Young bat Silverwing has always been more inquisitive and curious than his fellows. Frustrated by the rules that govern bat behaviour, he is incensed by the requirement that all bats must roost before the first light of day, a punishment imposed generations ago, after the great war between birds and land animals when bats declared neutrality because they belonged to both groups. The victorious birds branded the bats cowards, while the animals called them traitors, and bats were banished to the dark.
Desperate to see the sun, Shade disobeys the rule and incurs the wrath not only of his leaders but of the creatures who maintain the punishment - as a result, the colony's home tree is destroyed, forcing the group to leave early for their winter home. In the exodus Shade becomes separated from his group and, as this is his first migration, he doesn't know the way to their meeting place. As he tries to find the route on his own, Shade discovers many different kinds of creatures, and ways of life different from those he could ever have imagined, from villainous pigeons to Marina, a birghtwing bat with ideas of her own.
The first in a four book series (including the prequel Darkwing), Oppel draws from a complex mixture of mythologies to create an anthropomorphic world that, though aimed at younger readers, is quite adult. There are certainly adult themes, most striking of which is the cannibalistic attacks of two vampire bats.
I'm not a fan of wholly anthropomorphistic animal world - as I've mentioned many times before, though happy for animal protagonists and rich but fictitious animal cultures, I prefer my animals to behave like natural creations and not furry (or feathered) humans. I did finish Silverwing but have no intention of following the series through to its conclusion even though there are several unanswered questions (like the fate of Shade's father) left hanging. - Alex