As Worlds Break Apart and Join Together

It has now been 1,500 years since the end of the Mid-Ultimocene. Serina’s ice caps have vanished entirely, except for a small glacier at the south pole. Sea levels have risen severely, flooding coastal regions and destroying exposed islands that rose during the ocean age, taking with them such evolutionary novelties as the ptarmenguin, which could no longer swim well enough to flee to distant higher ground. It is not only recent islands which have been drowned beneath rising waves but also the Meridian Islands, which rose from the sea in a burst of volcanism a little over 20 million years ago. Coasts of these islands began receding a thousand years ago. Five hundred years ago, all that remained above water were six isolated islands, formerly the islands’ highest hilltops. Now just one of these refuges is left - and it is flooding too.

Crowded upon a single island half the size of Manhattan, only a few animal species have made it this far. A few flightless birds, beach-dwelling amphibious snarks, and burrowing burdles live packed close together on what remains of the land, a damp and soggy coastal marsh with only a few small patches of dry upland. All of them live in fear - except for the prismatic gupgop, whose poison leaves it invulnerable - of the island’s singular apex predator. One individual steppestalker, the lighter-colored descendant of the shadowstalker and the heaviest tribbat ever to live, has ruled this last island for twenty-one years. Though poor-swimmers and flightless, they are tall and long-legged, and this one alone managed to wade here from a neighboring flooded islet decades ago, and so overcame an instinctive aversion to deep water. The last of his kind, he has ruled the last remnant of a once wide world in excellent fitness, adapting to catch fish in the shallows and able to overpower virtually everything else which was left marooned along with him. The king of the island stalks boldly and with confidence, knowing no-others exist here which can challenge him. Yet his successes, and his innovations, have gone unnoticed. There are no others left, no females with which to mate. His adaptability will benefit him alone, for it has come too late for his species.

Now, however, even his rule is ending. The tide comes in stronger every day, and at its height leaves almost nowhere dry to retreat. All the islands’ trapped animals scramble to shelter upon the tallest rocks, predator and prey momentarily forgetting their rivalry to flee a universal danger - the ocean that now threatens to eat up all of their world in big, angry bites. It lifts up thick mats of dead and living vegetation and soil, held together by thousands of years worth of interwoven roots, and raises them off the rocky foundation of the island. When the tide retreats, some of these floating rafts go with it, pulling away from the islands and drifting out to sea. Small animals find themselves stuck, accidental sailors, and watch as their island home grows distant on the horizon. Day by day the island breaks up, tossed in the waves and pulled to pieces. Most of the rafts break up within days and sink in the water. A few, however, are large and stable. They last for many weeks. For animals with slow metabolic rates which can survive prolonged periods of starvation, or which can eat whatever can be found on or next to the raft in the sea, survival is possible for quite a long time. Beneath the burning sun and with no freshwater to drink, most creatures unable to fly away succumb to exposure and dehydration in just a few days. The bodies of flightless birds feed the hardier sailors - burdles and snarks, one of which can survive long periods without any drinking water except for dew, the other able to hydrate itself from the sea out from which it only recently evolved. Burrowing burdles and gupgops smell the scent of death and emerge from hiding in the wet, tangled mess of sticks and roots and mud, and the dead give them life.

And for a lucky few, after more than a month at sea, the currents that have carried their ships have been kind. Land appears on the southern horizon, and burdles jump ship to swim to solid ground. Gupgops wait until the rafts wash up on their own before they hop off and disperse across the beaches. A few might be attacked by some bird or other predator naive to them before they learn, very quickly, that to bite one is to experience incredible disgust and a taste that will linger in its mouth like wax for days. The colonists all find a strange world, filled with unfamiliar life. Carrion is scattered widely across the shore, the bodies of evolution’s losers as a hot, acidic ocean no longer supports a stable food web. Piles of rotting bodies of porplets, molodonts and sealumps are covered in thick, shifting layers of hungry flies, verminfan birds, and carrion-eating beetles, creating a stench that would knock a human over with disgust, but which the burdle - a willing scavenger - finds irresistible. Foxtrotters and snowscroungers are aliens to the burdle as much as it is to them. One day they will be rivals, competing for food and territory. But there is no need today. There is more food than any of them will be able to eat for the next few centuries, by which time they will have grown used to each other as if they had always shared one habitat, just as the snowscrounger and foxtrotter, once separated on opposite ends of the globe, now do. The end of the Mid-Ultimocene destroys many creatures’ worlds… yet here, upon Serinaustra, it also brings them together.

~~~

Hundreds of miles away, the king of the islands’ reign has ended. Marooned on a single rock, with the waves lapping at its feet, it stares out at the endless horizon on all sides. Too heavy to raft away, and too fearful of the open ocean to have tried to swim, there is now nowhere to go. He hangs on for days, growing weak and sick from drinking seawater, until the ocean is halfway up to his neck and at last the waves dislodge him from his perch and carry him away. Exhausted now, at last he gives in to the force of the sea. Taking one final breath, he sinks into the murky abyss below. 

The steppestalker was a large subspecies of the shadowstalker, adapted to the open tundra environment that was common across the Meridian Islands late in the ice age. With no enemies of its own, this biggest of the tribbats, in form that varied slightly over time, was the islands' apex predator for several million years. Yet not even these fierce animals can now survive the inundation of their refuge with rapidly rising sea levels, as the End-Ultimocene ice age, which has held the world of birds in its grip for millions of years, now meets a cataclysmic end.