslands and other open country (AOU 1983). Migrants may roost at night on ground in very large fields (Ridgely and Gwynne 1989). Nests typically in solitary tree, bush, or small grove; many nests on old black-billed magpie nests; sometimes on rock ledge. Readily nests in trees in shelterbelts and similar situations produced by humans (Gilmer and Stewart 1984). Recently reported nesting in city trees and on railway signal gantry in Regina, Saskatchewan (Condor 94:773-774). In the Central Valley of California, nests often are within one mile of a riparian zone; Great Basin nests, usually in junipers, are not near riparian zones (Biosystems Analysis, Inc. 1989). Evidently often returns to area where it nested in previous year.

GREAT BASIN AND MOJAVE HABITAT:
Swainson's Hawks have adapted to agricultural landscapes in Nevada. An ideal landscape for the Swainson's Hawk provides large riparian nesting trees, agricultural fields, and open shrublands within relatively close proximity (GBBO 2010). Swainson's Hawks in the Great Basin occupy the Juniper/Sagebrush community typical to the area. In California, Swainson's hawk habitat generally consists of large, flat, open, undeveloped landscapes that include suitable grassland or agricultural foraging habitat and sparsely distributed trees for nesting (England et al. 1997). Populations in the Great Basin often use juniper trees (Juniperus sp.) for nesting (England et al. 1997), and at least three known nest sites in the Mojave Desert are in Joshua trees (Yucca brevifolia) (California Natural Diversity Database 2009) (PCCP 2010). In addition to Joshua trees, this species was also known historically from the Mojave Yukka (Yucca schidigera) and possibly desert riparian habitats (Bloom 1980).


Adult Food Habits: Carnivore, Invertivore
Immature Food Habits: Carnivore, Invertivore
Food Comments: Vertebrates (mainly mammals) dominate the diet during the breeding season; invertebrates (especially crickets and grasshoppers) are common food at other times and sometimes for nonbreeders in summer. Hawks wintering in Argentina ate mainly dragonflies (Condor 95:475-479, Wilson Bull. 105:365-366). Mammals consumed often include young ground squirrels and pocket gophers. Depending on availability, also eats other small mammals, snakes, lizards, birds, amphibians, and some carrion (e.g., road kills). Hunts for insects on ground; may also catch insects in air. Hunts while soaring or from perch. Does not feed during most of migration (occasional feeding during initial and terminal stages) (Palmer 1988).
Adult Phenology: Diurnal
Immature Phenology: Diurnal
Length: 53 centimeters
Weight: 1069 grams
Economic Attributes Not yet assessed
Help
Management Summary
Help
Biological Research Needs: Determine degree of competition with B. jamaicensis.
Population/Occurrence Delineation
Help
Group Name: Hawks and Falcons

Use Class: Breeding
Subtype(s): Feeding Area, Nest Site
Minimum Criteria for an Occurrence: Evidence of historical breeding, or current and likely recurring breeding, at a given location, minimally a reliable observation of one or more breeding pairs in appropriate habitat. Be cautious about creating EOs for observations that may represent single breeding events outside the normal breeding distribution.
Mapping Guidance: If nest site is separated from feeding area by more than 100 meters, map as separate polygons.
Separation Barriers: None.
Separation Distance for Unsuitable Habitat: 10 km
Separation Distance for Suitable Habitat: 10 km
Separation Justification: Separation distance a compromise between usually relatively small home ranges and obvious mobility of these birds. Home ranges variable, ranging from about 0.5 to about 90 square kilometers; the latter figure refers to nests where birds commuted some distance to feeding grounds. A number of studies give mean home ranges on the order of 7 square kilometers, which equates to a circle with a diameter of about 3 kilometers; three times that home range gives a separation distance of about 10 kilometers. Home ranges: Ferruginous Hawk, mean 5.9 square kilometers in Utah (Smith and Murphy 1973); range 2.4 to 21.7 square kilometers, mean 7.0 square kilometers in Idaho (Olendorff 1993); mean 7.6 square kilometers in Idaho (McAnnis 1990); mean 90 square kilometers in Washington (Leary et al. 1998); Red-tailed Hawk, most forage within 3 kilometers of nest (Kochert 1986); mean spring and summer male home ranges 148 hectares (Petersen 1979); Hawaiian Hawk, 48 to 608 hectares (n = 16; Clarkson and Laniawe 2000); Zone-tailed Hawk, little information, apparent home range 1-2 kilometers/pair in west Texas (Johnson et al. 2000); White tailed Kite, rarely hunts more than 0.8 kilometers from nest (Hawbecker 1942); Prairie Falcon, 26 square kilometers in Wyoming (Craighead and Craighead 1956), 59 to 314 square kilometers (reported by Steenhof 1998); Aplomado Falcon, 2.6 to 9.0 square kilometers (n = 5, Hector 1988), 3.3 to 21.4 square kilometers (n = 10, Montoya et al. 1997). Nest site fidelity: high in Zone-tailed Hawk; all seven west Texas nesting territories occupied in 1975 were reused in 1976 (Matteson and Riley 1981). Swainson's Hawk: In California, dispersal distances from natal sites to subsequent breeding sites ranged from 0 to 18 kilometers, mean 8.8 kilometers (Woodbridge et al. 1995); in contrast, none of 697 nestlings in Saskatchewan returned to the study area; three were found 190, 200 and 310 kilometers away (Houston and Schmutz 1995).
Inferred Minimum Extent of Habitat Use (when actual extent is unknown): 3 km
Inferred Minimum Extent Justification: Foraging range variable; 3 kilometers is the mean diameter in several species.
Date: 13Mar2001
Author: Cannings, S.

