The helix finbird is a large, solitary pinnavian apex predator distributed across Coan-Schell, as well as the coastal cliffs of Vileus and Roscourd-Yalia. Comparable in size to the largest pinnavians, its body measures roughly a meter and a half in length with wingspans reaching 5–6 meters.

Etymology

From English fin + bird.

Morphology

This finbird is distinguished by a thin, lightweight body adapted for rapid descents and maneuverability. The fur is reflective white with muted orange markings along the wings. Its translucent pseudofins contour the wings and flanks, shorter and sharper than those of related species, designed to flex with the wind during high-speed dives. Large eyes provide excellent vision for spotting prey from great heights, while the jaw bears pronounced canines adapted for piercing. Its claws are wide, black, and equipped with long talons.

Physiology

The fur is resistant to the heat of direct sunlight. The reduced body mass allows it to remain agile and efficient in the air.

Diet

Helix finbirds are primarily scavengers, feeding almost exclusively on marpichi carcasses, though they will actively hunt live marpichi when food is scarce.

Mechanisms

Pseudofins flex with the wind to aid high-speed dives.

Behavior

Life Cycle

Reproduction occurs opportunistically, most often in early spring or autumn. Females lay 2–4 eggs per litter, leaving them in the male’s nest before departing; males alone raise the young. Cubs remain immobile for up to four months and require extended parental care. Adults can live between 18–20 years.

Social Structure

Individuals patrol fixed coastal ranges, usually returning to the same nest year after year unless it is destroyed.

Ecology

As the apex predator of Coan-Schell, the helix finbird plays a vital role in regulating marpichi populations. The species is closely tied to schell helices, where it builds nests at the highest points. Outside of Coan-Schell, it prefers sheer coastal cliffs.