Barn swallows return to the Fraser Valley

Nesting swallows can eat up to 850 insects a day, writes Janne Perrin

Barn swallows may seem like messy house guests

Janne Perrin

For the Observer

After spending the winter 7,000 miles away, barn swallows (Hirundo rustica) have been spotted in the Fraser Valley. From their wintering grounds in Central and South America, Barn Swallows fly about 600 miles per day to return to North America to breed.

Barn swallows are one of the seven species of Neotropical migrant swallows that nest in Canada.  Under the Migratory Birds Convention (1995 Protocol), all swallows and their eggs and nest are protected from disturbance or destruction. It is also illegal under the BC Wildlife Act to destroy these birds or their eggs.

Barn swallows, a six-inch long dark blue-backed and orange-breasted insectivore with a deeply fork-tailed, were listed in 2011 as threatened by COSEWIC (Committee on the Status of Endangered Wildlife in Canada).

This is alarming as barn swallows offer people important ecosystem services.

Their numbers have declined by 70% in the last 40 years. Decline is attributed to loss of nesting and foraging habitat, decline in insect populations and mortality due to climate change.

The barn swallow eats only insects usually foraging within 30 feet of the ground near water. Mayflies, mosquitoes, beetles, moths and other flying insects make up a large part of its diet. A single barn swallow can consume 60 insects per hour or a whopping 850 per day.

A breeding barn swallow makes about 29 visits to its nest each hour of daylight with about 20 insects in a pellet in its throat. That would be over 400 trips a day. It takes 18 to 23 days for a hatchling to leave the nest. A second brood is often reared with the first brood’s juveniles assisting in feeding the nestlings. You do the math on the number of insects eaten!

Nests are made of mud and lined with grass and feathers and are built from late April through to June. A barn swallow pair gathers mud and rolls it into a pellet and then carries it back to the nesting site in their bills. The cup-shaped nest is built in the rafters or eaves of buildings, on bridges, in mine shafts or on other man-made structures.

Unfortunately a breeding pair of swallows cause us humans concern as we think the nests are dirty and messy. A little ingenuity (newspaper, a shelf) takes care of the mess.  And consider these birds consume hundreds of insects every day so inviting a family of them into the backyard provides free pest control.

Last year, Harrison’s Ken Burningham hosted a family. He wrote “I have a beautiful bird’s nest on my back deck balancing on a clothes line pulley.“  The Ramada Inn’s parkade entrance hosted several pairs and some even nested in the parkade itself. Chantilly’s Gelato Parlor has allowed a pair to nest under their awning for many years. Barn swallows return to the same site year after year and will reuse an old nest.

A big thanks to these environmentally friendly Harrisonians! Barn Swallows play important ecological and biological roles in our environment and make a significant contribution to Canada’s economy.

Look for them swooping over the lagoon – they drink and bathe on the wing — or gathering mud for their nests along the muddy shore.  Enjoy as by September most have headed back to South America.

Learn more at www.learner.org/jnorth/swallow/index.html.