2021 Barn Owl Habitat, Habits, and Prey Teacher's Guide by Passport to Wildlife

BARN OWLS

Habitat, Habits & Prey

For Teachers and Students

Owl Pellet Dissection Lab Inside!

Thank you for starting an adventure in learning with the Habitat, Habits, & Prey instructional guide! We hope it will enhance your exploration into prey and predator relationships, conservation, and stewardship of owls and other species. Owl Brand Discovery Kits (OBDK) encourages the duplication of the guide for educational purposes and you do not need permission to do so. No part of this publication may be reproduced or transmitted in any form for resale purpose or by any means, electronic or mechanical, including photocopy, recording, or any informational storage and retrieval system, without permission in writing from OBDK. Contact Us Email: chris@obdk.com Mail: OBDK.com, 3029 69th Ave W, Suite H, University Place WA 98466 Copyrighted Material. All rights reserved. 2021 OBDK. OBDK is a registered trademark of Owl Brand Supply Company. Printed in the United States of America.

ls Barn Os w and Prey

Habitats, Habit Table of Contents

Let’s Get A Couple Things Straight......................................................4 How to Use This Guide...........................................................................6 MEET THE BARN OWL & RELATED SUBJECTS.......... Page 8 Why Do We Explore Owls?....................................................................8 Which Owls Do We Explore?............................................................... 10 Owl Basics............................................................................................... 11 What Do We Learn From Great Horned Owls?................................. 13 Why Study the Barn Owl?................................................................... 15 Barn Owl Pellet Dissection?................................................................ 15 HABITAT............................................................................ Page 16 Where Do Barn Owls Live?............................................................. 16 Barn Owls & Vantage Points?......................................................... 18 HABITS.............................................................................. Page 20 The Perfect Homemaker................................................................ 20 The Perfect Hunter...........................................................................22 Eyes of a Hunter...............................................................................23 Locating Prey Through Hearing.................................................... 24 Talons: An Owl’s Hungry Grasp.................................................... 26 PREY.................................................................................. Page 28 Prey & Reproduction....................................................................... 28 Variety of Prey................................................................................. 28 What Animal Preys on Barn Owls?.............................................. 30 What Can We Do To Save Barn Owls?.......................................... 31 Helping Out Owls Together You and the HOOT Project Make a Difference!...........................32 Owl Pellet Dissection Lab................................................ Page 34 Pellet Formation Chart.........................................................................36 Exercise 1 – Constructing a Food Web . ........................................... 38 Exercise 2 – What’s on the Outside? ................................................39 Exercise 3 – What’s on the Inside? .................................................. 40 Exercise 4 – Bleaching & Mounting Bones to the Charts . ............ 41 Owl Brand Discovery Kit Bone Identification Charts..................... 42

Let’s Get A Couple Things Straight... It’s Not Poop! Would you believe that this is the most common misconception among children and adults alike when discussing owl pellets? It’s true! As my team promotes the benefits and fun of dissecting Barn Owl pellets, it seems that many people, including teachers, have the same initial reaction—”Gross...owl poop?” It’s a surprisingly great opportunity to engage with people about the anatomy and unique digestive characteristics of Barn Owls, why we study them, and how this basic science experiment can lead to fascinating findings and outcomes. Our Owl Brand family continued to impact classrooms by developing an exciting, no obligation website of cool resources for teachers and students called Kidwings.com. We introduced Kidwings 2.0 in 2016 and are releasing 3.0 to include expanded sections on other iconic apex predators such as bears, wolves, mountain lions, and more! We also began a short film series titled Kidwings Explores: Barn Owls and Kidwings Explores: Wolves -- all made possible by terrific fans and family members, including teachers and students from around the world! In early 2021, our team was excited to build a better Virtual Pellet in the form of the Sherlock Bones Mystery Lab. This free online tool is the perfect way to introduce young and old alike to owl pellets. One can’t mistake the importance of this lesson after playing the game.

Our websites continue to expand and work together to introduce and inspire young people while encouraging educators around the world. The following websites were created with you in mind. You will find movies, videos, articles, and even an online pellet so that everyone in any place can enjoy our labs. Boost Your Classroom With These Websites

• • • •

Online Film Labs about Raptors www.kidwings.com Learn about Canines, Carnivores & Conservation www.wolfcenter.org Fun & Affordable Anatomy Focused Labs www.obdk.com The Mysterious Missing Mouse Virtual Pellet www.SherlockBonesMystery.com

Children hold the promise of the future in their hearts and minds. Together, we can ignite their curiosity for learning. Whether your learning is in the classroom, a living room, or the wild, we’re grateful to be part of your inspiration to students around the world.

