The Return of Swallows: Nesting Practices

Can you believe it? It's April this week! It feels like we have made it through the worst of winter and are now getting to experience the return of many of our favourite migrants. Throughout the next month we will see the return of some really fascinating birds: swallows! Generally, swallows are aerial insectivores. Because they rely so strongly on insect populations, they have to wait until there is food supply to move back into our area. 

Swallows are fascinating birds. They are beautiful to watch swoop swiftly through the air with their iridescent colours. 

We are going to overview some of the Swallow species you can see here in Southern Ontario, what they look like, and how they nest. Because swallows are cavity nesters, there are ample opportunities to provide nesting spaces for them to nest on your property. 

1. Tree Swallows 

Tree Swallows are easily distinguishable from some other swallow species by their colouring. Their backs are a bright iridescent blue, with bright white bellies. They nest in tree cavities making them frequenters of nesting boxes as well. 

Tree Swallow poking out of its nesting box. Photo by Heather Kerrison 

They are typically found near bodies of freshwater, as these areas are highly dense in insects, their main source of food. They spend a lot of time sitting on, flying near or defending their nest box so its always a good place to see them. Because of the territorial nature of nest box selection, it's a good idea to have two placed a distance apart, so that Bluebirds could take one, swallows the other. 

Tree Swallow bringing a feather into its nesting box. Photo by Kristen Martyn. 

2. Barn Swallows 

Barn Swallows are listed as a threatened species in Ontario. Their declines are partly attributed to losses in available nesting sites, including open barns, and amount of habitat available for foraging (i.e; open agricultural areas). They almost exclusively nest on manmade structures. 

Artificial Nesting Site for Barn Swallows. Photo by Kristen Martyn. 

Above you can see an example of an artificial nesting site for Barn Swallows, you may have seen these in farmers fields and wondered what the structures are for- Barn Swallows!

Barn Swallow in made nest. Photo by Kristen Martyn. 

They look to build mud formed cups against man-made structures. They nest in a variety of areas including eaves and rafters of buildings.  They particularly like cross beams of barns, sheds and stables. 

3. Cliff Swallows 

Cliff Swallows look strikingly similar to Barn Swallows. 

Cliff Swallows have more white bellies whereas Barn Swallows have a continuation of their cinnamon like colouring. Barn Swallows also have longer forked tails and longer, slimmer bodies than Cliff Swallows. 

Cliff Swallow in its nest. Photo by Kristen Martyn. 

Their mud nests are built in colonies, also often attached to manmade structures, as well as cliffs. They feed mostly in areas near and over water, therefore areas near water are where you are most likely to see them. 

Cliff Swallow nest colony, attached to a manmade structure. Photo by Heather Kerrison. 

4. Purple Martins 

Purple Martins are the largest of the swallows in Ontario and are also aerial insectivores. Identified and named by their deep iridescent purple plumage.  Since humans started supplying nest boxes, Purple Martins have become increasingly more urban and now live mostly near cities and towns. They will visit multiple sites before choosing where they will nest. They typically nest in colonies, which is why Purple Martin nesting boxes are more complex and often "condominium style". 

Purple Martin perched on nesting condominium. Photo by Heather Kerrison. 

Purple Martin Nesting Boxes. Photo by Kristen Martyn. 

I don't know about you, but I am very excited to see these birds back. With their boisterous chirps, acrobatic flight, and dazzling colours, they are a delight to see return each spring. 

If you are looking to have more nesting boxes on your property but don't know where to start, please stop into either Barrie or Newmarket. Our team is super knowledgeable and can help you decide what may work best for your area. 

Don't forget to look up!

Warmly, 

Heather