Famous
for impaling their victims, these songbirds first use a special
maneuver to break the necks of small rodents.
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A
Loggerhead Shrike with its prey. Photo: All Canada Photos/Alamy
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Its no secret that
the shrikes are formidable predators. The grayscale songbirds of
the open country might look as harmless as mockingbirds, but these
black-masked butcherbirds, as theyre known, pack
more fierceness ounce for ounce than any other bird in the country.
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Loggerhead
Shrike
Lanius ludovicianus
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Northern
Shrike
Lanius borealis
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Northern
Mockingbird
Mimus polyglottos
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The nine-inch carnivores
catch and kill a wide variety of preygrasshoppers, crickets,
beetles, lizards, mice, frogs, and small birdsthat can often
be as big as they are; one was once observed carrying off a Northern
Cardinal after "a noisy struggle lasting less than a minute,
by which time the cardinal was dead."
On top of that, their
lifeless quarry can be seen gruesomely impaled on sharp objects
like twigs and barbed wire throughout the southern United States
and northern Canada, where Loggerhead Shrikes and Northern Shrikes
range, respectively. (The Loggerhead population has declined by
more than 80 percent since the 1960s, possibly due to pesticides
killing their insect prey.) This macabre behavior, which is not
a Game of Thrones-esque warning to other birds but a form of food
storage, led Wired to declare the Loggerhead Shrike by far
the most metal of birds. The editorial staff of Audubon are
inclined to agree.
But while ornithologists
have long known that shrikes impale their prey, no one knew for
certain how these songbirds managed to catch and kill relatively
large vertebrates. A new analysis of high-speed video footage finally
reveals the answer: They grasp mice by the neck with their pointed
beak, pinch the spinal cord to induce paralysis, and then vigorously
shake their prey with enough force to break its neck. Okay, then.
The shrike's hunting
strategy is often compared to that of raptors like eagles, hawks,
and falcons: Theyll sit on an elevated perch, scan the ground
below, and pounce on any spotted prey. But this new research, which
focused specifically on Loggerhead Shrikes, shows that the two have
vastly different kill methods. Raptors have powerful wings to carry
heavy loads and sharp, strong talons to catch prey, as well as to
manipulate and tear flesh apart. Shrikes, though, are stuck with
dinky passerine feetgood for little except delicately perching
on branches. This lack of leg musculature and weaponry needed to
withstand a struggle means the songbirds have to kill quickly.
As the new study reveals,
once shrikes induce paralysis with a precise bite to the neck, they
roll their heads rapidly to vigorously shake their immobilized food.
According to the researchers, this back-and-forth whipping motion
generates accelerations of up to six g-forcesroughly the same
amount of force felt by passengers on high-g rollercoasters, or
the whiplash experienced by victims of low-speed, rear-end car crashes.
This is more than enough force to snap the vertebrae of a large
rat or break a mouses neck, and its all generated by
the roll of a Loggerhead Shrikes head.
A headbanging, prey-impaling
death-bird? You can't get much more metal than that.
Loggerhead
Shrike
The Loggerhead Shrike is a songbird with a raptors habits.
A denizen of grasslands and other open habitats throughout much
of North America, this masked black, white, and gray predator hunts
from utility poles, fence posts and other conspicuous perches, preying
on insects, birds, lizards, and small mammals. Lacking a raptors
talons, Loggerhead Shrikes skewer their kills on thorns or barbed
wire or wedge them into tight places for easy eating.
https://www.allaboutbirds.org/guide/Loggerhead_Shrike/
Slow-motion
video reveals killer whiplash butcherbirds use to take
down prey
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Loggerhead
Shrike Range
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Northern
Shrike Range
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