|File name||Lead Author||Year||Type|
|County of San Diego MSCP Monitoring Summary Report January 1998 - June 2007||County of San Diego||2007||report|
|Ramona Grasslands: Historical Perspective||Bittner, David||2008||report|
Distribution occurs from western North America throughout the Great Plains of the U.S., into Central America, migrating as far south as Argentina .
A rare migrant of San Diego County. Sightings have occurred in Borrego Valley, Lakeside, Warner Springs, and El Centro .
CESA- Threatened .
Generally found in plains, dry grasslands, and open woodlands . Forages in open grasslands, small open woodlands, and sparse shrublands .Nesting occurs in shrublands, grasslands, riparian areas, and agricultural landscapes .
There are no recognized subspecies .
Migration is diurnal . Nearly the entire population migrates between breeding grounds in western North America to wintering grounds in the lowlands of Argentina. Overall migration can take up to 2 months (20,000km) . Flocks will begin to disperse from Argentina in late February to mid-March and migrate back late August into September .
Arrival to breeding grounds begin around March or April . Nest will be constructed 7-15 days after arrival and takes one or two weeks to complete . Nests are typically built in trees, shrubs, or a small group of trees along a stream . Young are altricial and inactive for the first 8-10 days, but able to stand at about 13-17 days. Young can feed themselves at about 23-26 days, but the female may still feed them for up to 32 days. Juveniles first attempt to fly at 29-33 days and fly at around 38-46 days .
Young are fed rodents, rabbits, and reptiles . However, when not breeding, adults feed almost exclusively on insects, primarily grasshoppers .
Pesticides are a large cause of mortality for Swainson's Hawks. Illegal shooting is also a threat to Swainson's Hawk populations .
 Unitt, P. 1984b. The birds of San Diego County. San Diego Society of Natural History Museum no. 13:1-276.
 California Department of Fish and Wildlife, Natural Diversity Database. July 2017. Special Animals List. Periodic publication. 51 pp.
 Bechard, M. J. 1982. Effect of vegetative cover on foraging site selection by Swainson's Hawk. Condor no. 84:153-159
 Woodbridge, B. 1991. Habitat selection by nesting Swainson's Hawks: a hierarchical approach. Master's Thesis, Oregon State Univ., Corvallis.
 Retrieved [October, 24, 2017 ], from the Integrated Taxonomic Information System (ITIS) (http://www.itis.gov).
 Smith, N. G. 1980c. "Hawk and vulture migrations in the neotropics." In Migrant birds in the neotropics: ecology, behavior, distribution, and conservation., edited by A. Keast and E. S. Morton, 51-65. Washington, D.C: Smithsonian Inst. Press.
 Fitzner, R. E. 1978. Behavioral ecology of the Swainson's Hawk (Buteo swainsoni) in southeastern Washington. Phd Thesis, Washington State Univ., Pullman.
 McConnell, S., T. J. O'Connell and D. M. Leslie. 2008. Land cover associations of nesting territories and three sympatric budeos in shortgrass prairie. Wilson Journal of Ornithology no. 120 (4):708-716.
 Bechard, M.J., C.S. Houston, J.H. Sarasola, and A.S. England. 2010. Swainson’s Hawk (Buteo swainsoni). In The Birds of North America Online, No. 265 (A. Poole, Ed.). Cornell Lab of Ornithology, Ithaca, New York.
 Wheeler, B.K., C.M. White and J.M. Economidy. 2003. Raptors of Western North America: The Wheeler Guide.