Dusk - Kenneth Oppel

65 million years ago: the last dinosaurs are dying out, the mammals are beginning to take over the earth and the very first bats are learning how to fly. Our young hero Dusk, a chiropter
a small arboreal glider
discovers an unusual ability. The only member of his colony capable of powered flight, Dusk becomes an outcast. But after his colony is massacred by a prowl of carnivorous felids (proto-cats), a homeless and hunted Dusk may prove to be its salvation. Set during a dynamic evolutionary moment in earths history, Dusk tells the story of the very first bat, and a colonys perilous journey to find a new home.