On the Range
Winter Coats!
By Deborah Walker
Did you know? Horses have survived some of the most severe environments and weather in the most unique ways. They have naturally evolved in ways that cause them to not only survive, but to thrive in extreme conditions.
In cold weather there are several mechanisms the horse is biologically capable of enacting. The horse’s skin's ability to thermoregulate consists of 6 areas: skin, coat, arteries in skin and legs, respiratory system, fat, sweat glands. Five of these are designated for keeping the horses warm in cold temperatures.
The coat (hair) changes 2 times a year through what's called the photoperiod mechanism. In simple terms, sensors in the horse’s skin react to changes in the length of daylight hours, not how warm or cold it is! Horses begin to grow their winter coats right after summer solstice as daylight periods become shorter and shorter. And at about winter solstice, shedding starts to occur as daylight periods become longer. The thickness of the coat will depend on how cold the climate is and the horse’s diet and breed. In rain, the deeper layers of hair will remain dry next to the skin due to a layer of oil on the outer hair. In colder weather, moisture will often freeze on the top layer of the coat as an extra layer of protection. The horse’s coat has another insulating characteristic; there are small air pockets that get trapped in the hair, slowing down the escape of body heat and holding it close to the horse’s skin. Horse’s are very equipped to handle cold weather and the coat is just one way. Next month we’ll talk about the legs and hooves and the unique physiology of keeping those areas warm in snow and ice.
Sharing the Range - The Tarantula!
By Alexis and Brooklyn Kirk
It’s October on the Virginia Range and things are getting a little Spooky! The days are getting shorter, the leaves are starting to change, and the horses have some hairy eight-legged friends. That’s right! The desert tarantula is another fascinating creature that roams the Virginia Range in Nevada.
August through October is mating season for these gentle giants; their most active time of the year. After dusk, male tarantulas can often be seen wandering the range in search of a mate. Females stay close to their burrows as they wait for their potential suitors. If the female finds the male does not suit her, she will eat him and wait for the next. If she approves, she is able to produce 500 to 1000 spiderlings at each mating. Even then, she may still eat her mate. This is why male tarantulas live approximately 7-8 years, while the females can live 20 years or more.
Tarantulas can grow quite large, with a leg span of 4 inches in diameter. That’s big enough to cover a grown man’s entire hand! Their body and legs are covered with tiny black or brown hairs. These hairs can both help them to find food, and prevent them from becoming food. Tarantulas will use their hair to sense the vibrations of nearby prey, and then chase it down. To defend against attackers, hairs on their abdomen can be released by kicking their back legs. These barbed hairs can be quite irritating. This is how they stay safe on the range.
As the temperatures cool, mating season will come to a close. The desert tarantulas tuck into their burrows where they will be protected from the cold, only emerging to hunt when it’s warm.
Be sure to watch where you're walking on the Virginia Range because you might see one of these furry creatures!
Photos by Deana Kirk