Tree Swallow (Tachycineta bicolor)
The Tree Swallow is a common sight in central Alberta. This distinctive blue and white Swallow gracefully chases insects above rural agricultural fields. They spend almost all of their time flying and catching insects. Despite how common they are, they are in decline.
Why they Matter to Us
Tree Swallows eat mosquitoes and other flying insects.
They frequently use nest boxes so we can watch them grow and learn about them.
Tree Swallows are in steep decline (49% from 1966 to 2014.) Like other insectivores, this is due to pesticide use, habitat loss, and climate change.
Due to their visibility, Tree Swallows act as an indicator of environmental harm.
How You Can Help
Don’t use pesticides in your garden or farm, particularly neonicotinoid pesticides. These wash into natural waterways and reduce insect numbers so the Tree Swallows don’t have as much food to eat.
Put up a nest box. Tree Swallows like open areas such as agricultural fields.
Reduce your carbon footprint to reduce impacts of climate change.
How to Identify
Identify by Sight
To identify the Tree Swallow, look for these distinguishing features:
Vivid blue back, head, and wings, though these may appear grey in young birds.
Very small and flat bill.
Very long wings compared to the rest of their bodies.
Small size: Tree Swallows are 12-15 cm in length, up to a whopping 25g in weight, and a wingspan of 30-35 cm.
Identify in Flight
To identify the Tree Swallow as it flies by, look for these clues:
Extreme grace and agility while flying. Will dive and perform other acrobatic maneuvers to catch insects.
White underside and vivid blue upperparts.
Identify by Sound
Tree Swallows have a chattering song that they frequently make while flying and while stationary. Because they often gather in large numbers, they can make quite the racket!
Click here to listen to the many sounds of a Tree Swallow.
Where to Find
You can find Tree Swallows in all parts of North America except the high Arctic. They breed from the tundra to the central United States, and they winter throughout most of Central America.
Despite their name, Tree Swallows prefer open areas like agricultural fields or wetlands. They get their name from their tendency to nest in tree cavities. This protects their young from predation. They like to be near wet or open areas because wetlands produce much of their preferred food.
The female builds the nest.
They may have up to 7 young, and they may nest twice in one season.
They are very social and like to breed in large groups.
Sometimes they take the same mate year after year.
They are migratory. They breed in Canada, spend a couple of months resting up in the central USA, then fly to Central America for the winter.
They primarily eat insects that they must catch by flying. This includes a wide variety of insects including: dragonflies, damselflies, flies, mayflies, ants, wasps, beetles, stoneflies, butterflies, and moths.
In the nest, their eggs and young may be predated by raccoons, black bears, chipmunks, mink, weasels, deer mice, feral cats, American Kestrels, Common Grackles, American Crows, and Northern Flickers.
Outside the nest, adult Tree Swallows can be predated on by other bird species, including: Sharp-shinned Hawks, Merlins, Peregrine Falcons, and Black-billed Magpies.
The oldest known Tree Swallow was 12 yrs when caught during banding in Ontario.
Tree Swallows use nest boxes. As forests and dead trees are cut down, these birds lose habitat. You can put up a nest box to counter this.
Tree Swallows are some of the most graceful birds in the air, relying on incredible acrobatics to catch insects while flying.
Help conserve homes for Tree Swallows by donating to EALT today!
Winkler, D. W., K. K. Hallinger, D. R. Ardia, R. J. Robertson, B. J. Stutchbury, and R. R. Cohen (2011). Tree Swallow (Tachycineta bicolor), version 2.0. In The Birds of North America (A. F. Poole, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bna.11
BirdLife International. 2016. Tachycineta bicolor. The IUCN Red List of Threatened Species 2016: e.T22712057A94316797. http://dx.doi.org/10.2305/IUCN.UK.2016-3.RLTS.T22712057A94316797.en. Downloaded on 23 May 2018.