New (sky) currents

The immense territorial changes between the Cambiocene and the beginning of the Biancocene brought significant disruptions to Antarctic ecosystems, but they also brought about new developments. Species adapted to open habitats underwent a rapid diversification, and new species appeared in Antarctica. As always, the great distance from other continents acts as a major filter, allowing only flying and marine species to reach the region.

Among the new arrivals in Antarctica there is a large scavenger parrot species known as the carrion parstriker (Psittagyps titanicus). Unlike typical vultures, this carnivorous parrot has maintained a fairly strong bite force that enables it to feed on tough tissues such as skin and muscles. Due to its superficial consumption of carcasses ("ripper" method), the carrion parstriker hasn't evolved the typical bare neck seen in the well-known vultures of the genus Gyps, but it does possess a dense plumage except to the distal part of the head, similar to that of a cinereous vulture.
Given its size, the carrion parstriker dominates over other scavenger birds and often engages in kleptoparasitism, stealing prey even from sheardogs when they are in a flock. The aggressive nature of the carrion parstriker in claiming carcasses often benefits the smaller scavengers that go unnoticed by the large bird. Among these scavengers, one species stands out for its anatomical uniqueness. However, this species is not a bird but a mammal known as gargouille (Ambulomyotis durophagus).

While identifiable as bats due to its muzzle and winged patagia, gargouilles exhibit a condition we can call hyperterrestriality. Despite being excellent flying animals, gargouilles seem highly adapted to moving also on the ground. Their limbs are held much more upright than their bat relatives, optimizing walking on the ground. They support their weight with the sole of their foot and a single finger (the thumb), free from the patagium of the hand, which has developed into a giant claw. These adaptations are attributed to their primarily scavenger diet: unlike their ancestors, the vesper bats, gargouilles feed at ground level and have had to adapt to this new lifestyle. Their bite is proportionally the strongest among any Antarctic mammal, allowing them to pierce the tough skin of carcasses to reach their favorite body parts: internal organs ("gulper" method).
Due to their long, erect hind legs, gargouilles are incapable of sleeping upside down like their ancestors, which brings them into competition with birds for nesting and perching sites. To avoid unnecessary aggression, these bats prefer to give birth in burrows dug on the ground, which are built thanks to their long hind claws. 

Gargouilles  are not strictly obligate scavengers and may occasionally feed on live prey, typically insects but also small rodents, which they capture by intercepting them in their underground dens. Although they possess a fair amount of ecological plasticity, their semi-fossorial habits prevent them from living in areas covered by permafrost. Despite being more robust than their relatives, the front limbs of gargouilles are still fragile and not suitable for digging into icy ground.
The flight of gargouilles is highly variable but usually involves gliding to minimize energy consumption. Currently, the species is found in Antarctica near the Reliquia Forest and various regions of the coldvanna, but it's completely absent from the trample steppe due to a continuous layer of permafrost just a few decimeters beneath the surface.