Chris Anderson, President Owl Brand Supply Company Owl Brand Discovery Kits Email: chris@obdk.com

Kidwings

The HOOT Project

How to Use This Guide Best Practices for the Habitat, Habits, & Prey Guide Our goal is to connect places of learning to students around the world. Our websites and print resources are available for your use in a wide variety of way and we have some suggestions on how to maximize their use! Here is the flight pattern we recommend to enhance your owl pellet dissection lab. View the Videos. Before dissecting your barn owl pellets, have your students view our films, Kidwings Explores Barn Owls, beginning with Home Sweet Home and ending with Owl Rescue. These short videos are about 8 minutes in length and created to add context to your experience by introducing students to barn owl habitats, adaptations, and important visual connection.

Dissect a Virtual Pellet with Sherlock Bones & Sir Whetson. Sherlock will guide your students through an online game that will introduce students to owl pellet dissection as this narrated game teaches the names of important prey anatomy. This important step is instrumental in preparing students for the lab with a genuine owl pellet. Other considerations include having your students report back to you via the “Share” options upon completion. You can click on Sherlock Bones or find the game in the iTunes and Android marketplaces. Assign Chapters of the Habitats, Habits, & Prey Guide. This guide is broken up into several chapters that make a great foundation for learning for students. Assigning 1 or 2 chapters per week leading up to the lab will enhance your dissection experience and provide important details about barn owls, why we study them, why it is important to working to save them, and builds an important base of understanding for other subjects you may enjoy down the road. Other Terrific Resources. Our resource are not limited to OBDK. com! We publish articles regularly at WolfCenter.org/C3 on the subjects of Canines, Carnivores, and Conservation as well as a classroom, one that is in English and Spanish! In addition, you can find a nest full of resources at Kidwings.com that cover a wingspan of information about birds and other critters.

Meet the Barn Owl

Meet the Bar n Owl & Related Subjects Why Do We Explore Owls? At night we sometimes hear owls without catching a glimpse of them. Owls are mysterious to us day-walkers and, let’s face it, this piques our curiosity. There are reasons for our cryptic curiosity, and these reasons play into owls’ mythological presence in art, literature, and folklore. There are also scientific reasons behind their mysterious behavior —behavior that helps ensure their survival in a world of predators and prey. Throughout time, certain animals have captivated the human imagination. Tales of these iconic animals are told around campfires and in places of learning — even showing up in pop culture via movies, cartoons, advertising and gift shop merchandise. Predators in particular – be they lions, bears, wolves or owls —hold a distinct fascination for people of all ages. We are drawn to these mysterious animals. We have much to learn about these peculiar creatures. Understanding owls’ ecological role in our present world and understanding the value they bring to both urban and rural environments is of vital importance. Kidwings hopes to broaden current understanding of predators by taking a scientific approach to looking at owls. The study of owls can lead to a raised awareness of critical environmental issues, such as

Meet the Barn Owl

how we approach nature and how we live within a balanced ecosystem in a way that ensures future generations will enjoy the same flora and fauna that we presently enjoy. The study of owls can also yield practical applications. For example, one study, reported in the Journal of Vision (July 2011), demonstrated the use of owls as a model to explore the advantages and mechanisms of stereo-vision (stereopsis), a capability they share with humans. [Source: Owls see in stereo much like humans do, Robert F. Van der Willigen, Journal of Vision, June 2011, Disparity sensitivity in man and owl: Psychophysical evidence for equivalent perception of shape-from-stereo, Robert F. van der Willigen, Wolf M. Harmening, Journal of Vision, January 2010] Other more common owl studies relate to owl pellets. Owl pellets are very important to science because, when we study the components of an owl pellet, we find bones of the animals that the owl has eaten. If a scientist finds small rodents and bats, it is possible to learn what species of prey live in a particular area. If a scientist picks up pellets regularly, then he or she can observe owl prey selection over time. The growth or decrease of the owl prey populations is indicated by the bones in the owls’ pellets. Studying the abundance of these prey animals reveals critical information about potential pests (mice, voles, bats, birds, etc.) for farming communities and also provides information about diseases and