Use Class: Nonbreeding
Subtype(s): Foraging area, Roosting area
Minimum Criteria for an Occurrence: Evidence of recurring presence of wintering birds (including historical); and potential recurring presence at a given location, usually minimally a reliable observation of 5 birds (this can be reduced to 1 individual for rarer species). Occurrences should be locations where the species is resident for some time during the appropriate season; it is preferable to have observations documenting presence over at least 20 days annually. Be cautious about creating EOs for observations that may represent single events.
Separation Barriers: None.
Separation Distance for Unsuitable Habitat: 10 km
Separation Distance for Suitable Habitat: 10 km
Separation Justification: Separation distance somewhat arbitrary; set at 10 kilometers to define occurrences of managable size for conservation purposes. However, occurrences defined primarily on the basis of areas supporting concentrations of foraging birds, rather than on the basis of distinct populations.
Date: 15Apr2002
Author: Cannings, S.
Population/Occurrence Viability
Help
U.S. Invasive Species Impact Rank (I-Rank) Not yet assessed
Help
Authors/Contributors
Help
NatureServe Conservation Status Factors Edition Date: 15Feb1996
NatureServe Conservation Status Factors Author: Hammerson, G.
Element Ecology & Life History Edition Date: 30Mar1995
Element Ecology & Life History Author(s): Hammerson, G.

Zoological data developed by NatureServe and its network of natural heritage programs (see Local Programs) and other contributors and cooperators (see Sources).

References
Help
  • Alabama Ornithological Society. 2006. Field checklist of Alabama birds. Alabama Ornithological Society, Dauphin Island, Alabama. [Available online at http://www.aosbirds.org/documents/AOSChecklist_april2006.pdf ]

  • Allen, C. R., S. Demarais, and R. S. Lutz. 1994. Red imported fire ant impact on wildlife: an overview. The Texas Journal of Science 46(1):51-59.

  • American Ornithologists Union (AOU). 1998. Check-list of North American Birds. 7th edition. American Ornithologists Union, Washington, D.C. 829 pages.

  • American Ornithologists' Union (AOU), Committee on Classification and Nomenclature. 1983. Check-list of North American Birds. Sixth Edition. American Ornithologists' Union, Allen Press, Inc., Lawrence, Kansas.

  • American Ornithologists' Union (AOU). 1983. Check-list of North American Birds, 6th edition. Allen Press, Inc., Lawrence, Kansas. 877 pp.

  • American Ornithologists' Union (AOU). 1998. Check-list of North American birds. Seventh edition. American Ornithologists' Union, Washington, D.C. [as modified by subsequent supplements and corrections published in The Auk]. Also available online: http://www.aou.org/.

  • Andersen, M.D. 2011. HUC10-based species range maps. Prepared by Wyoming Natural Diversity Database for use in the pilot WISDOM application operational from inception to yet-to-be-determined date of update of tool.

  • Andersen, M.D. 2011. Maxent-based species distribution models. Prepared by Wyoming Natural Diversity Database for use in the pilot WISDOM application operational from inception to yet-to-be-determined date of update of tool.

  • Bechard, M. J., R. L. Knight, D. G. Smith, and R. E. Fitzner. 1990. Nest sites and habitats of sympatric hawks (BUTEO spp.) in Washington. J. Field Ornithol. 61:159-170.

  • Bechard, Marc J. 1982. Effect of Vegetative Cover on Foraging Site Selection by Swainson's Hawks. Condor 84:153-159.

