City life may help Darwin's finches survive bloodsucking flies

Finches found only in the Galapagos Islands are under attack from bloodsucking fly larvae, but those that live in cities may have an edge compared with their countryside counterparts: they lose less blood and have higher rates of survival during infestations.

The avian vampire fly (Philornis downsi) was accidentally introduced to the Galapagos archipelago a few decades ago. The flies lay eggs in bird nests, where maggots that hatch later burrow into nestlings’ skin and drink their blood. Infestations of the invasive parasites …