Owl Pellet Dissection

What is an Owl Pellet? An owl pellet is the feces that is regurgitate. Owl's cannot digest fur, feathers and bones, that is the main reason of regurgitation. An owl will still produce urea. Pellets range in size, it all depends on the size of the owl and the amount it has eaten.

Background The owl pellets that will be distributed to the students come from barn owls. Barn owls are medium sized owls with large heads and long legs. The size of the cranium is due to the enhanced sight sensitivity for seeing in the dark as well as the vast aural capacity enabling the owls to hear the faintest sound made by their prey. The barn owls are found all across the globe. They are mostly found in fields and pastures because of the increased rodent population, their favorite prey. All owls have an interesting way of dealing with their food. After digesting the nutritious parts of the small animals they eat, they regurgitate all of the undigested parts in a small pellet. The pellet is composed of bones, fur and teeth. Because barn owls don't tear their prey to pieces, there is always a complete skeleton of at least on rodent in every pellet. Every bone from the skull to the last tip of the tailbone can be found. A good observer with a little patience will be able to piece together the incredible skeletal masterpiece. sources: Human Body Module FOSS 1992 Edition

Objectives This activity is designed to give students a "hands-on" interaction with the process of different animal digestions, the skeletal system, predator and prey anatomy and how its anatomy is tailored for its survival.

Bones to Look for.

AnimalLab GroupClass TotalTotal% Shrew12.6 House Mouse Vole Deer mouse Mole00 Rat00 Bird00 Insect00 Other00 Total38.5- Total pellets10- Average/pellet3.85-

Produce Graphs

Create a Food web Using the following data

EatsTaken by GrassConverts Radiant energyGrasshopper, vole, deer mouse, house mouse, Gopher, DDD SeedsConverts Radiant energybeetle, vole, deer mouse, Gopher, songbirds, DDD grasshopperGrass, SeedsShrew, songbirds, DDD Beetle Seeds Shrew, songbirds, DDD Garter SnakeDeer mouse, vole, beetleOwl, DDD gopherGrass, seedsBarn owl, DDD shrew Beetle, grasshopper, vole, deer mouse, house mouse, Barn owl, DDD songbirds seeds, grasshopper, BeetleBarn owl, DDD Deer mouse Grass, seeds Barn owl, DDD voleGrass, seedsShrew, Barn owl, DDD Barn owl?DDD

Food Chain

Food web

An ecological pyramid is constructed based on one of three types of data: –number of organisms –the amount of biomass –amount of energy. Each feeding (trophic) level passes 10% of its stored energy to the next level. –Therefore, if the producers had 10,000 units (calories) of available energy, –the herbivores would receive 1000 units, –the primary carnivores 100 units –the secondary carnivores 10 units.

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Extra credit Create a game using the previous data with the objective of creating a game (with explained rules) to teach about food webs and ecological relationships –Cards should be made Grass Eat: Converts Radiant energy Taken by: Grasshopper, beetle, vole, deer mouse, house mouse, Gopher, DDD

Virtual wl/index2.htmhttp:// wl/index2.htm josh1.HTMhttp:// josh1.HTM

Sites Used for Pictures and References josh2.htmhttp:// josh2.htm _owlpellet.htmlhttp:// _owlpellet.html es/Owls2/owl_lab.htmhttp://cas.bellarmine.edu/tietjen/Laboratori es/Owls2/owl_lab.htm