-


Home | Species Database | Species Accounts | Bibliography | Researchers | Related Sites | Login

William S. (Bill) Clark
   Photo

William S. (Bill) Clark

   Biography

Bill Clark is one of the world's leading authorities on raptor identification and taxonomy. He is the author of over 100 papers and books on raptor taxonomy and distribution, including A Field Guide to the Raptors of Europe, the Middle East, and North Africa (1999) and forthcoming volumes on the raptors of Mexico and Central America and the birds of prey of Africa. With Brian Wheeler, he co-authored A Field Guide to Hawks of North America (1987, 2001) and A Photographic Guide to North American Raptors (1999). He is widely traveled, leading popular raptor tours around the world (as "Raptours"), and he is a widely sought lecturer on diurnal birds of prey.

Raptours
P. O. Box 531467  
Harlingen,  Texas  78550  United States
Phone: 956 364-0415
Email: raptours@earthlink.net


   Research Interests

Raptor migration
Raptor field identification
Molt of remiges
Raptor hybrids
Raptor taxonomy

Species of Interest: 
  • White-tailed Hawk
  • Harris's Hawk
  • Parabuteo unicinctus
  • Geranoaetus albicaudatus


   Publications

COMMENTS REQUESTED: I would appreciate any comments or suggestions on the following four draft PowerPoint presentations. They may be sent to me at raptours@earthlink.net. Thanks! Bill.

Extreme tail variation in adult Harlan's Hawk. (PowerPoint presentation, November 2015)       pdf

Harlan's Hawks differ from Red-tailed Hawk. (PowerPoint presentation, February 2014)       pdf

Is Harlan's Hawk a subspecies of Red-tailed Hawk? Review of publications that advocate such -- and why their taxonomic justifications are not convincing. (PowerPoint presentation, November 2015)       pdf

Harlan's Hawks are & have been breeding within the Red-tailed Hawk range in western Canada. (PowerPoint presentation, January 2014)       pdf

PAPERS:

Clark, W.S. 2017. Group size of Harris's Hawks (Parabuteo unicinctus) in south Texas. Wilson Journal of Ornithology 129(2):364-368.       pdf

Clark, W.S. 2017. Response to Monroy-Ojeda et al. 2016. Wilson Journal of Ornithology 129(2):417-420.       pdf

Clark, W. S. and N. John Schmitt. 2017. Raptors of Mexico and Central America. Princeton U. Press, Princeton NJ.

Clark, W.S., S.C. Galen, J.M. Hull, M.A. Mayo, and C.C. Witt. 2017. Contrasting molecular and morphological evidence for the identification of an anomalous Buteo: a cautionary tale for hybrid diagnosis. PeerJ 5:e2850: DOI 10.7717/peerj.2850       pdf

Galindo, R., M. Gustafson, R. Rodriguez, and W.S. Clark. 2016 Gray Hawk fledged five juveniles in south Texas. Bulletin of the Texas Ornithological Society 49(1-2):86-87.       pdf

Clark, W.S. and P.H. Bloom. 2016. Plumages by sex of adult and basic III Rough-legged Hawks (Buteo lagopus). Wilson Journal of Ornithology 128(4):867-873.       pdf

Marsden, M., M. Miller, and W.S. Clark. 2016. Winter nesting of White-tailed Kite in south Texas. Bulletin of the Texas Ornithological Society 49(1/2):84-85       pdf

Buij, R., W.S. Clark and D.G. Allan. 2016. First records of Red-necked Buzzard Buteo auguralis for southern Africa, with notes on identification of Buteo buzzards in the subregion. Bulletin of the African Bird Club 23(1):46-63.       pdf

Clark, W.S. & P.Pyle. 2015. Commentary: a recommendation for standardized age-class plumage terminology for raptors. Journal of Raptor Research 49(4):513-517.       pdf

Clark, W.S.. 2013. Catching eagles Indian style. pp. 334-337 in D.H. Ellis (ed.). Enter the realm of the Golden Eagle. Hancock House, Surrey, B.C. and Blaine, WA.

