Nesting and baby birds
Most songbirds pair up in the spring; finding mates by singing, dancing and making nests to impress
A safe, warm place to nest, secure from predators and out of the wind and rain is essential
Food sources nearby are also required – both fuel for the parent birds as they rush around, as well as insects to feed the nestlings on. Parents time their breeding to coincide with the time of year when there are most insects around with which to feed their young.
In the nest
Eggs take around 11-15 days to incubate and hatch depending on species. Clutch sizes vary by species, weather and food availability.
Nestlings are born very tiny and helpless; the parents will spend nearly all their time hunting for insects to feed their hungry babies, as well as cleaning out the nest and keeping their nestlings warm.
The nestlings will grow very quickly and (depending on species) within about 2-3 weeks will have feathers and be ready to fledge (becoming fledglings) and leave the nest.
Leaving the nest
Fledglings, encouraged by their parents, leave the nest in fits and bursts. A lot tend to fall out of the nest. Some take to the wing straight away, others are slower to work it out.
Once they leave the nest fledglings do not return. Parents may return for a second brood, or make an entirely new nest. Sometimes nests are reused by other parents, even other species.
Out and about
The parents will spend some time showing the fledglings where to find food and fend for themselves, but after this the youngsters are on their own.
Issues
During this whole process the mortality rate is very high. Disease, competition from nest-mates, injury and predation by cats, rats, grey squirrels, magpies, crows, jays, badgers and foxes (to name a few), cause nearly half of baby birds to die in the first 2 weeks.
Magpies are particularly a problem at this time – over half of nests that fail due to predation are because of magpies
Parents try to compensate for this by having large broods. The more food that is available, the larger the brood that parents will try to feed.