  • Bechard, Marc. 1983. Food Supply and the Occurence of Brood Reduction in Swainson's Hawk. Wilson Bulletin. 95(2):283-242.

  • Bednarz, J. C. 1988a. Swainson's hawk. Pages 87-96 in Glinski et al., eds. Proc. Southwest Raptor Manage. Symp. and Workshop. Nat. Wildl. Fed. Sci. and Tech. Ser. No. 11.

  • Bednarz, J. C. 1988c. A comparative study of the breeding ecology of Harris' and Swainson's hawks in southeastern New Mexico. Condor 90:311-323.

  • Bednarz, J. C., and S. W. Hoffman. 1988. The status of breeding Swainson's hawks in southeastern New Mexico. Pages 253-259 in Glinski et al., eds. Proc. Southwest raptor management symposium and workshop. Nat. Wildl. Fed. Sci. and Tech. Ser. No. 11.

  • Beebe, F.L. 1974. Field studies of the Falconiformes of British Columbia: vultures, hawks, falcons, eagles. B.C. Prov. Mus. Occas. Pap. No. 17, Victoria, 163pp.

  • Behle, W. H. 1981. The birds of northeastern Utah. Utah Museum of Natural History Occasional Publications 2: i-iv + 1-136 pp.

  • Behle, W. H., E. D. Sorensen, and C. M. White. 1985. Utah birds: a revised checklist. Occas. Publ. No. 4, Utah Museum of Natural History, Univ. of Utah, Salt Lake City, Utah. xv + 108 pp.

  • Biosystems Analysis, Inc. 1989. Endangered Species Alert Program Manual: Species Accounts and Procedures. Southern California Edison Environmental Affairs Division.

  • BirdLife International. 2004b. Threatened birds of the world 2004. CD ROM. BirdLife International, Cambridge, UK.

  • Bloom, P.H. 1980. The status of the Swainson's Hawk in California, 1979. Wildlife Management Branch, Nongame Wildl. Invest, Job II-8.0. Calif. Dept. Fish and Game, Sacramento, California.

  • Bohlen, H.D. 1989. The birds of Illinois. Indiana University Press, Bloomington, IN. 221pp.

  • Buteo swainsoni/Swainson's Hawk. Copyright Dave Fraser.

  • California Department of Fish and Game (CDF&G). 1990. 1989 annual report on the status of California's state listed threatened and endangered plants and animals. 188 pp.

  • California Natural Diversity Database (CNDDB). 2009. RareFind, Version 3.1.0. (May 30, 2009). California Department of Fish and Game, Sacramento, CA.

  • Campbell, R.W., et al. 1988. Species Notes for Selected Birds, Vol. 2 in A.P. Harcombe, tech. ed. 1988. B.C. Minist. Environ., Lands and Parks, Wildl. Branch. Rep. R-16. 131pp.

  • Campbell, R.W., N.K. Dawe, I. McTaggart-Cowan, J.M. Cooper, G.W. Kaiser, and M.C.E. McNall. 1990. The Birds of British Columbia Vol. 2: Nonpasserines: Diurnal Birds of Prey through Woodpeckers. Royal British Columbia Museum, Victoria, BC.

  • Canadian Wildlife Service. 1995. Last Mountain Lake and Stalwart National Wildlife Areas: Bird Checklist - Fourth Edition. Environment Canada. Ottawa, ON.

  • Canavelli, S. B., M. J. Bechard, B. Woodbridge, M. Kochert, J. J. Maceda, and M. E. Zaccagnini. 2003. Habitat use by Swainson's Hawks on their Austral wintering grounds in Argentina. Journal of Raptor Research 37:125-134.

  • Cannings, R.A., R.J. Cannings, and S.G. Cannings. 1987. Birds of the Okanagan Valley, B.C. Royal B.C. Mus., Victoria, BC. 420pp.

  • Cannings, R.J. 1998. The Birds of British Columbia - a taxonomic catalogue. B.C. Minist. Environ., Lands and Parks, Wildl. Branch, Victoria, Wildl. Bull. B-86. 266pp.

  • Clarkson, K. E. and L. P. Laniawe. 2000. Hawaiian Hawk, Buteo solitarius. In A. Poole and F. Gill, editors. The Birds of North America. No. 523. The Birds of North America, Inc., Philadelphia, PA. 16 pp.

  • Cooper, J.M. 1998. An Inventory Report on the Status of Diurnal Raptors (Ferruginous Hawk, Swainson's Hawk, Prairie Falcon, Peregrine Falcon) at Risk in the Southern Grasslands of British Columbia. B.C. Minist. Environ., Lands and Parks, Wildl. Branch. Working Rep. WR-92. 24pp.