Clark, W.S. 2012. The eagle genus Hieraaetus is distinct from Aquila, with comments on the name Ayres’ Eagle. Bulletin of the British Ornithologists’ Club 132:295-298.       pdf

Clark, W.S. 2012. Raptor banding in the Rio Grande Valley: Winter 2011-02012. Texas Birds Annual 8:6-12.       pdf

Duffy, K.E., W.S. Clark, and J.R. Hough. 2012. Probable Hen Harrier (Circus cyaneus cyaneus) at Cape May, New Jersey. North American Birds 66:4-8.       pdf

Clark, W.S. 2011. (Review of) Hawks at a distance, by Jerry Liguori. Texas Birds Annual 7:61-62.

Clark, W.S., C. McIntyre, O. Hatzofe, and E. Gorney. 2011. Booted Eagle Hieraaetus pennatus longevity record. Sandgrouse 33:181.       pdf

BOOK REVIEW Liguori, J. 2011. Hawks at a distance. Princeton University Press       pdf

Dénes, F.V., L.F. Silveira, S. Seipke, R. Thorstrom, W.S. Clark, and J.-M. Thiollay. 2011. The White-collared Kite (Leptodon forbesi Swann, 1922) and a review of the taxonomy of the Grey-headed Kite (Leptodon cayanensis Latham, 1790). Wilson Journal of Ornithology 123:323-331.        pdf

Millsap, B..A., S.H. Seipke, and W.S. Clark. 2011. The Gray Hawk (Buteo nitidus) is two species. Condor 113:326-339.       pdf

Seipke, S.H., F.V. Dénes, F. Pellinger, R. Thorstrom, J.-M. Thiollay, L.F. Silveira, and W.S. Clark. 2011. Field identification of White-collared Kite Leptodon forbesi and similar-looking species in north-east Brazil. Neotropical Birding 8:29-39.       pdf

Clark, W.S. 2009. Extreme variation in the tails of adult Harlan's Hawks. Birding 41:30-36 + supplement.       pdf

Clark, W.S. 2009. Juvenile Forest Buzzard in Kgalagadi Transfrontier Park. Gabar 19:28-30.       pdf

Clark, W.S., M.A. Patten, and J.C. Wilson. 2009. Dark Sharp-shinned Hawk Accipiter striatus from California is melanistic. Bulletin of the British Ornithologists' Club 129:254-255.       pdf

Clark, W.S. 2008. Hybrid Bald Eagle x Steller's Sea-eagle from Vancouver Island, British Columbia. Birding 40:28-31.       pdf

Simmons, R.E., T. Hardaker, and W.S. Clark. 2008. Partial albino African Marsh Harrier at Langebaan, South Africa. Gabar 19:16-21.       pdf

Seipke, S.H., and W.S. Clark. 2008. [First documented record of the Short-tailed Hawk (Buteo brachyurus) in Santiago del Estero, Argentina. Revista Nuestras Aves 53:35. (In Spanish)       pdf

Bloom, P.H., W.S. Clark, and J.W. Kidd. 2007. Capture techniques. Pp. 193-219 in D.M. Bird and K.L. Bildstein (eds.), Raptor research and management techniques. Hancock House Publishers, Surrey, British Columbia.        pdf

Clark, W.S. 2007. Raptor identification, ageing, and sexing. Pp. 47-56 in in D.M. Bird and K.L. Bildstein (eds.), Raptor research and management techniques. Hancock House Publishers, Surrey, British Columbia.        pdf

Clark, W.S. 2007. Taxonomic status of the Forest Buzzard Buteo oreophilus trizonatus. Ostrich 78:99-102.       pdf

Clark, W.S. 2007. Taxonomic status and distribution of Mangrove Black Hawk Buteogallus (anthracinus) subtilis. Bulletin of the British Ornithologists' Club 127:110-117.        pdf

Clark, W.S. 2007. Solitary Eagles: possible in Texas? Texas Birds Annual 3:16-18.       pdf

Clark, W.S. 2006. Interspecific communal winter night roost in South Texas. Journal of Raptor Research 40:177-178.       pdf

Clark, W.S., and P. Christy. 2006. First record of Oriental Honey Buzzard Pernis ptilorhynchus for Gabon and sub-Saharan Africa. Bulletin of the African Bird Club 13:207-210.       pdf

