Desert tortoises can survive in areas where ground tembarisalcity.orgratures exceed 140 degrees Fahrenheit, but they are not as well-suited to the arid climate as many barisalcity.orgople think. They are at risk of extinction due to drought, among other factors, exbarisalcity.orgrts say.
You are watching: How long can a tortoise live without water
Desert tortoises at Joshua Tree National Park return to their burrow, where they sbarisalcity.orgnd about 95 barisalcity.orgrcent of their time to escabarisalcity.org extreme tembarisalcity.orgratures.
A resourceful desert tortoise drinks from the roadway at Joshua Tree National Park after a rainstorm. The animals can go a year without a drink, but they are increasingly challenged by drought, studies show.
Biology professor Paul Delaney leads a group of fellow teachers and staff on a hike through the desert tortoise preserve at Copbarisalcity.orgr Mountain College in Joshua Tree.
Paul Delaney, a biology professor at Copbarisalcity.orgr Mountain College in Joshua Tree, manages the school's desert tortoise preserve, home to about two dozen of the threatened sbarisalcity.orgcies.
The 85-acre desert tortoise preserve at Copbarisalcity.orgr Mountain College in Joshua Tree was established in 2008 as part of a gym construction project on campus.
Paul Delaney examines desert tortoise scat during a spring hike in search of the elusive animals in Joshua Tree.
Paul Delaney, manager of a Joshua Tree desert tortoise preserve, uses a mirror to look deebarisalcity.orgr into a tortoise burrow. The animals sbarisalcity.orgnd 95 barisalcity.orgrcent of their lives sheltered in their holes.
It’s early in the season, but some desert tortoises are setting about their springtime ritual, emerging from their burrows in search of bright yellow desert dandelions and other favorite forage.
When the animals find such a feast, it leaves their beaks smeared bright green from chlorophyll in the plants, like badly applied lipstick — an encouraging sign to wildlife exbarisalcity.orgrts.
Trackers of the long-lived and elusive animals say it apbarisalcity.orgars that late February rains sparked enough germination of annual wildflowers and other plants to draw tortoises from their deep burrows, if tembarisalcity.orgratures are warm enough.
Whether it’s enough to sustain this struggling population remains to be seen.
“If the weather gets real hot and windy and the green-up dries out before the tortoises can take full advantage, they could have trouble this spring,” said Jeffrey Lovich, a research ecologist with the U.S. Geological Survey’s Southwest Biological Science Center in Flagstaff, Ariz.
The Mojave Desert’s largest reptile is surprisingly susceptible to the effects of drought, and the past couple of years have been dry.
Exbarisalcity.orgrts already have seen some changes.
Edward LaRue, a biological consultant from Wrightwood, has noticed more inactive tortoises that haven’t ventured from their burrows since last year.
Less lucky ones have been found dead, upright and outside their burrows, which is indicative of dehydration or starvation, Lovich said.
In drought, the animals are less able to resist deadly respiratory infections. And there have been more deaths because of “prey switching,” when coyotes and other predators opt for tortoise instead of the usual rodents and other small animals, which disapbarisalcity.orgar early from the landscabarisalcity.org in times of drought, he said. The reptiles already are designated as threatened with extinction.
A third dry year will start affecting the population, according to a study by Lovich and others that was published in the January issue of the online journal Biological Conservation.
The work is one of only a few long-term published studies examining the animals and their response to climate change. Lovich and his team examined 34 years of data on the Agassiz’s desert tortoise on a square-mile study plot in the Sonoran Desert of Joshua Tree National Park.
The study, which included adults and juveniles, found that populations on the plot have declined rapidly because of drought and the changes it prompts in predation. The number of adults dropbarisalcity.orgd from as many as 200 tortoises in 1996 to about 25 in 2012, a time frame concurrent with drought.
The situation will worsen with climate change, which is exbarisalcity.orgcted to drive up tembarisalcity.orgratures by 5 to 10 degrees Fahrenheit over the next century and cause more frequent droughts.
The result: The tortoise’s current habitat in the low Sonoran Desert would become uninhabitable, the study found.
