Desert Bighorn Sheep In The Santa Catalina Mountains

You may enlarge any of the images in this blog by clicking on it. Click again for a detailed view.

For those readers who are not familiar with Tucson and its environs, much of our community rests among mountain ranges.  In fact, Tucson and many of its suburbs sit in a bowl of a valley, surrounded by four distinct mountain ranges.  Our home is at the northern edge of the Tucson suburbs, located close to the base of the Santa Catalina Mountains.  The Santa Catalinas are a range of steep mountains that, together, form a ridge that extends for well over ten miles.  They are forbiddingly rugged, rising almost vertically in many places.  The range is punctuated by deep valleys and craggy peaks.

The Santa Catalinas were at one time home to a herd of Desert Bighorn Sheep. They disappeared from the range a number of years ago, most likely due to loss of  habitat and to overhunting.  A few years ago, Arizona’s Game and Fish Commission decided that the mountains were suitable for re-introduction of the sheep.  The agency released a small, mixed herd of these animals and there were subsequent releases as well. The release wasn’t without controversy.  Professional hunters shot and killed several Mountain Lions in order to reduce predation on the sheep.

The sheep seem to have done pretty well.  In the past couple of years there have been fairly frequent sightings of these animals, as they descend the mountain slopes to browse near recreation areas and a few residential subdivisions.

Recently, my friend Dan called me to advise me that a herd of sheep was hanging out near the base of the mountains.  I immediately jumped in my car and raced to the location.  Sure enough, and to my great delight, there were six Bighorns, all of them rams, relaxing only yards away from the street.  One of these rams is an especially muscular animal, substantially larger than the others, and I was able to make a sequence of images over the course of several minutes, tracking him as he ranged down the slope and, eventually, interacted with one of his fellow rams.

Bighorn Sheep are native to North America. Desert Bighorns are one of several subspecies of these animals.  As their name implies, Desert Bighorn Sheep have adapted to living under harsh desert conditions.  These animals seldom need to drink, extracting the moisture that they need from the vegetation that they browse on.  Like other Bighorns, Desert Bighorns have concave hooves that enable them to run up and down steep slopes with ease.  These animals are capable of ascending and descending nearly vertically, without difficulty.

They are fairly large animals.  An adult Desert Bighorn Ram may weigh up to about 280 pounds (about 127 kg.).  I won’t hazard a guess about the weight of the individual that I photographed.  However, he was substantially larger than any of the five other rams in the little herd that I observed.

The males of all Bighorn subspecies are renown for their horns.  Horns, unlike a deer’s antlers, are permanently affixed to the sheep’s skull (male deer and elk shed their antlers each year and then, regrow them).  A Bighorn’s horns grow throughout the animal’s lifetime.  They can become so long that they interfere with the ram’s vision.  Rams often rub their antlers against rocks or other objects to eliminate the horns’ tips.  A ram’s set of horns is quite heavy: on an older ram they can weigh 30 pounds or more (more than 13.6 kg.). Ewes also have horns but they are much smaller than those of the males.

The next image shows off this ram’s muscularity and agility.  That slope may not look terribly steep but I doubt if many humans could run down it and maintain their balance.

In the final image a second ram engages in a bit of apparently playful contact with my subject.

Neither animal showed aggression towards the other.  The big ram tolerated his smaller companion’s interaction.  It might be a very different story during breeding season in autumn.  Then, rams challenge each other for the right to mate and head-butting contests become serious and, at times, extraordinarily violent.  You’ll notice that there’s a large gouge in my subject’s horn on the right side of his head, perhaps the consequence of one of these battles.

Images made with a Canon 5Div, 400mm f4 DO II lens+1.4x telextender, M setting (auto ISO), ISO 500, f6.3 @ 1/2000.

One Reply to “Desert Bighorn Sheep In The Santa Catalina Mountains”

  1. cintwigg says:

    It is amazing to me that these big, muscular animals extract all of their moisture from the vegetation they browse on. It was very interesting to learn about these gorgeous animals. Thank you!

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