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The Clark's Nutcracker
(Nucifraga columbiana), is a large passerine bird, in the family
Corvidae. It is slightly smaller than its Eurasian relative Spotted
Nutcracker (N. caryocatactes). It is ashy-grey all over except
for the black-and-white wings and central tail feathers (the outer
ones are white). The bill, legs and feet are also black. It occurs
in western North America from British Columbia and western Alberta
in the north to Baja California and western New Mexico in the
south. There is also a small isolated population on the peak of
Cerro Potosí (3,700 m) in Nuevo León, northeast
Mexico. It is mainly found in mountains at altitudes of 900-3900
m in pine forest. Outside the breeding season, it may wander extensively
to lower altitudes and also further east as far as Illinois (and
exceptionally, Pennsylvania), particularly following any cone
crop failure in its normal areas.
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The most important
food resources for this species are the seeds of Pines (Pinus
sp.), principally the two cold-climate (high altitude) species
of white pine (Pinus subgenus Strobus) with large seeds P. albicaulis
and P. flexilis, but also using other high-altitude species like
P. balfouriana, P. longaeva and P. monticola. During eruptions
to lower altitudes, it also extensively uses the seeds of pinyon
pines. The isolated Cerro Potosí population is strongly
associated with the local endemic Potosi Pinyon Pinus culminicola.
Surplus Pine seed
is stored, usually in the ground for later consumption, in numerous
caches of 5-10 seeds each spread over a wide area (up to 20
× 20 km). The birds regularly store more than their actual
needs (up to 100,000 seeds per bird!) as an insurance against
seed theft by other animals (squirrels, etc.); this surplus
seed is able to germinate and grow into new trees, thus the
bird is perpetuating its own habitat.
Above Images From The U.S. Fish and Wildlife Service
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