In Supersize Crocs, Rom takes viewers along as he sets off on his own hunt to find the last of the leviathans. Venturing to Ethiopia’s Lake Chamo, the riverbanks of India’s northern border with Nepal, and to the Adelaide River of Australian outback, Rom hits the hotspots of supersize croc habitats as he searches for signs of life among the brackish waters. Rom will share with viewers his insight and fascination with the cryptic world of crocs. Along the way, viewers will learn about ancient croc survival skills as well as how crocs are ideally designed to be the most successful freshwater predator.

Will he find his supersize croc among the three titans of the croc world: the Nile crocodiles, saltwater crocodiles and gharials? Tune in to find out.

To order a copy of Supersize Crocs, please visit the NATURE Shop.

Online content for Supersize Crocs was originally posted February 2007.

The Steller’s sea lions that populate the Alaskan coastline are powerful, playful, and sometimes rowdy creatures who bump and jostle each other on land but acquire a sublime gracefulness in the water. They are also the subject of a strange and tragic mystery: Steller’s sea lions are rapidly disappearing from one of the last great wildlife strongholds of the world, and no one knows why.

Naturalist filmmaker Shane Moore, who has been working in the Alaskan wilderness for much of the past 10 years, brings a sense of urgency and new understanding to this puzzle in A Mystery in Alaska.

As scientists and environmentalists race the clock to find answers, pressure has been growing on Alaska’s fishing industry to suspend most of its pollock fishing, on the suspicion that it is robbing Steller’s sea lions of an important source of food. But new research illustrated in this film shows that a broad combination of factors could be responsible for the sea lions’ plight.

To order a copy of A Mystery in Alaska, visit the NATURE Shop.

Online content for A Mystery in Alaska was originally posted May 2003.

Can the King of Beasts be copied? That is the question some conservationists are pondering as lion populations dwindle worldwide. They say cloning — using advanced biological techniques to create genetic duplicates of existing lions — could become part of the effort to save the big cats. Other experts, however, are skeptical. Cloning lions would be difficult and expensive, they argue, adding that it won’t really solve the major problems facing the big cats, such as habitat loss. For the moment, they say, the money would be better spent on more traditional conservation efforts.

It’s a debate that couldn’t have even occurred a decade ago. Cloning a mammal was beyond the reach of science until 1996, when researchers managed to create a cloned sheep named Dolly. Since then, scientists have learned how to clone a host of other mammals, including mice, sheep, cows, dogs, and small cats. In 2002, scientists in Texas announced that they had cloned a domestic cat. They named the genetic replicate kitten “CC,” for “carbon copy.”

The breakthrough got some cat conservationists thinking. Cloning, they realized, could be a way to preserve the gene pool of dwindling cat populations, and perhaps create robust animals that could eventually be returned to the wild. In theory, genes could even be taken from the frozen tissues of dead animals, then reintroduced into populations through cloning. In essence, the dead could “walk again.”

In 2003, one conservation center began to follow through on these ideas. In New Orleans, the Audubon Center for Research of Endangered Species succeeded in cloning the first African wildcat, the bigger, wilder cousin of the common domestic cat. Eventually the team produced seven clones. Then, in 2005, the researchers went a step further. Two of the clones were allowed to mate, producing eight kittens. The births confirmed the idea that maybe, someday, cloned animals might be used to repopulate endangered species.

“We couldn’t be happier with these births,” Audubon researcher Betsy Dresser said at the time. “By improving the cloning process and then encouraging cloned animals to breed and make babies, we can revive the genes of individuals who might not be reproductively viable otherwise, and we can save genes from animals in the wild.”

Ultimately, she said, similar techniques might be used to reinvigorate populations of endangered small cats, such as Asia’s fishing cats and India’s rusty spotted cat, the world’s smallest feline. “The goal is to use whatever tools we can to help boost these populations,” explained Dresser. She cautioned, however, that while cloning could help conservation, “no single approach is going to solve the incredibly complex problem of disappearing wildlife.”

That complexity has helped spark controversy in India, where in 2004 scientists announced ambitious plans to clone the highly endangered Asian lion. Fewer than 300 are believed to exist, and the small group of Indian researchers said they wanted to spend $1 million to clone and restore the big cats.

The announcement drew criticism from conservation groups, who said the project raised false hopes. One problem, they noted, is that even if scientists succeeded in cloning the lions, their natural habitat is rapidly being lost to farms and development. “We spend millions of rupees trying to clone…lions, but where will we put them?” Belinda Wright of the Wildlife Protection Society of India asked reporters.

In addition, experts predict that cloning a lion won’t be easy. The vast majority of cloning experiments end in failure, they say, noting that it took more than 300 tries to create Dolly the sheep. Adding to the challenge is the fact that every mammal species has its own biological quirks when it comes to reproduction. Cloning a dog proved far more difficult than cloning a cat, for instance, because of some details of its reproductive biology.

In India, lion cloning advocates predict those technical problems will be overcome. So far, however, no scientist has succeeded in cloning one of the big cats. For the moment, weighing the potential risks and benefits of making copies of the King of Beasts remains a mostly hypothetical debate.

Across Africa, the King of Beasts is in trouble. In the late 20th century, wildlife preserves were created to curtail safari hunting, but the African lion population continues to decline. Their numbers have dwindled from 100,000 in the early 1990s to no more than 30,000 and as few as 16,000 today. What could be endangering the King of Beasts?

In the mid-1990s a mysterious disease spread rapidly through the lion population in Tanzania and Kenya. An investigation revealed that the big cats had contracted canine distemper from jackals and hyenas that were picking it up from dogs in nearby villages. The spread of the disease was quickly halted and today lion numbers in the affected areas are back to previous levels.

