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Swainson’s Hawks: Migration and Colouration

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By Courtney Collins

You may have seen a Swainson’s hawk (Buteo swainsoni) without even realising it as they are a common sight throughout the spring, summer, and even early fall in most of Alberta, often in urban areas.[1] These amazing raptors are white, grey, and brown and can be seen on light poles, fence posts, and trees, scanning open areas for insects and rodents. They also spend time soaring above open grasslands (or urban green spaces) looking for prey. Interestingly, these hawks will also hunt on foot and can sometimes be seen chasing prey this way.[2] Hawks in the Buteo genus are fairly bulky with shorter tails and, the Swainson’s hawk is no exception.[3]

Light morph Swainson’s hawk soaring (photo credit Vik Hewitt, 2021)

Master Migrators

Swainson’s hawks are unique in that they have the longest migration of any raptor in North America. While they spend the warmer weather in much of the Canadian prairies and American Midwest, they migrate ahead of the cold weather to Argentina.[4] This migration route can be over 19,000 km for some.[5] When these amazing hawks migrate, they can form groups – or ‘kettles’ – of thousands of birds.[6] While these large groups aren’t seen in Canada, there are spots through the United States, Mexico, and South America that you can see this incredible sight.[7]

Colour Morphs

Like all bird species, Swainson’s hawks have colour variations depending on age. There are two main colour morphs for adults, light and dark. The light morph, most common in Alberta and anywhere east of the Rocky Mountains, has a white or cream (potentially with some reddish-brown) belly and underside; the dark morph has a reddish-dark brown belly and underside.[8] Both adult morphs have a reddish-brown head.[9] These two morphs are quite distinctive, and one would be forgiven for thinking these were two different species. Juvenile Swainson’s hawks also have both a light and dark morph and their colourations are also distinctively different. All juveniles have a ‘speckled’ or ‘streaked’ appearance, including their head, with pale edges on the tips of their wings. However, the light morph hawks have a white or cream colour under darker speckles, while the dark morph hawks have darer colouring overall, showing less creamy colouration.[1]

Swainson’s hawks breed in the summer and can be territorial during this time.[2] The warmer weather brings excellent opportunities to enjoy these amazing raptors from a safe distance. See if you can spot the difference between adults and juveniles, and perhaps even see variations in colour morphs!


[1] All About Birds, “Swainson’s Hawk”, The Cornell Lab, 2023. https://www.allaboutbirds.org/guide/Swainsons_Hawk/id

[2] All About Birds, “Swainson’s Hawk”, The Cornell Lab, 2023. https://www.allaboutbirds.org/guide/Swainsons_Hawk/lifehistory


[1] Alberta Government, “Human-wildlife conflict – Raptors”, Alberta Government, 2023. https://www.alberta.ca/raptors#:~:text=In%20urban%20areas%2C%20one%20of,the%20loud%20noises%20they%20make.

[2] All About Birds, “Swainson’s Hawk”, The Cornell Lab, 2023. https://www.allaboutbirds.org/guide/Swainsons_Hawk/lifehistory

[3] All About Birds, “Swainson’s Hawk”, The Cornell Lab, 2023. https://www.allaboutbirds.org/guide/Swainsons_Hawk/overview

[4] All About Birds, “Swainson’s Hawk”, The Cornell Lab, 2023. https://www.allaboutbirds.org/guide/Swainsons_Hawk/lifehistory

[5] All About Birds, “Swainson’s Hawk”, The Cornell Lab, 2023. https://www.allaboutbirds.org/guide/Swainsons_Hawk/lifehistory

[6] All About Birds, “Swainson’s Hawk”, The Cornell Lab, 2023. https://www.allaboutbirds.org/guide/Swainsons_Hawk/overview

[7] All About Birds, “Swainson’s Hawk”, The Cornell Lab, 2023. https://www.allaboutbirds.org/guide/Swainsons_Hawk/overview

[8] All About Birds, “Swainson’s Hawk”, The Cornell Lab, 2023. https://www.allaboutbirds.org/guide/Swainsons_Hawk/id

[9] All About Birds, “Swainson’s Hawk”, The Cornell Lab, 2023. https://www.allaboutbirds.org/guide/Swainsons_Hawk/id

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