Ducks, Geese, and Swans (Anatidae)

Abraham, K.F. 2005. The Cackling Goose: not new to Ontario. OFO News 23: 2-6.

Cox, C. and J. Barry. 2005. The identification, molts, and aging of American and Eurasian Wigeons in female-type plumages. Birding 37(2): 156-164.

Jackson, G. D. 1991. Field identification of teal in North America: Part I. Birding 23: 124-133.

Jackson, G.D. 1992. Field identification of teal in North America: female-like plumages – part II. Birding 24: 214-223.

Jordan, M. 1988. Distinguishing Tundra and Trumpeter Swans. Birding 20: 223-226.

Leafloor, J.O. and D.H. Rusch. 1997. Clinal size variation in Canada Geese affects morphometric discrimination techniques. Journal of Wildlife Management 61: 183-190.

Leafloor, J.O., J.A. Moore, and K.T. Scribner. 2013. A hybrid zone between Canada Geese (Branta Canadensis) and Cackling Geese (B. hutchinsii). The Auk 130(3): 1-14, 2013.

Martin, P.R. and B.M. Di Labio. 1994. Identification of Common X Barrow’s Goldeneye hybrids in the field. Birding 24: 104-105.

Merendino, M.T and Ankney, C.D. 1994. Habitat use by Mallards and American Black Ducks breeding in central Ontario. Condor 96: 411-421.

Mlodinow, S.G., P.F. Springer, B. Deuel, L.S. Semo, T. Leukering, T.D. Schonewald, W. Tweit, and J.H. Barry. 2008. Distribution and identification of Cackling Goose (Branta hutchinsii) subspecies. North American Birds 62: 344 – 360.

Moser, T.J. and R.E. Rolley. 1990. Discrimination of Giant and Interior Canada Geese of the Mississippi Flyway. Wildlife Society Bulletin 18: 381-388.

Mowbray, T.B., C.R. Ely, J.S. Sedinger, and R.E. Trost. 2002. Canada Goose (Branta canadensis). In The Birds of North America, no. 681 (A. Poole and F. Gill, Eds.) Academy of Natural Sciences, Philadelphia, and American Ornithologists’ Union, Washington, D.C.

Pattern, M.A. and M.T. Heindel. 1994. Identifying Trumpeter and Tundra Swans in the field. Birding 26: 306-319.

Pearce, J.M. and K.S. Bollinger. 2003. Morphological traits of Pacific Flyway Canada Geese as an aid to subspecies identification and management. Journal of Field Ornithology 74: 357-369.

Petrie, S. and M.L. Schummer. 2002. Waterfowl responses to zebra mussels on the lower Great Lakes. Birding 34: 346-351.

Toochin, M. 1998. Possible anywhere: Tufted Duck. Birding 30: 370-383.

Trauger, D.L. 1974. Eye color of female Lesser Scaup in relation to age. Auk 91: 243-254.


Wading Birds (Ardeidae, Threskiornithidae)

Dickerman, R.W. and K.C. Parkes. 1968. Notes on the plumages and generic status of the Little Blue Heron. Auk 437-440.

Pratt, H. Douglas. 1976. Field identification of White-faced and Glossy Ibises. Birding 8: 1-5.

Davis, W.E. 1999. Identification review: Black-crowned and Yellow-crowned Night-Herons. Birding 31: 410-415.


Hawks and Vultures (Accipitridae, Cathartidae, Pandionidae)

Carrolan, T. 2010. Redtails R Us. Retrieved from

Dickerman, R. 1989. Identification of Red-tailed Hawks wintering in Kansas, Kansas Ornithological Society.

Dunne, P., D. Sibley, and C. Sutton. 1988. Hawks in Flight. Houghton Mifflin (Boston).

Iron, J. 2012. Dark morph Red-tailed Hawk: calurus or abieticola? TOC Newsletter,  Toronto Ornithological Club.

Liguori, J. and B. Sullivan. 2010. Comparison of Harlan’s with Western and Eastern Red-tailed Hawks. Birding 42(2) :30-37.

Liguori, J. and B. Sullivan. 2014. Northern Red-tailed Hawk (Buteo jamaicensis abieticola) revisited. North American Birds V 67: no. 3 374-383.

