Hawkyenas

The hawkyenas of Serinarcta's plains and savannahs are, quite possibly, the pinnacle of gravedigger diversity in the hothouse. This is not for any remarkable feat of behavior, or of spectacular intellect. It is for one simple thing. Hawkyenas are the only gravediggers, indeed the first of all bumblets since the late Cryocene over 200 million years ago, to have arms that bend. Descendants of the early hothouse crested kittyhawk, these birds are the only gravediggers to have become cursorial predators on four legs, a lifestyle which has required specializations of their front legs to extend their stride and improve their maneuverability. Hawkyenas retain the specialized arm anatomy of all living bumblets, in which the upper bones of the arm are entirely absent, and the wrist is massive, connecting to the scapula in their place. This derivation, which occurred in small wing-powered burrowers, allowed bumblets to crawl on all four legs, and eventually to walk upright again on what was once their wings, now a single, unjointed leg. But being adapted to run at speed, and for long periods, the hawkyena has developed a new wrist-like joint through the fusion and enlargement of their uppermost metacarpal bones. These newly separated bones evolved as their paired fingers became larger and more prominent in burrowing ancestors, and were long ago adapted from the "thumb" joint, or alula, and the tip of the fused second and third fingers of the wing, which ultimately became a single bone, and then was split into several over millions of years, allowing these new digits to bend. Until this lineage arose, no bumblet existed which could bend its arm between shoulder and fingertips.

Hawkyena forearms now resemble their hind legs; the shoulderblades project slightly forward, almost like a knee, while the upper wrist is a single bone that connects to the newly fused upper metacarpal by a flexible hinge joint. The fingers have rotated in the process to face forward, providing improved traction and reducing stresses on their bones that could lead to injury. This new front "ankle" of the animal does not yet quite look like an elbow, because it is still significantly shorter than the upper arm. Nonetheless, it angles forward, bends in the same way, and provides greater fluidity to their gait, allowing hawkyenas to run at faster speeds, and much more elegantly than other quadrupedal gravediggers. They are social endurance predators which hunt in packs, targeting prey such as loopalopes, snoots and unicorns. They have flexible spines, as in the related stoatshrikes, and can gallop with a mammal-like gait where the back bends with each cycle of their gait. Prey is killed with the serrated beak which is virtually unchanged from the earliest bumblebadgers, and the neck is relatively long and flexible to reach ahead and snap at fleeing targets, to grab them by the rump or flank. Yet their new-found mobility in their arms is also put to use when hunting, and their hooked claws are also used to try and trip up their prey by reaching ahead and grabbing their hind legs.

Though there are only a few genera of hawkyena, they have already evolved to fill a range of niches, varying in size from just over knee high to as large as a wolf. A sampling of species is seen below.

1. Aveulpix tenebroculus (meaning dark-eyed fox-bird.) Commonly called the spectacled foxcrow. One of the smallest and most gracile hawkyena genera, foxcrows are very widespread, adapable, solitary hunters of ground-dwelling birds like snifflers and small seedsnatchers no bigger than rabbits, and generally very skittish, for they know they are not the biggest nor the toughest animals around. Spectacled foxcrows range over Serinarcta from the nightforest to the firmament, with a very wide range of plumage patterns which change over their range from black to mostly orange. The prominent black and white markings on the eyes are normally present in all subspecies, but can range from small white patches only above the eyes to piebald animals mostly spotted with white. Nesting in burrows, pairs live together year-round and share their small kills with each other and their young. The white dorsal crest of plumage can be raised when threatened, but normally hangs loosely over the rump.

2. Canicorvax cornifrons (meaning horn-browed dog-raven.) Named for two prominent feather crests over each eye, the horned gravehound is a forest-dweller endemic to the nightforest, which hunts big game larger than itself in packs of up to twenty animals. Unicorns are a favored prey, and they are killed not through any complex technique, but simply through overwhelming numbers and many savage bites. A good swimmer, horned gravehounds range sporadically into the floodforest and will readily follow fleeing prey into the water, drowning it. The crest on the back is short and hangs permanently down, now being of little use to communicate in dark, thickly vegetated habitat.

