The histogram below shows the incomplete knowledge of the bird
as of the end of 2003, with just 30 observations.
The picture as glimpsed at first was of a short
winter season, 23 September to 20 January and subsequent
northward migration, 26 March (2003) to 11 May. The birds
are not seen at all
during the summer months, consistent with nesting in woodlands
further north from the Trent valley.
In comparison, using 1083 observations
over 22 years,
a more complete pattern emerges.
Data from 2009-2020 indicate that migrating birds
nowadays constitute no more than an October "shoulder" to the main
Just six observations occurred in and close to the
midsummer months (9 May, 11 May, 16 August, and 18, 23 and 30 September),
less than 1 percent of the total.
In spring, the last remaining birds (of the "99 percent",
those that definitely leave)
summer breeding grounds to the north, no later than 23 April. They return gradually
in the fall to overwinter. with the first arrivals generally around the 03-16 October
(rarely noted as early as 30 September or as late as 01 November).
At Presqu'ile provincial park, roughly 40 km to the south, the junco is a common spring migrant (late March to mid-May) and abundant fall migrant (mid- September to early November). There are three summer records, and the bird is also an uncommon winter resident (LaForest, 1993, pp.364-365). In Peterborough county, to the northwest, the junco is a common migrant which also overwinters, and some stay in the summer, mostly in the north of the county (Sadler, 1983, p.153; Cadman et al., 1987, pp.464-465). The presence of "visiting" birds makes it hard to determine migration times, but suggested ranges are 06 March to 16 May in spring, and 16 August to 20 October in the fall. The bird typically starts nesting in Ontario in the second half of April, and in summer is most abundant in the far north of the province, in the northern Hudson Bay Lowlands (Cadman et al., 2007, pp.572-573).
Cadman,MD, Eagles,PFJ and Helleiner,FM (1987) Atlas of the Breeding Birds of Ontario. Federation of Ontario Naturalists and Long Point Bird Observatory, published by University of Waterloo Press, 617pp.
Cadman,MD, Sutherland,DA, Beck,GG, Lepage,D and Couturier,AR (editors) (2007) 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, 706pp.
LaForest,SM (1993) Birds of Presqu'ile Provincial Park. Friends of Presqu'ile Park / Ontario Ministry of Natural Resources, 436pp.
Pearson,TG (editor) (1917) Birds of America. Garden City Books, New York. See Part III, pp.45-47.
Sadler,D (1983) Our Heritage of Birds: Peterborough County in the Kawarthas. Peterborough Field Naturalists / Orchid Press, Peterborough, ON, 192pp.
Here is a fine new (January 2021) 10-minute video on
"Dark-eyed juncos - fun facts about their winter habits" by Lesley the Bird Nerd.