#mojave desert tortoise

[uncharismatic-fauna]

Mosey On with the Mojave Desert Tortoise

Also known as the California desert tortoise, or more simply the desert tortoise, Gopherus agassizii is one of the few tortoise species native to North America. As its name implies, it is found only in the Mojave and Sonoroan deserts, from northern Mexico into the southwestern United States; there it is the state reptile of California and Nevada. Their habitat consists mainly of of desert scrub, where temperatures can reach over 60 °C (140 °F); however, in the southern reaches of its range, the desert tortoise can also be found in tropical deciduous forests.

To beat the heat, G. agassizii digs burrows where they can rest when its too hot or too cold to forage, and where they can aestivate during the hottest months of the summer and hibernate in the winter. These burrows can be quite extensive, reaching 10 m (32 ft) long, and up to 25 tortoises may share the same burrow. Individuals will often dig out several burrows in their territory, which can range anywhere from 3 to 25 hectares (7 to 61 acres). Many of these burrows will also become homes for other animals, including rattlesnakes, gila monsters, squirrels, burrowing owls, and quail.

Like all tortoises, the Mojave desert tortoise is herbivorous. Most of its food is grass, but due to the limited choice in the desert they may also consume wildflowers, shrubs, and cacti-- both fruits and new growth. Due to their hard shells, this species has few predators as adults, but hatchlings are vulnerable to foxes, coyotes, birds of prey, and gila monsters.

Very little rain falls in the desert, and so the desert tortoise is well adapted to do without; the species stores up to 40% of its body weight in water in its bladder, to be absorbed later. Individuals will also dig shallow 'watering holes' in the ground, to be visited after rainfall. G. agassizii also gets much of its water content from its diet, and can go up to a year without drinking.

Desert tortoises typically mate in the spring, from March to May, though mating can continue until autumn. Males seek out and fight each other for access to females, typically by ramming each other or attempting to flip each other over. However, this species is also one of the few known to engage in homosexual activity, particularly between males. Because this is not a species that mates for life, or maintains strict social hierarchies, the purposes of this intercourse is unknown.

Females can store sperm for up to eighteen months, and typically lay their eggs in the following year from May to July in clutches of 3 to 8. These eggs are laid in a deep nest dug into the ground, and take 90 to 135 days to hatch. Young emerge in the fall, and receive no parental care. If they survive, individuals may take between 10 to 16 years to become fully mature, and can live to be 80 years old.

Desert tortoises are well adapted to blend into their environments. The shell is typically a brown or dull yellow, while the body is tan or dusty grey. There is little difference between males and females, save that males are slightly bigger and have a concave plastron (lower shell) to accommodate mounting onto a female. The species is medium sized, ranging between 11 to 23 kg (24.23 to 50.66 lb) in weight and 25 to 36 cm (10 to 14 in) in length.

Conservation status: The IUCN has ranked the Mojave desert tortoise as Critically Endangered. Their primary threats include habitat fragmentation and loss, predation by feral dogs, and road mortality. The population is estimated to have declined by 90% since the 1980s. However, conservation programs are being implemented to preserve critical habitat, and several zoos and conservancies have captive breeding programs for the species.

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Photos

Dana Wilson

Bruce D. Taubert

Sandra Leander

[rjzimmerman]

Excerpt from this story from the LA Times:

The California Fish and Game Commission has formally recognized the Mojave desert tortoise as endangered.

The designation, granted Thursday, is the latest in a long series of steps to try to protect the dwindling population of the desert creature, which biologists say is heading toward extinction.

The tortoise was designated as threatened under the California Endangered Species Act in 1989 and as threatened under the Endangered Species Act in 1990. In 2020, Defenders of Wildlife, Desert Tortoise Council and Desert Tortoise Preserve petitioned to change the tortoise’s status to endangered, which would give it higher priority and funding for conservation measures such as habitat protection and recovery efforts.

The commission then granted temporary endangered species to the desert tortoise while it considered adding it permanently to the list.

A recovery plan was created in 1994, and then revised in 2011 after there were issues implementing the recovery strategies.

