Welcome to the High Life Highland Countryside Rangers blog! Join us here for lots of info from the team about local wildlife across the Highlands. We will be sharing our knowledge with you on a variety of subjects, such as fungi, birds, mammals and insects. Each of the Rangers will also provide an insight into some of the projects they are involved in and the work they do on the ground to help protect the biodiversity of the Highlands.
Owl Pellet Investigation
Many species of birds produce pellets, this includes crows, gulls, kingfishers, terns, dippers, swallows and of course the more familiar owls. The regurgitated pellets contain well “packaged” undigested remains of eaten prey, mostly containing fur, bones, and feathers but also beetles, shells, worm parts [Chaeta or bristles], fish scales and sometimes odd things too. Owl’s pellets are perhaps the easiest to look at and to find and are quite suitable for simple study at home or for school pupils.
Clearly it depends on a bird’s diet what you may find within a pellet, this makes for a very interesting study to discover what small mammals inhabit the area in which you find the owl pellets, some small mammals are not so easy to catch in mammal surveys but owls are better hunters. If you come across an owl roost or have an old barn which they may use as a nesting site, pellets should be found lying scattered below or in nest boxes if put up – but clearly not during the nesting period.
It is very simple to dissect owl pellets, some people prefer to do this from the dry state but tiny bones can be quite fragile, so I prefer to wet them, putting a little disinfectant in the water for safety, salmonella has been picked up, probably from mammal faeces in the pellet. You could put them in the freezer for a spell which would also work but don’t forget they are there! It is also possible to buy owl pellets online and, in most cases, they would have been sterilized but its more fun to collect your own. Gloves may be used at your discretion.
Using a paper plate or a petri dish, place the pellet in the water which it quickly soaks up and the fur is easier to separate from the bones with tweezers or cocktail sticks, place the bones to the side of the plate or on a separate dish sorting them into similar sizes and shapes. The skulls are easy to identify from the eye sockets and teeth, try to pair up similar lower jaws, magnifying glasses or a binocular microscope is useful. There are many online guides to help identify the remains found in pellets and the mammal society produces an excellent little booklet on that very subject “The Analysis of Owl Pellets” available to buy from them. Although this one is quite scientific simpler guides are available. A quick search on the computer came up with over four million hits in forty seconds – it is a popular subject. There are also charts on the bones of different species available to download, one included here as an example.
Odd, unexpected things you may find could include bird bones, or a bird ring [which you can trace], frog remains, mole skulls or even bats. A friend who lived in a farmhouse more than once witnessed an owl pursuing bats. You also might not expect to find anything alive in an owl pellet, but beetle larvae and some moth larvae [like little caterpillars] are quite often come across feeding within the pellet on the fur or feathers plus some fungi too, it is a living ecosystem on its own.
If you lay all the collected bones out orderly on black card and glue them with a spot of PVA glue or similar you can create an attractive fascinating picture of your owl’s latest meals – a great class project. More practical advice and tips can be found on the Barn Owl trust website and others.
For an interesting hobby – or business, some people actually design jewellery made from the skeletal remains from pellets, have a look online, quite fascinating.
Donald Mitchell – Countryside Ranger, Northwest Sutherland
Previous Blog Posts:
Rare Bumblebee Home Visit – July 2022
Dipper – March 2022
Tardigrades – February 2022
Highland mammals project – January 2022
Ardersier Seashore Day – Working with Refugee Families – December 2021
“Fungi Should I Eat It” – November 2021
“Misunderstood Moths Blog” – October 2021
“Pink Blob & Dog Vomit Pt Two” – September 2021
“Pink Blob & Dogs Vomit Pt One” – August 2021
“Scottish Primrose” – July 2021
“Watching Otters in The Highlands” – June 2021
“The Barn Owl” – May 2021
“A Hidden Highland Cave” – April 2021
“Ranger Toad Transport” – December 2020
“How Fungi Developed Agriculture” – December 2020
“Corvids – Let’s crow about it!” – November 2020