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Black-billed Magpie had a colorful association with early Americans,
frequently following bison-hunting Native Americans and living on the
refuse of their hunts. When Lewis and Clark first encountered magpies
in 1804 in South Dakota, these birds were bold, entering tents to steal
meat and taking food from the hand.
The Black-billed Magpie makes a very large nest that can take up to 40
days to construct. It's a lot of work, but a study found that it only
used about 1% of the daily energy expenditure of the pair. Laying eggs,
on the other hand, takes 23% of the female's daily energy budget.
Like most members of its family, the Black-billed Magpie is known as
a predator on nests of other birds. Although it will take eggs and nestlings,
these items actually make up only a tiny portion of the magpie's diet.
In England, one study found that songbird density actually increased when
Eurasian Magpie density increased.
The Black-billed Magpie frequently lands on large mammals, such as deer
and moose, to remove ticks from them. The magpie eats the ticks, and then
hides some for later use, as members of the crow and jay family often
do with excess food. Most of the ticks, however, are cached alive and
unharmed, and may live to reproduce later.
Black-billed Magpies have some interesting feeding behaviors! They feed
by flipping over cow manure looking for insectsand will steal food from
predators. They also hoard food when there is an excess.
Scatter-hoarding of food by magpies is usually only for short term; items
are recovered within 1-2 d. Often covers cache with stone or leaf, and
apparently remembers many cache sites by sight or smell. In field test
of olfactory abilities, magpies were able to recover significantly more
hidden caches of raisins and suet if they had been scented in cod liver
oil.
As soon as young leave nest, they mob American Crows, as well as American
Kestrels, but their parents do not. Young appear to learn from their parents
what is dangerous, and then practice mobbing behavior on relatively safe
predators, such as the above and Sharp-shinned Hawks
Dominant young males seem to take inordinate risks around dangerous predators,
such as pulling tails of Cooper's Hawk or Northern Goshawk, perhaps to
gain social recognition, since no food was involved.
Hand-reared magpies are renowned for hoarding shiny, bright objects,
but this behavior has never been observed in wild magpies
Magpies flock around dead magpies (called "gatherings"). The
magpie that finds the dead bird may begin calling excitedly. Other magpies
are attracted and perch in trees or other nearby structures, calling loudly.
Up to 40 birds might gather within minutes after a dead magpie is spotted.
Some magpies fly down 1 or 2 at a time and walk around the body calling
loudly, often pecking at the wings or tail.
On the ground, usually walks, often with apparent swaggering gait. When
in a hurry or about to take off, hops, sometimes intermixing short flights
with hops. This fly-hopping behavior appears to be used as visual signal
to stimulate flock to follow; as the first magpie to leave a flock does
this, then others frequently follow. Long tail allows quick changes in
direction, almost instantaneously.
Rarely fights. After failure to establish dominance relationships with
vocal and visual signals, individuals sometimes jump into air in attempt
to kick each other. May lock feet; then the more dominant bird stands
over the more submissive one, which lies on its back. Amid much excited
calling, dominant bird repeatedly and violently jabs with its bill at
chest of submissive bird. Commotion attracts any nearby magpies, which
stand around calling loudly. Often a bystander pulls tail of dominant
bird, which causes it to turn around, often freeing the downed bird before
it is harmed.
Treetop-Sitting is a behavior that denotes ownership of space. It might
not look like a territorial display, but it is equivalent to song in other
songbirds. An individual simply sits in top of tree for extended periods
of time, with white flanks fluffed so that dark wings are hidden. Black
ends and white middle make this bird highly visible; this behavior allows
it to advertise its presence inexpensively and overlook its own and its
neighbor's territories.
Mean life expectancy 3.5 years for males 2.0 years for females. Oldest
banded bird on record 15 years, 1 month old. Two captive birds lived 20
years.
Bold behaviors-will enter tents to steal food.
Join the fun and count Black-billed Magpies to help scientists! It's
simple!
- Go to Crows Count and
learn how you can help scientists understand more about magpies and other
crow relatives.
Learn more about Black-billed
Magpies at All About Birds.
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