In the remote area of Death Valley National Park known as Devil’s Hole, six men suit up for a long day of desert exploration. But these explorers are swapping their dusty hiking boots and water bottles for neoprene wetsuits and oxygen tanks.

As NATURE’s Life in Death Valley reveals, the men are part of a specialized team of divers who assemble in this 40-acre pocket of Death Valley four times a year to monitor the population of the park’s most surprising desert creature: the critically endangered Devil’s Hole pupfish. Death Valley may seem an unlikely habitat for a fish, but this tiny species has managed to thrive here for thousands of years despite epic changes in its environment.

When summer temperatures spike to 120 degrees, it’s difficult to imagine Death Valley in an ice age. But twenty thousand years ago, the valley rested beneath a vast lake system where the ice-age ancestors of these pupfish swam. As the climate warmed, the lake dried and formed separate pools, and the fish that were once part of the same parent population began to develop unique characteristics in response to their individual environments, eventually evolving into several distinct species of pupfish.

But it’s the fragile Devil’s Hole species that has made the biggest waves throughout history, primarily due to the place it calls home. Located in southern Nevada, the “hole” itself is a fissure in the earth’s surface that split open 60,000 years ago to reveal an astonishing underworld: a water-filled limestone cavern. Ironically, beneath the hottest, driest place in the Western Hemisphere stretches a vast aquifer system. The opening at Devil’s Hole is one of the few places in Death Valley where the water from this system meets the surface.

“This is the only place on the planet where this fish exists naturally,” says Zane Marshall, head diver for the Devil’s Hole Pupfish Recovery Team. “Scientists have estimated that it has been in isolation here in excess of 25,000 years.”

Marshall’s team is part of a larger recovery effort that includes representatives from the National Park Service, the Department of Fish and Wildlife, and Nevada’s Division of Conservation. “This pupfish is the most restricted vertebrate species in the world,” says Marshall.

It was that exact notion that prompted President Harry Truman, in 1952, to protect the unique pupfish and its habitat by designating Devil’s Hole a disjunct part of Death Valley National Monument. For nearly two decades, the fish enjoyed a protected haven.

But by the late 1960s, development and nearby farming beyond the boundaries of the monument began to take a toll on the water levels in Devil’s Hole. As the pupfish do most of their feeding and spawning on an algae-carpeted limestone shelf just a few inches below the surface, a small drop in the water level was all it took to bring the fish to the brink of extinction.

What ensued was a bitter contest over water rights that pitted developers against conservationists and the federal government against a corporate farm. In the end, the fish reigned victorious. In 1976, the U.S. Supreme Court issued a landmark ruling that protected not only the fish but also their fragile habitat by specifically stating that water levels in Devil’s Hole must remain high enough to completely cover the spawning shelf. As a result of the ruling, development was halted, and the fish became one of the very first species to be protected under the Endangered Species Act.

Since then, Devil’s Hole has been cordoned off from park visitors by a chain-link fence that runs the perimeter of the hole. Only members of the recovery team are permitted access in order to perform quarterly counts of the fish. From 100 feet beneath the surface, the team works their way up in pairs, counting and measuring every fish they see. This provides them with an index of how the population is doing.

Despite 30 years of federal protection, recent counts suggest grim news: the fish’s population is once again plummeting. Linda Manning, a biologist for Death Valley National Park has been working closely with the Pupfish Recovery Team. “Right now we are very concerned because we recently had the lowest count in 32 years — only 123 fish,” she reports.

This time, however, the reasons for their decline are not so clear. Due to its protected status, study of Devil’s Hole has been extremely restricted. “We don’t yet understand everything that is going on in this system,” says Manning. “It’s a real puzzle. You wonder what the dynamics are. What’s impacting the fish? How are they making it? We’re just starting to get a handle on it, but there’s just still so much more to know.”

What they do know is that it is a harsh environment for a fish. The water temperature is 93 degrees Fahrenheit, food sources are extremely limited, and sunlight only hits the surface of the spawning shelf four months out of the year. “It’s pretty amazing that they’ve actually survived for thousands of years in this environment,” says Manning. “I just hope they can continue.”

