The Barn Owl The barn owl is found all over America ------------------------------------- ------------------------------------- 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 Predator: hunt and kills ------------------------------------- ------------------------------------- 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 ------------------------------------- ------------------------------------- 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 ------------------------------------- ------------------------------------- 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 ------------------------------------- ------------------------------------- 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? ------------------------------------- ------------------------------------- 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

Indigestible Items

How long does it take? ------------------------------------- ------------------------------------- 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? ------------------------------------- ------------------------------------- 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 Small rodents Blunt snout and chunky bodies ------------------------------------- ------------------------------------- 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 ------------------------------------- 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 Smallest of all mammals Thick fur ------------------------------------- ------------------------------------- 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 ------------------------------------- ------------------------------------- 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 ------------------------------------- ------------------------------------- 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 ------------------------------------- ------------------------------------- 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”

Dissecting Owl Pellets ------------------------------------- ------------------------------------- Read the lab instructions carefully! Dissect the owl pellet Determine what prey the owl has eaten Put the skeleton back together again Answer the lab questions Throw everything away Wash your hands!