Bladebeaked Burrowing Burdle

The Meridian Islands are the most comfortable place to live if you are a land animal on Serina now. Their position at the equator and the open water that surrounds them continues to maintain a mild climate where accumulating snow is still infrequent and daytime temperatures comfortable. During the day a shroud of mist often persists over the land through which the sun is filtered, but wide plains of grass and short-growing woody plants thrive. Nights however drop below freezing, and such rapid temperature swings bring strong and bitter-cold winds that sweep acoss the land. Here more than anywhere the seasonal extremes come hard and fast in the span of just half a day. Plants must have antifreeze-properties in their sap for their youngest growth to survive, and the ability to rapidly kickstart their growth as soon as the morning thaws the frost from their leaves.

For animals it is mostly easier. Most native vertebrates are endotherms. Sparrowgulls such as the pitpocket, gadawing and gagglefowl are still the dominant bird guild as the landmass has historically lacked trunkos, and though in recent times semi-aquatic sealumps have colonized the sea coasts, they rarely move far inland. Molodonts arrived a few million years ago and have now established themselves firmly into the ecology, but they remain small, burrowing creatures and are mainly seed-eaters. Seraphs are among the most numerous grazers but none have lost the power of flight they rely on to disperse when food has been depleted in a given area, a tendency that has resulted in the extinction of the poorly-mobile grazing crabs known as quadclaws. There are no canitheres nor circuagodogs upon the islands, and so large terrestrial tribbats fill their role as ground-based hunters. Of these the biggest being the steppestalker, a tall plains-dwelling descendent of the shadowstalker.

There is one predator here which is very unlike the rest however, for it lacks either feathers or a hair-like coat to keep in warmth. With a highly specialized metabolism that it can adjust as necessary, the burrowing burdle is remarkably well-adapted to life in this land of sharp temperature swings. By night it retires to a deep underground shelter just beneath the frost line, which is dug out with the keratinized tips of its wrists, and lowers its metabolic rate, maintaining warmth only in its core while a counter-current of blood exchange keeps the extremities just above freezing. Come morning the burdle violently shivers for about an hour, quickly raising its whole-body temperature back to a warm equilibrium, until it can comfortably leave its den and spend the day foraging for food.

The bladebeaked burrowing burdle is the only living species of burdle now, the direct descendant of its closely-related predecessor five million years ago, and similar in most regards except for being considerably bigger and with a sharper beak, for it is now more predatory. Its size has risen by several times and it now weighs up to 150 lbs. Well-built with brown fat that insulates its muscles and organs, it compensates for its lack of insulating integument, and its increased body mass and smaller surface area provide protection against heat loss. Its skin is still very dark to absorb solar energy, and it still practices ancient behaviors its fully cold-blooded ancestors relied on to survive; to aid in its digestion, it will bask whenever possible to reduce its internal energy requirements and so require less to eat.

As the eggs they once specialized in eating are now considerably rarer from molodont predation and subsequent better protection provided by their parents, the burrowing burdle must now hunt for more of its food. It hunts throughout the warm day and digs out molodonts from their burrow. Those it can catch it dispatches them with a crushing bite to the spine, and it also follows its nose to carrion if it can find it. When the weather cools after sunset the burdle waddles back to its den, its rotund condition preventing it from cooling quickly, and once settled in and cooling most of its body its energy requirements decrease substantially. Compared to a similarly-sized fully-endothermic bird, it requires just 30% of the daily caloric intake, and so the burdle can get by on just a few good meals per week - a great advantage in a changing climate.

The bladebeaked burrowing burdle has no predators of its own as an adult, as its tough armored skin and ornery nature protect it well. If it is threatened it will hiss and puff itself up and does not require much provocation to lunge and bite, with its jaw strength sufficient to crack bone, though it does not generally prey on living animals larger than rabbits. Its small young are much more vulnerable, and though parental care past hatching is rather minimal, the young are not evicted from the burrow immediately and may huddle and utilize their mother’s body heat at night to keep themselves warm when they are very small. During the day they disperse, hunting whatever they can catch - often earthworms and snails, both of which abound in the cool and damp climate of the islands.

Female burrowing burdles incubate their clutches of rubbery-shelled eggs in their burrows for about two months, and keep them warmer than ambient temperatures by shivering. During brooding she will not leave them at all to feed, lest they be vulnerable to predators, and so she can only nest when she has a surplus of fat reserves to sustain herself with. To build up enough fat takes time, and breeding can only occur every two years.