Between 2001 and 2020, population densities in tortoise conservation areas went down by an average of 1% per year in the Colorado Desert and Eastern Mojave Recovery units, according to a February 2024 California Department of Fish and Wildlife report.

The minimum density for the tortoises to remain viable is 3.9 adults per square kilometer, according to the report. Only 2 out of the 10 designated tortoise conservation areas currently meet that threshold.

Sadly, California’s state reptile — formally Gopherus agassizii — is hurtling toward extinction. Vehicle strikes, urban encroachment, hungry ravens, military maneuvers, disease, drought, extreme heat, wildfires, illegal marijuana grows and development of massive solar farms are all pushing the species to the brink.

The tortoises live in the rocky foothills north and west of the Colorado River in California, Arizona, Utah and Nevada. They feed on grasses, cacti, herbs and wildflowers.

They hibernate for up to nine months each year and are most active from March to June and September to October. The sleep pays a longevity dividend — the tortoises can live for 50 to 80 years.

[tortoise-time]

Aster in her cooler (right) and Dandelion trying to squeeze in, too (right)! Firefly is also there.

[tomwindeknecht]

The Mojave Desert is a beautiful and fragile ecosystem that is home to a variety of plants and animals, including the desert tortoise. Here are a few things we can do to keep it this way:

- Stay on the trails. This helps to protect the plants and animals that live in the desert. - Pack out what you pack in. This includes trash, food scraps, water bottles, etc. - Don't disturb wildlife. This means keeping your distance from animals and not feeding them.

[sourb0i]

If I ever learned how to make mods for video games the only mod I would make would be to add Mojave desert tortoises to Fallout New Vegas. Not a lot of them, but if you're prone to wandering off road you might encounter one. It doesn't do anything, and there's no achievement. There's just a tortoise.

[covenawhite66]

Tortoises have survived the winter and a female has lasted eggs. The hatchling turtles have been raised indoors to be let loose later.

The tortoise species had a 90% in the last 20 years creating a need for this program

[dancesingay]

I have a Sulcata Tortoise named Tortie, my girlfriend named her. She's quite baby.

Today, the goal is to buy some weed, I just have to wait one more hour before the shop opens. My mom's mom gave me an early inheritance, since she said she's giving all her money to the Jehovah's Witnesses in her will. I only met her once in my life, so to me, it's just a random check. Regardless, I'll smoke one up for you, lady! You're not dead yet, but may God save your soul when you are.

[probablyasocialecologist]

The United States solar energy boom is finally taking off - in the worst way. In the Mojave desert and other federal lands across the West, utility-scale installations are putting gigawatt-hours of energy on the board and powering millions of homes. But the designs are sloppy, the labor conditions are horrific, and the environmental damage is incalculable. Ancient joshua trees are being clear cut, endangered desert tortoises are being left for dead, the vast biotic carbon stores of Mojave soils are being upturned, and the reflectivity of enormous expanses of desert are being altered, affecting the planetary climate. ​But it doesn't have to be this way. There's a type of energy that requires no fuel and no land. It hardly even needs transmission lines, as it can be built at the site of use: rooftop solar. Every hour of the day, rooftops across the United States soak up enough sun to generate petawatts of power. Estimates for their potential to offset US energy demand range from 13 percent to over 100. Yet at present, only around 2 percent of US energy is generated by rooftop. ​And then there's land area that's already been developed. Just by building solar on degraded lands, focusing on superfund sites, reservoirs, and farmland, researchers estimate we could generate more than enough to offset today's national energy demand. While there are points of dispute concerning some projections, the conclusion is clear: between the potential of degraded lands, rooftops, wind, and storage - plus existing hydro, nuclear, and other zero carbon energy sources, there's really no need to tear up the rare and fragile ecosystems of our deserts.

[uncharismatic-fauna]

Uncharismatic Fact of the Day

Although they may not look like it, tortoises can be fearsome fighters. When male Mojave desert tortoises meet, they try to flip each other over with the curved horns on their lower shells as a form of dominance.

(Image: A Mojave desert tortoise (Gopherus agassizii) by the US Fish and Wildlife Service)

If you like what I do, consider leaving a tip or buying me a ko-fi!

