Wyvern

The **wyvern** (*Megachirodraco horridus*) is a species of very large non-avian scansoriopterid theropod dinosaur that originally did not exist, but has since been created by SciiFii and introduced throughout the forests, open woodlands, grasslands, shrublands, and mountainous regions across Eurasia and North America to help boost biodiversity. The wyvern is a rather large member of its family, growing to be about 90–105 centimeters (2 feet 11 inches–3 feet 5 inches) tall and has a 2.1–2.7 meter (6 feet 11 inches–8 feet 10 inches) wingspan. The male can range in weight from 5.8 to 18 kg (13 to 40 lb). The heaviest verified specimen was about 21 kg (46 lb). The species is gregarious, especially in winter when gatherings of several dozen wyverns may occur. Male and female groups do not mix outside of the breeding season. The wyvern has a stately slow walk but tends to run when disturbed rather than fly. Running speeds have not been measured but adult females have been known to outrun red foxes (*Vulpes vulpes*) and wolves (*Canis lupus*), which can reach a trotting speed of 48 km/h (30 mph).

Both sexes are usually silent but can engage in deep grunts when alarmed or angered. The displaying adult male may produce some booming, grunting and raucous noises. The female may utter some guttural calls at the nest and brooded young make a soft, trilling call in communication with their mothers. The species is omnivorous, taking different foods in differing seasons. During the spring and summer, the wyvern feeds mainly on seeds, fruits, insects, spiders, and scorpions, while during fall and winter, the wyvern typically feeds on smaller vertebrates, nuts, pine needles, leaves, and carrion.

Wyverns engage in lek mating. All wyverns have polygynous breeding habits, in which one male displays to attract several females, and mates with them all. Males display at regularly used sites, each male utilizing several dispersed leks or display areas. These displays usually take place in the mornings and evenings. The courtship displays of the males are impressive and elaborate, successfully advertising their presence to potential mates. The males hold their heads backwards, with cheeks bulging, the crest is held erect, the snout open and they inflate their gular pouches, forming a bright red throat "balloon", similarly to those of frigatebirds. During this display the oesophagus inflates to as much as four times its normal size and resembles a balloon. They also puff out their frontal neck feathers which are splayed upwards showing their white underside. The white may be visible up to 1 km (0.62 mi) away during display. Their wings are drooped and their tails are raised upwards and forwards onto their backs like a turkey, the rectrices being held vertically and their undertail coverts fluffed out. They enhance their performance with an exaggerated bouncing gait. When displaying they stride about with their necks puffed out, their tail fanned and their wings planed and pointed downward. They also emit a low-pitched booming noise when the neck is at maximum inflation and snap their toothy snouts open and shut. Several males dispersed over a wide area gather to display but usually one is dominant and the others do not display in his presence and move away. The displaying males are visited by the females who presumably select the male with the most impressive display. Occasionally fights between males can be serious during the mating season when display areas are being contested, with the two competitors smashing into each other's bodies and stabbing each other with their snouts. They may stand chest-to-chest, tails erect, snouts locked and 'push' one another for up to 30 minutes.

Following the display, the copulation begins with the female lying down next to the dominant displaying male. He stands over her for 5–10 minutes, stepping from side to side and pecking her head in a slow, deliberate fashion, tail and crest feathers raised. She recoils at each peck. He then lowers himself onto his tarsi and continues pecking her until he shuffles forward and mounts with wings spread. Copulation lasts seconds after which both stand apart and ruffle their plumage. The female then sometimes barks and the male continues with his display.

The female makes no real nest. The female wyvern lays her eggs on the ground in a shallow, unlined hollow, rather than the typical scrape. This nest is usually located within 4 meters (13 feet) of a tree or shrub, termite mound or an outcrop of rocks. The hollow may measure 300–450 mm (12–18 in) in diameter and be almost completely covered by the female when she's incubating. Due to their ground location, nests are often cryptic and difficult for a human to find, unless stumbled onto by chance. The same site is sometimes reused in successive years. The wyvern is a solitary nester and there is no evidence of territoriality amongst the females. Usually three eggs are laid, though seldom 2 or 4 may be laid. Clutch size is likely correlated to food supply. They are cryptically colored with the ground color being dark buff, brown or olive and well marked and blotched with shades of brown, grey and pale purple. Eggs are somewhat glossy or waxy and have a pitted-looking surface. Egg size is 81 to 86 mm (3.2 to 3.4 in) in height and 58 to 61 mm (2.3 to 2.4 inches) width. The eggs weigh individually about 149 g (5.3 oz), with a range of 121 to 178 grams (4.3 to 6.3 oz).

The female, who alone does all the brooding behavior without male help, stays at the nest 98% of the time, rarely eating and never drinking. Occasionally she stretches her legs and raises her wings overhead. The female regularly turns the eggs with her snout. The female's plumage is drab and earth-colored, which makes her well camouflaged. She occasionally picks up pieces of vegetation and drops them on her back to render her camouflage more effective. If they need to feed briefly, the females go to and from the nest with a swift, silent crouching walk. If approached the incubating bird either slips unobtrusively from the nest or sits tight, only flying off at the last moment. The incubation period is 22 to 28 days. The young are precocial and very well camouflaged. The lores are tawny, the crown tawny mottled black. A broad white supercilium bordered with black meets on the nape, extending down the centre of the nape. The neck is grey with irregular black stripes from behind the eye and from the base of the lower mandibles. The upper parts are tawny and black with 3 black lines running along the back. The underparts are brownish. When the chicks hatch, the mother brings them a steady stream of food, most of it soft so the chicks can eat it easily. Captive hatchlings weigh 78 to 116 grams (2.8 to 4.1 oz) on their first day but grow quickly. The precocial chicks are able to follow their mother around several hours after hatching. After a few weeks, the young actively forage closely with their mothers. They fledge at 4 to 5 weeks old, but are not self-assured fliers until 3 to 4 months. On average, around 67% of eggs successfully hatch (testimony to the effective camouflage of nests) and around one of the two young survive to adulthood. In more arid regions, breeding success has been found to be greatly reduced during times of drought. Most young leave their mothers in their second year of life, but do not start breeding until they are fully mature at three to four years old in both sexes in studies conducted both of wild and captive wyverns. The lifespan of wild wyverns is not known but they may live to at least 28 or possibly 32 years old in captivity.

The conservation status of the wyvern is **Least Concern** due to successful conservation efforts, the wyvern's wide range and its tolerance to many of the human activities.