Archangels: Flying Giants

The Flying Giants

With the evolution of the quadrupedal metamorph birds, flying birds have now managed reached sizes unforeseen ever before in their history. Able to use their wings, and not just their hind legs, to aid in launching off the ground, they can grow larger and heavier than strictly bipedal animals and many become gigantic. Their wrists elongate into a flight finger much like a pterosaurs', except instead of a membrane it still sports row after row of long veined feathers. Clawed digits on the wrist evolve into a crude padded hand upon which weight is born, while the wing digit - in fact a fusion of the second and third digit of the hand - folds upwards along the arms when on the ground. Once the form evolved, it diversified greatly.

The first of the flying giants were generalist, crane-like animals not much larger than bustards, which were omnivorous. With a quadrupedal gait well-suited to taking flight at large sizes, but long necks and rather weak bills, they were as well-adapted to grow very large as were Earth's pterosaurs, yet poorly-suited to become similarly predatory. Instead, under this different selective pressure, they gave rise to large herbivores, species which took to grazing like oversized geese and living in highly nomadic flocks which can soar on thermals and cross the supercontinent in a matter of weeks, following rain and converging where food is abundant and scattering as it becomes scarce. Known as archangels, they are most often colored mostly or entirely white, the color which most reflects harmful solar radiation at high soaring altitudes. Standing up to twenty feet tall, weighing up to four hundred and fifty pounds, and with wingspans that may reach more than forty feet, they are among the largest flying birds ever to live. Traveling thousands of miles over land, guided by their sense of smell in the constant pursuit of the stormy weather that produces the flushes of vegetation they require on the seasonal plains of the interior, they are true nomads that stay never too long in one place. They migrate in flocks that at times become thousands strong, traveling in V-shaped formations of twenty to thirty individuals which themselves group together in even larger groups that may extend for miles high in the atmosphere. When they find the rains, the flocks glide down to the ground, their immense wings spread out, and land awkwardly at a run on the ground, first with their feet and then catching themselves at the last minute with their wings, occasionally tripping and falling forwards. The excitement of the group is easy to see now as their trumpet-like calls fill the grassland and the birds gather in smaller groups, some birds keeping alert while the rest lower their heads to the ground to graze. They now gorge on the newly sprouting grasses and during this time rarely fly, folding their wings against their arms and preferring to gallop even if pressed by predators until the very last minute, when they will laboriously take flight from a run and vault themselves into the air like a hang glider.

above: a flock of massive archangels come in for a landing, causing a herd of serezelles to scatter in their wake. With forty-five foot wingspans, the birds are as large as airplanes and must surely be an intimidating sight, though the zebirbs needn't fear; so long as they don't inadvertently tumble over them as they make their landings, the archangel is a harmless and a mild-mannered herbivore.

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Their method of feeding is that shared by Earth's waterfowl - they process their food rapidly, digesting what parts of it they can as quickly as possible and holding only a small amount of forage in their gut at any one time so as not to weigh themselves down excessively. They are thus inefficient feeders and have to feed for most of their waking hours for many days at a time in order to lay down sufficient fat reserves for several days of subsequent traveling when the rains move on and food in one location runs low. The life of an archangel is thus one of feasting and fasting. When the rains blow elsewhere and the grass dies back, the flock takes flight once more to follow, hopefully by that time having produced enough fat to keep them going until they reach greener pastures again.

Archangels are so large that take-off and landing are both awkward affairs; indeed, with a full stomach, they may not be able to take flight without a headwind and thus when sufficient conditions do appear the entire flock will usually lift off at once. Because they are competent on the ground, this is not a major handicap unless there is a long spell of windless weather at the same time food begins to dwindle, in which case the largest and heaviest birds may starve. Once in the air, however, archangels are extraordinarily efficient flyers which can soar effortlessly on high thermals for many miles. To increase their surface area, they have developed hind wings on their legs which when spread behind them function as additional airfoils, helping them to stay airborne with as little effort as possible.

Archangels are placental birds, but they have very different adaptations from other groups and are among the most primitive and strangest among their clade. All of these flying giants retain their offspring internally, and development through the larval stages now occurs in utero as in the the ornkeys and the serezelles. However, to minimize the amount of weight they must carry, which would affect their ability to fly, archangel embryos still enter a pupal stage while in utero, creating a mucous sac full of amniotic fluid in which to mature from the featherless pink larvae into a recognizable bird chick. This sac is voided from the mother's body before hatching. This sac functions like an egg, but differs from that of a more basal bird both structurally and internally. It is soft-shelled and rubbery; its embryo is no longer reliant on the minerals of the eggshell for its development so the shell of the pupal sac contains no calcium. Archangels carry many developing larval embryos at a time, which pupate simultaneously in response to hormonal cues so that the mothers can lay clutches of these "eggs" all at once. They deposit them in warm, moist soil where they will remain moist and leave their development to chance. They pay no further attention and will have moved on far away once the tiny chicks emerge, feathered and fully capable of flight. As the vast majority of the giant flyers are highly nomadic and follow transient food sources either on the seasonal plains or out at sea, they cannot afford to settle down for long to protect their pupating chicks themselves.

The pupating archangel chick, once outside its mother's warm body, cannot maintain its own body temperature and is effectively ectothermic, relying entirely on warm ambient conditions to grow, and so the rate at which they develop varies considerably. When they do emerge, the chick shivers violently for some minutes, sometimes for more than an hour, to generate body heat and raise its core temperature until it is warm enough to fly. Once their metabolism is initiated in this manner, the chick can maintain its heat via thermogenesis and has transitioned to a warm-blooded metabolism which it will maintain though its adult life. To maintain its internal heat however, it must then find food quickly or starve. The chick is superprecocial at birth, able to take flight as soon as it has warmed itself, but is nonetheless so much smaller than the adult that it must occupy a very different niche, and the juveniles of almost all groups start life as small insectivores living in or along the edges of forests or wetlands, regardless of what they will eventually come to eat as adults. Even those of the archangels, which as adults will be herbivores, cannot subsist on such a diet in infancy, requiring a more protein-rich diet incorporating many insects for the first few years of life in order to reach their adult size. They therefore spend their first years living in these environments exclusively, leaving them to join with the nomadic flocks only when several years old. Maturity in most of the giants is fairly slow among birds, with adult size and sexual maturity not attained for six to ten years.