Owl Pellet Dissection: Building a Food Web and Data Collection
Science Lab · Grade 7
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Type
science_lab
Pre Lab
Background: Barn owls are remarkable **predators** that play a critical role in their **ecosystem** — the community of living organisms and their physical environment that interact as a system. Because owls swallow small animals whole or in large pieces, their stomachs must separate what can be digested from what cannot. Soft tissues like muscle and organs are broken down and absorbed for energy, but hard materials like bones, teeth, fur, and feathers cannot be digested. These indigestible remains are compressed into a tight, oval package called a **pellet**, which the owl regurgitates — or coughs up — through its beak roughly 10–24 hours after eating. Each pellet is essentially a biological record of exactly what the owl consumed.
By carefully dissecting owl pellets and using a **bone identification** chart, scientists — and students like you — can determine which **prey** species the owl ate. Prey are the organisms that a predator hunts and consumes for food and energy. Common prey found in barn owl pellets include meadow voles, house mice, shrews, and occasionally small birds or insects. Identifying the skulls, jawbones, and limb bones inside a pellet is like solving a biological puzzle. The more bones you find and identify, the more complete your picture of the owl's diet becomes.
Once prey species are identified, this information can be used to construct a **food web** — a diagram that shows the feeding relationships and **energy transfer** among multiple organisms in an ecosystem. Energy flows in one direction: from producers like grasses and seeds, through primary consumers like mice and voles, and finally to secondary consumers like the barn owl. Analyzing data from many pellets gives us a broader, more accurate view of how energy moves through the ecosystem and how the barn owl connects to the organisms around it.
Vocabulary
Term: food web
Definition: A diagram showing the complex network of feeding relationships and energy transfer among multiple organisms in an ecosystem.
Term: prey
Lab Type
Post Lab
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Teacher Notes
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Experiment Design
Research Question
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