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The Paradise Tree Snake (Chrysopelea ornata)
The paradise tree snake (Chrysopelea paradise) is a very beautiful tree snake which lives in Southeast Asia. It ranges from the Philippines and Indonesia, up through Malaysia, Myanmar and into India. The snake particularly enjoys climbing into the crowns of coconut palms where it feeds on arborial lizards (which it immobilizes with extremely weak venom). The snake lives in a variety of habitats including mangrove swamps, rainforests, tree plantations, gardens, and parks. It stands out because of its attractive pattern of yellow on black (sometimes tinted with red).
Paradise Tree Snake Flying!
What really sets the paradise tree snake apart from other pretty tropical snakes however is its impressive ability to fly—or at least to glide. The snake holds onto its launching platform with the end of its tail and dangles the majority of its body into a j-shape. The daring reptile then swings back and forth and launches itself through the air! The snake sucks in its stomach and flares out its ribs so as to take the shape of a flying wing and then it slithers through the air making lateral motions with its body in order to cause air pressure underneath it to push its body up. Smaller snakes (which are better gliders) can glide up to 100 meters (over 300 feet) and are reckoned by biomechanical locomotion specialists to be finer gliders than colugos and gliding squirrels.
A Colugo photographed in mid-glide
In the vanishing rainforests of Southeast Asia there lives a vanishing order of mammals named the Dermoptera. The entire Demoptera order consists of only two species (for contrast, all 3000 plus different species of catfish are in a single order of fish–the Siluriformes). The arboreal gliding Dermoptera are more commonly called Colugos. Measuring 35 to 40 centimeters (14 to 16 in) in length and 1 to 2 kilograms (2.2 to 4.4 lb), Colugos are the size of a very small cat. They are the most accomplished gliders among all of the mammals and they have been known to glide as far as 70 meters (230 feet) between tall rainforest trees. Both species of Colugos are complete herbivores. They live on fruit, flowers, nuts, and shoots which they digest with highly effective stomachs and extremely long intestines. Although colugos have digestive organs well-suited to their lives in the trees, they are unexpectedly terrible climbers. Without opposable thumbs or powerful muscles they must awkwardly “hop” up trees while clinging desperately to the bark with sharp little claws. Fortunately their proficiency at gliding means they can sail laterally from tree to tree without losing too much altitude. It should be mentioned that colugos are sometimes called “flying lemurs” though they are not lemurs and can not truly fly.
Cynocephalus variegatus (© 2006 Jwee)
Very little is known about Colugos (if you really want to make a crazy nature documentary, here’s your chance). They are shy, nocturnal loners who live in the tops of huge trees. Colugos are hunted by eagles, owls, and humans, but they adapt well to different habitats and can live in primary and secondary forests (as well as in human created monocultures such as coconut and rubber plantations). During the day they shelter in holes or cling beneath branches. The only major exceptions to their largely solitary lives occur among nursing mothers who care for young colugos for 2 to 3 years—a remarkably long time for a small animal. Although colugos are placental mammals, they have strangely marsupial habits. Babies are born in an undeveloped form and cling to their mother’s belly for six months (even as she glides between trees!). Mother colugos can shelter their infants by folding their flying membranes around the little ones in a warm snuggie-like pouch.
Colugo (Cynocepahlus variegatus) and baby on a Mango Tree (Photo: Gerardo Angelo)
The lengthy period during which Colugos are dependant on their mother becomes more comprehensible when their family relationships with other mammals are untangled. Colugos are closely related to tree shrews, but, looking at them more carefully something seems oddly familiar. That is because there is one other mammalian order which they are even more closely related to then the tree shrews—the primates. According to molecular biologists, they are the most closely related to us of all other orders of living things.
I’m always surprised by how numerous and varied the cephalopods are. A quick jaunt down the taxonomical branches of their family tree reveals marvelous creatures to delight even the most jaded marine biologist–and, we are still discovering new cephalopods all of the time!
Today’s post, however, is not a larger examination of squids and allied cephalopods (although I have been thinking about adding a “mollusk” category to this blog and embarking, to some small degree, on such a task), instead we are concentrating on a very specific and unusual behavior practiced by certain squid in dire circumstances—namely flying.
A Red Flying Squid (Ommastrephes bartramii) zips along above the Sea of Japan. Notice how the squid has altered its shape to become aerodynamic. Original photograph by Geoff Jones.
Flying fish are well known for their aerial prowess, but flying mollusks (for such is, of course, what squid are) seem almost to strain credibility. To imagine a cousin to the stolid clam whipping through the air propelled by jet propulsion takes temerity…or at least it would, if such behavior were not well documented. Many different species of squid from around the world have been observed leaping out of the water to avoid heavier predators. In fact the common names of several commercially important squid reflect this: Spanish fishermen hunt for voladores “flyers”, Nototodarus gouldi is commonly known as the arrow squid, and Japanese Flying Squid (Todarodes pacificus) is a mainstay in Ika Sushi.
The Caribbean Reef Squid (Sepioteuthis sepioidea) propels itself above the waves with a jet of water.
These flying squid are not merely popping out of the water for a moment before returning: some of the creatures form their tentacles into a fan/wing then stretch out a membrane running along their body and actively flap the fins at the front of their mantle. The Journal of Molluscan Studies cites an example of a squid flying 6 meters (20 feet) above the water for a total distance of 55 meters (180 feet) thus outdoing the Wright Brothers’ first flight! I wonder if the ancient belemnites (extinct squid-like cephalopods of the past) were ever able to fly in such a way or if this is a new feature of cephalopod evolution–maybe in a few million more years we will have even more deft flying mollusks zipping around with the sparrows.
A cool acronym…or a harbinger of days to come?
ferrebeekeeper 