  • Craighead, J. J., and F. C. Craighead, Jr. 1956. Hawks, Owls and Wildlife. The Stackpole Company, Harrisburg, Pennsylvania, and the Wildlife Management Institute, Washington, D.C.

  • Demarchi, M.W. and M.D. Bently. 2005. Best Management Practices for Raptor Conservation during Urban and Rural Land Development in British Columbia. B.C. Minist. of Environ., Victoria, B.C. MoE BMP Series.

  • Division of Natural Resources, Navajo Fish and Wildlife Department. 1995. Endangered Species List for The Navajo Nation.

  • Dobos, R.Z. 1998. Ontario Bird Records Committee Report for 1997. Ontario Birds 16(2):51-80.

  • Dodd, N. L. 1988d. Fire management and southwestern raptors. Pages 341-347 in Glinski et al., eds. Proc. Southwest raptor management symposium and workshop. Nat. Wildl. Fed. Sci. and Tech. Ser. No. 11.

  • Dorn, Jane L. and R.D. Dorn. 1990. Wyoming Birds. Mountain West Publishing, Cheyenne.

  • Dunn, E. H., C. M. Downes, and B. T. Collins. 2000. The Canadian Breeding Bird Survey, 1967-1998. Canadian Wildlife Service Progress Notes No. 216. 40 pp.

  • England, A. S., M. J. Bechard, and C. S. Houston. 1997. Swainson's Hawk (Buteo swainsoni). No. 265 IN A. Poole and F. Gill, editors, The birds of North America. The Academy of Natural Sciences, Philadelphia, PA, and The American Ornithologists' Union, Washington, DC. 28pp.

  • England, A.S., M.J. Bechard, and C.S. Houston. 1997. Swainson's Hawk (Buteo swainsoni). in A. Poole, and F. Gill, eds. The Birds of North America, No. 265. Acad. Nat. Sci., Philadelphia, PA, and Am. Ornithol. Union, Washington, DC.

  • Fisher, A.K. 1893. The hawks and owls of the United States in their relation to agriculture. Washington U.S. Dept. of Agriculture Bull. no. 6. 210 pp.

  • GBBO (Great Basin Bird Observatory). 2010. Nevada Comprehensive Bird Conservation Plan, ver. 1.0. Great Basin Bird Observatory, Reno, NV. Available online at www.gbbo.org/bird_conservation_plan.html

  • Gilmer, D. S., and R. E. Stewart. 1984. Swainson's hawk nesting ecology in North Dakota. Condor 86:12-18.

  • Godfrey, W. E. 1986. The birds of Canada. Revised edition. National Museum of Natural Sciences, Ottawa. 596 pp. + plates.

  • Gough, G.A., Sauer, J.R., Iliff, M. Patuxent Bird Identification Infocenter. 1998. Version 97.1. Patuxent Wildlife Research Center, Laurel, MD. http://www.mbr-pwrc.usgs.gov/id/framlst/infocenter.html

  • Harlow, D.L., and P.H. Bloom. 1989. Buteos and the Golden Eagle. Pp. 102-110 in B.G. Pendleton, ed. Proceedings of the western raptor management symposium and workshop. Natl. Wildl. Fed. Scien. Tech. Ser. No. 12.

  • Harrison, C. 1978. A Field Guide to the Nests, Eggs and Nestlings of North American Birds. Collins, Cleveland, Ohio.

  • Hawbecker, A. C. 1942. A life history study of the white-tailed kite. Condor 44:267-276.

  • Hayward, C. L., C. Cottam, A. M. Woodbury, and H. H. Frost. 1976. Birds of Utah. Great Basin Naturalist Memoirs 1: 229 pp.

  • Hector, D. P. 1988b. Aplomado Falcon (Falco femoralis). Pages 315-322 in R. S. Palmer, editor, Handbook of North American birds. Vol. 5: Family Accipitridae, Family Falconidae. Yale University Press, New Haven, Connecticut.

  • Hess, I.E. 1910. One hundred breeding birds of an Illinois ten-mile radius. Auk 27:19-32.

  • Hilty, S.L. and W. L. Brown. 1986. A Guide to the Birds of Colombia. Princeton University Press, Princeton, USA. 836 pp.

  • Hoffman, S.W., et.al. 1992. Patterns and recent trends in counts of migrant hawks in western North America: 1977-1991. Draft. Prepared by HawkWatch International, Albuquerque, NM, for U.S. Fish and Wildlife Service, Office of Migratory Bird Management, Washington, DC.

