Inbreeding in wild animals shows surprising mix of positive and negative effects.
Inbreeding can affect the health of offspring from related parents. The Chatham Island black robin, a highly inbred bird species, showed that inbreeding can lower survival rates for young birds. Surprisingly, chicks with highly inbred mothers had better survival rates. This unexpected result suggests that inbreeding can have both positive and negative effects on individual fitness in highly inbred populations.