Delmarva Fox Squirrel No Longer Endangered

The critter had held the dire designation since 1967.

The Delmarva Peninsula fox squirrel will be removed from the Endangered species list next month, the U.S. Fish and Wildlife Service (FWS) announced.

Watch "Racing Extinction" on Discovery Channel, Dec. 2, at 9 PM ET/PT.

The move has been a long time coming. The squirrel was one of 78 species to be listed under the original Endangered Species Preservation Act of 1967, a forerunner of today's Endangered Species Act, which became law in 1973.

At about 15 inches in body length, minus the tail, Delmarva fox squirrels are larger than other squirrel species, and unlike more typical squirrels they're not usually seen in urban and suburban environments. Instead, they live on rural, forested lands and in agricultural fields.

The animals once ranged in healthy numbers on the Delmarva (Delaware, Maryland, Virginia) Peninsula. But mid-20th-century forest clearing for timber harvesting, agriculture, development, and hunting decimated the animal almost completely.

Now, though, its numbers are so robust that the squirrel is no longer considered at risk of extinction.

According to the FWS, the squirrel has increased its range, since being listed, from four to 10 counties. Its population is now estimated at 20,000, covering nearly 30 percent of the peninsula, primarily in Maryland.

Official's say the Endangered Species Act has put the Delmarva fox squirrel back on the map.

"The Act provides flexibility and incentives to build partnerships with states and private landowners to help recover species while supporting local economic activity," said the U.S. Department of the Interior's Principal Deputy Assistant Secretary for Fish and Wildlife and Parks, Michael Bean. "I applaud the states of Maryland, Delaware and Virginia, and the many partners who came together over the years to make this day possible."

The Blackwater (Maryland), Chincoteague (Virginia) and Prime Hook (Delaware) national wildlife refuges are places nature lovers can check out the reinvigorated squirrel, the FWS said.

Hugging trees feels good and can even be healthy for many animals, according to a study in the latest issue of

Biology Letters

. There are several perks to being a tree hugger, but a surprising one is that trees help to regulate the hugger's body temperature. That's one reason why koalas are so often seen hugging trees.

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In fact, koalas have evolved bodies that are perfectly suited for the task. "Koalas have thinner fur in their bellies, which we suspect is to aid close contact with the tree trunk," senior author Michael Kearney told Discovery News. On hot days, he said that koalas "are aiming to cool the vital organs in their chests as well as their brains by losing heat through their chests and groin areas." Kearney is a zoologist at the University of Melbourne. He conducted the study with project leader Natalie Briscoe and four other researchers.

As part of the study, Briscoe, Kearney and their team examined how tree hugging affected koala body temperature. In this thermal image, purple tones are the coldest, with the lightest (yellow) colors indicating warmth. Orange tones show temperatures in between those two extremes. Trees gain heat from the koala body. As this happens, the koala cools off.

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Kearney explained that as a koala hugs, "The blood flowing through the body would continually replenish cooled blood near the parts of the koala in contact with the tree with warm blood from other parts of the body, with the ultimate effect of cooling the whole body down."

Briscoe, Kearney and colleagues shared that other animals, such as leopards, hug trees too. Leopards, other big wild tree cats and even tree-climbing house cats might look like they are just lounging on branches, but they too tend to hug trees, using the tree's cooler internal temps to cool down their bodies.

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Many bat species go to a lot of trouble to hug trees, having to hang on with their toenails. Some trees turn out to be better than others for body temperature regulation.

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Kearney explained, "Trees with smooth bark seem preferable because they have what's called a 'high thermal conductivity,' which means heat flows faster into or out of the object. Also, larger trees with thicker trunks are cooler."

Group hug, anyone? Many species of bats, and particularly those that consume fruit, frequently hug trees en masse. In addition to regulating body temperature, trees can provide food and shelter. Kearney added, "It helps to stay attached to the tree on a windy day."

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Cold-blooded animals, such as small reptiles, are more vulnerable to temperature extremes. By hugging trees, they help to control their body temps. Briscoe and her team are not sure if trees help to warm animals on cold days, but they haven't ruled out that possibility.

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This green tree monitor lizard appears to have found a perfect spot on a tree. Another green tree monitor lizard nearby benefits as well. The study found that Acacia trees were amongst the coolest during hot days. Acacias are therefore sought out by koalas and other animals.

Both big and small primates (such as this tiny tarsier) seem to enjoy hugging trees, gaining the body temperature regulation benefits. It's not entirely clear why trees are so good at keeping their cool.

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"We don't fully understand the mechanism," Kearney said, "but suspect it has to do, in part, with cool ground water being drawn up by the tree as it transpires, and in part because of the tree's thermal inertia." "Thermal inertia" is the degree of slowness with which the temperature of a body approaches that of its surroundings.

One of the two young chimps shown here is hugging what's left of a tree. Deforestation harms countless species. The new findings suggest that animals, ranging from large primates to small invertebrates, could become overheated during hot days without the cooling effect of trees on their bodies.

Squirrels, as for big cats, use trees as the ultimate lounging pads. Squirrels, such as this one, could be hugging trees to cool their body temperature. The squirrels and other animals might not consciously know this. To them, it likely just feels good.

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Being primates, our human ancestors likely spent a lot of their time hugging trees. Most trees are the perfect shape for hugging, given that we and many other animals can wrap two or more limbs around them.