How To Feed Owls
Owls are very challenging birds and although they can be kept as pets it is highly recommended not to look after them. They are wild animals and prefer to be on their own outdoors. It is very difficult indeed to domesticate them. Unfortunately with the Harry Potter series, keeping and looking after an owl has been seen as possible and easy however it is a lot harder that the books and films make out.
Even though owls are beautiful, magnificent and amazing, looking after them can be a difficult. In captivity they are smelly, dirty and need lots of your time. They are also predators and will need looking after a lot. Even those with years of experience of looking after birds have been badly injured and lost eyes.
In the wild
Naturally and in the wild when it comes to feeding habits, owls will often go for birds to a proportional size to them (they are true predators and not afraid of size!); they will also feed on insects and small mammals such as rats, moles, mice and squirrels however they can even go for larger mammals like hares. They will often swallow the small mammals in one go.
Even though owls do eat insects they will need to have small mammals like the ones explained above due to the nutrients, vitamins and minerals.
In Captivity (Barn Owls only)
As a general rule of thumb anything a cat brings home to your doorstep can be fed to an owl. However take caution with wild rats as they contain leptospirosis which is dangerous for humans to handle.
If you have decided to look after an owl in captivity then dead day old chicks is a popular choice. The poulty industry has a large supply of these and sell them at a reasonable price. They are high in protein, low in fat and have good levels of vitamins and calcium. These, where possible, should be provided fresh. Freezing the dead chicks can allow bacteria to spread. Owls can eat around one and a half to two and a half dead chicks a night. Do not feed the owls when there are extreme weather conditions such as too hot or too cold as the food you are feeding it will decompose or freeze.
Foods you should avoid are anything that has been shot by humans as the lead poisinging is dangerous to the owl. Pigeons are a no-no as they contain high levels of avian diseases. And rabbits should be avoided due to the bone fragments which can be fatal to an owl.
In An Emergency
If you have to feed an owl in an emergency then the Barn Owl Trust suggests feeding it on a diet of raw lean shin beef or chicken mussle. These foods should only be fed for a short period as they are nutrially deficient. Water is far more important in this regards. Contact your local wildlife trust for more information on what to do with the bird afterwards.
Remember than in the UK Barn owls are protected under the Wildlife and Countryside Act (1981) and it is illegal to disturb them. It is also illegal to release captive owls into the wild.