[rjzimmerman]

Excerpt from this press release from the Center for Biological Diversity:

A judge has rejected federal agencies’ approval of activities in the California Desert Conservation Area, including a vast network of off-road vehicle routes in the West Mojave Desert. The activities are driving desert tortoises and other threatened and endangered wildlife toward extinction.

Tuesday’s ruling is a victory for conservationists. In 2021 environmental groups sued the Interior Department, Bureau of Land Management and Fish and Wildlife Service over the 2019 West Mojave Route Network Project, which failed to minimize off-road vehicles’ harms to public lands and protect endangered and threatened species and their habitats.

U.S. District Judge Susan Illston ruled that the Bureau violated the Federal Land Policy and Management Act by designating off-road vehicle routes without basing its criteria on minimizing damage to resources. That includes habitat for species such as the endangered Lane Mountain milk vetch, which is found only in the western Mojave Desert.

The judge also ruled that the Bureau wrongly assumed that there would be no growth in off-road vehicle activity or harm to air quality from the new routes.

Under the West Mojave plan, the BLM adopted nearly 6,000 miles of dirt roads for off-road vehicle use (that’s enough to go approximately one-quarter of the way around the Earth’s circumference). This has led off-roaders to create hundreds of new illegal roads in fragile habitat that is supposed to be protected for desert tortoises. The desert tortoise population has now declined to unsustainable levels in the western Mojave Desert.

The court also invalidated the Fish and Wildlife Service’s biological opinion, ruling that the agency violated the Endangered Species Act by ignoring studies showing threats to the desert tortoise and harm from off-road vehicles and by relying on unenforceable mitigation measures. The judge also said the Fish and Wildlife Service used an irrational “surrogate” approach to determine the number of desert tortoises that would be killed or taken and failed to require enforceable measures to minimize harm to the animals. The Bureau violated the Act by relying on the Fish and Wildlife Service’s flawed analysis, the judge ruled.

[tortoise-time]

Hi there!

I'm a graduate student researcher currently studying cellular immunity in the Mojave desert tortoise. My research largely involves looking at the bactericidal ability of tortoise white blood cells across temperature and season. If anyone wants specifics, I'm happy to answer!

My advisor cares for a captive population of desert tortoises that are our study animals. We have proper permits and care for them under IACUC protocol. I have a lot of pictures and stories from my time doing research, so I thought it'd be fun to share them!

Our population is as follows:

Aster (spends most of her time sleeping in a cooler)

Big Boy (not actually the biggest boy)

Buttercup (everybody's favorite)

Cami (free loader #1)

Dandelion (cutest there ever was)

ET (does not live with the rest of them, too aggressive)

El Dorado (free loader #2)

Firefly (likes to beg, often gets bullied)

Gus (likes to bully)

Ivan (excellent at losing temperature equipment)

Lady G (expert egg layer)

Larrea (goes kind of crazy when moved)

Lover (sweet but simple)

Mallow (water slut)

Mama (only became a mama recently)

Phacelia (you're breaking my heart)

Piute (wants to be big, is not)

Plantago (smartest, prettiest male)

Shoshone (big sweet boy)

Virga (causes no problems)

[lizardsaredinosaurs]

When your OS has discontinued support, but you just... haven't... gotten around to updating... yet.

Mojave Desert Tortoise (Gopherus agassizii)

Mojave and Sonoran Deserts of western USA and Mexico

Status: Critically Endangered

---

Identifying with the tortoise right now. She'll get there... slowly.

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[nanistar]

travel montage!!!!! had a really rough time with the first page for some reason

animal costars: mojave rattlesnake (Crotalus scutulatus), desert tortoise (Gopherus agassizii), black tailed jackrabbit (rip) (Lepus californicus) As always, please read and sub on TAPAS! <prev

[covenawhite66]

Tortoises from the Mojave desert were taken out of their native habitats as eggs, raised by humans then released into the wild. They have now survived the winter brumation and are still thriving in their environment.

