<Tr> <Td> Egg in nest </Td> <Td> Nesting in progress </Td> <Td> Squabs </Td> <Td> A juvenile </Td> </Tr> <P> Incubation takes two weeks . The hatched young, called squabs, are strongly altricial, being helpless at hatching and covered with down . Both parents feed the squabs pigeon's milk (dove's milk) for the first 3--4 days of life . Thereafter, the crop milk is gradually augmented by seeds . Fledging takes place in about 11--15 days, before the squabs are fully grown but after they are capable of digesting adult food . They stay nearby to be fed by their father for up to two weeks after fledging . </P> <P> Mourning doves are prolific breeders . In warmer areas, these birds may raise up to six broods in a season . This fast breeding is essential because mortality is high . Each year, mortality can reach 58% a year for adults and 69% for the young . </P> <P> The mourning dove is monogamous and forms strong pair bonds . Pairs typically reconvene in the same area the following breeding season, and sometimes may remain together throughout the winter . However, lone doves will find new partners if necessary . </P>

What do mourning doves do in the winter