Cave Swallows in Oakville near Toronto

Two Cave Swallows at the small sewage treatment plant at Sedgewick Park in Oakville, near Toronto on 21 November 2015. They were feeding on flying insects over open water cells and perching on railings inside. They arrived recently brought in by the warm front, likely coming from northern Mexico and Texas while dispersing in the fall, probably after a good breeding season. This is a natural occurrence and unfortunately they will not survive.

They were active, flying around and catching flying insects, then resting on the pipes. Recently there has been a large irruption of Cave Swallows into eastern North America, including the East Coast, Quebec, New York, Ohio and southern Ontario. Cave Swallows that make it to Ontario in fall are believed to be the subspecies Petrochelidon fulva pelodoma, which breeds in the Southwest in Mexico and Texas.

Another two Cave Swallows were at nearby Bronte Harbour. Cave Swallows are undergoing a range expansion, so the birds we are seeing today may be the vanguard or the explorers for future generations. As Nathan Hood pointed out on Facebook, because of its microclimate, the Sedgewick Park treatment plant may temporarily keep these birds alive longer than elsewhere. Eventually in a mild winter some could survive.

 It was a rare treat to see these swallows and learn about their irruptions, behaviour, and how to identify them.