Clark, W.S., H.L. Jones, C.D. Benesh, and N.J. Schmitt. 2006. Field identification of the Solitary Eagle. Birding 38:66-74.       pdf

Clark, W.S., and N.J. Schmitt. 2006. Melanistic specimen of Black-chested Buzzard-eagle (Geranoaetus melanoleucus) with comments on the species' taxonomic position. Journal of Raptor Research 40:86-88.       pdf

Clark, W.S., and C.C. Witt. 2006. First known specimen of a hybrid Buteo: Swainson's Hawk (Buteo swainsoni) and Rough-legged Hawk (B. lagopus) from Louisiana. Wilson Bulletin 118:42-52.       pdf

Clark, W.S. 2005. Steppe Eagle is monotypic. Bulletin of the British Ornithologists' Club 125:149-153.       pdf

Clark, W.S., and P.H. Bloom. 2005. Plumages of Basic II and Basic III Rough-legged Hawks. Journal of Field Ornithology 76:83-89.       pdf

Clark, W.S., D. Fisher, B. Finch, B. de Bruijn, and I. Shani. 2005. Status of Beaudouin's Circaetus beaudouini and Short-toed Snake Eagles C. gallicus in Kenya. Bulletin of the African Bird Club 12:151-152.       pdf

Clark, W.S., M. Reid, and B.K. Wheeler. 2005. Four cases of hybridization in North American Buteos. Birding 37:256-263.       pdf

Clark, W.S. 2004. First dark-morph Hook-billed Kite fledged in the United States. North American Birds 58:170.       pdf

Clark, W.S. 2004. Is the Zone-tailed Hawk a mimic? Birding 36:494-498.       pdf

Clark, W.S. 2004. Immature plumages of the Eastern Imperial Eagles Aquila heliaca. Pp. 569-574 in R.D. Chancellor and B.-U. Meyburg (eds.), Raptors worldwide. World Working Group on Birds of Prey, Berlin.       pdf

Clark, W.S. 2004. Wave molt of the primaries of accipitrid raptors, and its use in ageing. Pp. 795-804 in R.D. Chancellor and B.-U. Meyburg (eds.), Raptors worldwide. World Working Group on Birds of Prey, Berlin.       pdf

Clark, W.S., and C. Barlow. 2004. Status of Short-toed and Beaudouin's Snake Eagles in The Gambia. Bulletin of the African Bird Club 11:25-27.       pdf

Clark, W.S. 2003. Specimen of rufous-morph Augur Buzzard Buteo augur in Zimbabwe. Bulletin of the African Bird Club 10:107-108.       pdf

Poh, L., and W.S. Clark. 2003. Adult male Oriental Honey Buzzards (race torquatus) have yellow eyes. Bulletin of the Oriental Bird Club 37:50-51.       pdf

Clark, W.S. 2002. Griffon Vulture is a species. Vulture News 46:24.       pdf

Clark, W.S. 2002. First nesting of a dark-morph Hook-billed Kite in the United States. North American Birds 56:260-262.       pdf

Clark, W.S., and D.R. Paulson. 2002. Specimen record of Short-toed Snake Eagle for Kenya is invalid. Bulletin of the British Ornithologists' Club 122:156-157.       pdf

Parry, S.J., W.S. Clark, and V. Prakash. 2002. On the taxonomic status of the Indian Spotted Eagle Aquila hastata. Ibis 144: 665-675.       pdf

Yosef, R., W.S. Clark, and S. Hoffman. 2002. An unusual Long-legged Buzzard Buteo rufinus at Eilat, Israel. Sandgrouse 24:60-63.       pdf

Bloom, P., and W.S. Clark. 2001. Molt and sequence of plumages of Golden Eagles, and a technique for in-hand ageing. North American Bird Bander 26:97-116.       pdf

Clark, W.S. 2001. First record of European Griffon Gyps fulvus for Kenya. Bulletin of the African Bird Club 8:59-60.       pdf

Clark, W.S. 2001. Ageing Bald Eagles. Birding 33:18-28.       pdf

Clark, W.S. 2001. Ageing eagles at hawk watches: what is possible and what is not. Pp. 143-148 in K.L. Bildstein and D. Klem (eds.), Hawkwatching in the Americas. Hawk Migration Association of North America, Wales, PA.