  • Houston, C. S. 1990. Saskatchewan Swainson's hawks. Am. Birds 44:215-220.

  • Houston, C. S., and J. K. Schmutz. 1995. Swainson's Hawk banding in North America to 1992. North American Bird Bander 20:120-127.

  • Howell, S. N. G., and S. Webb. 1995. A guide to the birds of Mexico and northern Central America. Oxford University Press, Oxford, UK.

  • Imhof, T. A. 1976. Alabama birds. Second edition. University of Alabama Press, Tuscaloosa. 445 pages.

  • Imhof, T. A. 1976. Alabama birds. Second edition. Univ. Alabama Press, Tuscaloosa. 445 pp.

  • James, R.D. 1991. Annotated Checklist of the Birds of Ontario (2nd ed., rev.). Life Sciences Miscellaneous Publications, Royal Ontario Museum, Toronto. 128 pp.

  • Janes, S.W. 1987. Status and Decline of Swainson's Hawks in Oregon: the Role of Habitat and Interspecific Competition. Oregon Birds 13(2):165-179.

  • Johnsgard, P. A. 1990. Hawks, eagles, and falcons of North America. Smithsonian Inst. Press, Washington, D.C. xvi + 403 pp.

  • Johnson, R. R., R. L. Glinski, and S. W. Matteson. 2000. Zone-tailed Hawk (Buteo albonotatus). No. 529 IN A. Poole and F. Gill, editors, The birds of North America. The Birds of North America, Inc., Philadelphia, PA. 20pp.

  • Keast, A., and E.S. Morton. 1980. Migrant birds in the neotropics: ecology, distribution, and conservation. Smithsonian Institution Press, Washington, DC.

  • Keir, J.R. 1976. Observations of Swainson's hawk nesting in northeastern Illinois. Wilson Bull. 88:658-659.

  • Kirk, D. A., D. Hussell, and E. Dunn. 1995. Raptor population status and trends in Canada. Bird Trends (Canadian Wildlife Service) 4:2-9.

  • Kirk, D. A., and C. S. Houston. 1995. Productivity declines in Swainson's hawks and their significance to population trends. Bird Trends (Canadian Wildlife Service) (4):19-20.

  • Kirk, D.A., and C. Hyslop. 1998. Population status and recent trends in Canadian raptors: a review. Biological Conservation 83 (1): 91-118.

  • Kochert, M. N. 1986. Raptors. pages 313-349 IN: A. Y. Cooperrider, R. J. Boyd, and H. R. Stuart, editors. Inventory and monitoring of wildlife habitat. Denver, CO: U.S. Department of the Interior, Bureau of Land Management, Denver Service Center.

  • LaRue, C.T. 1994. Birds of northern Black Mesa, Navajo County, Arizona. Great Basin Naturalist 54(1):1-63.

  • Leary, A. W., R. Mazaika, and M. J. Bechard. 1998. Factors affecting the size of Ferruginous Hawk home ranges. Wilson Bulletin 110:198-205.

  • Littlefield, A.D. and S.P. Thompson, and B.D. Ehlers. 1984. History and Present Status of Swainson's Hawks in Southeast Oregon. Raptor Research 18(1):1-5.

  • Matteson, S. W., and J. O. Riley. 1981. Distribution and nesting success of Zone-tailed Hawks in west Texas. Wilson Bulletin 107:719-723.

  • Mirarchi, R.E., editor. 2004. Alabama Wildlife. Volume 1. A checklist of vertebrates and selected invertebrates: aquatic mollusks, fishes, amphibians, reptiles, birds, and mammals. The University of Alabama Press, Tuscaloosa, Alabama. 209 pages.

  • Montoya, A.B., P.J. Zwank, and M. Cardenas. 1997. Breeding biology of Aplomado Falcons in desert grasslands of Chihuahua, Mexico. Journal of Field Ornithology 68(1):135-143.

  • Nelson, E.W. 1876. Birds of north-eastern Illinois. Bull. Essex Inst. 8:90-155.

  • Nixon, W. and C. Eckert. 2000. Yukon bird species at risk; status assessments. Canadian Wildlife Service (Whitehorse, Yukon), unpublished Report.

  • Olendorff, R. R. 1993. Status, biology, and management of Ferruginous Hawks: a review. Raptor Res. and Tech. Asst. Cen., Special Report. U.S. Dept. Interior, Bureau of Land Management, Boise, Idaho. 84 pp.