Brumation—a state of deep sleep specific to reptiles

Collaboration between:

Edwards Air Force Base in Southern California

San Diego Zoo Wildlife Alliance

The Living Desert Zoo and Gardens,

[mariacallous]

On a spring day in 1978, a fisherman caught a tiger shark in the lagoon surrounding Enewetak Atoll, part of the Marshall Islands in the north Pacific. That shark, along with the remains of a green sea turtle it had swallowed, wound up in a natural history museum. Today, scientists are realizing that this turtle holds clues to the lagoon’s nuclear past—and could help us understand how nuclear research, energy production, and warfare will affect the environment in the future.

In 1952, the world’s first hydrogen bomb test had obliterated a neighboring island—one of 43 nuclear bombs detonated at Enewetak in the early years of the Cold War. Recently, Cyler Conrad, an archeologist at Pacific Northwest National Laboratory, began investigating whether radioactive signatures of those explosions had been archived by some particularly good environmental historians: turtles.

“Anywhere that nuclear events have occurred throughout the globe, there are turtles,” Conrad says. It’s not because turtles—including sea turtles, tortoises, and freshwater terrapins—are drawn to nuclear testing sites. They’re just everywhere. They have been mainstays of mythology and popular culture since the dawn of recorded history. “Our human story on the planet is really closely tied to turtles,” Conrad says. And, he adds, because they are famously long-lived, they are uniquely equipped to document the human story within their tough, slow-growing shells.

Collaborating with researchers at Los Alamos National Laboratory, which was once directed by J. Robert Oppenheimer, Conrad was able to use some of the world’s most advanced tools for detecting radioactive elements. Last week, his team’s study in PNAS Nexus reported that this turtle, and others that had lived near nuclear development sites, carried highly enriched uranium—a telltale sign of nuclear weapons testing—in their shells.

Turtle shells are covered by scutes, plates made of keratin, the same material in fingernails. Scutes grow in layers like tree rings, forming beautiful swirls that preserve a chemical record of the turtle’s environment in each sheet. If any animal takes in more of a chemical than it’s able to excrete, whether through eating it, breathing it in, or touching it, that chemical will linger in its body.

Once chemical contaminants—including radionuclides, the unstable radioactive alter egos of chemical elements—make their way into scute, they’re basically stuck there. While these can get smeared across layers in tree rings or soft animal tissues, they get locked into each scute layer at the time the turtle was exposed. The growth pattern on each turtle’s shell depends on its species. Box turtles, for example, grow their scute outward over time, like how humans grow fingernails. Desert tortoise scutes also grow sequentially, but new layers grow underneath older layers, overlapping to create a tree ring-like profile.

Because they are so sensitive to environmental changes, turtles have long been considered sentinels of ecosystem health—a different kind of canary in the coal mine. “They’ll show us things that are emergent problems,” says Wallace J. Nichols, a marine biologist who was not involved in this study. But Conrad’s new findings reveal that turtles are also “showing us things that are distinct problems from the past.”

Conrad’s team at Los Alamos handpicked five turtles from museum archives, with each one representing a different nuclear event in history. One was the Enewetak Atoll green sea turtle, borrowed from the Bernice Pauahi Bishop Museum in Honolulu, Hawaii. Others included a Mojave desert tortoise collected within range of fallout from the former Nevada Test Site; a river cooter from the Savannah River Site, which manufactured fuel for nuclear weapons; and an eastern box turtle from Oak Ridge, which once produced parts for nuclear weapons. A Sonoran desert tortoise, collected far from any nuclear testing or manufacturing sites, served as a natural control.

While working at Los Alamos, Conrad met isotope geochemist and soon-to-be coauthor Jeremy Inglis, who knew how to spot even the most subtle signs of nuclear exposure in a turtle shell. They chose to look for uranium. To a geochemist, this might initially feel like an odd choice. Uranium is found everywhere in nature, and doesn’t necessarily flag anything historically significant. But with sensitive-enough gear, uranium can reveal a lot about isotope composition, or the ratio of its atoms containing different configurations of protons, electrons, and neutrons. Natural uranium, which is in most rocks, is configured very differently from the highly enriched uranium found in nuclear labs and weapons.