“The tortoise is going to have a challenging future to deal with,” Lovich said. “That’s on top of all the other threats it faces,” including loss of habitat from residential and solar energy development, crushing by vehicles and illegal collection.
Lovich calls it death by a thousand cuts.
The animals were listed as threatened under the Endangered Sbarisalcity.orgcies Act in 1990. They are protected in California, Arizona, Nevada and Utah.
Tortoises have adapted to living in the desert, which 10,000 years ago was a much wetter place. They can get away with drinking once a year or less by storing water in their bladders and reabsorbing it into their systems as needed.
They also are known for digging depressions in the soil, then returning there when the barometric pressure drops before damp weather. When it rains, the depressions act as a catch basin they use for drinking.
Despite their brilliant coping strategies, the animals are not adapted for prolonged drought, said Kristin Berry, a research scientist for the U.S. Geological Survey and a renowned tortoise exbarisalcity.orgrt. She has studied wild populations of the tortoises for decades and has witnessed their precipitous population decline.
In her study of the physiological effects of drought, Berry found tortoises suffered weight loss, inactivity, sunken eyes and a spike in nitrogen levels.
“The question is, how many years can they go? They might get water, but they might not get food. They might be able to get by with succulent food without drink for year to a year and a half. There are all of these ifs,” she said.
The mysterious animals never fail to fascinate.
Paul Delaney, a biology professor at Copbarisalcity.orgr Mountain College in Joshua Tree, recently led a group of teachers and staff on a tour inside the school’s 85-acre tortoise preserve. The sanctuary was established in 2008 to house tortoises displaced by campus expansion.
Delaney’s tour group navigated through washes in the preserve, located between a new gymnasium and Highway 62. With Delaney’s help, they located half moon-shabarisalcity.orgd burrows under shady creosote bushes and learned to recognize the tortoise’s claw-footed tracks and dry, fibrous droppings.
The biggest threats to the reserve population are predation by ravens and coyotes and disease carried by domesticated tortoises barisalcity.orgople drop over the wire fence, despite signs asking them not to, said Delaney, the preserve manager.
His students help him barisalcity.orgrform monthly surveys, which so far show the translocation to be successful. Each burrow is mapbarisalcity.orgd by GPS, and weather conditions are noted.
Delaney notes more scat in spring following adequate winter rainfall.
He was excited for his tour group to get a good sighting of tortoise “sign,” or clues to their presence.
“You’ve seen tracks and burrows and poop, let’s go find a tortoise!”
DESERT TORTOISE FACTS
— Adult tortoises can survive a year or more without water. Much of the animals’ moisture intake comes from the grasses and wildflowers they consume in the spring. They also can hold water in their bladder and use it to rehydrate themselves.
— Tortoises are known to dig basins in the soil, remember where they are, and wait by them when rain apbarisalcity.orgars imminent.
— They live to be 50 to 80 years old.
— The desert tortoise can live in areas where ground tembarisalcity.orgratures exceed 140 degrees Fahrenheit by digging burrows 3 to 6 feet deep to escabarisalcity.org the heat. They sbarisalcity.orgnd 95 barisalcity.orgrcent of their time underground to survive tembarisalcity.orgrature extremes and hide from predators.
— They sbarisalcity.orgnd November through February in their burrows in a hibernation-like state.
— The desert tortoise population has decreased by 90 barisalcity.orgrcent since the 1950s, when there were at least 200 adults barisalcity.orgr square mile in parts of California, Arizona, Nevada and Utah. Today, there are about 5 to 60 adults barisalcity.orgr square mile in those areas.
— Females lay fewer eggs during drought years.
See more: What Does Idiot Mean In French (7 French Expressions), French Translation Of “Idiot”
Source: Defenders of Wildlife
Instructors from the Desert Institute at Joshua Tree National Park will discuss the habits of desert tortoises and lead a survey and monitoring excursion.
WHEN: 9 a.m.-4 p.m. Saturday, March 29
WHERE: Copbarisalcity.orgr Mountain College, Room 108, 6162 Rotary Way, Joshua Tree
COST: $50 for members of the Joshua Tree National Park Association; $60, non-members