Liguori, J. 2000. Identification Review: Sharp-shinned and Cooper’s Hawks. Birding 32(5): 428-433.

Liguori, J. 2001. Pitfalls of Classifying Light Morph Red-tailed Hawks to Subspecies. Birding 33(5): 436-446.

Liguori, J. 2004. Dark Red-tailed Hawks. Birding 36(3): 501-506.

Liguori, J. 2004. How to Age Golden Eagles. Birding 36(3): 278-283.

Liguori, J. 2005. Hawks from Every Angle. Princeton University Press, Princeton, New Jersey.

Liguori, J. 2011. Hawks at a Distance. Princeton University Press, Princeton, New Jersey.

Pittaway, R. 1993. Subspecies and Morphs of the Red-tailed Hawk in Ontario Birds 11(1): 23-29. Ontario Field Ornithologists.

Pittaway, R. 1998. Northern Redtails. OFO News 16(1):4.

Pittaway, R. 1999. Fall Hawkwatching Guide. OFO News 17(3):1–8.

Preston, C.R. and R.D. Beane. 2009. Red-tailed Hawk (Buteo jamaicensis), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online:, doi:10.2173/bna.52 (BNA Online requires a subscription for full article access).

Ruddy, J. and J. Liguori. 2014. Northern Red-tailed Hawks: A site dedicated to the identification and natural history of abieticola Red-tailed Hawks. Retrieved from

Ruddy, J. 2014. Identifying Northern Red-tailed Hawks. eBird Canada.

Sullivan, B. and J. Liguori. 2009. Active flight feather molt in migrating North American raptors. Birding 41(4): 34–45.

Todd, W.E.C. 1950. A Northern Race of Red-tailed Hawks. Annals of the Carnegie Museum (Pittsburgh) 31: 289-296.

Wheeler, B. K. 2004. Aging and sexing Mississippi Kites. Birding 36: 508-519.


Shorebirds (Charadriidae, Scolopacidae, Haematopididae, Recurvirostridae)

Alstrom, P. 1987. The identification of Baird’s and White-rumped Sandpipers in juvenile plumage. Birding 19(2): 10-13.

Cox, C. 2008. Identification of North American peeps: a different approach to an old problem. Birding 40(4): 32-40.

Mlodinow, S. and M. Axelson. 2006. Gray-bellied Brant: identification and vagrancy. Birding 38(3): 48-55.

Mlodinow, S. 2001. Possible anywhere: Sharp-tailed Sandpiper. Birding 33: 330-341.

O’Brien, M. 2006. Willet: eastern vs. western subspecies. Birding 38(3): 40-47.

O’Brien, M., R. Crossley, and K. Karlson. 2006. The Shorebird Guide. Houghton Mifflin, Boston.

Pittaway, R. 1992. Point/counterpoint: Short-billed Dowitcher subspecies. Birding 24: 309-312.

Putnam, C. 2005. Fall molts of adult dowitchers. Birding 37: 380-391.

Wilds, C. and M. Newlon. 1983. The field identification of dowitchers. Birding 15: 151-165.

Wilds, C. 1982. Separating the yellowlegs. Birding 14: 172-178.

Wilson, A. 2005. Red-necked Stint: status and identification. Birding 37: 628-637.


Gulls, Terns, and Jaegers (Laridae)

Gosselin, M. and N. David. 1975. Field identification of Thayer’s Gull (Larus thayeri) in eastern North America. American Birds 29: 1059-1066. See:

Howell, S.N.G., and J. Dunn. 2007. A Reference Guide to the Gulls of the Americas. Peterson Reference Guide Series. Boston: Houghton Mifflin Harcourt.

Ingolfsson, A. 1969. Sexual dimorphism of large gulls (Larus spp.). Auk 86: 732-737.

Lehman, P. 1980. The identification of Thayer’s Gull in the field. Birding 12: 198-210.

Lethaby, N. and J. Bangma. 1998. Identifying Black-tailed Gull in North America. Birding 30: 470-483.

Post, P.W. and R.H. Lewis. 1995. Lesser Black-backed Gull in the Americas: occurrence and subspecific identity, part II – field identification. Birding 27: 370-381.