  • Olendorff, R.R. 1972. Large Birds of Prey on the Pawnee National Grassland: nesting habits and productivity 1969-1971. U.S. Intern. Biol. Prog. Tech.Rep. 151, Grassland Biome, Fort Collins, CO.

  • Olendorff, R.R. 1978. Populations of large raptors in northeastern Colorado 1970-1972. Raptor Res. Rep. 3: 185-205.

  • Palmer, R. S., ed. 1988b. Handbook of North American birds. Vol. 5. Yale Univ. Press, New Haven. 465 pp.

  • Parker III, T. A., D. F. Stotz, and J. W. Fitzpatrick. 1996. Ecological and distributional databases for neotropical birds. The University of Chicago Press, Chicago.

  • Parks Canada. 2000. Vertebrate Species Database. Ecosystems Branch, 25 Eddy St., Hull, PQ, K1A 0M5.

  • Peck, G.K. and R.D. James. 1987. Breeding Birds of Ontario: Nidiology and Distribution. Volume 2: Passerines. Life Sciences Miscellaneous Publication, Royal Ontario Museum, Toronto, Ontario. xi + 387 pp.

  • Pendleton, B. A. G., B. A. Millsap, K. W. Cline, and D. M. Bird. 1987. Raptor management techniques manual. National Wildlife Federation, Sci. and Tech. Ser. No. 10. 420 pp.

  • Petersen, L. 1979. Ecology of Great Horned Owls and Red-tailed Hawks in southeastern Wisconsin. Wisconsin Department of Natural Resources Technical Bulletin no. 111.

  • Peterson, R. T. 1980. A field guide to the birds of eastern and central North America. Fourth Edition. Houghton Mifflin Co., Boston, MA. 384 pages.

  • Presnall, C. C. 1935. The birds of Zion National Park. Proc. Utah Acad. Sci. Arts Lett. 12: 197-210.

  • Preston, C. R. 1998. Swainson's Hawk. Pages 118-119 in: H. E. Kingery, editor. Colorado breeding bird atlas. Colorado Bird Atlas Partnership and Colorado Division of Wildlife, Denver, CO. 636 pp.

  • Resource Inventory Committee. 1997e. Standardized Inventory Methodologies for Components of British Columbia's Biodiversity: Raptors, version 1.1. Prepared for the Resour. Inventory Comm., B.C. Minist. Environ., Lands and Parks, Victoria, BC. 56pp.

  • Ridgely, R. S. 2002. Distribution maps of South American birds. Unpublished.

  • Ridgely, R. S. and J. A. Gwynne, Jr. 1989. A Guide to the Birds of Panama. 2nd edition. Princeton University Press, Princeton, USA.

  • Ridgely, R. S., and J. A. Gwynne, Jr. 1989. A guide to the birds of Panama with Costa Rica, Nicaragua, and Honduras. Second edition. Princeton Univ. Press, Princeton, New Jersey. 534 pp.

  • Ridgway, R. 1889. The ornithology of Illinois. Vol. 1. Ill. State Lab. Nat. Hist. 520pp.

  • Risebrough, R. W., et al. 1989. Investigations of the decline of Swainson's hawk populations in California. J. Raptor Res. 23:63-71.

  • Rocky Mountain Bird Observatory. 2007. Land-bird Population Estimation Database. Online at http://www.rmbo.org/pif_db/laped/query.aspx

  • Root, T. 1988. Atlas of wintering North American birds: An analysis of Christmas Bird Count data. University of Chicago Press. 336 pp.

  • Rothfels, M., and M. R. Lein. 1983. Territoriality in sympatric populations of Red-tailed and Swainson's hawks. Canadian Journal of Zoology 61:60-64.

  • Schmutz, J. K. 1989. Hawk occupancy of disturbed grasslands in relation to models of habitat selection. Condor 91:362-371.

  • Schmutz, J.K. 1984. Ferruginous and Swainson's hawk abundance and distribution in relation to land use in southeastern Alberta. J. Wildl. Manage. 48(4):1180-1187.

  • Schmutz, J.K. 1987. The effect of agriculture on Ferruginous and Swainson's Hawks. J. Range Manage. 40:438-440.

  • See SERO listing

  • Semenchuk, G.P. 1992. The atlas of breeding birds of Alberta. Federation of Alberta Naturalists. 391 pp.

  • Shank, C.C. and K.G. Poole. 2016. Critical Breeding Periods for Raptor Species of the Northwest Territories. Report prepared by Turnstone Environmental Research and Aurora Wildlife Research for Environment and Natural Resources, Government of the Northwest Territories, Yellowknife. 27 pp.

