1. Module 16 – Part 4 Owl Pellet Dissection
Honors Biology
Module 16 – Part 4
Owl Pellet Dissection

2. The End is Near! Our last class will be on May 5, 2016
Grades will be given on that day.
We will be having a competition that will cover information learned throughout the whole year.

3. Quiz 30
April 28, 2016

4. Question 1
Name the 5 characteristics of mammals 1. 2. 3. 4. 5.

5. Mammalian Eye

6. 5 Characteristics of Mammals
Hair covering the skin
Reproduce with internal fertilization and usually viviparous.
Nourish their young with milk secreted from specialized glands.
Four chambered heart
Endothermic points

7. A. Vitreous Humour
B. Lens
C. Cornea
D. Pupil
E. Iris
F. Sclera
G. Optic Nerve
Retina
Extra Credit: The Muscle

8. Owl Pellet What you might ask is a pellet?
Owls and other raptors, as you may know, maintain a diet primarily, if not exclusively, of protein. In other words, they eat other animals.

9. Raptors are unlike humans who can cut, cook, and otherwise prepare our food to eliminate the indigestible portions. They also differ from carnivores like wolves that can tear the meat away from indigestible things like bones.

10. They often feed on small animals like rodents and smaller birds
They often feed on small animals like rodents and smaller birds. Weeding out the digestible from the indigestible parts of small animals like these when you only have a beak and talons to do so with isn't always easy. The solution that raptors have come up with is casting pellets.

11. As a raptor digests its meal, its body separates these indigestible parts such as bones and fur. This material binds together and is later expelled through an action that very much looks like the bird is vomiting. They are not vomiting however, and it is not the same thing as a cat expelling a hairball either.

12. Many people at one point in their lifetimes, whether it was in science class or just for fun, have dissected owl pellets. If you haven't had the pleasure, these pellets appear as small forms of bound up fur. Often you can see small bones if you look closely.

13. For more information

14. What is an Owl Pellet?

15. Experiment 16.D: Owl Pellet Dissection
Objective: To observe the contents of an Owl pellet.

16. 1. Carefully inspect the outside of the pellet and note its size and record the measurement.
Inspect whether there are any feathers visible, and whether there are any clues to where the pellet was found.
Guess how many different animal skeletons the pellet contains.

18. 4. Next, gently pull apart the pellet, being careful not to break any of the bones inside it. Use toothpicks or a probe to separate the bones from the fur or feathers.
Take special care when removing the skulls and jawbones, since they are the best way to identify the animals that the owl ate.

19. 5. Group similar bones together
5.Group similar bones together. When you've finished sorting the bones, roll the last bits of fur between your fingers to find little bones or teeth that might have been overlooked.

20. 6. Once you've found all the bones, try to reconstruct the skeletons of the animals.
7.Use an identification key to classify the bones. Owls usually eat more than one rodent before regurgitating the remains, so you should be able to find multiple bones that are similar.
8. Can you distinguish between the bones of different kinds of rodents based on their size?

22. Can you put together all the bones?

23. How many different kinds of animals did you find evidence of in the pellet?
10. How many animals were there in total?
11. What can you conclude about the eating habits of the owl that made your pellet?

24. As you write up you observations and conclusion, think about…
The food chain and explain the relationship between producers (plants) and consumers (animals that eat the plants or that eat other animals). Here are some simple relationships between the producers and consumers that are involved in a Barn owl's diet.
Plants, grasses, roots, seeds --> mice, rats, gophers, birds Plants --> insects --> frogs, birds Worms --> birds, moles Birds, mice, rats, frogs --> weasels Birds, mice, rats, gophers, frogs, moles, weasels --> Barn owls

25. Next week Honors Biology Jeopardy
Do we want to have a Cinco de Mayo party for the last half hour of class?