Sherony, D.F. and K.J. Brock. 1997. Jaeger migration on the Great Lakes. Birding 29: 372-385.

Wilds, C. 1993. The identification and aging of Forster’s and Common Terns. Birding 25: 94-108.

Zimmer, K.J. 1991. Plumage variation in “Kumlien’s” Iceland Gull. Birding 23: 254-270.


Owls (Tytonidae, Strigidae)

Owen, D.F. 1963. Polymorphism in the Screech Owl, Otus asio, in eastern North America. Wilson Bulletin 75: 183-190.

Pittaway, R. (2014, January) Recognizable Forms: Morphs of the Eastern Screech-Owl. Retrieved from


Hummingbirds (Trochilidae)

Heidcamp, A. 1997. Selaphorus hummingbirds: notes on identification. Birding 24: 18-29.


Woodpeckers (Picidae)

Dunn, J. 1978. The races of the Yellow-bellied Sapsucker. Birding 10: 142-149.

Ellison, W.G. 1992. Different drummers: identifying the rhythms of northeastern woodpeckers. Birding 24: 350-355.

Mlodinow, S.G., J.H. Barry., and C. D. Cox. 2006. Variation in Red-naped and Yellow-bellied Sapsuckers. Birding 38(6): 42-51.


Falcons (Falconidae)

Nicoletti, F. and D. Benson. 2000. Identification review: Gyrfalcon. Birding 32: 22-29.


Tyrant Flycatchers (Tyrannidae)

Brunton, D.F., and W.J. Crins. 1975. Status and habitat preference of the Yellow-bellied Flycatcher in Algonquin Park, Ontario. Ontario Field Biology 29: 25-28.

Hussell, D.J.T., T. Davis and R.D. Montgomerie. 1967. Differential migration of adult and immature Least Flycatchers. Birding-Banding 38:61-66.

Hussel, D.J.T. 1981. Migrations of the Least Flycatcher in southern Ontario. Journal of Field Ornithology 52: 97-111.

Hussell, D.J.T. 1982a. The timing of fall migration in Yellow-bellied Flycatchers. Journal of Field Ornithology 53: 1-6.

Hussell, D.J.T. 1982. Migrations of the Yellow-bellied Flycatchers in southern Ontario. Journal of Field Ornithology 53: 223-234.

Hussell, D.J.T. 1991a. Spring migrations of Alder and Willow Flycatchers in southern Ontario. Journal of Field Ornithology 62: 69-77.

Hussell, D.J.T. 1991b. Fall migrations of Alder and Willow Flycatchers in southern Ontario. Journal of Field Ornithology 62: 260-270.

Lee, C., A. Birch, and T. L. Eubanks. 2008. Field identification of Western and Eastern Wood-Pewees. Birding 40: 34-41.

Rowland, F. 2009. Identifying Empidonax flycatchers: the ratio approach. Birding 41: 30-39.

Whitney, B. and K. Kaufman. 1985a. The Empidonax Challenge: looking at Empidonax. Part I: Introduction. Birding 17: 277-287.

Whitney, B. and K. Kaufman. 1985b. The Empidonax Challenge: looking at Empidonax. Part II: Least, Hammond’s, and Dusky flycatchers. Birding 17: 277-287.

Whitney, B. and K. Kaufman. 1986a. The Empidonax Challenge: looking at Empidonax. Part III: “Traill’s” Flycatcher: the Alder/Willow problem. Birding 28: 153-159.

Whitney, B. and K. Kaufman. 1986b. The Empidonax Challenge: looking at Empidonax. Part IV: Acadian, Yellow-bellied, and Western flycatchers. Birding 18: 315-327.


Vireos (Vireonidae)

Bent, A. C. 1950. Life histories of North American wagtails, shrikes, vireos, and their allies. U.S. National Museum Bulletin 197.

James, R.D. 1978. Pairing and nest site selection in Solitary and Yellow-throated Vireos, with a description of a ritualized nest building display. Canadian Journal of Zoology 56: 1163-1169.

James, R.D. 1981. Factors affecting variation in the primary song of North American Solitary Vireos (Aves: Vireonidae). Canadian Journal of Zoology 59: 2001-2009.

