Giants and dwarfs of the bat world
Despite not liking too much the Ice Age of the middle Lentocene, bats have flourished in a moltitude of species, some large and some small (as always). Thanks to their flying capabilities they were able to colonize every piece of land in Antarctica: often, large islands far from the coast host at least one endemic species of bat.
Small species from mainland and islands
At least four different species of bats are present in continental Polarica, including a noctule that adapted to live in the Wilkes and Amery open shrublands: the lowland bat (Planinoctula wilkesesensis). This bat hunts moth, flies and other insects thanks to their very long wings, perfect for fastly moving in open habitats. During the warmest months of summer the lowland bat can be found at higher elevations, in contrast to their common name. Due to the absence of large trees in their ecosystem, this bat uses caves or ground holes for wintering.
While noctules have become the most abundant group of antarctic bats, myotis are still pretty widespread anyway: one of them (Myotismon berknerensis) is endemic to Berkner, an island 300 km/186 miles far from the mainland, parallel to the D.D. Shortly after the disappearance of the Ronne ice shelf, Berkner island sunk in the sea but then partially re-emerged because of a post-glacial rebound. The largest herbivorous species of the island is a 10 kg rallid that lives at very low densities: with such a low impact by herbivores, Berkner possesses one of the densest forests of Antarctica. Berkner myotis has greatly adapted to this unique ecosystem by reducing their wings, to better dodge plants in the undergrowth.
The bird-eating megabat
Some holocenic bats are known to eat birds, like the European giant noctule or the South American spectral bat. In Antarctica, a similar niche was occupied by the night hawktule (Noctularctos aviphagus), a monstrous bat that can weigh up to 800 grams (1.76 lbs ). They are so large that passerines comprise most of their annual diet. It's a very wholly bat, with a nearly uniform earth red fur and a yellow mane.
This flying predator mostly hunts during night, dawn or sunset* and uses echolocation to find their prey. In the warm season, these bats are solitarily, often found roosting on large trees at the edge of meadows and steppe-tundra. During the cold season they become colonial, overwintering together in humid caves. Its bite force is proportionally one of the strongest of any antarctic vertebrate, able to chew bones too. Despite preferring perching birds (including ground tyrants), the night hawktule (in rare situations) can also eat large moths and beetles but also take down rails and ducks of up to 2 kg/4.4 lbs.
Thanks to their size, hawktules have a proportionally lower metabolism than other bats, needing less food for sustaining themselves and enduring even a couple of days without eating.
*hunting periods change a lot for this species but also for other polar bats, since some locations of Antarctica experience midnight sun and polar night, while others possess classical civil days of 24 hours