3. Canicorvax vexirurtrus (meaning flag-backed dog-raven). The flagtailed gravehound of the wide-open plains of the firmament is the fastest hawkyena, reaching a speed of 50 miles per hour. An extremely swift coursing hunter of the quickest birds such as snoots and tribbetheres like dashrats, it specializes in prey small enough to kill with a single bite to the back. The dorsal crest is prominent and can be raised or lowered at will, allowing bonded pairs to flash communication to each other as they coordinate their high-speed hunt in pursuit of prey. One animal often drives the quarry into the path of the other, resulting in a high rate of hunting success.

4. Acerodactus spinascapulus (meaning spiny-shouldered sharp-biter.) The red hawkyena is the second largest species, which stalks the grasslands of Serinarcta, living alone or sometimes traveling in pairs. They have a powerful sense of smell and are preferential scavengers, pushing their way to a carcass with fierce displays of aggression accompanied by a naturally foul scent. This species is quite fast too, reaching a top speed of up to 40 miles per hour, but uses its natural agility to dodge out of the way of larger, but slower carnivores to steal a bite to eat more often than it chases down live prey. The feather crests of the red hyena are reduced in size except at the shoulder blades, where a few long, quill-like feathers can be erected over the hackles when the animal is excited. When it does hunt, the nimble red hawkyena frequently targets smaller subduing them with slashing bites to the hind leg.

5. Novarticularmus horridulus (meaning bristly-newly-jointed-arm). The bristly hawkyena is an apex predator, though far from the biggest in its environment. Despite being the largest species, bristly hawkyenas are the earliest divergent and most basal among them. A savannah dweller, these animals are social pack-hunters of thorngrazers and trunkos. Loose skin over their bodies makes them difficult to bite and hold in a fight, making them formidable opponents for most similarly sized carnivores. They retain the largest dorsal crest out of their group for social communication, which has been modified in other species.

This largest and fiercest member of the hawkyena lineage is also the most socially complex, now a far cry from the hostile territoriality of their distant ancestor, the savage gravedigger. It is no very gregarious, living in packs that are are made up of related females and unrelated males; they generally follow a matrilineal structure in which only males disperse. There are no pair bonds, but multiple females reproduce with multiple males. Childcare is semi-communal in that other pack members protect a common, shared den site, most often a shallow underground cave, in which all chicks are kept, and each female produces just one, or rarely two, young at a time. Only a chick's own mother provides food to it, however, though occasionally a male may assist in feeding chicks belonging to a preferred female partner, and males which feed young are more likely to chosen to mate with again in the future. Chicks begin hunting at six months and are fully grown at 18 months, which is when males leave their natal groups and join unrelated packs. Cooperative hunting behavior in the bristly hawkyena is extremely attuned and rivals that of sawjaws. A wide repertoire of loud trilling vocalizations help as many as twenty hunters to coordinate their efforts, single out a target, and effectively block off its escape and bring it down.

Unlike some predators, bristly hawkyenas don't take efforts to prevent their prey from hearing their calls as they approach, because their method of hunting is to run their victims down to exhaustion rather than to surprise them. Like wolves, these gravediggers can run for long periods at high speeds; though not as fast as bipedal sawjaws, they can nonetheless maintain a speed of 30 miles per hour for over 5 miles, and often run in relays so that as the first chasers tire, the rest of the pack can join in and finish the kill. Known for their ferocity and aggression, they have fast reflexes and the ability to bite repeatedly and very quickly in a confrontation, coupled with loose skin which means most rivals which bite them back cannot get a firm hold on them, as the hawkyena twists in its own skin and instantly turns to bite the biter back. Bristly hawkyenas in particular know that they are hard to win a fight against, and so do their rivals - they and often do drive smaller sawjaws or other predators off of their own kills, taking the carrion for themselves, even if they are outnumbered. Thanks to their "extra" loose skin, hawkyenas can survive severe bites without actual damage where it would matter, into their muscle. Even horrible-looking flesh wounds in which their skin is torn and left hanging will soon heal with minimal scar tissue. Because they are so prone to injury related to conflict that longer face or body feathers would simply be torn out constantly, the plumage on their face, chest, and legs is very short and little more than a short layer of hair-like fuzz. The exceptions are a short crest on the back of the head, and a prominent, banded feather ridge on their backs, which is erected to make themselves appear much bigger than they really are.