Molebirds

Molebirds are a locally abundant but isolated group of burrowing finches directly descended from the ground serins which can only be found in the southern half of North Anciska in the Cryocene. In the fifty million years since we last left off, evolutionary process has substantially reshaped and refined the basal canaries from an unspecialized relic reliant on the burrows of another animal to survive, into a capable digger in their own right. The ancient symbiosis of its ancestors with early burrowing crickets gradually dissolved as Anciska's climate became colder and its deserts gradually became replaced by grasslands and recently broad-leaf forests, with the crickets becoming increasingly adapted to a life wholly underground and independent of the surface - and thus no no longer reliant on the birds' keen eyesight to avoid aerial predators. Nonetheless, the canaries stayed with their symbionts, making use of their tunnels, long after the crickets required them, and over time they too developed their own adaptation to burrow. Their wings reduced to muscular arms suited to pulling themselves through tunnels and pushing aside soil, but unlike the bumblets - a burrowing viva group which utilize their wings to burrow - it was their beak that became their shovel. It began to grow continuously, replacing keratin that was worn away in chipping at the soil, and both jaws became sharply pointed and aligned to grind together like the teeth of a rodent.

above: a pair of molebirds; the majority of species are difficult if not impossible to identify physically, distinguished only by differences in vocalization.

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The feet became oversize and positioned far back on the body, useful to kick away loosened soil, while the eyes dwindled until they were so small as to leave their owner virtually blind. They followed their partners into the dark depths, never to return, in pursuit of nutritious roots, tubers, and insect larvae that they searched out with a newly redeveloped sense of smell. The soil provided shelter and stability in a cooling climate, and a safe and warm place to nest in almost any season, provided they went down deep enough. While their flying kin were forced to migrate southwards ever winter, the ground serins sought refuge much closer to home and avoided the harshest cold by simply burrowing to a depth where it didn't reach. Avoiding the most polar environments, where permafrost makes burrowing difficult, they thrive in the broad band of land between the southern coast and the tundra, busily tunneling out their largely secretive existence beneath meadows and forests and almost never coming intentionally to the surface. They have become extraordinarily efficient respirators, able to survive anoxic conditions in deep underground tunnels that would suffocate a human, as well as to allow them to roost and breed down and out of reach of most of their potential predators such as the large predatory mole crickets that can only get enough oxygen to support them just below the surface. Unfortunately the molebird cannot entirely cut off the surface world, for at least in the summer when it must forage daily for food, it must spend a substantial amount of its time in shallow tunnels very close to the surface and in reach of the roots or invertebrates it feeds on; it is here that the crickets may lie in wait and ambush them. In winter they are usually safe, for the crickets - unable to survive at the same anoxic depths as the molebird due to their less efficient respiration - must hibernate to survive the cold.

above: Once friends, now foes, these two old partners have definitely grown apart over the years; a blind carnivorous burrowing cricket snares in its claws a molebird as it forages near the surface.

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Additionally for a few nights in the spring, the molebird is forced to leave its refuge entirely in order to find a mate; on cloudy nights as the ground begins to thaw, they emerge in small groups all across the land and crawl above the ground on their bellies. Males emerge first and sing a raspy chirping song not unlike a cricket's, soon drawing attention from the females, which then emerge in response. Mating is quick, and a single copulation is usually all that it takes to fertilize a female, and once a pair has coupled they part ways and return underground, as every moment spent above it is a moment they are in danger of being killed by predators; indeed, males have an unfortunately self-detrimental tendency to not return to their burrows unless they successfully breed a female, instead spending many hours outside the burrow calling even after no more females emerge. As predators quickly converge on their conspicuous calls and a molebird is virtually defenseless on land, many if not most males that do not breed in the first few moments after nightfall are killed and eaten before morning as they call for female company, ensuring that not only do the least fit in the population not breed, but are actively culled, allowing the future young of the more successful breeders a higher availability of food and territory.