Barn Swallows: A Five-Year Perspective on Nesting at the Swallow Hotel
By: Julia Shewan (she/her), B.Sc, RPBio, Conservation Programs Assistant, CVWMA
As I look back on my time at the CVWMA, I realize it’s been a while since some news got out about our Swallow Hotel. Did you know the building turns five this year? It was being constructed right when I started working at the CVWMA in October 2018. It was built to provide compensation habitat for barn swallows that nested at the Interpretive Centre, as the centre was deconstructed in the fall of 2019. The idea was to have the Swallow Hotel available for the 2019 breeding season, and swallows could come check out the new digs and nest in cushy pre-built wooden nest cups. Sounds like a luxury hotel to me! Barn swallows are a species of conservation concern in Canada and loss of suitable nesting habitat is one of several threats faced by the species.
It's been fascinating to watch the progression of breeding activities over the years. Things were a bit slow in the first couple of years at the Swallow Hotel compared to the hustle and bustle of activity we’d seen previously underneath the Interpretive Centre. The first year, a single breeding pair nested once. The following two years, we inferred there were three and two breeding pairs respectively, each of which nested twice during the breeding season. Things started getting busy in 2022 and 2023, when we estimated that eight and fourteen breeding pairs were using the structure, respectively. The majority of breeding pairs in 2022 and 2023 made two breeding attempts through the season, and more rarely, some made three attempts and one pair was assumed to have nested only once. It was in these last two years that we saw swallows building their own mud nests inside and outside the structure, with successful breeding in these natural nests being recorded in 2023. It’s exciting to see swallows building natural nests, a trend we hope will continue in future years, although we will still maintain the wooden nest cups for any swallows that choose to use them.
Our monitoring results have really been encouraging when you look back across time. By in large, most breeding attempts in all years have been successful, with apparent nest success ranging from 76 to 100% from 2019 to 2023. By successful we mean that breeding pairs were able to raise at least one, but most often more than one, chick to fledging age. We’ve seen the range from just one fledgling up to five fledglings in a nest; in the latter case the young are quite pressed for space as they grow towards fledging age and may spend some time squished underneath or behind their siblings. It’s no wonder they leave these cramped quarters for the freedom of the sky as soon as they are able.
We will continue to monitor barn swallows nesting at the Swallow Hotel, hoping that more swallows find and use the structure in the future. We don’t know just how many swallow pairs the structure could support, and we hope further monitoring might help us answer this and other questions about this enigmatic and sensitive species. We appreciate that folks are interested in what’s going on inside the structure, especially considering what I’ve just spoken about. However, we ask the public to please avoid fully approaching or entering the structure during the breeding season (May through early September) to avoid disturbing breeding birds. If your curiosity gets the better of you, please don’t hesitate to reach out to us to inquire about the latest happenings inside the hotel! | 