Clark, W.S. 2001. Identification review: Crested Caracara in Basic I plumage. Birding 33:524-527.       pdf

Clark, W.S., and B.K. Wheeler. 2001. (Book) A field guide to hawks (of) North America. Revised ed. Peterson Field Guide Series no. 35. Houghton Mifflin, Boston, MA.

Clark, W.S., and C. Edelstam. 2001. First record of Cassin's Hawk Eagle Spizaetus africanus for Kenya. Bulletin of the African Bird Club 8:138-139.       pdf

Rasmussen, P.C., W.S. Clark, J. Parry, and N.J. Schmitt. 2001. Field identification of "Long-billed Vultures" (Indian and Slender-billed Vultures). Bulletin of the Oriental Bird Club 34:24-29.       pdf

Yosef, R., A.J. Helbig, and W.S. Clark. 2001. An intrageneric Accipiter hybrid from Eilat, Israel. Sandgrouse 23:141-144.       pdf

Clark, W.S. 2000. Field identification of Beaudouin's Snake Eagle Circaetus beaudouini. Bulletin of the African Bird Club 7:13-17.       pdf

Clark, W.S., and R.A.G. Davies. 2000. Taxonomic problems in African diurnal raptors. Pp. 121-133 in R.D. Chancellor and B.-U. Meyburg (eds.), Raptors at risk. World Working Group on Birds of Prey, Berlin.       pdf

Clark, W.S., C. Schultz, and O. Allen. 2000. Conservation of migrating raptors through banding; results of over 30 years of the Cape May Point Raptor Banding Project. Pp. 617-625 in R.D. Chancellor and B.-U. Meyburg (eds.), Raptors at risk. World Working Group on Birds of Prey, Berlin, and Hancock House, London.       pdf

Clark, W.S. 1999. Plumage differences and taxonomic status of three similar Circaetus snake-eagles. Bulletin British Ornithologists' Club 119:56-59.       pdf

Clark, W.S. 1999. (Book) A field guide to the raptors of Europe, the Middle East, and North Africa. Oxford University Press, Oxford.

Clark, W.S. 1999. Ayres's Hawk-Eagle Hieraaetus ayresi sightings in Cameroon. Bulletin of the African Bird Club 6:115-116.       pdf

Gorney, E., W.S. Clark, and Y. Yom-Tov. 1999. A test of condition-bias hypothesis yields different results for two species of sparrowhawks (Accipiter). Wilson Bulletin 111:181-187.       pdf

Clark, W.S. 1998. First North American record of a melanistic Osprey. Wilson Bulletin 110:289-290.       pdf

Clark, W.S. 1998. Little Sparrowhawk catches and eats a bat. Journal of African Raptor Biology 13:22-23.       pdf

Clark, W.S, and R. Clarke. 1998. Differences in tarsal length between adult female Montagu's and Pallid Harriers: an easy method to separate specimens. Bulletin British Ornithologists' Club 118:52-54.       pdf

Clark, W.S., and N.J. Schmitt. 1998. Ageing Egyptian Vultures. Alula 4:122-127.       pdf

Clark, W.S., and B.K. Wheeler. 1998. 'Dark-morph' Sharp-shinned Hawk reported from California is normal juvenile female of race perobscurus. Bulletin of the British Ornithologists' Club 118:191-193.       pdf

Clark, W.S., and R. Yosef. 1998. In-hand identification guide to Palearctic Raptors. International Birdwatching Center, Eilat, Israel.

