Journey North: Hummingbird Migration

As you read this true story about a remarkable hummingbird journey, click on any photo to enlarge it. Next, write about and discuss questions on this Handout.

We are both hummingbird banders for the Holiday Beach Migration Observatory (HBMO) located at Holiday Beach Conservation Area in Ontario, Canada. Holiday Beach Conservation Area is a park administered by the Essex Regional Conservation Authority. They allow us to band in a special section of the park during fall migration. The park has been designated as an Internationally Important Bird Area because it is a major fall migration site. That’s because the geography of this area of the Great Lakes causes a funneling effect that focuses migrating birds through the park area.

As volunteer hummingbird banders, you always hope that someone else will recapture a bird you banded. Because there are only about 200 people permitted to band hummingbirds in all of North America, the odds are not very good this will happen. About 100,000 ruby-throated hummingbirds have been banded. Of those, only about 100 have been recaptured by another bander. Can you figure out the ratio of birds banded to birds recaptured? What percentage of this species have been recaptured?

A central part of bird banding is placing a uniquely numbered band on a captured bird’s leg. Hummingbird bands are VERY small and have a letter and 5 numbers. Sheets of bands are supplied by the BBL to each bander. The bander cuts them out and sizes them for the species of hummingbirds being banded. The band number and all the information about the bird, including where and when it was banded, is sent to the Bird Banding Laboratory (BBL). They keep a central database for all the birds that have been caught.

A bander who re-captures a bird also submits data to the BBL. That way, each person can find out where and by whom the bird was banded and captured. We all follow the rules and report the event to the BBL. Hummingbird banders also have their own communication network on the Internet called Humband. This enables permitted banders to freely discuss issues and problems, and share information about this bird banding specialty. Banders will post band numbers and ask if anyone recognizes the number.

You can imagine our surprise when we saw a band number posted that looked familiar!

The posting on Humband on October 2, 2007 was from Charles R. Brower, who is a volunteer hummingbird bander in Texas. He asked if anyone recognized the band number E29705. I thought it looked like one we had used this season, so I checked our database. It turned out to be one Rachel had banded on September 15, 2007. This was a hatch year (meaning born this year) male ruby-throated hummingbird.

After I finished dancing around the room, I woke up my wife Rachel to give her the great news that we had a recaptured hummingbird. Then it was time to get down to work. What do you think we want to find out? What information do you think we needed to answer our questions?

First we entered the data into a Recapture sheet. We use a series of Excel spreadsheets for our record keeping. The Recapture sheet has a formula in one of the columns to calculate the “interval days”: the number of days between original banding and recapture. This one was easy. Can you figure out the interval based on the banding and recapture dates?

Once we knew how long between captures, the next thing was to figure out how far he traveled. What would we need to calculate the distance? Two data points are needed to determine a distance. This could be two city names, addresses, or latitude and longitude coordinates. The nearest city to Holiday Beach is Amherstburg, Ontario in Canada. Charles recaptured the bird near Sweeny, Texas.

I used two different sites on the Internet to check my distances, and they both gave me 1,135 miles. Canada uses the metric system of measurement so I needed to convert the miles to kilometers. One kilometer is equal to about 5/8th of a mile so you divide 1,135 by 5 and them multiply by 8 to convert the miles to kilometers. It came to 1816 kilometers.

Our little hummingbird covered an average of 67 miles or 107 kilometers per day. Before his trip, it was thought that they traveled about 50 miles or 80 kilometers per day. We named him Booker Sweeney because he had been “booking” it — which is a slang term for running or moving quickly — to Sweeney, Texas.

The 50 mile per day estimate may have to be rethought. Of course, in a good scientific endeavor, you need more than a single instance to make a general hypothesis. Finding something different from what we expect is one of the magic moments of any research. It reminds us that science is a dynamic ever-changing process. We must base our understanding on facts obtained using sound scientific method. This can change as we add new verifiable information.

At the time this article was written, there are several records associated with the recapture.

Special thanks to our intrepid voyager Booker Sweeney. He graciously stopped by Holiday Beach for his band and then made the remarkable journey to Sweeny, Texas in such a short time. Charles R. Brower, we are indebted to you for your efforts as a hummingbird bander that allowed you to meet up with Booker on his sojourn.

We hope you enjoyed learning some things about hummingbird banding and sharing our adventure with Booker Sweeney. Remember, volunteers in projects like this can contribute important knowledge and be part of a rewarding process!