How long do nightjars live, and at what age do they start breeding?

According to the BTO, European nightjars can breed from about one year of age. So a bird hatched one summer may be nesting the next, after its first winter in Africa.

They can also live a long time. The BTO records one individual that survived for more than 12 years. For a bird that migrates between its breeding grounds, including Latvia, and Africa every year, that is a long life.