Southern Shiver Bird

The Trivolans are a rather mundane genus, being restricted to Wallace II's south-western most continent, and not traveling much. This is only a trait in most, however, as the one exception to the trend, the T. Pulehellus species, has a drastically different tactic.

Following a large, annual migration period north, the T. Pulehellus all belong to one large flock, consisting of tens of thousands of individuals. Unlike most other members of the Genus they are not R-strategists, and require a whole year to teach their young how to survive outside the southwestern continent, where the entire flock nests and raises their young.

When not raising young, however, the flock moves on leaving those too young or raising said young behind for the year as they move out en mass to hunt, wreaking havoc on the continent directly north of their own, their travel directed by the island chains leading towards it.

They are a predatory species, being carnivorous, and prefer to take on larger targets as a group, devour the target as quickly as possible, then move on. Their smaller wings possess sharp, bone-and-metal-like ends to them, which limit the secondary wing's flying ability, but allow them to serve as blades which can be injected then torn out of meat both living and dead alike, allowing for fast kills and even faster devouring via the cutting of meat into smaller, easier to digest pieces.

The species, in a major similarity with the other members of its genus, possesses a relatively large intelligence for its size, being used for almost exclusively pattern recognition of which areas were plundered the year before (and there for won't have fully repopulated yet) as well as any notable individual organisms which survived before, and aren't worth attacking again, which are sometimes pestered instead, having rocks or other minor annoyances dropped from above whenever the flock flies overhead.

While not even close to possessing a system of writing or even the ability to understand it should one exist, the T. Pulehellus to possess enough memory to destinguish specific members of the flock, despite it's immense size. Not only this, but the species tends to make large, visible amounts of damage to the terrain when resting in between flights, through the routine sharpening of their secondary wings against hard rocks and bones. These marks can then be recognized by other members of the flock, telling them that others have already been here recently, as well as what specific individual made the mark, assuming at least one flock member knew the individual that did so. There are many marks, in fact, of which the original maker hasn't been known for centuries, yet the T. Pulehellus follow them anyway, leading to quite a few accidents when marks have been interpreted wrong.

The only place this does not apply is the nesting zone itself, which is covered in several millennium's worth of marks, with the coastlines of the nesting continent rocky and barren, not devoid of plants due to a lack of fertility or being devoured by the T. Pulehellus, but uprooted simply to make more room for blade-sharpening. In the last few centuries the flock as reached it's population cap, and the expansion of this area has stopped. Of note is that despite it's near total lack of other life, the area is covered in microscopic decomposers of all kinds, with some locations bearing layers of waste meters thick.

Overall, the Trivolans Pulehellus are a remarkable species, yet virtually unheard of outside of their region of migration, preferring to stick to well-worn paths than attempt to find new more fertile ones, and locked in place by their required nesting in their homeland.

P.S. - Several attempts have been made (usually by lost members of the flock) to set up new nests elsewhere, however almost all animals inside the T. Pulehellus's zone of travel are universally hostile, with any sign of nesting being utterly annihilated before it can even last one fully year.