Do birds only mate in spring?

Question

because i only seem to see baby birds in spring

Answer 1

Depends. Some birds do not mate in spring, but they probably aren't where you live.

Answer 2

Here in the US....yes.  Some species such as hummingbirds(Anna's), doves and pigeons will nest most of the year or have an extended breeding season and are not just limited to the spring season.  Some owls will nest almost year round as well.  In tropical parts of the world where there in warm weather year round allows for birds to nest year round.