12/11/2015 A Little Lady Travels a Long Way from Home

Holding bird

Research volunteer, Matthew Garrick, smiles as he prepares to release a young female American Kestrel that recently migrated from Moose Jaw, Saskatchewan, to Bee County, Texas (more than 1600 miles). The bird was trapped on November 29th, five miles southwest of Skidmore along FM 888. She was wearing a numbered metal band that had been secured around her leg in Canada while she was still in the nest. Biologist Carter Crouch added colored leg bands and applied harmless blue dye to her under parts so that she can be identified while she spends the winter here. Carter Crouch photo.

A Little Lady Travels a Long Way from Home

I am always amazed at the incredible migrations so many animals undertake during their lives. From lowly ladybugs and some butterflies to caribou, a number of birds, and even eels, many species travel long distances. Arctic Terns travel from pole to pole, twice a year.   Just recently, satellite-tagged eels have been found to head unerringly from the North Atlantic coast to the Sargasso Sea (over 1500 miles) to continue the breeding cycle.

Lots of species leave their breeding grounds as youngsters and go to where they have never been before. Many warblers hatch in the northern deciduous forests in spring, only to migrate to the tropics in the fall. Monarch Butterflies leave the Great Plains of North America, and five generations later, their great-great-great grandchildren overwinter in the mountains of Central Mexico. We are only beginning to understand how these animals do this.

Our awareness of these migrations has come about through the marking, banding, and tagging of individuals. Banding studies on birds have been going on for over 100 years. A banding “return”, the catching or relocating a marked bird, is always exciting. From banding returns, we have learned where certain species go for the winter, where they go to breed, how far they travel, and even how long they live.

Imagine putting a band on a bird that hatched out in your backyard, and discovering that just a few months later that that very bird was recaptured over a thousand miles away. Yes, that very bird! You would know because the band number had been entered into an international database. The finder alerts the Banding Office, and they send the bird’s information to both the finder and the original bander. It doesn’t happen very often, but when you do get a band return you are delighted!

This was the case for Jared Clarke. Jared is biologist and bird bander in Saskatchewan, Canada. In June of this year, he was monitoring American Kestrel nest boxes at a research station near Regina, Saskatchewan. On June 30, 2015, he banded a young female kestrel that had hatched out in one of those nest boxes. He watched her fly off to start her life as a wild bird. And fly she did!

This fall, another biologist and bird-bander, Carter Crouch, was observing the wintering kestrels on his study sites along rural roads in South Texas. One site is located just south of Beeville in Bee County. Carter was pleased to see that 13 of the 30 kestrels he had banded last winter were back on their same territories. Carter not only bands the kestrels with numbered metal bands, he also color-bands them. The kestrels he had banded in 2014 wear unique combinations of three, plastic, colored bands on their legs. These bands make it possible for researchers to examine a bird with binoculars and identify it without having to recapture it. Since Carter needs to identify the kestrels on the site at a glance, he also marks the breast with a colored dye.

However, he saw one kestrel that had only a metal band on its leg. He monitored its movements and found it was staying on a territory along Farm-to-Market road 888. He assumed that it was one of his birds that had somehow managed to remove its color bands. American Kestrels are raptors with strong, hooked beaks and it is possible that one might pry off the plastic bands. On November 29, 2015, Carter trapped the bird to get its number. When he did he was surprised to find that it wasn’t one of his birds at all!

While he had the bird in hand, Carter made the usual measurements essential to his study. By her plumage he was able to tell she was a young female. He also color marked the bird with a white band over a black band on her left leg and a black band over the metal band on her right leg. In addition, he painted the breast and under tail feathers of the bird with blue dye.

Then, he submitted the band number to the USGS Banding Office. That’s when he found out Number 1623-44426’s history.   She had been banded in Moose Jaw, Saskatchewan, just over five months ago. She was indeed a juvenile bird and she had just made a 1600-mile journey to a place she had never been before.

Both Jared and Carter were pleased to learn of this kestrel’s movements. Over the next few months, Carter will observe her behavior on her wintering grounds. He already knows she is staying on a stretch of road only about 500 yards long. There must be plenty of rodents and grasshoppers along these agricultural roadsides. After traveling over 1600 miles, she is usually found within an area just a few hundred feet long!

Carter is pretty sure that if she survives, she will be back here on the same territory next winter. But will she go back to the Moose Jaw area this spring? Will she breed there? Only time and Jared’s research will tell.

Male Kestrel

A male American Kestrel launches himself from a barren tree limb in pursuit of a hapless field mouse. Male kestrels are smaller than the females and evidence suggests that the “ladies” force their smaller counterparts into less productive winter hunting grounds. This may be one factor in the complex ecological web that has resulted in the dramatic decline of this species. Robert Benson photo.

Why is such research important? Since the late 1960s, breeding American Kestrels have been on a decline. The number of kestrels seen on Breeding Bird Surveys in New England and the Mid-Atlantic states has dropped some 88% in fewer than 50 years. No one knows why.   The reasons for population decline may include land use modification, climate change, predation by other birds of prey, competition by starlings for nest sites, and environmental contaminants.   We need to know more about where the kestrels go, what they are eating, and what’s happening on their breeding and wintering grounds. That is why Jared’s nest box studies and Carter’s home range and site fidelity studies are so valuable. And now a migratory connection has been established by their banding efforts. Hopefully this is just the beginning of the collection of a wealth of data to help in kestrel conservation.

As you drive along South Texas’s country roads, watch for kestrels on the powerlines. Maybe you will see one “hovering in mid-air waiting for a mouse to make the wrong move.” And maybe you will even see the blue-dyed breast of the little lady who traveled 1600 miles to get here! – Karen L. P. Benson

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