There are thirty-one
species of shrikes throughout the world.
Shrikes are medium-sized (~20 inches in length) passerine birds of the
family Laniidae,
the name being derived from the Latin word for butcher. Some shrikes are also known as
"butcher birds" because of their unusual feeding habits. Their beaks are hooked, like birds of
prey, indicating their predatory nature.
Most shrike species are found throughout Eurasia and Africa. There are just two species found in
North America: the Loggerhead and Northern Shrikes.
Shrikes are birds of
open country, especially grasslands and overgrown fields with scattered shrubs
and trees. They consume insects,
other invertebrates, amphibians, small to medium-sized reptiles, and small
mammals and birds. The design of
their beak allows them to quickly kill their prey with a bite to the back of
the neck. They use their beaks to
transport small prey, and their feet to carry something larger up to their own
body mass. But what they then do
with their prey is unique. They
impale their captured meal on a thorn, a sharp twig, or even barbed wire. They can then proceed to rip and tear
it apart into bite size pieces! If
the prey is too large to eat in one sitting, the shrike will leave it on its
spike and return later to finish.
Northern
Shrike with impaled mouse
Shrikes are
predators, but they lack strong feet and talons for holding prey down while
eating it. Therefore they have
instead evolved this unique adaptation for feeding as well as for courtship
displays. In some species of
shrikes, the larger the item the male impales, the more desirable he is to the
female. Also a study done in
Poland on the Great Grey (in Europe this is the common name for the Northern
Shrike species) Shrike showed that males impaled
their prey faster and with less attempts per impaling than females. The location of impaled prey also
differed. Males impaled prey in
more visible places, especially during the courtship and mating season, whereas
females found concealed locations.
Males will also
perform a courtship dance and song in order to attract a mate. They will bow, shiver their wings, and
zigzag up and down a branch. Some
shrikes will even impress the ladies by impaling shiny or colorful objects on a
thorn. Shrikes are typically
monogamous and together build a cup shaped nest off
the ground. The female incubates
the eggs while the male brings her food.
Unfortunately, a
trait shared among shrikes around the World is that many species have suffered
population declines. The
Loggerhead Shrike population has been decreasing across much of North America
and has all but disappeared from many areas, to the extent that captive
breeding programs have been started in an attempt to save some populations of
this bird.
Biologists believe
that habitat loss and pesticides are the chief reasons for their decline. In Missouri, the Loggerhead Shrike is
listed as a Species of Conservation due to its rapidly declining populations.
2 comments:
Nov 6,2014. I have just spent 20 minutes watching a Shrike eating a Sparrow in the bush outside my bedroom window.I had never seen such a thing so I had to google it to find out what bird it was.
Congratulations, Doug. You've just had the opportunity to watch something very few people have had the opportunity to see!
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