Meet the Barn Owl

their vectors that are present in an ecosystem. The main subject of this annual publication is Barn Owl ecology in relation to the bird’s habitat, habits and prey selection. Information gathered in this publication relates to food webs while considering regional differences in Barn Owl subspecies. Kidwings strongly believes that dissecting owl pellets can help students develop better investigative skills, as these explorations encourage students to develop cognitive thinking skills in a fun and interesting manner. This guide is divided into three sections: Habitat, Habits, and Prey. “Habitat” will reveal facts about where and how barn owls choose to raise their young and also includes information on how owls adapt to various niches. “Habits” will focus on some unique qualities and characteristics of the Barn Owl, including their special digestive system which makes them ideal to study. “Prey,” the final reading section, will focus on the relationship barn owls have with their food sources. After completing Barn Owls: Habits, Habitat & Prey, readers will enjoy a wealth of science-based knowledge that will deepen classroom interest in this exciting and fascinating subject. As teachers and students move into the lab portion of this comprehensive guide, each will be equipped with in-depth information that propels our understanding of Barn Owls, their habitat, habits and prey. Before we begin our exploration together, it’s important to identify exactly which owls are most prolific and available to learn from.

Which Owls Do We Explore? The most common owl we explore for educational purposes is the Barn Owl (Tyto alba). There are two good reasons for this exclusivity. One is the availability of the subject, as the Barn Owl lives on nearly every continent (with the exception of Antarctica) and has a comparable diet across the globe. Second, unlike some of their cousins, Barn Owls have a unique method of ingesting their prey whole

Meet the Barn Owl

and regurgitating a pellet that is conveniently packaged as a tightly compacted ball of fur, bones, and other material not needed for nutrition. Their voracious appetite is matched only by eager students wanting to learn about their diet! Another important owl we study, mainly because of the bird’s proximity to the Barn Owl in North and South America, is the Great Horned Owl. Great Horned Owls do not lend themselves as well to our investigations due to differences in how they ingest and digest their food. That being noted, as we work with students across the world, we find a growing interest in the more challenging study of the Great Horned Owl.

Owl Basics If you asked someone what sound an owl makes, most people would say, “Hoo!,” and that’s not necessarily incorrect. But the vocalizations various owls make distinguish them as uniquely as their appearances do. For example, a Barn Owl does not produce a “hoo,” but rather the “screech” that has been the source of many mythical stories told on dark, spooky nights. Screech Owls, on the other hand, rarely screech but rather have a staccato-like succession of hoots. The Great Horned Owl is known distinctly for its “hoo!” and is one of the most commonly heard owls in the wild. While the Barn Owl is present on nearly all continents, the Great Horned Owl is the most common owl of the Americas. It has feather tufts that can make it somewhat cat-like in appearance. These horns, referred to as “tufts,” easily distinguish it. Great Horned Owls are highly adaptable birds. Their habitats range from suburban areas, to forests, farmlands, and to places

Meet the Barn Owl

where there is an abundance of prey. Northern subspecies can migrate in winter months but prefer moderate climates where they can live for as many as 5 to 15 years. Barn Owls are cavity dwellers by choice, selecting tree holes, stumps, caves and abandoned structures. Sometimes they take the unoccupied nest of a Barn Owl or other large bird. There have been instances where our staff has seen a Barn Owl living in one end of a large structure and a Horned Owl at the other end. However, this is a rare occurrence because Barn Owls are frequently killed and preyed upon by Horned Owls. For the most part, Great Horned Owls are monogamous, meaning they choose one mate for life. Both parents will incubate their eggs, which can range from one to five eggs (2-3 eggs on average). A group of eggs laid during the same period is known as a “clutch.” Great Horned Owls are fiercely protective parents and known to attack humans who they perceive to be a threat.

