SNC 1P Sustainable Ecosystems and Human Activities Name______Date: Owl Pellet Dissection Objectives . Learn about the feeding behavior of an owl . Separate and identify the contents of a pellet . Speculate about the diet of an owl . Understand food chains and food webs Materials . Barn Owl Pellet . glue . Dissecting Tray . Piece of Paper . Forceps . Small Animal Identification charts
Procedure 1. Place an owl pellet in the dissecting pan and remove it from its aluminum-foil casing.
2. Examine the owl pellet and write down 2 observations about this pellet in the Owl pellet observation table 1.
3. Using the forceps, carefully break apart the owl pellet. Separate the fur or feathers from the bones. Be careful not to damage the small bones.
4. Place the bones into your plastic bag for safe storage until later in the lab.
5. Make 1 qualitative observation while performing the dissection and record it in the Owl Pellet observation table 1.
6. After you have carefully pulled out ALL the bones from your owl pellet, place each bone on the Owl Pellet Bone Bingo Board according to the correct type of bone. Use the bone reference sheets to help you indentify which type of bone you are looking at. Note: At this point of the lab, it is not necessary to determine which animal each bone came from!
7. Count the total number of each type of bone in your owl pellet and record the data in the Owl Pellet data table 2.
8. Count the total number of all the bones found in your owl pellet and record it in data table 1.
9. Use the skull reference sheets to help you identify the type of skull(s) you have in your owl pellet. Record this information in the Owl Pellet Observation table 1.
10. After you have identified the skull, try to recreate the animal from which the bones belong. Once you have the bones in the proper position for the animal, glue them down onto the paper plate. Make sure to write you and your lab partner's name on the plate. You will be graded on the correct positioning of the bones in your animal reconstruction.
11. Clean up your lab area. Rinse the dissecting tray and forceps. Throw away unused parts of owl pellet. Wipe down your lab area and wash your hands. SNC 1P Sustainable Ecosystems and Human Activities Name______Date: Owl Pellet Dissection
Owl Pellet Observations – Investigation
1. Owl pellet #
2. Measure the length and width of your owl pellet.
Length of your owl pellet
Width of your owl pellet
Mass of your owl pellet
3. Carefully examine the exterior of the pellet. Do you see any signs of fur ? any signs of feathers ? Owl Pellet Data Table Type of Bone Number of Bones Present in Owl Pellet
Skull
Jaw Bones
Pelvic Bone (Hip)
Rib Bones
Back Bones
Shoulder Blade
Upper Leg Bones
Lower Leg Bones
Owl Pellet Conclusion Questions – Thinking
1. Owl pellets not only can give us information about the diet of the owl, owl pellets also provide a habitat for other animals, in fact an owl pellet is a little ecosystem all on its own. Why kind of animals are found in the owl pellet ecosystem (Hint: read the background at the beginning).
2. Why do you think farmers might want owls in their barns? SNC 1P Sustainable Ecosystems and Human Activities Name______Date:
3. Owls, hawks, and eagles are types of raptors, animals which have hooked beaks and sharp claws, and are therefore adapted for seizing prey animals. Hawks and eagles differ from owls in that they eat their prey animals by tearing them into small pieces, picking out the flesh and avoiding most of the fur and bones. They also have strong stomachs which can digest most of the bone material which they might eat. The relatively small amount of indigestible bone and fur that remain will be compacted by their stomach muscles into a pellet similar to the owl's. Do you think an eagle pellet would be as useful for dissecting as an owl's? Why or why not?
4. Create a food chain using the following organisms: snake, field mouse, owl, grasshopper, grass. Label each organism as either carnivore, omnivore, producer, or herbivore.
5. What is the difference between a predator and prey? Is an owl the predator or the prey?
6. What might happen to the population of owls if there were a sudden population explosion of mice?
7. What might happen if the owl population suddenly decreased? SNC 1P Sustainable Ecosystems and Human Activities Name______Date: