What to call a baby bird can vary depending on the species and age of the bird. The name for a baby bird varies by species, which means there's not one unifying term to describe all baby birds. Instead, the generic term for a baby bird is 'chick'.
There are three different names for baby birds, that change depending on the bird's age and life stage.
We'll break down into further stages that are also used for different stages of a birds life below:
Hatchling is the term given for a bird that has recently hatched out of its egg. Baby birds as chicks or hatchlings are entirely dependent on their parents to provide food, care and protection.
The majority of hatchlings are born completely naked and often have just a few feathers on their skin. Generally speaking, they'll huddle with other nestlings at this stage to keep warm. Most chicks are also born with their eyes open, and they won't typically open for a few days. The beaks also tend to look extremely out of proportion, although they will soon grow into them.
Altrical is the term given to this state that many birds hatch like - particularly songbirds. It means they are born undeveloped, and their survival relies on their parent(s) to protect them and bring them food.
Generally speaking, most birds don't look that cute and can look very alien-like at this stage. Unless you happen to stumble across a nest or have the sad sight of a hatchling that has been ejected from the nest, you never tend to see birds in this state, as most of them will make their nests in safe and discreet places, away from predators.
The recently hatched chicks of a robin, also referred to as hatchlings
Nestling is the term given to a baby bird when it usually reaches three to thirteen days old. When they reach this next stage, they are slightly more capable than a hatchling but still require and are incredibly dependent on their parents care.
Birds at the nestling stage mostly have their eyes open now and tend to have a covering of 'real' feathers instead of the fluffy down they had when they were newly hatched. On closer inspection, the nestling feathers can look like they are covered with some sort of coating, and this is just where the feathers are new and still require grooming or 'fluffed'.
Nestlings generally still don't look or resemble their parents at all at this stage and can still look a bit strange!
Birds at their nestling stage
When baby birds reach the fledgling stage, this means that they are finally ready to leave their nests and step out into the world for the first time. This, on average, is anywhere between two and three works for most birds. After two to three weeks of growth, the nests can start to become crowded with all siblings reaching much larger sizes, so it's a good thing that they leave the nests!
Fledglings usually have the majority of their adult feathers and are starting to look much more like their parents. However, they are generally still not fully developed and can still have quite dull plumages. Both the tail and wings can also appear 'stubby' at this point, as the feathers are still not all there yet.
Once they have left their nests, it's not unusual for fledglings to be unable to fully fly just yet. They often spend the first few days out of the nest hopping and walking about with no problem. They can often be seen 'practising' flying, with occasional fluttering.
For the next few days (and sometimes weeks), fledglings will stay with their families. This is a vital period of time, where young birds will observe and learn from their parents on how to behave. How to forage for food is one of the most crucial things, and these young birds will watch their parents to learn how to do so.
Generally speaking, parents will still feed their young, as fledglings will often still beg for food. This can be observed on feeders and on the ground. Young birds will 'shake' their wings and call to let the parents know they want to feed, and most parents will continue feeding for a short period.
Parents will usually keep an eye on fledglings for some time and will intervene if their safety is at risk.
An American Robin recently fledged from the nest
Juvenile is the term that's the equivalent term for teenagers for birds. They are at a stage of their life where they are mostly capable of fending for themselves if necessary but still partially rely on their parents for food and protection.
When birds reach their juvenile stage, they will often spend a few weeks with their parents and will sometimes still beg for food. During this period, young birds will continue to learn things like hunting and catching food by watching their parents and other family members.
Juvenile birds are almost similar looking to their adult plumage, but can often still lack some of the vibrant colors or markings, found on the adult plumage.
A Juvenile Blackbird being fed
Some species of birds have unique names for their young. Some examples of these are:
The most common collective nouns to describe a group of baby birds is either a clutch or brood. Clutch is the term also given to the eggs laid by a bird in the nest.