Anatomy – Owl Chatter

Owls are savage hunters who often swoop down on their prey and once caught, often swallow them whole or at least in two – so what happens with the not so… enjoyable parts of the prey such as the hard bones, the beaks, the fur and the feathers? This is where owl pellets come into play! So… What are Owl Pellets? Owl Pellets are oval shaped little packages often the size of a man’s thumb made up of undigested food from the owls last meals, they are a combination of hard to digest parts of the prey’s body such as hair, feathers and bones and these end up being regurgitated from the bird’s beak in the form of a small pellet. An owl with the pellet that it just regurgitated. Don’t get this mistaken with faeces though, owl pellets are not the same as owl faeces as it doesn’t make its way through the whole of the owl’s digestive tract – and they do not have a scent! They are often misinterpreted as owl faeces because they do often look like how we may picture owl droppings since they are usually dark/black when fresh yet dry a little greyer. Actual Owl faeces are the complete opposite, they’re watery and mostly white and therefore do not emulate owl pellets at all. Its actually an incredible example of how an owls body works like a machine to sort the soft food from the hard difficult to digest food. Owls can’t easily separate their prey before consuming it as often they swallow it whole or in large pieces. Therefore, the stomach separates this all out by having two separate chambers to pass through… one that is known as the proventriculus where the digestible soft food gets liquidized for nutrients and another known as the gizzard which grinds down harder parts of the meal and sends all digestible food into the intestines. Anything too hard to digest gets tightly packed into a pellet and sent out via the beak. By allowing the tougher food to come back up the digestive tract and pass via the owl’s beak, it means they can avoid eating anything that will provide little to no nutritional benefit and just reap havoc on the owls body trying to pass it through. The pellet is coughed up a few hours after the meal often when the owl has begun to rest and this tends to only happen around once a day. Owls are not special by creating pellets, they are also created by other birds too such as crows, their pellets will differ depending on the meals they eat. They can differ slightly in size, colour, consistency and shape to a certain degree. Pellets are extremely helpful when it comes to gathering information about an owl/bird’s diet, by pulling these pellets apart you can figure out what exactly they have eaten recently. Fun fact – odd things can often be found within these pellets but I don’t just mean weird prey such as frogs, once someone found the bird ring off a Wren that lived 300 miles away – how this ended up being potential dinner to an owl we are not sure but it’s interesting nonetheless! These pellets are often found at roost sites below or inside the nesting site. How do I dissect a pellet? To dissect an owl pellet and find out what it reveals about an owl’s diet follow the below steps: Pellets can be analysed wet or dry but if you would rather extract the bones intact without breakage then you can soak a dry pellet in water for 24 hours to moisten anything. Dry pellets can sometimes fall apart slightly easier though. Use fingers gently or tweezers to pry the different objects apart. Please note that although you are not handling faeces it is still recommended to wash your hands with soap after handing any owl pellets. They still contain parts of dead animal carcasses and have been through an owl’s digestive tract so not the cleanest of environments! Begin by trying to separate the pellet into two and try and separate any bones found into their own pile. Get rid of any fur or softer material as this will be of no use to any dissections being done purely by the human eye. You can use something known as a dichotomous key to identify any bones that have been found. This is a key that helps identify things in the wild, you are asked a series of questions and each answer leads to a new one until full identification can be made. You can also identify the findings by paying close attention to the lower jaw bones found in the pellets as these are quite a good indicator of what species of animal the owl has eaten. Don’t forget to count how many different prey animals can be found within one pellet!