The ruffed grouse tends to skulk in the low cover, and may only be noticed when flushed, and forced to beat a noisy retreat. In the 15-year data, there is a clear spike in the period 2003-2008. On reflection, this is probably due to a period of long dog walks in which the keen nose of our Bernese-border collie cross flushed many birds that would otherwise have lain low, undetected, as the humans passed by. The grouse is present year-round in modest numbers, often unremarked. When flushed, the grouse is most often alone, but not infrequently in pairs and, on a handful of occasions as a group of three birds. In 2014 to date, the grouse has been noted just twice, on 29 March and 11 April. The grouse may detected in winter by tracks in the snow, like a smaller version of the bold, primeval claw marks of the wild turkey. In my notes, likely grouse tracks were described on 08 January 2000; 22 February 2004; 31 January 2010; and 02 and 14 February 2010. The grouse has been noted on farms in nearby townships, to the north near Round Lake (25 October 1998) and to the northeast, east of Wolf Lake in Tudor township (three birds flushed in succession, 17 January 2000).
The Seymour data indicate a quiet period from May to September, when the young
are hatched and raised, followed by a time of relatively frequent
sightings in the last quarter of the year, and lesser but still
regular sightings during the winter, not counting the
occurrence of tracks in the snow.
At Presqu'ile provincial park, roughly 40 km to the south, the ruffed grouse is a year-round breeding resident, most easily found in spring with the males drumming in display; and in winter, when birds tend to concentrate in conifer stands (LaForest, 1993, p.117).
In Peterborough county, to the northwest, the ruffed grouse is common. Sadler (1983, pp.67-68) offers an alternative explanation to our local observed peak in grouse observations, 2003-2009: "Found year-round, this common game bird is cyclic in numbers over about a nine-year period, regardless of variations in climatic or hunting pressures".
The ruffed grouse is distributed across southern Ontario, and breeds in every region of the province except the Far North (Cadman et al., 1987, pp.138-139). Poplar (aspen) and birch trees are an important part of the bird's habitat. Numbers are lower in intensively farmed areas (e.g., the far southwest of Ontario) and in urban regions such as the Greater Toronto Area. The fluctuation in population density noted by Sadler is affirmed, but shows up mainly in still-forested northern areas, rather than the scattered woodlots of the agricultural south. In the revised Bird Breeding Atlas (Cadman et al., 2007, pp.124-125) the ruffed grouse remains widespread in relatively modest numbers. Again, population cycles are noted in parts of the bird's range, in cycles that may vary from 2.5 to 10 years (the atlas' Bird Breeding Survey show recurring peaks of abundance in different areas, spaced 2 to 6 years apart). Clearly, a few more years'-worth of observations in Trent Hills would not hurt...
References
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.
Leopold,A (1966) A Sand County Almanac, with Essays on Conservation from Round River. Ballantyne Books, Inc., 295pp.
Sadler,D (1983) Our Heritage of Birds: Peterborough County in the Kawarthas. Peterborough Field Naturalists / Orchid Press, Peterborough, ON, 192pp.