Habitats of the Llano Estacado
Sanddunes
Photoessay: Critters of the Sanddunes
(photographs by Bill Loos, text by Burr Williams)
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When visiting the dunes in the morning, the first evidence of animals that are seen is tracks. This beetle track had even more loops and each and every loop was of the same dimensions.
If the sand is the least bit moist, incredible detail can be seen in the tracks. Notice the dewclaw tracks above the deer hoof track.
Where deer live, mountain lion live. Notice that the track has no toenail marks.
Anytime people walk about in West Texas, they have to keep a close eye on the ground. El cascabel es el jefe! A young diamondback rattler half-hidden in vegetation – but is he asleep or just waiting for prey?
Prairie rattlers are common in the dunes as well. On the hot sands they sometimes will throw themselves forward, which gives rise to the belief that sidewinder rattlesnakes live in the dunes, but that species only lives in Arizona and California.
Hike long enough in the dunes, and a person can see things most people never see - have you ever seen two rattlesnakes mating? Notice that the snakes are of two different colors.
Not every snake is poisonous. Some are friendly enough to be picked up - bullsnakes usually only struggle for a minute or two, and then settle down.
It is not a good idea to pick up a coachwhip, however. They have a mean streak that never ceases.
Quite a number of reptiles live in the dunes. This box turtle is of the western-most race - its yellow lines on its carapace are skinny and numerous.
Horny toads are more common nearer the areas with more compacted soil. Their main prey (harvester ants) rarely makes nests in the open dunes.
Harvester ants sting with impact - the sting can hurt for hours. Sometimes they do nest in looser sand!
In some of the dune region that are nearer gravelly soils Round-tailed Horny Toads can be found. There is possibly an ecological relationship between them and the honey-pot ants, but that is only a guess by casual observers.
La niña de la tierra, or Jerusalem Crickets are fascinating. They are very common in the dunes (at certain times.) On one warm December morning, hundreds of burrows in the steepest slip faces of the dunes were open. Could it have been a time for mating - or was it a response to recent rains?
Does the darker head on this Jerusalem Cricket mean it is a different species? Or did it recently molt and does their head color fade over time? (See this essay on Jerusalem Crickets.)
Where there are no caves, cave crickets live in animal burrows - usually abandoned ones, but sometimes in inhabited pocket gopher tunnels.
This appears to be one of the species of green scarab beetles. Why in the world is it pushing feral hog scat with its head - it is not a dung beetle! Beetles are one of the most common forms of live on the dune. A new species was found in 2005 at the Monahans State Park (See the essay on the new species.)
This green scarab has a short horn on its head. Is it a female of the longhorned species, or is it a different species?
The longhorned green scarab is incredible. Notice the yellow antennae!
Dung beetles are something that some cattle ranchers point to with pride. Some of the feeds given to cattle have medicines to rid the cattle of intestinal parasites, and seem to also effect dung beetles. Organic beef producers love their dung beetles and point to them as a sign that they are mindful of the environment.
It looks like a June beetle, familiar to town residents with street lights - but what a set of antennae!
When in the dunes, sometimes a person finds a plant that has scores of insects swarming over its blooms. At that time, this species of sand wasp (Bembix) can be seen.
After a rainstorm, a hiker can find a number of male tarantulas out cruising for mates.
Painted grasshopper populations fluctuate. One year the species is common, and then the next year they will be hard to find.
Ground mantids are easy to find during most of the growing season. They never get more than 2 inches long.
When a person camps in the dunes in late summer and early fall, this species of katydid can be heard singing at night.
Robberflies are predators, and are easily seen during the complete growing season. They wait on the tallest objects until a bee or a fly or a dragonfly wanders by.
Over a year's period, over 100 species of butterflies can be found in the sanddunes. The white flower is annual buckwheat, and the yellow is sanddune rabbitbrush – and both are only found in the sanddune regions.
Mammals are a little harder to find. Most are nocturnal. Early in the morning, or right at sunset is the best time to see mule deer.
Jackrabbits hang out under the shinoaks during the day.
Near the waterholes in the dunes are willows, salt cedars, and cottonwoods. And up in the trees, a porcupine is not an unexpected sight.
It pays to be careful around one of the most dangerous animals of the dunes - a sow feral hog with piglets.