Reasons for decline : All field and laboratory evidence points to cumulative effects of 

 chlorinated pesticides and their breakdown products obtained from its prey, especially 

 DDT and DDE , which have increased adult mortality and reduced production of young by 

 affecting reproductive mechanisms and causing eggs to become thin-shelled or otherwise 

 nonviable . Habitat destruction and collection of young and adults for falconry have also 

 been factors . 



Protective measures already taken : Peregrine falcons are protected by Federal law and 

 by States in the United States . Propagation techniques are being studied by Government 

 and private investigators and at Cornell University. 



Measures proposed : Eliminate use of food chain pesticides where possible. Responsible 

 agencies should set appropriate regulations for the protection of this species. Include in 

 international conservation agreements . Develop methods for captive propagation to bolster 

 wild population. Initiate management-oriented research and investigate the establishment 

 of refuges around known eyries . 



Number in captivity : Not precisely known, but number of peregrines from south of the 

 taiga in possession of falconers, zoos, and captive breeding projects believed to be less 

 than 20 (Cade) . 



Breeding potential in captivity : Probably poor . 



References : 



Berger, D. D. , D. W. Anderson, and R. W. Risebrough. 1970. Shell thinning in 



eggs of Ungava peregrines . Canadian Field-Nat. 84:265-267. 

 Bond, R. M. 1946. The peregrine population of western North America. 

 Cade, T.J. 1960. Ecology of the peregrine and gyrfalcon populations in Alaska, 

 Univ. Cal. Pub. Zool . 63:151-290. 



, CM. White, and J . R. Haugh. 1968. Peregrine and pesticides 



in Alaska . Condor 70:170-178. 



, and R. Fyfe. 1970. The North American peregrine survey, 1970. 



Canadian Field-Nat. 84:231-245. 



, J. L. Lincer, CM. White, D. G. Roseneau, andL. G. Swartz. 1971. 



DDE residues and eggshell changes in Alaskan falcons and hawks. Science 



(in press) . 

 Henderson, J. H. andD. D. Berger. 1968. Chlorinated hydrocarbon residues in 



peregrines and their prey species from northern Canada. Condor 70:149-153. 

 Herman, S. C, M. N. Kirven, and R. W. Risebrough. 1970. The peregrine falcon 



decline in California I. A preliminary review. Audubon Field Notes 24(4): 609-613. 

 Herman, S. G. 1971. The peregrine falcon decline in California; breeding status 



in 1970. Calif. Fish & Game Spec. Wildlife Investigations Report. 

 Hickey, J. J. (editor). 1969. Peregrine falcon populations, their biology and 



decline. University of Wisconsin Press, Madison, 596 pp. 

 and D. W. Anderson. 1968. Chlorinated hydrocarbons and eggshell 



changes in raptorial and fish-eating birds. Science 162: 271-273. 

 Leach, H. R. and L. D. Fisk. 1972. At the crossroads--a report on California's 



endangered and rare fish and wildlife. California Dept. of Fish & Game. 

 Marshall, D. B. 1969. Rare and endangered plants and animals of Oregon, Part 3. 



Birds. Extension Division, Oregon State University. 

 White, CM. 1968. Diagnosis and relationships of the North American tundra 



inhabiting peregrine falcons. Auk 85:179-191. 



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