Detailed explanation: Rocs

As the world of Az developed and life began to evolve, many species emerged that would not look out of place in reality, the world being bound to natural physics as it was. Yet, the differing environment of Az has lead to many wholly unique creatures to come into being. The Rocs are one of such developments.   For those versed in mythology, you may recognize rocs as originally middle eastern fantasy creatures, great birds who carried elephants off in their talons with ease. Of course on Az, rocs are no mere fable, but rather natural living creatures much the same way as the cattle and horses they prey upon.  

Physiology

  Rocs are birds, considered raptors like eagles and falcons, though they differ from their relatives by their enormous size, proportionally large heads and beaks in relation to body size, though this varies with species. That being said, the average size of rocs is roughly four meters tall, with the two main species of roc displaying wildly different wingspans.   On that note, by the time period that sapient species started recording history, few species of roc remained wildly present on Az, the most notable two being the Great Yddian roc and the Snow roc.  

The Great Yddian Roc

  Evidently, the Great Yddian roc is found solely on Yddian, sporting long legs, comparatively short wings for its size and gigantic talons over a foot long. While this species is capable of flight, it prefers running down its prey on foot, as its longer legs enable it to sprint at over 70 km/h, before either breaking the prey's spine with a swift gouging from the beak or slicing vital arteries with talons.   The only time this bird readily chooses to fly is when accessing their roosts on higher ground or to escape from a dangerous situation, as the act is quite tiresome for a heavy bird whose wings are not well built for the act. What these wings are built for, unusually, is combat. Yddian rocs have a bony spur located on the mid point of their wings, allowing for brutal strikes that can shatter a man's skull or seriously injure other large predators, all with little risk to the rocs wing breaking due to a thick lining of shock absorbent cartilage along the wing bone.  

The Snow Roc

  The Snow roc on the other hand exhibits far more traditional means of hunting associated with smaller raptors. Found all around Shutontas and sometimes the northern reaches of the Tall Stretch, Snow rocs are reputed by all for their gorgeous, thick plumage which shields them from the harsh conditions of their habitats.   Often slightly shorter than the Yddian, Snow rocs make up for this by having one of the largest wingspans of any flying creature ever, with only the Balloon and Imperial wyverns coming close to its average wingspan of 7.5 meters. As you might guess, this specification lends well to the Snow roc's preferred hunting method of gliding over swathes of land in search of suitable prey (deer, cattle and horses) before snagging it in their claws and carrying it back to the nest where it is finished off. More conservative than their Yddian counterparts, Snow rocs are wary of conflict with larger animals and would rather not fight unless cornered, lacking the bony spur the Yddian roc has acquired.  

Minor Sub-species

  Apart from these two species, sightings of rarer types of roc are not unheard of around the world, from the Jannid desert to the Aberrant archipelago and beyond, most likely close relatives of the Great Yddian variant.  

Life-cycle

  All roc species, however different, exhibit similar nesting and mating habits to one another, choosing elevated points like mountains and plateaus for nest sites, mating once with another individual for life and having either one or two chicks every seven or eight years. Average lifespan, excluding possible magic interference, lies around thirty-five to fifty years.