Skyland Bolter

The sky islands of the late hothouse provide nesting sites for vast flocks of mowerbirds, canary-sized sparrowgulls that graze on grassland vegetation. Singly, a mowerbird's food requirements are miniscule. But in flocks that rise into the billions, they can eat as much, pound per pound, as herds of millions of thorngrazers. That is a lot of meat, if you can take advantage of it - and mowerbirds remain the prey of choice for a variety of hunters. In the ten million years since the mowerbirds first exploded in number, their enemies have increased in size to match, becoming even more adept predators of these superabundant songbirds.

The skyland bolter is the biggest flapsnapper tribbat, a descendant of the grizzled guzzle now reaching a weight of 35 pounds. It has the widest mouth of any tribbat relative to its size, extending up to 24 inches across. A crepuscular predator of flying animals, skyland bolters are cryptically colored and spend the day with their wings folded around them, roosting near the summits of steep sky island cliffs face-down. They hold onto the surface with their tail claws and hang there quietly so as to blend into the surroundings, often among scattered shrubby vegetation. They do almost all their feeding in just one short window at dusk, when the mowerbird flocks gather from the surrounding grasslands and form dense flocks as they ascend to the island summits to roost. As light dims and birds whirl about the islands for just a few minutes a day, the bolter rises. It vaults itself from its perch and descends, fluttering on a 9 foot wingspan, and dropping into the flocks. The birds have expected its attack, and have waited to land until the enemies revealed themselves. Now, for a few harrowing moments, they twirl and spin in the air, their thousands, millions, and billions of bodies motion in sync.

For many enemies, the sight is hard to keep track of; how does one select one target among countless? But the skyland bolter is indisciminate. Its mouth is vast, all-devouring. It doesn't need to pick just one bird, but rather it drops through the flock when the birds are at their highest density. Then, in a state of free-fall, it shoves as many birds as it can into its jaws with its wings. In just seconds, it can stuff its mouth with dozens of prey items, helplessly swallowed alive. The hunter spreads its wings just before it falls to the ground, catching itself, and careening back to the cliffs. Satiated, it returns to the crags and there rests, grooming itself, before tucking back into sleep. The survivors quickly make their way to their roosts, so numerous as to not notice the losses that occur each and every evening in this way. 

These tribbats are not agile fliers; the weight of their huge, heavy jaws is ungainly in the air, even with long wingspans, and they rely on gliding downward onto flocks of prey to efficiently feed. They spend most of their time on the cliffs, largely immobile, and can sleep there over 19 hours per day. Males and females frequently share a cliff territory amicably, but each sex aggressively defends their roost from others of their own sex, so that each isolated island will generally support two bolters; larger sky island ridges support many more, which aggressively posture along the boundary lines at their neighbors and occasionally may lock jaws and engage in fierce bouts of combat. The male assists his mate with childcare and provides food to both her and his single offspring through regurgitation; the pup clings to the female's belly for several weeks before she ever leaves it on the cliff to hunt on her own, and for this duration the male is relied upon to catch food. After the pup can clamber along on its own, it may be left alone as both parents feed every evening. It instinctively freezes and hides against its backdrop when left this way, however, for skyland bolters are cannibals, and rival adults will not hesitate to swoop upon an unsupervised infant and gobble it right up, reducing future competition. The period of parental dependence is very long, and the young begins hunting on its own after six months of age. It will continue to associate with its parents and rely on them for some of its food until around one year of age, when the adults will have a second pup and drive off the older one, which would then pose a threat of cannibalism to its sibling.