In addition to conducting quarterly counts of the fish, the Park Service has installed monitoring wells near Devil’s Hole to keep an eye on the water levels, which have been dropping gradually over the past 14 years. Development and groundwater pumping in nearby Pahrump, Nevada, has long been suspected of affecting the water level in Devil’s Hole, though many Pahrump officials deny the allegations.

If the team doesn’t find a solution soon, the devastating effects may be far-reaching. “We definitely believe the pupfish are an indicator for the health of this system,” offers Manning. “When you start poking holes in the fabric of an ecosystem, over time it’s going to tear, and the impacts will be felt by everyone.”

Before that happens, the team will continue to do all they can to ensure the Devil’s Hole pupfish keep hold of their well-earned reputation as resilient survivors.

When the gray wolf was eradicated from Yellowstone National Park in the 1920s, more was lost than just the noble and fascinating predator. The park’s entire ecosystem changed. Now, nearly a dozen years since the wolves returned, the recovery of that system to its natural balance is well underway, say ecologists William Ripple and Robert Beschta of Oregon State University.

The researchers began studying the interaction of wolves with other parts of the ecosystem somewhat indirectly. “Back in 1997, I became aware that the aspen trees in Yellowstone were declining,” Ripple explains. “There was disagreement and confusion as to why these trees were disappearing, so I set out with graduate students to unravel this mystery.”

“We went out to the park and we cored the trees and studied the tree rings which show the annual growth, and we were able to age the trees that are still there,” Ripple says. The tree ring analysis indicated that the aspen, which usually regenerate themselves by sending off new shoots rather than by producing seeds, had stopped producing new trees during the first half of the 20th century.

Ripple and his colleagues looked at several possible variables that could be affecting the trees, from climate fluctuations to a changing natural forest fire regime. But the only factor that fit, Ripple says, was the browsing patterns of elk, which like to feed on the seedlings of aspen trees, and which are also a favored food of gray wolves: “The wolves were killed off from Yellowstone in the 1920s, which correlated with the start of the aspen decline. That led us to develop the hypothesis that the wolves were connected in some way to the aspen trees.” That connection, Ripple concluded, was mediated through elk: “We connected the dots: wolves affect elk; elk affect aspen; and therefore wolves affect aspen.”

Aspen grove (photo: NPS/J Schmidt; 1977)

Ripple and his colleagues subsequently discovered other changes. In some areas, willows — small, scrubby trees that grow in wet areas along stream beds — were starting to grow taller, because they were escaping predation by elk. In other areas, however, the willows continued to be heavily grazed upon. The same patchy changes were also seen with cottonwood trees, which also grow along streams.

“The more I looked at it the more I could see that what is going on may be an ecology of fear,” Ripple says. “The theory goes like this: the browser — in this case the elk — need to make behavioral decisions and tradeoffs as to how much time and energy to put into eating food versus how much time to be staying in safe places.” Those decisions affect where the animals concentrate their feeding efforts, and therefore the distribution of the vegetation they eat. “What we started noticing is that the plants were doing better where the terrain might favor the wolf a little bit more than the elk,” he says. For example, the elk might browse less in areas with poorer visibility (more dangerous to the elk because they can’t see if wolves are on the scene), or regions littered with heavy debris (a risk because it becomes an impediment to escape in the event of an attack).

Indeed, Ripple says, “we found that aspen were growing the tallest along streamside areas that had some downed woody debris or some downed logs nearby.”

Elk behavior and vegetation distribution aren’t the only factors impacted by the return of the Yellowstone’s wolves. Ripple suspects that the ripples of their recovery are reverberating throughout the entire ecosystem, in birds, fish, insects, as well as in other plants and animal species. Beavers, for example, are probably affected, he says. “The park service has been monitoring beaver since the wolves returned, and found that they have increased in numbers every year in the northern part of Yellowstone. Before the wolves returned, there really wasn’t much food for the beaver. But now with this growth of these plants — especially the willow — the beavers have more food, and they are also using the willows to build their lodges and their dams, which may be contributing to beaver population increases.”

