Coose, a flightless group of rails, were once one of the largest and most abundant vertebrates of Antarctica, found across any coastal habitat of the continent. Their unique adaptation to eat the poisonous leaves of canelos has allowed them to survive 20 million years with nearly no competition. However, with the increase of global temperatures, this adaptation has become a great penalty for their long-term survival.
As discussed in other guides, red canelos (Family: Winteraceae) are cold-adapted shrubs found across coastal wetlands, where thermal shocks are minimal. Due to global warming, coastal wetlands have become hotter, reducing the competitive potential of canelos. With the reduction of their primary food, interspecific competition with ducktails has drastically risen.

Coose are now found across a few small refuges, increasing endemisms. From a species richness point of view, this would seem the gold period of coose, with over 12 species found across Polarica and Marie Byrd archipelago. This is a false perspective, since the range of most species does not exceed 1000 km2 (400 sq mi); it would be only a matter of time before these small and fragile refugees will be wiped out by catastrophic events (wildfires, plague, famine, etc.).
Dwarfism has become a common characteristic of coose populations, with some becoming as small as a duck. 

The situation seems to be even more dramatic for a rarer species of coose called lacus (Lacus lacus), which can only be found in Lacus lake, a large wetland found near Amery bay (the second largest after Vostock lake) at 400 meters above the sea. This is one of the various species of coose that were able to persist inland, only thanks to the temperature mitigation by large bodies of water, creating an optimal habitat for canelos.
The lacus is one of the smallest coose, comparable in size to a large swamp hen. Their overall population probably does not exceed two thousand individuals, but still they were able to persist in these conditions for almost one million years. This was only thanks to their distinctive ecology: lacus are the most aquatic coose, rarely moving away from the coastline of their lake, where they feed on plants but also a large number of algae. Unlike ducktails, which usually eat superficial aquatic plants, lacus can submerge at 10 meters deep for browsing algae.
During the reproductive season, lacus take advantage of floating islands that are found in the middle of the lake, which are perfect nesting spots to avoid both terrestrial and flying predators. Chicks are raised for six months before becoming independent, still maintaining a social bond with their parents in adulthood. They are surely the most social coose ever, often roosting together in large groups (>60 individuals), a behavior that probably evolved to better watch out for predators.
Even a single unnecessary death is a great loss for this species, which will be surely annihilated by a genetic bottleneck in the next future. 

The age of coose is eventually coming to an end.