Great Horned Owls share the digestive system common to all owls. Similarly, Horned Owls will consume their prey whole when it is a smaller animal. This is followed by the regurgitation of a pellet that includes the fur, bones, and other parts of their prey not required as nutrition. They are known to prey on a huge variety of creatures, including raccoons, rabbits, squirrels, domestic birds, falcons and other owls. Great Horned Owls regularly eat skunks, and are one of the few animals with such an appeThe Great Horned Owl tite. They sometimes hunt for smaller game is the only animal that by standing or walking along the ground. regularly feasts on skunks! These owls have even been known to prey upon wandering cats and dogs. Because Great Horned Owls have a more diverse diet that includes small mammals and larger rodents, they often need to break up the bones of an animal in order to digest it. For this reason, it can be more difficult for the inexperienced eye to identify prey in a Great Horned Owl pellet. Like other birds of prey, Great Horned Owls

Meet the Barn Owl

GREAT HORNED OWL facts... To hear a great selection of owl sounds, Owl Brand recommends visiting Owl Calls & Sounds at this website: www.owlpages/sounds

are efficient nighttime hunters that strike from above and use their powerful talons to kill and carry animals several times heavier than themselves. Great Horned Owls are largely nocturnal, so they can be difficult to spot. But in the dark after sunset, or just before dawn, they can often be heard vocalizing with their well-known series of “Hoo hoos,” and can even be seen plucking at roadkill on country roads. Unlike Barn Owls which typically weigh under a pound, Great Horned Owls can weigh up to five pounds and are considered one of the heaviest and largest of the owls in the Americas.

What Do We Learn From Great Horned Owls? As an apex predator, Great Horned Owls have few natural enemies, but observing their habitat and hunting behavior reveals other reasons why they have such high survival rates. What natural enemies they do have are most threatening during the period when the female has eggs. Owl eggs make delicious meals for raccoons and even buzzards.

Meet the Barn Owl

GREAT HORNED OWL facts... The Great Horned Owl considers other owls and raptors a nutritious part of their daily diet. One bird that likes to give Great Horned Owls grief is the crow. They like to mob owls and attempt to outnumber them. It’s for good reason, too, as crows are tasty morsels for a Great Horned Owl.

Great Horned Owls are highly adaptable birds in that they will relocate or migrate to ensure their survival, as do most owls. If a forested area presents a threat by predator or lack of available food, they will move and reside in a manmade structure. We learn a lot of lessons from Horned Owls by studying their prey and there is no better way to identify prey than by dissecting owl pellets, the regurgitated remains of their diet.

Because Great Horned Owls break the bones of their prey in order to digest it, they will occasionally produce a chalky and porous pellet that resembles a grey ice cream cone. When picked up, it can easily fall apart because the chalky bones have been crunched up during the digestion process. Identifying the prey of the Great Horned Owl is an investigative puzzle, but a fascinating lesson nonetheless.

Meet the Barn Owl

Why Study the Barn Owl? Barn Owls have fascinated humans for many generations and for many reasons. From American Indian stories to Celtic myths to ancient hieroglyphics, the mysterious habits of the Barn Owl have inspired storytellers worldwide for centuries. Perhaps you have ventured out into the night and heard the banshee-like cry of a Barn Owl; or maybe you’ve been frightened by an overhead shadow falling across your path, disappearing as quickly as it appeared. Don’t be alarmed if you encounter these mysterious creatures. You have probably been a witness to one of creation’s most interesting nocturnal (night) hunters.

You now have your own dark and scary tale!

Barn Owl Pellet Dissection One of the most common scientific methods used to study and compare the diets of Barn Owls is owl pellet dissection. Because of the abundance of Barn Owl pellets throughout the world, these are inexpensive educational tools that also contain rich learning opportunities. The Barn Owl’s unique digestive system creates a pellet using undigested portions of its prey. The pellet is then orally expelled. If you find pellets scattered below a tree, look up carefully, you may see an owl roosting (resting on a fixed horizontal object) or nesting! In the “Prey” section of this booklet, we will go into more detail about the uniqueness of the Barn Owl diet and what makes it a valuable resource in science classrooms.

Habitat

HABITAT hab·i·tat habə·tat/ noun The natural home or environment of an animal, plant, or other organism.

hat makes Barn Owls unique and why are they a valuable species from which to learn? In this section, we’ll discuss some of the physical characteristics and behaviors that make Barn Owls such interesting members of the bird world, and we’ll explore owls’ important roles in pest management and science education.

Where Do Barn Owls Live? The Barn Owl is found nearly world-wide in countries with moderate climates — conditions where harsh temperatures and conditions do not present a threat to their reproduction process. Overall, Barn Owls are plentiful in number, useful in rodent population control, and a vital member of many different ecosystems. Studies involving Barn Owls reveal vital information to scientists, biologists, and students studying food webs, habitat, and other ecological topics.

