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