Thanks to their great adaptations and complex social structure, ducktails (Pygostylidae) are the dominant herbivores of Polarica. They are present in a multitude of forms, some no larger than a swan, others as heavy as a rhino. One of the most spectacular species are tower ducktails (or simply towers)(clade: Turrianatidinae), giants and slender herbivores with unique anatomical features, like the presence of spikes on their legs, an exaggerated number of cervical vertebrae and the complete lack of wings.

One species of tower ducktail have become cursorial, inhabiting the internal drylands of Polarica like the Day-Night steppe, browsing on low shrubs and the few willow trees present in the region: the steppe tower (Camelirampho longilineus).
Like other ducktails, its digestive system is very efficient, similar to a ruminant: thanks to its false teeth and rough tongue, food is already processed in the mouth, where it's chopped.
Steppe towers cover a similar niche to rotbills, which rapidly went extinct shortly after the disappearance of the Scrubring. 

They are usually found near rivers and lakes, where large riparian forests can be found all year. Due to their range's proximity to the South Pole, steppe towers must endure four months of complete darkness, with freezing temperatures. During this long period, their eyes increase the presence of rod cells that optimize night vision (to the detriment of color vision), like other vertebrates of this ecoregion.
They are highly social herbivores that live in family groups: like other large ducktails, eggs are brooded by subadults to reduce the risk of crushing them. After 40 days,  highly precocial chicks hatch from the eggs, capable of following the herd after a few minutes.
They are sturdy animals that can survive without food for even a week, thanks to a little hump on their back where they store fat.

Despite being larger than any holocenic bird, steppe towers are nothing compared to the massive obelisk (Bryophaganas gigas), the main browser of Belgrano wetlowland. Weighing over a ton, this walking skyscraper is one of the largest birds that ever existed, searching for food on branches as high as 5 meters.
This species has progressively lost all spikes of their legs, in favor of a large single spur, which is used for self-defense against large carnivores; a well-aimed kick from an obelisk is strong enough to fatally kill the toughest herdstalker of Polarica.

Obelisks' life is complex and extremely mutable: eggs are laid inside fermenting matter (like Ontoducks) which maintains the necessary heat for hatching. Chicks are born precocial and morphologically similar to adults and live in small groups that feed and defend each other from dangers. After 6 years, when youngs reach sexual maturity, the group separates and obelisks start a solitarily life.
Due to their enormous size, obelisks are virtually unable to run in adulthood, but that's not a problem since they are invulnerable to any predator.
Their trampling action has completely changed the spatial structure of Belgrano forests, causing the indirect disappearance of ground rostrids, which are now facing a big crisis.