Habitat

Barn Owls are able to live in a variety of homes and places. In our experience, we have found them living everywhere from rock crevices in the Lake District of Northern England to palm fronds along the Southern California coastline. Before barns were constructed across the Americas, the species used trees, bored-out holes in high river banks and any available place that kept their nests and roosts safe from predators. While their name is “Barn” Owl, they are in fact more appropriately recognized by biologists as Tyto alba, cavity dwelling owls. They make good use of natural and man-made environments and turn them into clever niches. Cavities are defined as holes and caves. When it comes to choosing nesting sites, these owls are not too picky. In a natural setting, they will inhabit tree cavities, crevices between the fronds of palm trees or small caves in cliffs and holes in river banks. They readily accept artificial cavities as well and have been found to nest in any snug, quiet enclosure ten or more feet off the ground. These might include rafters, openings between bales of hay, attics and unoccupied rooms in the upper stories of buildings. Other suitable nesting sites may be barrels, steel and plastic drums, and speciallydesigned nesting boxes. As humans populated landscapes in

Habitat

natural Barn Owl habitats, the species adapted and made good use of buildings, including grain silos, barns and other structures that served as protection from climatic elements. There are certain characteristics of an ideal Barn Owl habitat. These habitat traits typically revolve around two key functions which are closely connected in purpose: food and reproduction. Most animals will reproduce as abundantly as their food source allows and the Barn Owl is no exception. The choice of an ideal roosting and nesting place is not only ideal for their survival but essential to their species’ population.

Barn Owls & Vantage Points Before the construction of man-made habitats like silos, barns, and church steeples, Barn Owls navigated the landscape for safe and advantageous nesting and roosting sites. We call places that lend themselves to prime hunting and safety “vantage points.” Take a look at the photo at the top of the facing page. It shows something known as “whitewash.” This is a birder’s first sign that a Barn Owl may reside there. What makes this type of place ideal for any bird of prey is the way it sits above an open field or meadow. This field will likely supply year-long food for several Barn Owl families living in the pictured rock formation.

Habitat

If you ever hike below rocky vantage points, keep your eyes on the ground. If you locate a “bone-yard” you can probably look up and find a nesting site for owls—in this case, a Barn Owl. Around the base of these rocks, you’ll likely find owl pellets, feathers, bones and masses of fur. If you look beyond the rocks, however, you will almost always find a field of grain, grass, or other food source for the Barn Owl’s principle prey, the vole. The Barn Owl’s home almost always includes this central characteristic. Another important characteristic for a Barn Owl habitat is the direction the nest faces in relationship to weather, including wind, sun and rain. The most ideal habitat is one that is well-protected from these elements so that the offspring get an ideal start in life without weather presenting an obstacle to their survival. Additionally, the sun provides an incubator effect when the nest is facing the correct direction. The last important characteristic for an ideal habitat is safety from other predators. Because a number of other birds and many mammals find eggs to be a tasty meal, the female owl will choose a location that makes it difficult for these predators to access her chicks. In addition, she will choose a place that offers quick escape in case these predators desire to make a meal of her!

Habits

HABIT hab·it \ ’ha-bət\ noun A behavior pattern acquired by frequent repetition or physiologic exposure that shows itself in regularity or increased facility of performance,

arn Owls are not only stunning birds to see, with their unique facial disks and coloring, but they also possess many characteristics that make them interesting to study. From choosing the ideal nest in which to lay their eggs to the lethal efficiency of their hunting prowess, Barn Owls’ place in the skies above us is secured by some remarkable features.

The Perfect Homemaker Barn Owls are able to choose homes that meet their specific needs for safety, access to food, and as much shelter from weather elements as possible. A typical Barn Owl nest consists of a safe platform where eggs can be laid in a small area, decorated by debris such as feathers and pellets that the female has vomited around the nest. Additionally, the male will come and begin stacking up food around the nest that the female owl will consume until the eggs have hatched. Then she will tear pieces of prey to feed her young. When they are old enough, the young chicks will begin ingesting prey whole. Since they have a tremendous reproduction capacity, the owls need to eat constantly. In some regions, it is possible to observe them nesting year-round, raising as many as four clutches. Barn Owls in the most populated areas of the Southwest and Northwest United States begin selecting nesting sites in December or January. The nesting season is typically from February to May, with peak hatches in April.