“We are at the beginning of a grand ecological experiment,” Ripple says. “We were without wolves for seventy years, and we’ve just had them back in for 11 years, so we’re only just starting to see changes. It could take many decades for the ecosystem to recover.”

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The Cape Griffon vulture, the largest bird of its kind in Africa, is also one of the most endangered. Listed as “vulnerable” to extinction by the World Conservation Union (which is similar to “threatened” on the Endangered Species List) the Cape Griffon vulture has suffered a significant population decline over the past few decades. Among the dangers faced by the Capes, which are confined to a small area of south and southwest Africa, is electrocution on power lines. In addition, changes in the migration patterns of large game herds and an increase in domesticated animals (which are usually buried when they die) have diminished the amount of food available to the birds and led to dietary insufficiencies.

Of more concern, however, are mass accidental poisonings, says Maria Diekmann of the Rare and Endangered Species Trust (REST) in Namibia, where Cape Griffon vultures are the most endangered of all animal species. Farmers and ranchers commonly poison the carcasses of animals to kill predators like leopards and jackals, which prey on their livestock; the birds, which are carrion eaters and feed exclusively on dead animals, are inadvertently poisoned. “Poison is cheap, easy and effective. The problem is that they do it incorrectly or get incorrect information from the supplier and instead kill non-targeted species. I am also a farmer — our farm faces the cliffs of the last roosting site in Namibia — so I know the problems that they can have. We try hard to work with them,” says Diekmann.

Because of the gregarious nature of vultures, large numbers of the animals can be poisoned at once. “Vultures are incredibly social when eating,” Diekmann explains. “Numbers are security, so they will often wait until there are hundreds of birds to begin eating. A lot of followers and not many leaders. The problem is that if a carcass is poisoned you can kill 50 to 500 birds at once. I cannot think of any other species that this is possible with, and the Asian vulture crisis — 10 million birds dead in just over 10 years — has proved this.”

The Cape Griffon vulture has suffered a significant population decline over the past few decades.

“The Cape Griffon vulture is what I would call a ’super vulture.’ It is bigger, eats more, only roosts on cliffs; the needs are more specific. I think that all of our vulture species are declining. We just see it in the Cape first as the numbers were lower to begin with. [It] is an indicator species of what is probably going on with them all,” she says. The decline of vultures has particularly dramatic implications for the rest of the ecosystem. This is because vultures rapidly consume the bacteria-riddled bodies of dead animals, which would otherwise spread disease. The vultures themselves appear to be immune to many of these diseases. “The fact that they eat together and can consume a carcass in an hour seems to prevent most of these diseases from spreading to our wildlife and domestic animals,” Diekmann says.

To help conserve the Capes, Diekmann and her colleagues with REST, along with other vulture experts, have begun outfitting the birds with satellite telemetry collars, which allow their flight, breeding, and feeding patterns to be monitored and provide information about the sources of contaminants in their environment. “This gives us baseline data to work from, instead of checking the wind and guessing,” she says.

With these and other efforts, Diekmann is hopeful that the Capes can be saved: “Vultures respond well to conservation. A little goes a long way. If we can handle the poison issue, which we are starting to, that can save the population. I am not much of a gambler; I go for the win, and a loss here would be too big of a loss.

The epic history of the Druids, one of more than a dozen packs now occupying the 2.2 million acres of Yellowstone, is documented in NATURE’s In the Valley of the Wolves, was produced and shot in High Definition by Emmy-award winning filmmaker Bob Landis.

On the Web site for In the Valley of the Wolves, you’ll learn how the successful reintroduction of Yellowstone’s apex predator has changed the entire ecosystem of the park, and about the threats that these majestic animals continue to face on their road to recovery.

