Lab Activity The Food Web of a Barn Owl Lab Activity Discover what a barn owl eats by dissecting an owl pellet and piecing the bones together.

Let’s learn about the barn owl and its habits in an ecosystem. The barn owl is a consumer that is at the top of its trophic level within its niche. Barn owls are a nocturnal animal, or awake at night. They have specially designed eyes, ears, claws, and wings that have helped them adapt to catching their prey. They often live in our near country farms which aids in providing the owls with shelter and a food source. Their prey include mice, moles, voles, and other small animals.

An owl has unique eyes that allow it to be able to see at night. This is very important for them since they are nocturnal animals. Their eyes are very large and contain a large number of rods. Rods are structures inside the eye that sense the light in ones environment. They have so many of these rods, that they do not have room in their eyes for muscles or cones. Cones are structures that allow us to see colors. This makes their eyes unable to move in the eye socket. In order to be able to see, the owl has adapted and can now turn its head almost 360 degrees around in a circle. A Barn Owl’s Eyes How have they helped an owl adapt to night- time hunting?

Other Adaptations that Barn Owls have to survive The barn owl has many other characteristics that help them adapt and survive. The structure of their internal ears helps them to gather sound waves and direct them to the ear drum. The feathers that around their face help with the gathering of the sound waves since they do not have outer ears like humans. An owl’s talons (claws) and feathers also help them hunt. The owl is able to spread open its eight talons to grasp its prey and hold on. The feathers that cover their legs and feet protect them from the bites of the prey. The feathers of an owl are different from that of a bird. The owl’s feathers designed so that when they fly, they are silent. How does this help the owl? The prey will not hear the owl coming.

The Eating Habits of a Barn Owl Barn owls have a unique way of eating their food. The owl will swallow the prey whole, including the fur and bones. Since their digestive track cannot process the fur and bones, those materials are regurgitated as a hairball-like object known as an owl pellet. In the owl pellet will be the fur and bones of the animal they have eaten. The average owl will produce two pellets a day. By dissecting an owl pellet, you are able to piece together the animals eating habits and also the wildlife that live in the region.

Barn Owl Food Web Using this chart, give an example of a food chain for a barn owl. Based on this food chain, what types of animals might you find in your owl pellet?

Student Objectives  Read packet/background knowledge  Work with lab partner to dissect owl pellet.  Record results on lab report sheet.  Share results with class and record findings on graph.  Investigate owl dissection on wikispace

Owl Pellet Dissection Lab Activity  Materials Needed:  Barn Owl Pellets  Tweezers/paper  Hand lens  Toothpicks  Tray covered with black paper for holding all materials  Lab Report Sheets  Pencil to record data  Plastic bag

Before looking inside, record the following information below: Characteristic Description of Pellet Length Width Color Visible Bones Other Visible Items

Hypothesis Hypothesis – In the box below, write down what you think you may find in your owl pellet. Be specific.

Steps: 1. Gather all materials needed for lab. 2. Using the tweezers, gently pull the outer fur off the pellet. 3. Place the fur into one of the cups. Put the bones into the other cup. 4. Once all fur has been gone through, place bones on the bone sorting chart.

Place the bones on the chart to the right. Based on the bones found, what conclusion can you make about what the owl ate prior to regurgitating the pellet?