Clarke, R., V. Prakash, W.S. Clark, N. Ramesh, and D. Scott. 1998. World record count of roosting harriers Circus in Blackbuck National Park, Velavadar, Gujarat, north-west India. Forktail 14:70-71.       pdf

Corso, A., and W.S. Clark. 1998. Identification of Amur Falcon. Birding World 11:261-268.       pdf

Clark, W.S. 1997. Identification of perched Montagu's and Pallid Harriers. Birding World 10:267-269.       pdf

Clark, W.S. 1997. A dark morph for the African Marsh Harrier. Journal of African Raptor Biology 12:27-29.       pdf

Clark, W.S., and R. Yosef. 1997. Migrant Levant Sparrowhawks (Accipiter brevipes) at Eilat, Israel: measurements and timing. Journal of Raptor Research 31:317-320.       pdf

Clark, W.S. 1996. The validity of Archer's Buzzard as a species. Journal of African Raptor Biology 11:11-13.       pdf

Clark, W.S. 1996. Ageing Steppe Eagles. Birding World 9:269-274.       pdf

Clark, W.S. 1996. [Separation of Lesser Kestrel Falco naumanni from Kestrel F. tinnunculus (with remarks on American Kestrel F. sparverius)]in German with English summary. Limicola 10:57-78.       pdf

Clark, W.S. 1995. How fast is the fastest bird? Age-old speeds of Peregrine Falcons revised. Wildbird 9:42-43.

Clark, W.S. 1995. Capture and banding of migrant raptors. Israel Journal of Zoology 41:237-242.       pdf

Clark, W.S. 1995. Specimen of Eurasian Sparrowhawk verified. Journal of African Raptor Biology 10:39.

Clark, W.S. 1995. Sighting of Rufous-morph Booted Eagle in South Africa. Journal of African Raptor Biology 10:38.

Clark, W.S., and H. Shirihai. 1995. Identification of Barbary Falcon. Birding World 8:336-343.       pdf

Clark, W.S., and B.K. Wheeler. 1995. The field identification of Common and Great Black Hawks in Mexico and Central America. Birding 27:33-37.       pdf

Wheeler, B.K., and W.S. Clark. 1995. (Book) A photographic guide to North American raptors. Academic Press, London.

Clark, W.S. 1994. Elephanta--a great place to watch flying raptors. Hornbill 2:18-20.       pdf

Clark, W.S., and A.A. Khan. 1994. Sightings of two rare raptors, Lesser Spotted Eagle Aquila pomarina and Pied Harrier Circus melanoleucus, in Pakistan. Forktail 10: 173-175.       pdf

Clark, W.S. 1994. Species accounts for Asiatic raptors. In: del Hoyo, J., A. Elliot, and J. Sargatal (eds.), Handbook of the birds of the world, Vol. 2. Lynx Ed., Barcelona, Spain.

Farquhar, C.C., W.S. Clark, R.G. Wright, and M. Cuello. 1994. First record of interspecific cartwheeling between large raptors: Buteo poecilochrous and Geranoaetus melanoleucus. Journal of Raptor Research 28:274-275.       pdf

Prakash, V., N.V. Prakash, and W.S. Clark 1994. Oriental Honey Buzzard, Pernis ptilorhynchus, a new species for the Andaman Islands. Forktail 9:157-158.       pdf

Clark, W.S., and B.M. Beehler. 1993. Another continental India record of Accipiter gularis. Journal of the Bombay Natural History Society 90:505-506.       pdf

Clark, W.S., and N.J. Schmitt. 1993. Red-headed Falcon pirates prey from Montagu's Harrier. Journal of Field Ornithology 64:244-245.       pdf

Clark, W.S., and N.J. Schmitt. 1993. Field identification of the Rufous-bellied Eagle Hieraaetus kienerii. Forkail 8:7-9.       pdf

Clark, W.S. 1992. On the etymology of the name bal-chatri. Journal of Raptor Research 26:196.       pdf

Clark, W.S. 1992. Dark-morph Montagu's Harrier. Dutch Birding 14:178-179.       pdf

Clark, W.S. 1992. The taxonomy of Steppe and Tawny Eagles, with criteria for separation of museum specimens and live eagles. Bulletin of the British Ornithologists' Club 112:150-157.       pdf

Clark, W.S. 1992. Raptor count at Beidaihe, China, Fall 1991. Hawk Migration Studies 17:14-16.       pdf

Clark, W.S., and R. Banks. 1992. The taxonomic status of the White-tailed Kite. Wilson Bulletin 104:571-579.       pdf

Clark, W.S., and N.J. Schmitt. 1992. Flight identification of Indian raptors with pale wing bars. Journal of Bombay Natual History Society 82:1-3.       pdf

Clark, W.S., and R. Parslow. 1991. A specimen record of the Shikra for Saudi Arabia. Sandgrouse 13:44-46.