James, R.D. 1984. Structure, frequency of usage, and apparent learning in the primary song of the Yellow-throated Vireo, with comparative notes on Solitary Vireos (Aves: Vireonidae). Canadian Journal of Zoology 62: 468-472.

James, R.D. 1996. Yellow-throated and Solitary Vireos in Ontario: introduction and behavior of unmated males. Ontario Birds 14(2): 45-49.

Rice, J. 1978a. Ecological relationships of two interspecifically territorial vireos. Ecology 59: 526-538.


Swallows (Hirundinidae)

Lethaby, N. 1996. Identification of Tree, Northern Rough-winged and Bank Swallows. Birding 27: 111-117.

Wilds, C. 1985. Unraveling the mysteries of the brown swallows. Birding 17: 209-215.


Thrushes (Turdidae)

Aldrich, J.W. Geographic variation of the Veery. Auk 56: 338-340.

Aldrich, J.W. and F.C. James. 1991. Ecogeographic variation in the American Robin (Turdus migratorius). Auk 108: 230–249.

Dunn, J. 1981. The identification of female bluebirds. Birding 12(1): 4-10.

Evans, W.R. 1994. Nocturnal flight call of Bicknell’s Thrush. Wilson Bulletin 106: 55-61

Lane, D. and A. Jaramillo. 2000a. Field identification of Hylocichla/Catharus Thrushes. Part I: Molt and aging of spotted thrushes and field ID of Wood Thrush and Hermit Thrush. Birding 32: 121-135.

Lane, D. and A. Jaramillo. 2000b. Field identification of Hylocichla/Catharus Thrushes. Part II: Veery and Swainson’s Thrush. Birding 32: 242-254.

Lane, D. and A. Jaramillo. 2000c. Field identification of Hylocichla/Catharus Thrushes. Part III: Gray-cheeked and Bicknell’s Thrushes. Birding 32: 318-331.

Mactavish, B. (2014, April 19) The Mythical Black-backed Newfoundland American Robin. Retrieved from

Mclaren, I.A. 1995. Field identification and taxonomy of Bicknell’s Thrush. Birding 27: 358-366.

Ouellet, H. 1993. Bicknell’s Thrush: Taxonomic status and distribution. Wilson Bulletin  105: 545-754.

Rimmer, C. 1996. A closer look: Bicknell’s Thrush. Birding 28: 118-123.

Wallace, G.J. 1939. Bicknell’s Thrush, its taxonomy, distribution, and life history. Proceedings of the Boston Society of Natural History 41: 211-402.


Gnatcatchers (Sylviidae)

Dunn, J. and K. Garrett. 1987. The identification of North American gnatcatchers. Birding 19(1): 17-29.


Longspurs (Calcariidae)

Sullivan, B.L. and E.L. Kershner. 2003. Learning to identify difficult longspurs. Birding 35: 508-514.


Wood Warblers (Parulidae)

Binford, L.C. 1971. Identification of Northern and Louisiana Waterthrushes. California Birds 2: 1-10.

Burke, D.M. and E. Nol. 1998. Influence of food abundance, nest-site habitat, and forest fragmentation on breeding Ovenbirds. Auk 115: 96-104.

Collins, S.L. 1983. Geographic variation in habitat structure of the Black-throated Green Warbler (Dendroica virens). Auk 100: 382-389.

Craig, J. 1985. Comparative habitat use by Louisiana and Northern Waterthrushes. Wilson Bulletin 97: 347-355.

Curson, J. 1992. Identification of Connecticut, Mourning and MacGillivray’s Warblers in female and immature plumages.  Birders Journal 1: 275-278.

Curson, J. 1993. Identification of Northern and Louisiana waterthrushes.  Birder’s Journal 2: 126-130.

Dunn, J. and K. Garrett. 1997. A Field Guide to the Warblers of North America. Houghton Mifflin Co., Boston, MA.

Foster, M.S. 1967. Pterylography and age determination in Orange-crowned Warbler. Condor 69: 1-12.

Francis, C.M. and F. Cooke. 1986. Differential timing of spring migration in wood warblers (Parulidae). The Auk 103(3): 548-556.

Gartshore, M.E. 1988. A summary of the breeding status of Hooded Warbler in Ontario. Ontario Birds 6: 85-89.

