The Barn Owl -------------------------------------
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The barn owl is found all over America
Owls hunt in open fields and roost in old barns or open abandoned buildings
Nocturnal – hunt at night and sleep during the day
Carnivores: They only eat meat
Predator vs. Prey -------------------------------------
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Predator: hunt and kills
They prey on a number of species that live in open grasslands, farmlands, and marshes
Prey: voles, shrews, deer mice, bats, rats, small birds, and insects
Roosting -------------------------------------
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During the day: barn owls roost in trees, rocky cliffs, and building around farms.
They will build their nest and “sleep” during the day in dark places
Owl Pellets -------------------------------------
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Owl Pellets are the indigestible remains of food eaten by owls
Instead of being excreted with the other waste materials (poop), the waste is regurgitated.
Regurgitate: spit up
Owl Pellets -------------------------------------
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Owl Pellets are a compact mass of hair, bones, teeth, claws, bird’s beaks, and chitinous remains of insects (body shells)
Lots of birds regurgitate! Over 300 species of birds have been found to produce pellets
Where do they put it? -------------------------------------
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Indigestible materials (fur and bones) are compacted in the stomach called a gizzard
The gizzard presses it all together and then passes it to the proventriculus
The proventriculus is a storage pouch until the bird it ready to regurgitate
How long does it take? -------------------------------------
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An owl will produce an owl pellet after most meals
An owl will eat two to four times a day
It takes approximately 6.5 hours for an owl to digest its food and then regurgitate a pellet.
What does dissecting tell you? -------------------------------------
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Dissecting an owl pellet can tell scientists what kind of diet the owls are eating Feeding habits Conditions of the
ecosystem Identification of prey Owls swallow their food
whole, so their pellets contain entire skeletons that can be studied
Prey: Voles -------------------------------------
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Small rodents Blunt snout and
chunky bodies Their fur is soft and
dull grey Habitat – meadows,
dry plains, forests, and marshy areas
Omnivores: plants, seeds, nuts, insects
Active day and night
Prey: Deer Mouse -------------------------------------
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Small rodent Abundant in North
America Habitat: brush, under
trees, rocks Deer like coloring of the
fur: brown on top, white on bottom
Nocturnal: hunt at night Omnivores: plants,
seeds, nuts, berries, insects, human food
Population: Females can have a litter of 12 babies every 21 days! The babies will mature in 7 weeks and have babies too!!
Prey: Shrews -------------------------------------
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Smallest of all mammals
Thick fur Insectivores: eat
insects Habitat: hide in dense
(thick) vegetation (plants) near water and are seldom seen
They will hunt day and night
Dissecting Owl Pellets -------------------------------------
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The owl pellets have been autoclaved (cooked at high temperatures) and DO NOT contain any harmful bacteria or diseases
No gloves necessary Lab safety: Wash your
hands when finished with the activity
Dissecting Owl Pellets -------------------------------------
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Dissecting Method: Carefully pick apart
each pellet by hand Hair and feathers are
teased away from the bones
Lab instruments needed: dissecting probes, magnifying lens, paper towel, black paper
Dissecting Owl Pellets -------------------------------------
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A magnifying lens is necessary to examine the fine structures of teeth for final prey identification
Use the bone identification chart to determine the species of prey
Try to put the prey skeleton “back together again”
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