Clark, W.S. 1990. Spotted Eagle wtih rufous nape patch. British Birds 83:397-399.       pdf

Clark, W.S. 1990. Birding in Israel. Birding 22:48-50.

Clark, W.S. 1990. Migration and movements. Pp. 152-163 in I. Newton and P. Olsen (eds.), Birds of prey. Facts on File, New York.

Clark, W.S., and D. Forsman. 1990. The plumage of the subadult male marsh harrier. Dutch Birding 12:181-185.       pdf

Clark, W.S., R. Frumkin, and H. Shirihai. 1990. Field identification of the Sooty Falcon. British Birds 83:47-54.       pdf

Clark, W.S. 1989. The rufous morph of the Booted Eagle. Dutch Birding 11:57-60.       pdf

Clark, W.S., P.H. Bloom, and L.W. Oliphant. 1989. Aplomado Falcon steals preys from Little Blue Heron. Journal of Field Ornithology 60:380-381.       pdf

Clark, W.S., and B.K. Wheeler. 1989. Field identification of the White-tailed Hawk. Birding 21:190-195.       pdf

Clark, W.S., and B.K. Wheeler. 1989. Unusual roost site selection and staging behavior of Black-shouldered Kites. Journal of Raptor Research 23:116-117.       pdf

Clark,W.S., K. Duffy, E. Gorney, M. McGrady, and C. Schultz. 1988. Supernumerary primaries and rectrices in some Eurasian and North American raptors. Journal of Raptor Research 22: 53-58.       pdf

Clark, W.S., and Y. Leshem. 1988. Partial albino Lappetfaced Vulture in Kenya. Ostrich 59:44-45.       pdf

Frumkin, R., and W.S. Clark 1988. Is there a dark morph of the Sooty Falcon? Ibis 130:569-571.       pdf

Clark, W.S. 1987. The dark morph of the Marsh Harrier. British Birds 80:61-70.       pdf

Clark, W.S. and E. Gorney. 1987. Oil contaminationof raptors migrating along the Red Sea. Environmental Pollution 46:307-313       pdf

Clark, W.S., and B.K. Wheeler. 1987. (Book) A field guide to hawks (of) North America. Peterson Field Guide Series no. 35. Houghton Mifflin, Boston, MA.

Clark, W.S. 1986. Raptors. In P. Tucker (ed.), Bird identification guide. American Birding Association, Austin, TX.

Clark, W.S. 1986. The migrating Sharp-shinned Hawks of Cape May Point, N.J. In M. Harwood (ed.), Proceedings of the Hawk Conference IV. Hawk Migration Association of North America, Carbondale, PA. 393 pp.

Clark, W.S. 1986. What is Buteo ventralis? Birds of Prey Bulletin 3:115-118.

Clark, W.S. 1986. The rufous morph of the Booted Eagle. Pp. 21-24 in International bird identification. Proceedings of the 4th International ID meeting, Eliat, Israel.

Clark, W., K. Duffy, E. Gorney, M. McGrady, and C. Schultz. 1986. Raptor ringing at Eilat, Israel. Sandgrouse 7: 21-28.       pdf

Clark, W.S. 1985. Observations on behavior of Bald Eagles in summer. Pp. 180-190 in J.M. Gerrard and T. M. Ingram (eds.), The Bald Eagle in Canada: Proceedings of Bald Eagle Days 1983, Winnipeg, Manitoba, Canada.

Clark, W.S. 1985. Migration of the Merlin along the coast of New Jersey. Raptor Research 19:85-94.       pdf

Clark, W.S. 1985. Methods used to study raptor migration. Pp. 229-236 in I. Newton and R. Chancellor (eds.), Conservation studies on birds of prey. International Council for Birds of Prey, Cambridge, UK.

Clark, W.S. 1985. The migrating Sharp-shinned Hawk at Cape May Point: banding and recovery results. Pp. 137-148 in M. Harwood (ed.), Proceedings of Hawk Migration Conference IV. Hawk Migration Association of America, Rochester, NY.