If canine distemper was halted, why have lions continued to decline? An ever-expanding human population has led to competition between herders and lions for land and food. Lions living at the edge of the preserves sometimes stray from protected areas in search of easy prey. The Maasai and other ranchers will often kill them to protect their livestock and source of livelihood.

But as NATURE’s The Vanishing Lions shows, Africans are now struggling to reverse the decline. Everyone from scientists and conservationists to Maasai herders and ranchers is working together to find solutions. Travel to Kenya’s famed Serengeti Plains, the wildlife-rich Laikipia Plateau, and elsewhere in Africa as NATURE explores efforts to allow people and lions to coexist and prosper.

To order a copy of The Vanishing Lions, visit the NATURE Shop.

Online content for The Vanishing Lions was originally posted April 2006.

This episode premiered Sunday, April 19, 2009.

GRADE LEVEL: 5-8

TIME ALLOTMENT: Two 45-minute class periods

OVERVIEW:

The loneliest animals are the last of their kind on the planet. Scientists warn that up to 100 species a day are being pushed toward extinction. Sadly, many of these creatures are endangered because of human actions. Nature: The Loneliest Animals profiles a variety of captive breeding programs, designed to bolster these dwindling animal populations.

Using segments from this program and other Web resources, students will discuss different ways that animal species become extinct, and analyze how human actions can positively and negatively influence a species’ population. Students will also discuss the benefits and challenges of helping an endangered species through captive breeding, and will prepare “news segments” for the class to present research on endangered species.

OBJECTIVES

Students will be able to:

• Compare and discuss different causes of extinction;
• Name several currently highly endangered species, and describe how people are trying to bring them back from the brink of extinction;
• Research an endangered species, and present information from online, print, and broadcast resources in an oral report.

MEDIA RESOURCES:

Video:

NATURE, The Loneliest Animals, selected segments

Clip 1: Yangtze giant soft shell turtle

Clip 2: Sumatran rhinoceros

Clip 3: Lemurs

Clip 4: Black-Footed Ferret

Clip 5: Imperiled Lives

Access the streaming and downloadable video segments for this lesson at the Video Segments Page.

Web sites

Yangtze Giant Soft-shell Turtle (China)

Asian Turtle Conservation Network: Rafetus Swinhoei

Fact page on the endangered soft-shell turtle

China’s Turtles: Emblems of a Crisis (New York Times)

Article about the Chinese breeding effort for Rafetus Swinhoei

Sumatran Rhinoceros (Sumatra, Indonesia)

International Rhino Foundation:

Sumatran Rhino Sanctuary

[NOTE: page features graphic photo of two rhinos mating.]

Information about Sumatran Rhinos from the Indonesian sanctuary

Sumatran Rhino

General information about the endangered Sumatran Rhino

News from the Field – International Rhino Foundation Blog

Latest news in Rhino research

Lemurs (Madagascar); including Golden-Crowned Sifaka

Duke University Lemur Center

Information on the many species of lemur at the Duke University Center, including the endangered Golden-Crowned Sifaka

Black-Footed Ferret (United States)

Prairie Wildlife Research

Black-footed ferret conservation information

STANDARDS:

National Science Education Standards

http://www.nap.edu/openbook.php?record_id=4962

LIFE SCIENCE: Content Standard C

As a result of their activities in grades 5-8, all students should develop understanding of

• Diversity and adaptations of organisms
  • Biological evolution accounts for the diversity of species developed through gradual processes over many generations. Species acquire many of their unique characteristics through biological adaptation, which involves the selection of naturally occurring variations in populations. Biological adaptations include changes in structures, behaviors, or physiology that enhance survival and reproductive success in a particular environment.

o        Extinction of a species occurs when the environment changes and the adaptive characteristics of a species are insufficient to allow its survival. Fossils indicate that many organisms that lived long ago are extinct. Extinction of species is common; most of the species that have lived on the earth no longer exist.

SCIENCE IN PERSONAL AND SOCIAL PERSPECTIVES: Content Standard F

As a result of activities in grades 5-8, all students should develop understanding of

• Populations, Resources, and Environments
  • When an area becomes overpopulated, the environment will become degraded due to the increased use of resources.
  • Causes of environmental degradation and resource depletion vary from region to region and from country to country.

MATERIALS:

For the class:

• One computer with Internet access and audiovisual projection system, for screening video segments
• “Last of their Kind” Answer Key (PDF) (RTF)
• [Optional - toothpicks, stopwatch, and flour, for the Extinction Simulation extension activity - see the "Loneliest Animals Extinction Simulation" (PDF)

For each group of 2-3 students:

• Computer with Internet access

For each student:

• “Causes of Extinction” Student Organizer (PDF)(RTF)
• “Last of their Kind?” Student Organizer (PDF) (RTF)
• “Explore a Species” Student Organizer (PDF) (RTF)

PREP FOR TEACHERS

Preview all of the video segments and Web sites used in the lesson.

Download the video clips used in the lesson to your classroom computer, or prepare to watch them using your classroom’s Internet connection.

Bookmark the Web sites used in the lesson on each computer in your classroom. Using a social bookmarking tool such as del.icio.us or diigo (or an online bookmarking utility such as portaportal) will allow you to organize all the links in a central location.

Make copies of student organizers listed in the “Materials” section.

Proceed to ACTIVITIES

Excerpts from the NATURE episode, “The Loneliest Animals”

Downloadable QuickTime versions of the video segments:
(Note: To download a video, right click on the video title and click “Save Link As…’ or “Save Target As…”. On a Mac, press the CTRL key and simultaneously click the mouse, then save the link.)

Clip 1: Yangtze Giant Soft-Shell Turtle

Clip 2: Sumatran Rhinoceros

Clip 3: Lemurs

Clip 4: Black-Footed Ferret

Clip 5: Imperiled Lives