Anyone who has ever put bird feeders in their gardens will know that birds eat – a lot.
The items that they consume are extremely varied, ranging from seeds and nuts to things like suet cakes. What is not widely known, though, is that birds have a unique internal method of breaking down the food they eat.
Every animal develops a system for digestion that suits the particular foods it favours, and birds are no exception. Their situation when it comes to eating is unusual, though, because they do not have teeth. They do, however, have beaks or bills they use to pick up items of food, but also to tear them into smaller and more manageable pieces.
The swallowing process is not much different to that of human beings, with the tongue being used to help ease food down into the digestive tract, but that’s where things become more interesting. Before the stomach, birds have something called a crop. This stores excess food, before moving it down into the stomach for digestion later, and is how birds are able to eat large amounts quickly.
A bird’s stomach is made up of two chambers: the proventriculus and the gizzard. The first of these produces acids that help in breaking large bits of food down. The gizzard has muscles that grind up the food further, helped by grit or pebbles the bird has consumed.
Finally, the nutrients from what is left are absorbed in the small intestine and caeca.
So, the next time you fill up your bird feeders, you’ll know a bit more about the intricate inner workings of these feathered garden visitors!
