What better way to start out the new year than by learning about some animals that fly (or glide) without wings! Thanks to Llewelly for suggesting the colugo!

Colugo looking startled:

A colugo, flying, which startles everyone else:

Flying fish! ZOOM!

A flying gurnard, not flying:

Flying squid! ZOOM!

Flying squid close-up, mid-zoom:

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

It’s the first week of a new year, so let’s start it off right and learn about some animals that fly without wings.

The first of our non-winged flying animals is a suggestion from Llewelly, who sent me some links about it and we both freaked out a little because it’s such an awesome animal. It’s called the colugo, and technically it doesn’t fly, it glides. It looks kind of like a big squirrel and kind of like a small lemur, and in fact it’s also sometimes called a flying lemur. But it’s not closely related to squirrels or lemurs. It’s actually not related closely to anything alive today.

Before we learn about the colugo specifically, let me explain a little bit about gliding animals. Gliding animals have a flap of skin called a gliding membrane or patagium. In the case of gliding mammals, like the flying squirrel or the colugo, the patagium connects each foreleg with the hindleg on that side. When the animal wants to glide, it stretches its legs out, which also stretches out the patagium. For a long time scientists assumed that the patagium was just skin and didn’t do anything except increase the animal’s surface area and act as a sort of parachute. But it turns out that the patagium contains tiny muscles like those recently discovered in the membranes of bat wings. And the skin between the fingers of the bat’s forelimbs, which creates the wings, are actually considered patagia. In fact, any gliding membrane, even if it’s part of a real wing, is considered a patagium, so birds actually have them too.

The colugo has a patagium between its legs like other gliding mammals, but it also has a patagium between its hind legs and its tail, and even its fingers and toes are connected with small patagia. It’s the most well-adapted mammal known for gliding, so well-adapted that it can glide incredible distances. One was measured as having glided almost 500 feet in one jump, or 150 meters. This is almost the length of two football fields.

The colugo lives in South Asia and is endangered mainly due to habitat loss. It grows to about 16 inches long, or 40 cm, with a small head, big eyes, and little round ears. It’s gray with some mottled white and black markings that help hide it against tree trunks, and its legs are long and slender. It eats plants. We don’t know a whole lot about the colugo, because it’s shy and lives in the treetops of tropical forests, but what we do know is really weird.

For instance, its babies. If you listened to episode 45 about monotremes, where we also discuss the differences between marsupial and placental mammals, you may remember that placental mammal babies are born mostly developed while marsupial mammal babies are born very early and finish developing outside of the mother, either in a pouch or just clinging to the mother’s fur. Well, the colugo is a placental mammal, but its babies are born extremely early, more like a marsupial. They finish developing outside of the mother, which takes six months or so, and the mother colugo keeps her tail curved up most of the time so that her patagium is wrapped around her babies like a pouch.

The colugo has weird teeth, too. The front teeth, or incisors, are shaped like tiny combs. This is similar to the incisors of lemurs, which look like tiny combs because the lemur uses them as tiny combs to groom its fur. But unlike any other mammal known, some of the colugo’s upper incisors have two roots instead of just one. Why? No one knows.

So what is the colugo related to? For a long time,