Title:     "Aurora Alaska Cliff"

© Alaska Artist Dianne Roberson

Sheep | Northern Lights | Alaska

Stock #  DA 134

Digital Art

Color Print on glossy paper

Size:  20" wide by 16" High     $ 45.00                            

Size:  14" wide by 11" High     $ 35.00                            

Description:    A Dall Sheep  with the Northern Lights in the sky behind him.   Also know as the Aurora Borealis,
these lights are best viewed in the cold dark winter months.   Male dall sheep, or rams, are distinguished by
massive curling horns.  The females, or ewes, have shorter, more slender, slightly curved horns.  Rams resemble
ewes until they are about three years old.  After that, continued horn growth makes them easily recognizable.  Horns
grow steadily during spring, summer and early fall.  In late fall or winter, horn growth slows and eventually ceases.  
This is probably a result of changes in body chemistry during breeding season.  This start-and-stop growth of
horns results in a patterns of rings called annuli which are spaced along the length of the horn.  As rams mature,
their horns form a circle when seen from the side.  Ram horns reach half a circle in about two or three years and a
full circle or “curl” in seven to eight years.  Most populations occupy distinct summer and winter ranges, although
some are sedentary.  Migrations are correlated with snow depth, temperature and plant phenology.  Most of the
year is spent in the winter range in wind-swept areas that expose forage.  Adult males can occupy six seasonal
home ranges: Pre-rutting, rutting, midwinter, late winter and spring, salt-lick, and summer.  Females usually have
four ranges: Winter, spring, lambing, and summer.  Lambs inherit home ranges from older individuals and they
return annually to these inherited ranges.

The diet of Dall sheep varies from range to range.  During summer, food is abundant and a wide variety of plants
are consumed.  Winter diet is much more limited and consists of primarily dry, frozen grass and sedge stems
available when snow is blown off the winter ranges.  Sheep travel to rocky areas called mineral licks in spring to eat
the soil, which contains high levels of sodium and other minerals.  Since ewes and rams use licks, young rams
may leave nursery groups and join other rams at this time.  This random dispersal of young rams among unrelated
ram herds increases genetic diversity of the species.  Many sheep visit mineral licks during spring and often travel
many miles to eat the soil at the base of these unusual soil formations.

Rams establish a dominance hierarchy in the summer, in which rank is determined by horn size.  This ranking is
not just for access to females, since there are no females present in the summer range, but also for social order.  
Usually dominance is settled without fighting, but if there is similar horn size, as when different bands meet,
dominance is settled by a fight.  These fights are often thunderous.  The two males will back off ten or twelve
meters and then rush together, colliding headlong. Usually little harm results, and after several bouts the rams
separate.  Mating occurs in late November and early December, with the young, called lambs, born in late May or
early June.  As lambing approaches, ewes seek solitude and protection from predators in the most rugged cliffs
available on their spring ranges.  Ewes bear a single lamb and the ewe-lamb pair remains in the lambing cliff a
few days until the lamb is strong enough to travel.

Northern Lights

Also know as the Aurora Borealis, these lights are best viewed in the cold dark winter months in Alaska.   The
beautiful blaze of the
Northern Lights, or Aurora Borealis, begins when energetic electrically charged particles
accelerate along the magnetic field lines into the upper atmosphere, where they collide with gas atoms, causing
the atoms to give off light. The air lights up rather like what happens in a fluorescent light tube.  The colors reflect
gases, the most usual yellow-green color coming from oxygen. Red coloring is also due to oxygen with a
contribution from nitrogen and violet is due to nitrogen. The charged particles originate from the sun, and it is the
“weather” conditions on the sun that decide whether or not we will see the aurora.

The website address will not be printed on your print.  This print is treated with an ultra violent protective coating.  It
will be rolled and inserted into a mailing tube if ordering a glossy paper print, if ordering stretched canvas this print
will be boxed.   The print  will be mailed first class by the U.S. Postal Service and insured.
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Phone:  1-404-462-4615
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Alaskan Art by Alaskan Artist Dianne Roberson
Copyright  2012        ©   Dianne Roberson    All rights reserved.