  • Sinclair, P.H., W.A. Nixon, C.D. Eckert and N.L. Hughes. 2003. Birds of the Yukon Territory. UBC Press, Vancouver, BC. 595pp.

  • Smith, D. G., and J. R. Murphy. 1973. Breeding ecology of raptors in the eastern Great Basin of Utah. Brigham Young University Science Bulletin, Biol. Ser. 13:1-76.

  • Smith, N. G. 1980. Hawk and vulture migration in the Neotropics. Pages 51-65 in B80KEA02NAUS.

  • Steenhof, K. 1998. Prairie Falcon (Falco mexicanus). In A. Poole and F. Gill, editors, The Birds of North America, No. 346. The Birds of North America, Inc., Philadelphia, PA. 28 pp.

  • Stiles, F. G. and A. F. Skutch. 1989. A guide to the birds of Costa Rica. Cornell University Press, Ithaca, New York, USA. 511 pp.

  • THOMPSON,M.C., AND C. ELY.1989. BIRDS IN KANSAS VOLUME ONE.

  • Terres, J. K. 1980. The Audubon Society encyclopedia of North American birds. Alfred A. Knopf, New York.

  • U.S. Fish and Wildlife Service (USFWS). 2000. Management plan for Alaskan raptors. Unpublished report. Migratory Bird Management, Juneau, Alaska. 73 pp.

  • USGS Patuxent Wildlife Research Center. 2006. North American Breeding Bird Survey Internet data set. Available online at: (http://www.pwrc.usgs.gov/bbs/retrieval/).

  • USGS. 2008a. Alaska Off-road Breeding Bird Survey: Database of Bird Distribution (ALMS). Available online at http://www.absc.usgs.gov/research/bpif/OBS/database/index.html. (Accessed 5/15/2008).

  • Wauer, R. H., and D. L. Carter. 1965. Birds of Zion national Park and vicinity. Zion Nat. Hist. Assoc., Springdale, UT. 92 pp.

  • Woodbridge, B., K. K. Finley, and P. H. Bloom. 1995. Reproductive performance, age structure, and natal dispersal of Swainson's Hawks in the Butte Valley, California. Journal of Raptor Research 29:187-192.

  • Woodbridge, B., K.K. Finley, and S.T. Seager. 1995. An investigation of the Swainson's Hawk in Argentina. J. Raptor Res. 29:202-204.

  • Yukon Bird Club. 1995. Yukon Warbler: Newsletter of the Yukon Bird Club - Fall 1995. 20pp.

  • Yukon Bird Club. 1997. Yukon Warbler: Newsletter of the Yukon Bird Club - Winter 1997. 36pp.

  • Yukon Bird Club. 2002. Yukon Warbler: Newsletter of the Yukon Bird Club - Spring 2002. 16pp.

  • Yukon Bird Club. 2008. Yukon Warbler: Newsletter of the Yukon Bird Club - Fall 2008. 26pp.

  • Yukon Bird Club. 2009. Yukon Warbler: Newsletter of the Yukon Bird Club - Spring 2009. 36pp.

  • Yukon Bird Club. 2010. Yukon Warbler: Newsletter of the Yukon Bird Club - Spring 2010. 30pp.

  • Yukon Bird Club. 2014. Yukon Warbler: Newsletter of the Yukon Bird Club - Spring 2014. 12pp.

  • Zook, J. L. 2002. Distribution maps of the birds of Nicaragua, Costa Rica, and Panama. Unpublished.

  • eBird. 2016. eBird: An online database of bird distribution and abundance [web application]. eBird, Cornell Lab of Ornithology, Ithaca, New York. Available: http://www.ebird.org. Accessed in 2016.

Use Guidelines & Citation

Use Guidelines and Citation

The Small Print: Trademark, Copyright, Citation Guidelines, Restrictions on Use, and Information Disclaimer.

Note: All species and ecological community data presented in NatureServe Explorer at http://explorer.natureserve.org were updated to be current with NatureServe's central databases as of March 2019.
Note: This report was printed on

Trademark Notice: "NatureServe", NatureServe Explorer, The NatureServe logo, and all other names of NatureServe programs referenced herein are trademarks of NatureServe. Any other product or company names mentioned herein are the trademarks of their respective owners.

Copyright Notice: Copyright © 2019 NatureServe, 2511 Richmond (Jefferson Davis) Highway, Suite 930, Arlington, VA 22202, U.S.A. All Rights Reserved. Each document delivered from this server or web site may contain other proprietary notices and copyright information relating to that document. The following citation should be used in any published materials which reference the web site.

