Swainson's Hawks Are Passing Through

On their way to their northern breeding grounds

Every spring Swainson’s Hawks migrate through Southern Arizona on their way up to their northern breeding grounds and every fall, they pass through our area once more on their way down to their wintering grounds in South America. I have documented their spring migration in previous posts here and here.

I’ve been waiting for this year’s migration to begin. The first week in April I took an early morning ride with a friend through farmland in Pinal County. We only saw two Swainson’s, but one bird gave us tremendous looks.

We had spent almost two hours cruising the farmland and were on our last road heading back towards Interstate 10 when we came across this handsome looking Swainson’s Hawk on an aged fencepost. Parking the car, we were able to watch it for quite a while. Finally, the bird began to stretch. It was getting ready for flight. Raptors stretch for similar reasons that athletes stretch before an event. They are relieving muscle tension, increasing blood flow, and warming up.

The term used when raptors stretch their wings over their back is called a “warble”. The bird’s wrists are bent and almost touch the bird’s head while the bird is simultaneously bending down. Raptors are very relaxed during this stretch.

The Swainson’s Hawk then drops its wings slowly.

Having stretched out, the Swainson’s Hawk turned to fly off. It crouched down and got ready for a fast and strong push down with its legs.

And it was off!!

We were hoping to find a flock of Swainson’s. During their northern migration they travel in large groups. Southern Arizona is one place where it is possible to find a group of Swainson’s as they rest overnight before beginning the next day’s journey. While we did not find a large group on this field trip, we know they are around. I’ll keep looking for them......

Birdnote has a nice story about the southward migration of Swainson’s Hawks that happens in the fall.

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If you are interested in learning more about the birds that are migrating through your community right now, check out the BirdCast, by the Cornell Lab. Type in your county name to get detailed information about the birds migrating overhead tonight! It is a fascinating site!! All of the rest of the BirdCast bird migration tools are available here.