The Girraspbird

The Girraspbird (Longicollapteryx procerus) is a large Phyllapterygid and, in fact, the tallest bird ever to exist. Though it tips the scales at "just" three-hundred kilograms, it stands five meters high in a resting position. These extreme proportions are only possible in one type of environment: open savanna, with scattered palm-grasses in an otherwise flat, grassy expanse. In such areas, there are few small arboreal folivores like those that exist in denser forests, but there are still millions of trees available for exploitation. The girraspbird has answered the call of this vacant niche, prowling the savannas of every Panapterran continent. In just the last two million years or so, it has evolved from a small, basal raspbird of about thirty kilos to a behemoth over ten times larger. This is in no small part due to the world's savanna ecosystems growing dramatically over the same period, with all three continents seeing their fragmented interiors reshaped into vast, continuous, and mostly homogeneous landscapes suitable for these giants. Girraspbirds find the greatest success where trees are spaced-out enough not to be connected by shadeblades, as such networks function as a highway for leaf-eating Loxoditheres that compete with the Phyllapterygids for food.

 Like the oldest members of its family, the girraspbird has a rough, sandpapery tongue that helps it strip vegetation off branches. In this species, there are also a series of larger fleshy protrusions that aid in gripping objects. Together, these two adaptations make it possible for this bird to eat up to five kilograms of foliage per minute. Its beak is used little during feeding and mostly just serves as a holding chamber for this tongue when it isn't reaching for something. Once food is in its stomach, digestion is relatively inefficient, as raspbirds don't have any fore- or hindgut fermentation abilities. This means that it must consume far more plant matter than, for example, a Muridiungulate of its mass. Still, the speed at which it processes its food makes this only a small hindrance, and with just a few hours of foraging per day it can get all the energy it needs. 

At such a massive size, girraspbirds run a serious risk of crushing their own eggs during the incubation process. To prevent this, up to twenty females will each lay their individual eggs in a single nest, guarded by a dominant male who possesses a fan of light, fluffy tail feathers. He sits just in front of the clutch, which he arranges in a semicircular arc, so he can keep them warm without putting his weight onto them. The eggs have a conical shape, and the father arranges them with the thin ends pointing toward himself. Hatching at around 30 centimeters long and just under two kilograms apiece, the chicks have a lot of growing to do before they can set out on their own. By this time, the females will have dispersed into their non-breeding-season herds of 3 to 5, leaving only the father to care for over a dozen young. He treads lightly, careful not to step on the curious chicks. Every now and then, he may even let them climb his body so he can show them how to reach the best leaves in the treetops. Though it will be years before they can reach these heights on their own, the lesson won't be forgotten and will serve them well later in life. Within nine or ten months, the growing girraspbirds reach about ten percent of their adult size and are ready to fend for themselves. They leave their father's care willingly, just as he begins courting a new harem and preparing to raise the next year's clutch. 

Despite the fact that the savannas of Abeli, Ailuropia, and Loxodia are separated by vast stretches of other biomes, a single subspecies of girraspbird can be found across all these areas. This is because Longicollapteryx juveniles are extreme generalists with the ability to disperse across distances unthinkable to any other land-dwelling bird. As soon as they begin living independently, they head for the forests where a greater volume of calorie-rich food can be found. They abandon the diet of leaves they were reared on and which they will one day adopt again, becoming omnivores as they begin the fastest-growing stage of their lives. They never stay in one place long, moving twenty or more kilometers every day. Though they spend their time in densely wooded regions, they inevitably stumble upon patches of open savanna from time to time. Once they reach a subadult size - no less than 200 kilograms - they return to their favorite of the savannas they found along their travels. Males fight to establish territories in these prime locations, while females remain nomadic, continuing to travel throughout the savanna for the rest of their lives.