Dodoves
The insular aliens

In the last million years, volcanic activity has sharply increased in Weddell and Ellsworth islands: large eruptions have greatly expanded the suface of the latter island and they have also created a volcanic ark that connects the two archipelago like a stepping stones corridor. The two islands are now only separated by a small channel, which is called Dodo's strait.
Lots of terrestrial animals profited by this channel, like dodoves, which have successfully colonized Weddell. Thanks to their great competitiveness and adaptability, these large columbids were able to nearly wipe away the endemic ducks that rule the island: wedducks.
With the disappearance of these once abundant herbivores, the ecosystem of Weddell was devastated: lots of predators (like brontocranes and large stiltpeckers) died out, favoring generalistic carnivores like wotters, the only geotters present on the island.

The survivors

Of the 15 species of wedducks present 3 million years ago, only four were able to survive the competitive pressure of dodoves. They are all descendants of the ontoduck, a wedduck with a very differentiated ecological niche between juveniles and adults. With a so specialized ecological niche, these birds were minimally affected by the dodove invasion.
The most abundant is the Ontomonte (Muntimoanas selettiva), a two meters tall wedduck that mainly lives in the humid part of the Vertical Forest. Like their ancestor, young spend their life in large social groups that later split up in adulthood. In the first year of life, ontomonti are mainly carnivorous, with insects and small vertebrates comprising most part of their diet; as they grow older, their digestive system becomes more complex, enabling the digestion of cellulose. Young are also more cursorial, with slender bodies and longer tarsus, while adults are sturdier with a graviportal structure of the legs to better move in the Vertical Forest.
Due to their solitary life, ontomonti can easily fall prey to pantters, jaguar-sized wotters with a semiarboreal lifestyle, but this doesn't impact much on their overall population, which is relatively abundant for an insular species (over 400.000 individuals according to the summer census).

In the high tundra plateau of Weddell, ontomonti give way to another wedduck, the ontorock (Murimoanas clownipes): this bird is characterized by two comically large feet, that make it really clumsy while running. Despite the appearance, these feet are extremely useful for the animal to safely move on steep terrains. No terrestrial predators are able to follow an ontorock path without risking their lives on a cliff. Only flying carnivores (like incubos) can pose a threat to this anatid, which usually avoid them by hiding in large thickets or caves.
Once very numerous, ontorocks now comprise no more than 20.000 individuals: their tundra habitats is slowly reducing due to global warming, increasing the conflict with ontomonti, which are following the forest expansion.

The new dominators

Despite their recent appearance, dodoves have become very diversified in Weddell, with over 7 species now present on the island.
One species, the scrub dodove (Longidodo aridum) was able to adapt to the arid environment of the Weddell forest-steppe: the warm dry conditions experienced in this ecoregion favor the growth of large evergreen shrubs, which are browsed by this dodove thanks to their long neck. The neck is also used by rivals as a weapon in mating fights, where males repetitively hit their opponent in a similar way to giraffes.

Lowlands are dominated by gigantic species, the gogiga (Dodogiga gagogigo), a large highly-social dodove that performs an extremely long migration across the year. They are lowland-adapted birds that feed in the widespread wetlands of eastern Weddell during winter, while in the summer they move in Ellsworth Island, meaning that they are forced to cross the Dodo's strait two times a year. Lots of predators, both terrestrial and aquatic, take advantage of this great event by attacking weak individuals and collecting an enormous amount of food that can last for weeks.
Gogigas are one of the most communicative animals of Antarctica, with a very complex language that is used to interact and increase social status in their herd. They live in fairly large groups of up to 80 individuals, each one capable of recognizing all members of their herd by the frequency of their calls.

Unlike other clever birds, like Day-Nightgrabbers, gogigas' society is less family-centered, with more than a dozen of unrelated old females that lead a single herd. Internal conflicts are also rarer and usually solved with ritual battles, where the members challenge each other with soft pecks and shrill screams. These "conflicts", while surely not dangerous, can be very exhausting, lasting for even half an hour in the worst cases.