The typical migration through, and residence and breeding of these birds at Presqu'ile provincial park, roughly 40 km to the south, occurs from mid-April to late September, with extreme sightings on 13 April and 16 November (LaForest, 1993, pp.251-252). Birds seen in the park after mid-May are part of the local breeding population, while fall migrants move through from late July to late September. In Peterborough county, to the northwest, the barn swallow has been noted from 03 April to 05 October (Sadler, 1983, pp.112,177).
The town of Pembroke, on the right (Ontario) bank of the Ottawa River, has been famous since the mid-20th century for large seasonal roosts of swallows, a total of six species of swallows and martins (Theberge, 1989). These roost in willows growing on a sandbar, and are preyed upon by small numbers of merlin, the mid-sized falcon known also as a pigeon hawk.
References
LaFOREST,SM (1993) Birds of Presqu'ile Provincial Park. Friends of Presqu'ile Park / Ontario Ministry of Natural Resources, 436pp.
SADLER,D (1983) Our Heritage of Birds: Peterborough County in the Kawarthas. Peterborough Field Naturalists / Orchid Press, Peterborough, ON, 192pp.
THEBERGE,JB (1989) Pembroke swallows. In "The Natural History of Ontario" (Theberge,JB editor), McClelland & Stewart Inc., Toronto, 397pp., 316-317.