These small winged creatures can glide expertly on the air currents, even travelling through clouds. They can bank deliberately to turn, never flapping their triangular wings. To descend, these strange creatures wheel in increasingly tight spirals until they disappear behind some peak. The aerial ballet they do is very unique.There are numerous varieties of springwing, including the lesser mountain springwings, which have striped wings, are two meters long, and are undisputable masters of their habitat.
Another species is the greater mountain springwing, which is half again as large as its lesser cousin and sports a cranial crest, which in some specimens curves nearly to the spine. In many instances this massive crest is used in midflight dominance displays, often leading to seriously torn wings - a wound that is nearly always fatal, as it results in a crash on the rocks below.The springwings, in general, live in one of the most difficult regions of Darwin IV. They appear to be a species in transition, comfortable both on the jagged slopes and in the chill alpine air, moving from one element to the other so quickly as to seem uncertain of which domain they are a part of. During the day they light on the cliffs to feed, mate or simply climb about. Though they are expert mountaineers, making use of nearly invisible footholds, the bulk of their time is spent gliding between the peaks, following the pungent odor of alpine cliff-polyps, their sole forage. It is a beautiful sight to see these gaily-colored mountain-dwellers flitting from one escarpment to the next, in and out of a mountain's blue shadows. They fill the air with their metallic sonar clicking, a sound unlike the pinging of the majority of Darwin IV's fauna.
A springwing can steer for a particular ledge with remarkable aerodynamic precision. At the precise instant that its legs and hindspur touch down, it folds its leathery wings snug against its body, the leading-edge rib fitting tightly into a long lateral groove. Behind and on either side of its head, its large, well-developed balance fins twitch nervously. The creature can take short, deep breaths of the cold, scent-laden air as it explores a cliff. A moment later it will be rewarded with a small clump of mauve cliff-polyps. The springwing can push its beaked mouth into the cluster of these plants, clinging stubbornly to the rocks, and commence to pop off the succulent, globular tips. At times, a sudden hail of small pebbles from above spooks it. In a matter of seconds, the creature turns to the shelf's edge and digs its hindspur into the ground. Then, arching its back, it snaps out over the abyss and, wings extended, sails away.
The darkness of night generally brings about a slowing of activity among the mountain herbivores, with most springwings and other creatures bedded down by nightfall. Whether this is due to their diurnal clocks winding down or to the increase of crepuscular predators, both flying and rockbound, it remains uncertain.