Volume 42 Number 3 123 with many territories, it has not been occupied annually. Of course, the birds could have been missed in years with poor coverage. Nests found in two previous seasons (2016 and 2017) were built in typical sites in small shrubs, so the terri- tory does contain suitable “natural” nesting sites. During a follow-up visit on 30 July 2024, Winnie Poon and I were able to locate two recently fledged young from this nest (Figure 5), so it was evidently successful. According to the literature, nesting by Northern Mock- ingbirds on artificial structures occurs only rarely across their extensive range in North America. Thus far, it seems to be even more unusual in Ontario, at the northern limit of their breeding range. Literature Cited Bent, A.C. 1948. Life Histories of North American Nuthatches, Wrens, Thrashers and their Allies. United States National Museum Bulletin 195. Washington, D.C. 475pp. Cadman, M.D., D.A. Sutherland, G.G. Beck, D. Lepage and A.R. Couturier (Eds.). 2007. Atlas of the Breeding Birds of Ontario, 2001–2005. Bird Studies Canada, Environment Cana- da, Ontario Field Ornithologists, Ontario Ministry of Natural Resources and Ontario Nature. Toronto, ON. xxii + 706pp. Farnsworth, G., G.A. Londono, J.U. Martin, K.C. Derrickson and R. Breitwisch. 2020. Northern Mock- ingbird (Mimus polyglottos), version 1.0. In Birds of the World (A.F. Poole, Editor). Cornell Lab of Ornithology, Ithaca, NY. https://doi.org/10.2173/bow.nomoc.01 Laskey, A.R. 1962. Breeding Biology of Mockingbirds. Auk 79:596–606. Means, L.L. and J.W. Goertz. 1983. Nesting Activities of Northern Mocking- birds in Northern Louisiana. The South- western Naturalist 28:61–70. Peck, G.K. and R.D. James. 1987. Breeding Birds of Ontario: Nidiology and Distribution. Vol. 2: Passerines. Royal Ontario Museum, Life Sciences Miscellaneous Publications. Alger Press. Toronto, ON. 387pp. Peck, G.K and R.D. James. 1998. Breeding Birds of Ontario: Nidiology and Distribution. Vol. 2: Passerines (First Revision — Part B: Thrasher to Warblers). Ontario Birds 16:11–25. Smith, R.B.H. and W. Poon. 2006. The changing status of the Northern Mockingbird in the Greater Toronto Area. Ontario Birds 24:106–159. Smith, R. and W. Poon. 2007. Northern Mockingbirds in the Greater Toronto Area: The Nesting Season 2007. Toronto Birds 1:130–134. Roy B.H. Smith Richmond Hill, Ontario Email: gtabirder@gmail.com