The Swamp-Wing, Xamopteryx, is a bizarre, winged, almost bat-like frog with the ability of flight from the swamps of Skull Island. It has a 4-8 inch wingspan.
Skull Island’s swamp-wings are among the oddest results of selective pressures on an otherwise defenseless food source. In response to the threat of predation, a variety of frog has evolved with enlarged membranes between their front digits and back along their forelimbs to their tails in a feature analogous to a bat’s wings. While the forelimbs are enlarged, the rear legs are small by frog standards and their ability to jump is limited to a boost for takeoffs.
Their facial features are stunted and almost tadpole-like in appearance. Swamp-wing mouths sport a fan of needlelike “teeth”: Not true teeth, they are sharpened serrations on the frog’s jaw, protruding through their gums. Like so many of their strange features, these are unique to the genus.
Swamp-wings are not accomplished flyers. The extent of their aerial prowess is frequent short-distance flights. It is a barely controlled glide, punctuated by rapid flapping fits. However, it is enough to get them from tree to tree in the swamps and away from bigger predators in the water or on land.
Once mature, the species avoids swimming as much as possible. In the water they are easy prey for large bony fish (like needlemouths), reptiles (like baby Foetodon) and birds (like Profanornis spinosus), their wings being ill-adapted for swimming. Agile climbers, with gripping pads on their back and front digits, they live mostly on the boughs of wet-rooted trees or in floating vegetation. Their flight is not accurate enough to allow them to reliably hunt on the wing; therefore, most of their diet is small invertebrates caught while grounded.
Growth and Change
Swamp-wings lay eggs in clusters of hundreds, hidden amongst the reeds and water weeds in an effort to avoid the attention of larger predators. Eggs that survive the two weeks of development hatch out into tiny tadpoles that are already active hunters, pursuing small insects and other arthropods in the safety of the weeds.
At seven weeks old, tiny spurs begin to form on the flanks that will eventually become legs.
Forelimbs continue to grow, sprouting fingers to crawl around underwater, relying less and less on their tails for propulsion. By 12 weeks the tails begin to shrink and the eyes bulge.
By 15 weeks the youngsters resemble adults more than tadpoles. While not yet fliers, their increasing reliance on air-breathing compels them to leave the water, clambering about on logs, roots, and floating vegetation.