Tuesday, July 10, 2018

Up Close With Horns and Collars

The morning sun was warming up the eastern edge of the Great Basin Desert as I turned off the pavement and onto a dusty gravel road that would lead me several miles to the base of a rocky hillside with sparse vegetation.  I had studied Google Maps to pinpoint an area that looked promising for Great Basin Collared Lizards and was on my way to check it out. I was anxious to begin my search so I was moving along at a steady clip.  A a cloud of dust was trailing behind me until I caught a glimpse of a tiny anomaly on the surface of the path ahead. I recognized the shape as a Desert Horned Lizard just in time to ensure that my tires straddled it as I passed over and attempted an abrupt, but safe, stop. After the cloud of dust dissipated a glance at the rear view mirror confirmed that the lizard was still safe and sound in its original position. A spontaneous expression of "Happy day!" escaped my lips as I approached the tiny, modern-day dinosaur. It's always a good day when you encounter a horned lizard.

I moved the lizard to a safer place and captured some images with both the Nikkor 200-500mm and the Micro Nikkor 105mm (macro) lenses. The armor of these guys is fascinating if you really take the time to examine it.

The macro lens allowed me to capture some of the finer details of its natural body armor. The images that result from the macro lens give the five-inch lizard the appearance of a larger and fierce creature. In reality, they are small and quite docile, even sluggish. When threatened they may attempt to lay low and blend in with their surroundings, sometimes half burying themselves in sand, or make a quick but short dash to nearby vegetation where they remain motionless, again hoping to blend in with their surroundings.

Here is detail of one of the two longest occipital  horns.

And another head shot, this time from beneath the blunt snout. If you were an ant, the primary component of the horned lizard diet, you'd be concerned if you looked up and had this in your view.

The shapes of thorns, warts, and granular scales mix with varied colors in this image of the left side of the lizard's back. The colors often vary from one individual to another as they tend to match the common colors of their local environment.

The image below shows the keeled scales protecting the forearm and the lateral row of shark-tooth-like scales that are found on both sides of the lizard.

Shortly after leaving the Desert Horned Lizard I arrived at the base of the rocky hillside I pinpointed on Google Earth. I've been told by a paleontologist friend that these rocks are from the Middle Cambrian period so they are believed to be over 500 million years old.

Here is another image I captured later that morning at another location I explored. Both of these images show typical habitat for the Great Basin Collared Lizard in northern Utah.

The first collared lizard of the day was small and blended in quite well with its limestone surroundings. A small cluster of tiny red mites can be seen between the base of the tail and the left hind leg. I later came to understand that it is common for mites to ride along on these lizards.

This female, the most striking lizard of the morning, displayed some nice orange striping as it basked on the top of a small mound of lichen-covered rocks. Typically, the females are less colorful than their male counterparts, but they develop the bright orange stripes during breeding season.

She was quite cooperative even after eventually moving to the top of another rock.

This male's collars were accentuated with white/creamy contrasting lines and a bluish tint on the neck, shoulders, and back.

The males varied in appearance. This one lacked the bluish coloring and had a couple of dark lines on the upper back and more fine white spotting than the one above, which appeared to have more of darker spots on a light base. Many males show the faint vertical line that can barely be seen running down the top of part of the tail.

This image provides a nice look at the large head and strong jaw structure of the collared lizard.

Several clumps of mites were seen on the should of this guy, along with a small group in the ear.

I really enjoyed see the results of these head shots. So much detail in the eye and and face were captured, including my faint reflection in the pupil.

I captured the following images when I realized that this individual was shedding old skin for a newer, brighter look.

These collared lizards are about 4 1/2 inches from snout to vent and their tails can add another 7 or more inches to their total length. They tolerate higher temperatures than most lizards in their territories. They use their speed to secure prey that primarily consists of arthropods but also includes some vegetation and even smaller lizards.

I eventually made several trips to various locations to document Great Basin Collared Lizards. During that process I enjoyed the accidental discovery of some unique bird nests. One of those nests was occupied by an elusive nocturnal bird, a Common Poorwill. I'll be putting together a post to share progressive images of the Poorwill nest site in the next few days. It was a rare opportunity to follow and document that progression with images from eggs to hatchlings to fledglings.

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