To find the highly enriched uranium hidden among the normal stuff in each turtle shell sample, Inglis wore a full-body protective suit in a clean room to keep his uranium from getting in the way. (“There’s enough uranium in my hair to contaminate a picogram of a sample,” he says.) Inglis describes the samples like a gin and tonic: “The tonic is the natural uranium. If you add lots of natural uranium tonic into your highly enriched uranium gin, you ruin it. If we contaminate our samples with natural uranium, the isotope ratio changes, and we can’t see the signal that we’re looking for.”

The team concluded that all four turtles that came from historic nuclear testing or manufacturing sites carried traces of highly enriched uranium. The Sonoran desert tortoise that had never been exposed to nuclear activity was the only one without it.

They collected bulk scute samples from three of their turtles, meaning that they could determine whether the turtle took in uranium at some point in its life, but not exactly when. But the researchers took things a step further with the Oak Ridge box turtle, looking at changes in uranium isotope concentrations across seven scute layers, marking the seven years of the turtle’s life between 1955 and 1962. Changes in the scutes corresponded with fluctuations in documented uranium contamination levels in the area, suggesting that the Oak Ridge turtle’s shell was time-stamped by historic nuclear events. Even the neonatal scute, a layer that grew before the turtle hatched, had signs of nuclear history passed down from its mother.

It’s unclear what this contamination meant for the turtles’ health. All of these shells were from long-dead animals preserved in museum archives. The best time to assess the effects of radionuclides on their health would have been while they were alive, says Kristin Berry, a wildlife biologist specializing in desert tortoises at the Western Ecological Research Center, who was not involved in this study. Berry adds that further research, using controlled experiments in captivity, may help figure out exactly how these animals are taking in nuclear contaminants. Is it from their food? The soil? The air?

Because turtles are nearly omnipresent, tracing nuclear contamination in shells from animals living at various distances from sites of nuclear activity may also help us understand the long-term environmental effects of weapons testing and energy production. Conrad is currently analyzing desert tortoise samples from southwestern Utah, collected by Berry, to better relate exposure to radionuclides (like uranium) to their diets over the course of their lives. He also hopes that these findings will inspire others to study plants and animals with tissues that grow sequentially—like mollusks, which are also found in nearly all aquatic environments.

The incredible migratory patterns of sea turtles, which sometimes span the entire ocean (as anyone familiar with Finding Nemo may recall), open up additional opportunities. For example, sea turtles forage off the Japanese coast, where in 2011 the most powerful earthquake in Japan’s history caused a tsunami that led to a chain reaction of failures at the Fukushima Daiichi Nuclear Power Plant. With lifespans of up to 100 years, many of those turtles are likely still alive today, carrying traces of the disaster on their backs.

Recently, the Japanese government started slowly releasing treated radioactive water from the Fukushima Daiichi plant into the Pacific Ocean. Scientists and policymakers seem to hesitantly agree that this is the least bad option for disposing of the waste, but others are more concerned. (The Chinese government, for instance, banned aquatic imports from Japan in late August.) Through turtle shells, we may better understand how the plant’s failure, and the following cleanup efforts, affect the surrounding ocean.

The bodies of these creatures have been keeping score for millennia. “For better or for worse, they get hit by everything we do,” Nichols says. Maybe, he adds, “the lesson is: Pay more attention to turtles.”

[wachinyeya]

https://ictnews.org/news/biden-designates-avi-kwa-ame-a-national-monument

Joe Biden designates Avi Kwa Ame a national monument

President Joe Biden announced on Tuesday Avi Kwa Ame as a national monument in Nevada, following up on a promise he made in late 2022.

Biden also declared a national monument in Texas and the creation of a marine sanctuary in U.S. waters near the Pacific Remote Islands southwest of Hawai'i.

Biden spoke at the White House Conservation in Action Summit at the Interior Department with Fort Mojave Indian Tribal Chairman Timothy Williams commending him during his introduction.

“Under his leadership we have a seat at the table and we are seeing an unprecedented era and opportunity for our tribal communities,” Williams said. “And we are all grateful to the president for taking historic action to combat the climate crisis and conserve and restore our nation’s land and waters.”