Getty, S. R. 1993. Call-notes of North American Wood Warblers. Birding 25: 159-168.

Harris, A. 1990. Palm Warblers use upland cutovers as nesting habitat in northwestern Ontario. Ontario Birds 8: 84-87.

Hough, J. 1996. Pine and “baypoll” warblers: plumage variation and identification problems. Birding 284-291.

Hubbard, J.P. 1970. Geographic variation in the Dendroica coronata complex. Wilson Bulletin 82: 355-369.

Hutto, R.L. 1981. Seasonal variation in the foraging behavior of some migratory wood warblers. Auk 98: 765-777.

Johnston, D.W. 1976. Races of Palm Warbler killed at a Florida TV tower. Florida Field Naturalists 4: 22-24.

Lehman, P. 1987. Immature Blackburnian and Cerulean Warblers: a cautionary note. Birding 19: 22-23.

Ouellet, H. 1967. The distribution of Cerulean Warbler in the province of Quebec. Auk 8: 272-274.

Raveling, D.G. and  D.W. Warner. 1965. Plumages, molt and morphometry of Tennessee Warblers. Bird banding 36: 169-179.

Regelski, D.J. and R.R. Moldenhauer. 1996. Discrimination between regional song forms in the Northern Parula. Wilson Bulletin 108: 335-341.

Shapiro, L. 2005. Hybrids of Golden-winged and Blue-winged Warblers. Birding 37: 278-287.

Whitney, B. 1983. Bay-breasted, Blackpoll, and Pine Warblers in fall plumage. Birding 15: 219-222.


 Sparrows (Emberizidae)

Aldrich, J.W. 1940. Geographic variation in eastern North America Savannah Sparrows (Passerculus sandwichensis). Ohio Journal of Science 40: 1-8.

Aldrich, J.W. 1984. Ecogeographical variation in size and proportions of Song Sparrows (Melospiza melodia). Ornithological Monographs No. 35, American Ornithologists’ Union, Washington, DC.

Atkinson, C.T. and C.J. Ralph. 1980. Acquisition of plumage polymorphism in White-throated Sparrows. Auk 97: 245-252.

Banks, R.C. 1964. Geographic variation in the White-crowned Sparrow Zonotrichia leucophrys. University of California Publications in Zoology 70:1-123.

Beadle, D. and J. Rising. 2002. Sparrows of the United States and Canada: The Photographic Guide. Princeton University Press, New Jersey.

Dunn, J. L., K. L. Garrett, and J. K. Alderfer. 1995. White-crowned Sparrow subspecies: Identification and distribution. Birding 27: 183-200.

Dunn, J. 2002. The identification of Pink-sided Juncos. Birding 34: 432-443.

Garrett, K.L., J.L. Dunn, and R. Righter. 2000. Call notes and winter distribution in the Fox Sparrow complex. Birding 32: 412-417.

Lowler, J.K. 1961. Polymorphism in the White-throated Sparrow, Zonotrichia albicollis (Gmelin). Canadian Journal of Zoology 39: 281-292.

Mclaren, I.A. and A. G. Horn. 2006. The Ipswich Sparrow: past, present, and future. Birding 38: 52-59.

Murray, B.G. Jr. 1969. A comparative study of Le Conte’s and Sharp-tailed Sparrows. Auk 86: 199-231.

Pyle, P. and P. Henderson. 1990. On separating female and immature Oporornis warblers in the fall. Birding 22: 222-229.

Pyle, P. and D. Sibley. 1992. Juvenal-plumaged Le Conte’s Sparrows on migration. Birding 24: 70-76.

Pyle, P. and S. N. G. Howell. 1996. Spizella sparrows: intraspecific variation and identification. Birding 28: 374-388.

Rimmer, C.C. 1986. Identification of juvenile Lincoln’s and Swamp Sparrows. Journal of Field Ornithology 57: 114-125.

Rising, J.D. 2001. Geographic variation in size and shape of Savannah Sparrows (Passerculus sandwichensis). Studies in Avian Biology 23.

Rising, J. 2010. The many Savannah Sparrows. Birding 42: 44-55.

Sibley, D. 1996. Field identification of the Sharp-tailed Sparrow complex. Birding 28: 197-208.