Bildstein, K.L., W.S. Clark, D.L. Evans, M. Field, L. Soucy, and E. Henckel. 1984. Sex and age differences in fall migration of Northern Harriers. Journal of Field Ornithology 55:145-150.       pdf

Clark, W.S. 1984. Agonistic "whirling" by Zone-tailed Hawks. Condor 86:488.       pdf

Clark, W.S. 1984. Field identification of accipiters in North America. Birding 16(6): 251-263.       pdf

Clark, W.S., and C.M. Anderson. 1984. First specimen record of the Broad-winged Hawk for Washington. Murrelet 65:93-94.       pdf

Heredia, B., and W.S. Clark. 1984. Kleptoparasitism by White-tailed Hawk (Buteo albicaudatus) on Black-shouldered Kites (Elanus leucurus) in southern Texas. Raptor Research 18:30-31.       pdf

LeFranc, M.L., and W.S. Clark. 1984. (Book) Working bibliography of the Golden Eagle and the genus Aquila. National Wildlife Federation Science and Technology Series no. 7. National Wildlife Foundation, Washington, D.C.

Clark, W.S. 1983. The field identification of North American eagles. American Birds 37:822-826.       pdf

Clark, W.S. 1982. Turtles as a food source of nesting Bald Eagles in the Chesapeake Bay region. Journal of Field Ornithology 53:49-51.       pdf

Henny, C.J., and W.S. Clark 1982. Measurements of fall migrant Peregrine Falcons from Texas and New Jersey. Journal of Field Ornithology 53:326-332.       pdf

Clark, W.S. 1981. A modified dho-gaza trap for use at a raptor banding station. Journal of Wildlife Management 45:1043-1044.       pdf

Clark, W.S. 1981. Flight identification of common North American buteos. Continental Birdlife 2:129-143.       pdf

Lincer, J.L., W.S. Clark, and M.L. LeFranc. 1980. (Book) Working bibliography of the Bald Eagle. National Wildlife Federation Science and Technology Series no. 4. National Wildlife Federation, Washington, D.C.

Clark, W.S., and M.E. Pramstaller. 1980. Field identification pamphlet for North American raptors. Raptor Information Center, National Wildlife Federation, Washington, D.C.

Clark, W.S. 1978. Spring hawk movement at Sandy Hook, NJ -- 1977. New Jersey Audubon Society Occasional Paper No. 133.       pdf

Dunne, P.J., and W.S. Clark. 1977. Fall hawk movement at Cape May Point, N.J.-1976. New Jersey Audubon Society Occasional Paper no. 130.

Clark, W.S. 1976. Cape May Point raptor banding station -- 1974 results. North American Bird Bander 1:5-13.       pdf

Clark, W.S. 1975. Analysis of data. Pp. 87-97 in M. Harwood (ed.), Proceedings of the North American Hawk Migration Conference. Hawk Migration Association of North America, Washington Depot, CT.

Clark, W.S. 1974. Second record of the kestrel (Falco tinnunculus) for North America. Auk 91:172.       pdf

Clark, W.S. 1974. Cape May Point raptor banding station -- 1973 results. EBBA News 37:51-64.

Clark, W.S. 1974. Occurrence of Swainson's Hawk substantiated in New Jersey. Wilson Bulletin 86:284-285.       pdf

Clark, W.S. 1973. Cape May Point raptor banding station-1972 results. EBBA News 36:150-165.

Clark, W.S. 1972. Migration trapping of hawks (and owls) at Cape May, N.J. -- fifth year. EBBA News 35:121-131.

Clark, W.S. 1970. Migration trapping of hawks (and owls) at Cape May, N.J. -- third year. EBBA News 35:181-190.       pdf

Clark, W.S. 1967. Partial albino Red-tailed Hawk. Maryland Birdlife 23:233.

Clark, W.S. 1967. Modification of the bal-chatri trap for shrikes. Eastern Bird Bander News 30:147-149.



Home | Species Database | Species Accounts | Bibliography | Researchers | Related Sites | Login

Copyright © 1999-2012 The Peregrine Fund. All Rights Reserved.
-