Huon Tree Kangaroo
Tree kangaroos' cloud forest habitat is rugged and wet, making the animals difficult to study.
We all know birds and squirrels hang out in trees, but it can a tall order to think of more exotic examples like koalas.
These Australia and New Guinea natives have arms stronger than the more well-known red and gray kangaroos, as well as large claws to help their grip, Trevor Holbrook, coordinator of the Tree Kangaroo Conservation Program, based at Seattle's Woodland Park Zoo, says by email.
Their cloud forest habitat, threatened by destruction and fragmentation, is “extremely rugged, steep, wet, and densely forested,” which makes them difficult to study, Holbrook says.
They’re well disguised, too.
The endangered Matschie's tree kangaroo, for instance, has "reddish-brown fur camouflaged with the moss that grows on trees,” Holbrook says.
These Southeast Asian mammals have traits perfectly suited for arboreal life, such an flexible ankle joint that rotates 180 degrees and a prehensile tail with “leathery bare patch at the end” that provides good traction, says Joanna Lambert, a biologist at the University of Colorado, Boulder by email.
A flexible collarbone supports their upper bodies as they move through branches, and forward-facing eyes allows for "excellent depth perception, important for judging distances between branches."
Another binturong fun fact: Their pee happens to smell like hot buttered popcorn.
Helen’s Flying Frog
Helen's flying frog is one of 90 species of flying frog, known for sailing between trees. Its “huge webbed hands and feet that act like parachutes when they glide from the canopy,” Jodi Rowley, a biologist at the Australian Museum, says by email.
Rowley discovered Helen's flying frogs in 2009, naming the species for her proud mother. (Related: “'Fantastic' New Species of Flying Frog Found—Has Flappy Forearms.")
The amphibians, found in Southeast Asia’s lowland forests, come down from the trees to breed, laying their eggs on leaves hanging over temporary pools of water. The tadpoles then drop into those pools, she says.
Orangutans and Gibbons
Primates are the most arboreal mammals, having lived aloft for 55 million years, Lambert says. That includes us, though we’ve gone terrestrial, like our chimpanzee kin.
Orangutans of Southeast Asia are the largest tree-dwellers in the world, weighing up to 180 pounds. They compensate for their heavy frames by what Lambert calls “quadrumanous cautious climbing:" using “both hands and both feet to grab onto branches as they move.”
Gibbons, of South Asia, are quite the opposite.
These 12 species are the “only true brachiators,” meaning they swing through the trees with a hand-over-hand grip, she says. Wide and flexible shoulders also help them swing up to 20 feet between branches.
Flying squirrels of North America nest, sleep, and breed in tree cavities, Marne Titchenell, wildlife program specialist at Ohio State University, says by email. The mammals descend to forage for nuts, berries, and insects.
They glide from tree to tree aided by their patagium, a flap of skin extending from wrist to ankle. A muscular lining keeps the flap close to their body when they’re not airborne. Sharp claws help them stick the landing.
Think “Gonna Fly Now,” but for a different Rocky.