Swarth, H.W. 1920. Revision of the avian genus Passerella with special reference to the distribution and migration of the races in California. University of California Publications in Zoology 21: 75-224.

Todd, W.E.C. 1953. Further taxonomic notes on the White-crowned Sparrow. Auk 70: 370-372.

Woods, P. 1999. A Familiar Mystery: Polymorphism and the White-throated Sparrow. Birding 31: 263-267.

Zink, R.M. and A. E. Kessen. 1999. Species limits in the Fox Sparrow. Birding 31: 508-517.

Zink, R.M., and 6 co-authors. 2005. Mitochondrial DNA variation, species limits, and rapid evolution of plumage coloration and size in the Savannah Sparrow. Condor 107:21-28.


Blackbirds (Icteridae)

Lee, C. and A. Birch. 1998. Field identification of female and immature Bullock’s and Baltimore Orioles. Birding 30: 282-295.


Finches (Fringillidae)

Benkman, C.W. 1989. Breeding opportunities, foraging rates, and parental care in White-winged Crossbills. Auk 106: 483-485.

Benkman, C.W. 1990. Foraging rates and timing of crossbill reproduction. Auk 107: 376-386.

Czaplak, D. 1995. Identifying Common and Hoary redpolls in winter. Birding 27: 446-457.


North America

Benton, T.G., D.M. Bryant, L. Cole, and H.Q.P. Crick. 2002. Linking agricultural practice to insect and bird populations: a historical study over three decades. Journal of Applied Ecology 39: 673-687.

Bolgiano, N.C. 2004. Cause and effect: changes in boreal bird irruptions in Eastern North America relative to the 1970s Spruce Budworm infestation. American Birds 58: 26-33.

Bruderer, B. and F. Liechti. 1998. Flight behavior of nocturnally migrating birds in coastal areas — crossing or coasting. Journal of Avian Biology 29: 499507.

Buffington, J.M., J.C. Kilgo, R.A. Sargent, K.V. Miller, and B.R. Chapman. 1997. Comparison of breeding bird communities in bottomland hardwood forests of different successional stages. Wilson Bulletin 109: 314-319.

Crossley, R. 2011. The Crossley ID Guide: Eastern Birds. Princeton, NJ: Princeton University Press.

Dunn, J.L. and J. Alderfer. 2011. National Geographic Field Guide to the Birds of North America. 6th ed. Washington, D.C.: National Geographic Society.

Elliot, L. 1999. Music of the Birds: A Celebration of Birdsong. Houghton Mifflin Harcourt., Boston, MA.

Howell, S.N.G. 2010. Molt in North American Birds. Peterson Reference Guide Series. Boston: Houghton Mifflin Harcourt.

Jaramillo, A. 2006. Tales from the cryptic species. Birding 38(3): 30-38.

Karlson, K.T. and D.A. Rosselet. Birding by impression: a different approach to field identification. Birding 39: 56-63.

Kaufman, K. 1984. Terminology and bird topography. Birding 16: 191-196.

Kaufman, K. 1990. Advanced Birding. Houghton Mifflin Co., Boston, MA.

Peterson, R.T. 2008. Peterson Field Guide to Birds of North America. Houghton Mifflin Co., Boston, MA.

Sibley, D.A. 1994. A guide to finding and identifying hybrid birds. Birding 26: 163-177.

Sibley, D.A. 2014. The Sibley Guide to Birds. 2nd ed. New York: Alfred A. Knopf.

Wilds, C. 1989. The terminology of plumage and molt. Birding 21: 148-153.



Godfrey, W.E. 1966. The Birds of Canada. Bulletin 203. National Museum of Canada. Ottawa.

Godfrey, W.E. 1986. The Birds of Canada. Revised Edition. National Museum of Canada. Ottawa.

Manning, T.H. 1952. Birds of the west James Bay and southern Hudson Bay coasts. Bulletin 125. National Museum of CanadaOttawa.

Todd, W.E.C. 1963. Birds of the Labrador Peninsula and Adjacent Areas. Carnegie Museum, Pittsburgh, Pennsylvania, and the University of Toronto Press, Toronto, Ontario.



