Term 4 Environmental Issues students were tasked with a very interesting assignment. To discover what owls eat by dissecting their pellets and reconstructing animal skeletons found with them.

These pellets are small masses of indigestible food that the owls regurgitate, which can be used to study energy flow in an ecosystem. The owl pellets used in the study came from the Pacific Northwest and Southeast regions of the U.S.

Seniors Kristi Meechan and Tatiana Reigada dissecting their owl pellets.

The pellets were divided among the students, who worked in pairs to dissect each pellet. Using forceps and dissecting needles, they carefully broke open the pellets and separated out the different components. What they found was astonishing; bones, teeth, feathers, and fur from several different types of animals including birds, mice, rats, voles, and gophers.

Nanea Gutierrez '12 cleaning a bone fragment.

“In studying the biological magnification of pesticides, like DDT, in Rachel Carson's novel "Silent Spring," students developed a greater appreciation of food chains and food webs after dissecting owl pellets,” explained Environmental Issues teacher, Michelle Rumschlag.

Using an Owl Pellet Bone Chart as a guide, students had to identify the different types of bones and which animal they belonged to. Their assignment also required them to record how many skulls they found and if they were from different animals, and how close they came to finding a complete skeleton.

Whole rodent skull from an owl pellet.

One group found three separate skulls within one pellet.