Biologists band rare bird on Fort Jackson
March 6, 2014
FORT JACKSON, S.C. (March 6, 2014) -- The Loggerhead shrike is listed as a species of concern in South Carolina and is considered a rare or uncommon sighting in the state. Shrikes are predatory birds slightly smaller than a robin that prefer open grassed habitat interspersed with shrubs, low trees, power lines, and fences. This habitat encompasses much of Fort Jackson's cantonment area, including Darby Field, Semmes Lake recreational area, and areas around the Strom Thurmond Building.
Sam's on a mission to capture and band adult American kestrels on post. DeMent holds a Federal Master Banding permit and is studying dispersal of American kestrels in the southeastern United States. Having captured and banded six kestrels and one Cooper's hawk earlier in the day, the two were passing the Strom Thurmond Building when they spotted a shrike overlooking the parking lot.
Rikard said he felt this was an opportune time to attempt to capture and band the shrike as no shrikes had ever been banded on the installation. Successfully banding this species would allow data to be entered into the database at the Bird Banding Laboratory, U.S. Geological Survey Patuxent Wildlife Research Center, in Laurel, Md. It would also allow DPW biologists to identify this bird on post, follow its movements, and learn more about how the bird uses cantonment area habitat for feeding and nesting.
A bal-chatri trap was quickly set in the grassed parking lot medium about 50 yards from the perched shrike. This trap is a small wire cage with monofilament nooses attached to the top. A mouse is placed out of harm's way inside the trap and serves as the lure. Movement of the mouse, which is one of the shrike's preferred foods, attracts the bird. When the shrike lands on the trap, the nooses ensnare the bird's feet.
Within minutes of setting the trap, the keen-eyed shrike landed on it and became ensnared. The bird was carefully removed, placed in a canister to keep it contained and calm, and taken to the truck for processing. Its weight was recorded, a feather removed for DNA analysis, and a uniquely numbered aluminum U.S. Fish and Wildlife Service band was placed on its leg. As this bird was being processed, a second shrike landed and became ensnared. The first bird was released, and the second one was retrieved for processing.
"Two shrikes back-to-back on one trap occasionally happens, but it is not a common event," DeMent said. "These birds become totally focused on the lure and are intent on capturing the prey. Even though the second bird observed the first one being caught, the lure was too irresistible to pass up."
Loggerhead shrikes feed on a variety of small prey, including insects, spiders, small snakes, frogs, lizards and sometimes take small birds. They prefer to perch on power lines, short trees, or other conspicuous perches overlooking open areas when hunting. Shrikes habituate easily to human disturbances and can sometimes be approached within ten yards before flying.
"A common name for the Loggerhead shrike is butcher bird. This name comes from the bird's habit of impaling its prey on thorns in a tree or on barbed wire and returning later to eat it," Rikard said. "Each summer, I occasionally see large grasshoppers, lizards and praying mantises impaled on the barbed wire fences outside my office on Essayons Way. Some researchers suggest this helps anchor larger prey for tearing with its strongly hooked beak as the shrike doesn't have large hawk-like talons to shred its food. Others believe the bird is storing the prey for later consumption."
Loggerhead shrikes can easily be mistaken for the more common Northern mockingbird. The shrike can be identified by its gray body with black wings, disproportionately large head, white wing patches, black mask, black tail and dark hooked bill. The Audubon Society has listed the Loggerhead shrike as a bird species in decline. Nationwide, this species' population had decreased 72 percent since 1967.