Austen, M.J.W., M.D. Cadman, and R.D. James. 1994. Ontario birds at risk: status and conservation needs. Federation of Ontario Naturalists and Long Point Bird Observatory, Don Mills.

Cadman, M.D., D.A. Sutherland, G. G. Beck, D. Lepage, and A.R.Couturier (eds). Atlas of the Breeding Birds of Ontario, 2001-2005. Bird Studies Canada, Environment Canada, Ontario Field Ornithologists, Ontario Ministry of Natural Resources, and Ontario Nature, Toronto, xxii + 706 pp.

James, R.D. 1991. Annotated Checklist of the Birds of Ontario. Second Edition. Life Sciences Miscellaneous Publications. Royal Ontario Museum, Toronto.

Peck, G.K., and R.D. James. 1987. Breeding Birds of Ontario: Nidiology and Distribution. Volume 2: Passerines. Life Sciences Miscellaneous Publications. Royal Ontario Museum, Toronto.

Weir, R. D. 1989. The birds of the Kingston region. Kingston Field Naturalists, Kingston, Ontario.



Kroodsma, D.E. 1979. Vocal duelling among male Marsh Wrens: evidence for ritualized expression of  dominance/subordinance. Auk 96: 506-515.

Kroodsma, D.E. 1984. Songs of the Alder Flycatcher (Empidonax alnorum) and Willow Flycatcher (Empidonax trailli) are innate. Auk 101: 13-24.

Kroodsma, D.E. 2005. The Singing Life of Birds. The Art and Science of Listening to Birdsong. Houghton Mifflin Co., Boston, MA.

Kroodsma, D.E. 2009. Birdsong by the Seasons.  Boston, Masschusetts, Houghton Mifflin Co., Boston, MA.

Marler, P., and M. Tamura. 1962. Song dialects in three populations of the White-crowned Sparrow. Condor 64: 368-377.

Marler, P., and H. Slabbekoorn. 2004. Nature’s Music: The Science of Birdsong. London: Elsevier Academic Press.

Mcnair, D.B. and R.A. Forster. 1983. Heterospecific vocal mimicry by six oscines. Canadian Field Naturalist 97: 321-322.

Thorpe, W.H., and P.M. Pilcher. 1958. The nature and characteristics of subsong. British Birds 51: 509-514.


My Publications

Ruddy, J. and J. Liguori. 2014. Northern Red-tailed Hawks: A site dedicated to the identification and natural history of abieticola Red-tailed Hawks. Retrieved from

Ruddy, J. 2014. Identifying Northern Red-tailed Hawks. eBird Canada.

Ruddy, J. 2016. Photo Quiz. OFO News 34(1): 15-16.

Ruddy, J. 2016. Photo Quiz. OFO News 34(2): 15-16.

Ruddy, J. 2016. Photo Quiz. OFO News 34(3): 15-16.

Ruddy, J. 2017. Photo Quiz. OFO News 35(1): 15-16.

Ruddy, J. 2017. Photo Quiz. OFO News 35(2): 15-16.

Ruddy, J. 2017. Photo Quiz. OFO News 35(3): 15-16.

Ruddy, J. 2018. Photo Quiz. OFO News 36(1): 15-16.

Ruddy, J. 2018. Photo Quiz. OFO News 36(2): 15-16.


Facebook Sites of Interest

Advanced Bird ID:

Field Naturalists of Ontario:

Hawk ID:

Ontario Birds:

OFO – Ontario Field Ornithologists:

Ottawa-Gatineau Hawkwatchers:

Ottawa Field-Naturalists’ Club:

North American Gulls:

RIFF RAFF Hawkwatch Group:

Simcoe County Banding Group:


Blogs & Websites of Interest

Brandon Holden’s blog:

Bruce Di Labio’s blog:

Gillian Mastromatteo’s blog:

Jacques Bouvier’s blog:

Jean Iron & Ron Pittaway’s site:

Jerry Liguori’s Blog:

Josh Vandermeulen’s blog:

Mike Burrell’s blog:

Ontario Field Ornithologists:

Ontario Bird Checklist:

OntBirds archive:


The Afternoon Birder:


Birding Ethics

Ontario Field Ornithologists:

Ottawa Field-Naturalists’ Club:

Guided bird tours throughout eastern Ontario and beyond!