Citation for data on website including State Distribution, Watershed, and Reptile Range maps:
NatureServe. 2019. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available http://explorer.natureserve.org. (Accessed:

Citation for Bird Range Maps of North America:
Ridgely, R.S., T.F. Allnutt, T. Brooks, D.K. McNicol, D.W. Mehlman, B.E. Young, and J.R. Zook. 2003. Digital Distribution Maps of the Birds of the Western Hemisphere, version 1.0. NatureServe, Arlington, Virginia, USA.

Acknowledgement Statement for Bird Range Maps of North America:
"Data provided by NatureServe in collaboration with Robert Ridgely, James Zook, The Nature Conservancy - Migratory Bird Program, Conservation International - CABS, World Wildlife Fund - US, and Environment Canada - WILDSPACE."

Citation for Mammal Range Maps of North America:
Patterson, B.D., G. Ceballos, W. Sechrest, M.F. Tognelli, T. Brooks, L. Luna, P. Ortega, I. Salazar, and B.E. Young. 2003. Digital Distribution Maps of the Mammals of the Western Hemisphere, version 1.0. NatureServe, Arlington, Virginia, USA.

Acknowledgement Statement for Mammal Range Maps of North America:
"Data provided by NatureServe in collaboration with Bruce Patterson, Wes Sechrest, Marcelo Tognelli, Gerardo Ceballos, The Nature Conservancy-Migratory Bird Program, Conservation International-CABS, World Wildlife Fund-US, and Environment Canada-WILDSPACE."

Citation for Amphibian Range Maps of the Western Hemisphere:
IUCN, Conservation International, and NatureServe. 2004. Global Amphibian Assessment. IUCN, Conservation International, and NatureServe, Washington, DC and Arlington, Virginia, USA.

Acknowledgement Statement for Amphibian Range Maps of the Western Hemisphere:
"Data developed as part of the Global Amphibian Assessment and provided by IUCN-World Conservation Union, Conservation International and NatureServe."

NOTE: Full metadata for the Bird Range Maps of North America is available at:
http://www.natureserve.org/library/birdDistributionmapsmetadatav1.pdf.

Full metadata for the Mammal Range Maps of North America is available at:
http://www.natureserve.org/library/mammalsDistributionmetadatav1.pdf.

Restrictions on Use: Permission to use, copy and distribute documents delivered from this server is hereby granted under the following conditions:
  1. The above copyright notice must appear in all copies;
  2. Any use of the documents available from this server must be for informational purposes only and in no instance for commercial purposes;
  3. Some data may be downloaded to files and altered in format for analytical purposes, however the data should still be referenced using the citation above;
  4. No graphics available from this server can be used, copied or distributed separate from the accompanying text. Any rights not expressly granted herein are reserved by NatureServe. Nothing contained herein shall be construed as conferring by implication, estoppel, or otherwise any license or right under any trademark of NatureServe. No trademark owned by NatureServe may be used in advertising or promotion pertaining to the distribution of documents delivered from this server without specific advance permission from NatureServe. Except as expressly provided above, nothing contained herein shall be construed as conferring any license or right under any NatureServe copyright.
Information Warranty Disclaimer: All documents and related graphics provided by this server and any other documents which are referenced by or linked to this server are provided "as is" without warranty as to the currentness, completeness, or accuracy of any specific data. NatureServe hereby disclaims all warranties and conditions with regard to any documents provided by this server or any other documents which are referenced by or linked to this server, including but not limited to all implied warranties and conditions of merchantibility, fitness for a particular purpose, and non-infringement. NatureServe makes no representations about the suitability of the information delivered from this server or any other documents that are referenced to or linked to this server. In no event shall NatureServe be liable for any special, indirect, incidental, consequential damages, or for damages of any kind arising out of or in connection with the use or performance of information contained in any documents provided by this server or in any other documents which are referenced by or linked to this server, under any theory of liability used. NatureServe may update or make changes to the documents provided by this server at any time without notice; however, NatureServe makes no commitment to update the information contained herein. Since the data in the central databases are continually being updated, it is advisable to refresh data retrieved at least once a year after its receipt. The data provided is for planning, assessment, and informational purposes. Site specific projects or activities should be reviewed for potential environmental impacts with appropriate regulatory agencies. If ground-disturbing activities are proposed on a site, the appropriate state natural heritage program(s) or conservation data center can be contacted for a site-specific review of the project area (see Visit Local Programs).

Feedback Request: NatureServe encourages users to let us know of any errors or significant omissions that you find in the data through (see Contact Us). Your comments will be very valuable in improving the overall quality of our databases for the benefit of all users.