Watch an online-exclusive video. In this video, Emmy Award-winning wildlife cinematographer Bob Landis discusses the making of the film, including the ideal circumstances for filming a predation scene; the importance of spending a vast amount of time in the field; the uniqueness of Yellowstone’s Druid wolf pack, and more.

To order a copy of In the Valley of the Wolves, visit the NATURE Shop.

Online content for In the Valley of the Wolves was originally posted November 2007.

Beautiful, elegant, and intelligent, parrots have long been coveted and caged by humans. With over 340 species living in the Americas, Asia, Africa, and Oceana tropic zones, our world should be brimming with parrots. But today, parrots are one of the most threatened families of birds. Nearly a third of parrots worldwide are threatened — a statistic three times greater than the threat to all bird species.

Several factors are responsible for such grim statistics about these colorful birds. Poaching for the pet trade may be the biggest. The stress and damage from the capture, transit, and quarantine of parrots take a serious toll on the fragile birds. It is estimated that for every parrot in a pet store, three have died in transit. Ever since the Wild Bird Conservation Act made it illegal to commercially import parrots into the United States from countries without conservation strategies, most pet shop parrots are captive-bred. However international trade in wild-caught parrots remains a concern. It is estimated that 88 percent of parrots, parakeets, and lovebirds imported into Britain between 1995 and 2000 were caught in the wild.

Destruction of their natural habitats due to clearing of tropical rainforest and to agricultural development has also taken its toll. To make matters worse, as seen in “Parrots in the Land of Oz,” parrots are grain eaters and so are treated as pests by farmers.

The biggest parrot victims appear to be the larger, more colorful parrots like macaws and cockatoos. Not only are they more sought after but they have smaller broods; hence, it takes them longer recover and repopulate. The largest flying parrot, and possibly the noisiest, the macaw has paid a price for its willingness to be tamed and trained as a human pet. Over half of all macaw species are on the endangered list. The Spix’s macaw, a delicate, pale blue bird, was considered one of the world’s most endangered species. For ten years, only one lone male was known to exist in the wild in a small arid region of savanna scrubland in northeastern Brazil known as the “caatinga.” Then, in 2000, this last wild bird disappeared. There is currently an international captive breeding program for the bird, and the hope is to re-introduce the macaw to the wild — eventually.

One species of macaw that scientists hope to save before it suffers a fate similar to Spix’s macaw is the red, yellow and blue-plumed scarlet macaw. With only 300 macaws left in Guatemala’s nature reserve, the primary-colored creatures are in danger of being wiped out in that country. At fault are poachers, drug traffickers and land invaders, who slash and burn the bird’s jungle habitat. Thousands of acres of forest are cut down to make way for settlers and clandestine airstrips for drug traffickers moving cocaine from Colombia up into the United States. To keep an eye on their numbers, researchers recently fit two scarlets with satellite collars to track them in northern Guatemala and southern Mexico. With hope, the watchful eye of science will help protect these beautiful birds from further danger.

While over one million may have roamed at the time of Columbus’ arrival, today less than forty Puerto Rican Parrots remain in the wild. Their decimation has been so relentless that the gregarious Puerto Rican Amazon, or the Puerto Rican Parrot, is one of the ten most endangered species of birds in the world. Habitat destruction throughout the 19th and 20th centuries drastically reduced the bird’s numbers. As early as 1968, conservation efforts began to protect this species with the goal of saving it from extinction. A recovery program sought to establish a wild population and hopefully down-list the species from endangered to threatened.

A diminutive, yet plump parrot with a small, fragmented range in New South Wales and Queensland, the Coxen’s fig parrot has virtually vanished from the wild. Sadly, recent surveys have come up with only a few fleeting sightings, and no active nests have been discovered. The Australian native’s original habitat included lowland coastal rainforests, but these have mostly been cleared.

If humanity is to reverse the trend and save these magnificent creatures from extinction, it is essential that we immediately begin to conserve the habitats of threatened parrots and to be aware of politics of the pet parrot trade. As smart as parrots are, only humans can stop the devastation that some of the most vulnerable species have experienced at our hands.

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