Barn Owls (Tyto alba) are found throughout the temperate regions of the world. This worldwide range categorizes the Barn Owl as a cosmopolitan species. The Barn Owl traditionally lived and hunted in open grasslands and nested in large, hollow trees or caves. This still holds true today, but as man cleared land for agricultural use the Barn Owl has been able to adapt and expand its territory, taking advantage of the millions of acres now used for raising crops and grazing cattle. Even the man-made structures in these areas are often exploited by Barn Owls as nesting sites. These include lofted barns, silos, grain bins, fire towers, duct work in abandoned gins and factories, culverts, and occasionally even wells.
As with most other raptors (a collective term for all hawks, falcons, eagles, and owls), the Barn Owl feeds primarily on mammals and other birds. The types of mammals and birds that Barn Owls choose make their pellets ideal for classroom study. Favored among Barn Owl prey are the insectivores (shrews and moles), small rodents (mice, voles, and rats), and small birds (sparrows, blackbirds, and starlings). These prey animals all commonly thrive in the areas where Barn Owls live. This is because insectivores, small rodents, and many birds feed on the naturally occurring vegetation, as well as agricultural crops and insects that feed on these crops.
Barn Owls are masters at the art of hunting. Their nocturnal (night time) skills are second to none. They are specially adapted with large, saucer-like facial disks around each eye. These facial disks act like satellite dishes, concentrating light into the eyes and sound into the ears. Such physical characteristics allow Barn Owls to hear the footsteps of a tiny mouse under the leaves while flying overhead and spot a mouse nearly 100 meters away while in the pitch dark. This combination of low-light visibility and pinpoint accuracy in locating the slightest noise ranks Barn Owls among the deadliest of predators for mice, shrews, and other potential prey. To make matters even worse for their prey, Barn Owls have a special feather at the leading edge of each wing that allows them to quietly approach their prey. The edge of these feathers resembles a comb with short, soft teeth that filter the air going over the wing surface and prevent the wings from “whistling”. This gives the Barn Owls silent flight so that their prey never even hears them coming. The prey are then clasped with the Barn Owl’s feet which are modified into sharpnailed, clasping talons. The Barn Owl’s beak has a special notch in the upper mandible that fits over the spine at the neck of the prey. A quick pinch from the beak breaks the neck of the prey and the hunt is over.
Some large owls, like the Great Horned Owl (Bubo virginiana), feed on relatively large mammals including rabbits, skunks, and opossums. Great Horned Owls locate and capture prey in much the same way as Barn Owls. Once captured, these large prey are stripped of their flesh, much like we strip the meat from a chicken leg before eating it. Few bones are consumed, and those that are only represent a small portion of the prey animal’s skeleton. In contrast, the Barn Owl generally swallows prey whole. The entire carcass is swallowed head first, in one large gulp. When a Barn Owl swallows a rat, it is comparable to a 100-pound person swallowing a 25-pound ham in one bite! Barn Owls may do this 2-3 times each night. However, if smaller prey is being captured, the owl may feed more frequently.
Predators such as wolves and cougars chew their meals. This chewing grinds the bones so that they can pass through the digestive tract. Since owls do not have teeth, the bones of their meals cannot be ground up and passed. Instead, they are expelled in a much more intriguing way: Once swallowed, the owl’s meal passes through the esophagus and comes to rest in a glandular stomach where digestive enzymes break it down. Fleshy portions (meat, organs, and fat) are passed along through the muscular stomach for digestion. The indigestible parts (bones, claws, and hair or feathers) remain in the glandular stomach. Here they get mashed into a slick bolus that is then regurgitated. (Figures 1-3). This bolus is what we call a “pellet”. Since Barn Owls feed on small animals that are generally swallowed whole, their pellets contain complete skeletons and are ideal for classroom investigation. They also are invaluable for field biologists who study the dynamics of prey populations and their availability to other predators in a given area.
Most students will dissect pellets produced by Barn Owls. Pellets from this species are used for two reasons. First, the Barn Owl is often associated with man-made structures in agricultural regions, thus making the pellets more readily available. Second, the feeding habits of the Barn Owl generally produce pellets that contain complete skeletons, a must for classroom studies that will investigate not only food-web aspects, but also general and comparative skeletal anatomy.
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- Introduction to Owl Pellets Lab Activity - Regurgitated owl pellets contain the indigestible parts of their prey. By dissecting an owl pellet, students can identify the small animals that are prey for the owls. The pellets are steam sterilized, not fumigated, and individually wrapped.
Hoo Eats Who? Making an Owl Food Web Lab Activity - Students gain an overall perspective of owls’ diets and their place in the food web with this enjoyable activity. They arrange stickers of animals on a large piece of paper to create a food web and draw lines to show predator-prey relationships.- Investigation of Northwest vs. Southeast Owl Pellets Lab Activity - Using prey remains of owls from the northwestern and southeastern regions of the U.S., students identify and compare the raptors’ diets. They also construct a food web with the information they obtained. The owl pellets are sterilized and individually wrapped.
- Owls and Owl Pellets Reference Poster - Point out habits and characteristics of owls, and the contents of owl pellets, all featured on this unique, comprehensive poster. It’s an ideal supplement to lectures and a handy reference for students as they conduct owl pellet dissection investigations; the detailed prey identification key helps students recognize the materials they’ll find in their owl pellets.
Resource Manual for Owl Pellets - The various types of raptors, their hunting methods, nesting habits, and more are detailed in one comprehensive reference volume. Use the manual when working on owl pellet dissection; identify pellet contents with the illustrated dichotomous keys to skulls and other owl pellet materials, and diagrams of vole and shrew skeletal anatomy. It includes a thorough study of raptors’ eating habits, including prey consumption, digestion, owl pellet formation and content, and food webs. As an added benefit, the volume also includes clip art for you to utilize on your own worksheets, tests, and charts.- Owl Pellets Preserved Specimen - Approach the study of raptors and their hunting characteristics from an entirely different aspect. Owls regurgitate the indigestible remains of their meals; the regurgitated “pellets” contain the fur and skeletal parts of their prey. By dissecting the pellets and examining the bones and bone fragments, students learn about the small animals upon which the owls feed. Compare owl pellets from the Northwest with those of the Southeast to determine the differences in prey. Each WARD’S owl pellet is autoclaved and hand-tested to ensure sterility, making them safe for use in your classroom and lab.
- Owl Pellet Dissection Chart Set - This set of eight simple and effective charts, lend understanding to the characteristics of owls as well as provide guidance in the owl pellet dissection process. Each chart includes vivid illustrations and instructive information. Charts include the owl’s food web, a bone sorting chart, a pellet information chart, and skeletal diagrams of a shrew, bird, mole and vole.
- The Barn Owl: Introduction to Owl Pellet Labs Video - Careful examination of owl pellets leads students to discoveries regarding ecology, the food chain, and the nature of predators vs. prey. The bird’s habitats and habits can be learned by viewing this concise, instructional video, which is the perfect prelude to your owl pellet lab. Then, a young student demonstrates the procedure for dissecting a pellet, while a thorough voice-over narration comments on the action.
Owl Pellet and Common Prey Riker Mount - This Riker mount shows the skull and mandible of five different prey animals, together with an intact owl pellet and a partially eroded owl pellet. All specimens are labeled.
