Dogs Trained to Find Endangered Animals

Many dogs are very hard - working animals. They have been helping people for thousands of years. Dogs protect our homes. They help people with disabilities. They team up with rescue workers in search -and - rescue operations. And now, dogs can add another job to their resumes—finding endangered animals! The official title for this kind of work is conservation detection dog.

Luke Edwards is a dog owner and trainer. He is training two border collies (边境牧羊犬), named Rubble and Uda, to become conservation detection dogs.

He says that border collies are good for this kind of work because they have a great, sense of smell. The dogs also have great stamina—the mental and physical strength to work long hours .

Recently, the dogs went on their most difficult job yet - finding the Baw Baw frog. This frog is one of Australia ‘ s most endangered animals.

The work is difficult mainly because of the search area. Just to get to the place where the frogs live. the dogs and their trainers must walk far distances through alpine(高山)forests . It is difficult but important work.

A deadly fungus (真菌)has killed nearly all of Australia’s Baw Baw frogs. In fact, scientists say these creatures could disappear in the next five to ten years.

Zoos Victoria is a group set up to protect wildlife. Conservation experts there claim that since 1980 the deadly fungus has killed off 98 percent of the Baw Baw frogs.

So. Zoos Victoria is trying to save the frogs. Experts there raise them and have them reproduce. They call it their captive breeding program.

Historical accounts often described the now-extinct California grizzly bears as huge beasts ready to attack humans and livestock at any time. But according to a new paper, scientists say the truth might have been less dramatic: The bears ate a mostly vegetarian diet and were smaller than previously described. California grizzly bears once roamed in the Golden State. But European settlers often hunted, poisoned and trapped the creatures. Over time, because of these human activities, the California grizzly population declined. The last reliable sighting of a California grizzly bear occurred 100 years ago in 1924, and the animals disappeared completely sometime after that.

Researchers wanted to get a better understanding of the factors that accelerated the bears’ extinction. They also hoped to gain more insight into the creatures’ behavior, size and diet. To do so, they turned to documents and California grizzly specimens in natural history collections. They measured the animals’ skulls and teeth and analyzed their bones and pelts. The researchers found that California grizzly bears were much smaller than the 2,000 pounds often reported at the time. Historical accounts might not necessarily have been wrong, but they might have only included the largest bears. In addition, analyses of the animals’ bones and skins suggest the bears were primarily eating plants, which stands in contrast to their fear some hyper carnivorous (超级食肉的) reputation. “The bears likely increased meat consumption due to landscape changes coupled with the arrival of livestock,” says study co-author Alexis Mychajliw. However, researchers found the animals still ate a majority vegetarian diet and killed far less livestock than historical accounts suggested.

By digging beyond the bears’ reputation, the researchers gained a more accurate understanding of the California grizzly’s biology and natural history. And since scientists and land managers often rely on historical accounts when reintroducing animals to their former habitats, the study serves as a reminder that those old newspapers and journals do not tell the whole story.

Migratory (迁移的) birds are specially adapted to find their way over extreme distances. Now, the new research of Kaspar Delhey and other researchers has discovered an unexpected way that migratory birds keep their cool during such backbreaking journeys: lighter-colored feathers (羽毛).

“We found across nearly all species of birds, migratory species tend to be lighter colored than non-migratory species,” said Delhey. “We think that lighter feather coloration is selected in migratory species because it reduces the risk of overheating when exposed to sunshine. Lighter surfaces absorb less heat than darker ones, as anybody wearing dark clothes on a sunny day can demonstrate! This would be particularly important for long-distance migrants that undertake extensive flights during which they cannot stop to rest in the shade.”

Delhey and his coworkers had been studying the effects of climate on bird coloration. Their earlier studies showed that, in general, lighter colored birds are found where temperatures are high and there is little shade. That’s in part because the birds’ lighter feathers help to keep them cooler in the hot sun. Then the researchers came across studies by others showing that some birds fly higher during the day compared to at night.

“Because flying higher is likely costly, these changes require an explanation,” Delhey says. “One possibility was that flying higher, where it is colder, would offset the heat absorbed by the feathers when the sun was shining.”

If so, they realized, another way to reduce the risk of overheating would be to absorb less solar radiation in the first place. It raised a question: have migratory species evolved (进化)   lighter feathers?

To find out, they did much research. Their findings show bird species get increasingly lighter as they migrate more. So, resident birds tend to be darker than short-distance migrants. Short-distance migrants are darker than bird species that travel farther. Delhey said the effect suited different types of birds. The same held true in waterbirds and ground-living birds, too.

The findings are another reminder of the important role of temperature and climate factors more broadly in the evolution of shaping the coloration of animals. They also help better understand the impacts of global warming and underlying adaptive evolutionary responses.