Williams was among the proponents to make Avi Kwa Ame, also known as Spirit Mountain, a national monument. It’s considered sacred to the Mojave people and for the nine other Yuman-speaking tribes along the Colorado River, as well as the Hopi and Chemehuevi Paiute tribes, Williams said.

The site in southern Nevada spans more than 500,000 acres near the Arizona and California state lines. It’s home to bighorn sheep, desert tortoises and a large concentration of Joshua trees, some of which are more than 900 years old. It’s also listed on the National Register of Historic Places.

It took more than three months for Biden to make the announcement.

“It’s a place of reverence, it’s a place of spirituality, it’s a place of healing and now it will be recognized for its significance it holds and be preserved forever,” Biden said. “I look forward to visiting it myself.”

He thanked Williams and the legislative leaders who advocated for Avi Kwa Ame including Nevada Rep. Dina Titus, Democrat, who sponsored a bill to protect the rugged region near the Mojave National Preserve from development, including solar farms and a proposed wind farm.

“To the native people who point to Avi Kwa Ame as their spiritual birthplace, and every Nevadan who knows the value of our cherished public lands: Today is for you,″ Titus tweeted.

The Honor Avi Kwa Ame coalition, which includes tribes, local residents, state lawmakers and conservation groups, said its members were "overjoyed" to learn the site will be a new national monument.

"Together, we will honor Avi Kwa Ame today — from its rich Indigenous history, to its vast and diverse plant and wildlife, to the outdoor recreation opportunities created for local cities and towns in southern Nevada by a new gorgeous monument right in their backyard," the group said.

Interior Secretary Deb Haaland released a press release praising the announcement.

“I am grateful to President Biden for taking this important step in recognition of the decades of advocacy from tribes and the scientific community, who are eager to protect the objects within its boundaries,” Haaland stated.“Together with tribal leaders, outdoor enthusiasts, local elected officials, and other stakeholders, we will manage this new monument for the benefit of current and future generations.”

In Texas, Biden plans to create the Castner Range National Monument in El Paso. It’s the ancestral homeland of the Comanche and Apache people, and its cultural ecology is considered sacred to several Indigenous communities.

The designation will protect the cultural, scientific and historic objects found within the monument's boundaries, honor U.S. veterans, service members and tribal nations, and expand access to outdoor recreation on public lands, the White House said.

Located on Fort Bliss, Castner Range served as a training and testing site for the U.S. Army during World War II, the Korean War and the Vietnam War. The Army ceased training at the site and closed Castner Range in 1966.

The Castner Range monument "will preserve fragile lands already surrounded on three sides by development,'' help ensure access to clean water and protect rare and endangered species, said Rep. Veronica Escobar, Democrat-Texas.

“The people of El Paso have fought to protect this for 50 years. Their work has finally paid off,” Biden said.

Biden designated his first national monument, in Colorado, last year. In 2021, he restored the boundaries for Bears Ears National Monument in Utah after they were significantly narrowed by President Donald Trump, a Republican.

In the Pacific, Biden will direct the Commerce Department to consider initiating a new national marine sanctuary designation within 30 days to protect all U.S. waters around the Pacific Remote Islands. If completed, the 777,000 square miles, southwest of Hawaii, will help ensure the U.S. reaches Biden's goal to conserve at least 30 percent of ocean waters under U.S. jurisdiction by 2030, the White House said.

Among Hawaiian state leaders, Biden thanked Native Hawaiian leaders who “worked tirelessly to protect our oceans. I want to thank you. I genuinely mean it, it wouldn't have happened without you.”

Biden also announced a series of steps to conserve, restore and expand access to public lands and waters across the country, the White House said.

The proposals seek to modernize management of America's public lands, harness the power of the ocean to help fight climate change, and better conserve wildlife corridors. Biden also will announce new spending to improve access to outdoor recreation, promote tribal conservation and reduce wildfire risk.

Bidden added he’s committed to working with tribal leaders and legislative leaders on bringing “healthy and abundant” salmon run back to the Colorado River system.

“There’s nothing beyond our capacity if we work together,” Biden said.