Occasionally, new nests may be started as late as March.

Habits

By July, most nest sites have been vacated by the young, who have fledged (flown) to nearby trees or buildings for the final stages of their development. A second nest for the season with the same mate may be started in the same or in a different location. The owls may have different mates during subsequent mating seasons. Males may have two mates at the same time, nesting as much as a mile apart during a single season if there is a shortage of males in the area. The clutch size varies, and commonly has as many as eight eggs. Up to 15 eggs have been seen in several nests. One case in Texas records an extraordinary clutch containing 27 eggs in a single nest box. Even more amazing is that all the owls survived beyond the juvenile period, 18 weeks. The hen (female) lays one egg every two or three days and begins incubating immediately after the first egg is laid. The eggs are incubated for 30 to 33 days each. The chicks hatch in the order in which they were laid, which results in siblings with as much as a two week age difference. It is always an interesting sight to see a more developed owlet with a younger sibling that just hatched from its egg. During the incubation period, the female remains on the eggs almost continuously. She is fed by the male, but nevertheless, loses much of her stored fat. While nesting, the hen often becomes skittish and restless. During this time she is reluctant to leave the nest unguarded. If she is forced to flee in a state of panic and fear, she may abandon the nest. For this reason, it is wise not to disturb a nesting hen during the early part of the breeding season in order to protect the unhatched young owlets.

Habits

A parent frightened away from the nest after the incubation period will instinctively return to the nest to continue caring for his or her young. However, during the day in April or May the young owlets are likely home alone. The parents will be found roosting in a quiet location nearby. Having worked all night hunting to feed the hungry chicks, they no doubt want some peace and quiet.

While an adult Barn Owl may eat one rodent per night, each owlet may eat between two to five, depending on the size of the chick and the size of the rodent. During the course of the breeding season, as many as three thousand rodents and small birds may be consumed by the parents and their family of five owlets. If all goes well, young owls will have made their first flight to a nearby tree or building at approximately eight weeks of age. At this stage they begin final preparations for life on their own -- mastering their skills of flying and hunting, while learning how to avoid predators like the Great Horned Owl. The parents continue feeding the young for another four to six weeks. At approximately 18 months of age, the young will begin the reproductive process themselves.

The Perfect Hunter As hunters, Barns Owls are well-adapted creatures. If you are lucky, you might be fortunate enough to see one in flight, but it is doubtful you will hear the flapping of its wings. Unlike the noisy flight of the pheasant, pigeon or duck, an owl’s extraordinary light body weight, wingspan, and feathers are uniquely designed to render them almost silent in flight. Barn Owls have the ability to fly silently and, compared to other large bird species, they have the reputation for being the most stealthy. There are reasons for that! The leading edge of an owl’s wing has feathers covered in small features called hooks and bows that break up the flowing air

Habits

into smaller micro-turbulence. These smaller areas of turbulence roll along the owl’s wings toward the trailing edge, which is made up of a flexible fringe that breaks up the air further as it flows off the trailing edge, resulting in a larger reduction of aerodynamic noise. Remaining noise that would be noticed by an owl’s prey is absorbed by velvety down feathers on the owl’s wings and legs. These soft feathers absorb high frequency sounds that most prey, as well as humans, are sensitive to. These features enable owls to remain undetected when they fly. It’s believed that the wing’s serrated leading edge is most effective at reducing noise when the wing is at a steep angle—which would happen when the owl is close to its prey and coming in for a strike! Mice, shrews, voles, rats, moles, small birds and insects rarely know what hit them when they become the main item on the menu of the Barn Owl. The Barn Owl flies differently when hunting during the daylight hours. This generally happens only when it is feeding its young.

Eyes of a Hunter While many people believe the Barn Owl is blind during the day, it actually has eyes that are well equipped for diurnal (daytime) hunting. The owl has a muscular iris, designed to respond like an automatic shade or curtain. This feature allows just the right amount of light to pass through the cornea or window of the eye, then through

Humans use muscles to move their eyeballs. The large eyes of an owl do not move within the eye socket. Instead, the owl rotates its head to observe the world around it, as if it were looking through a pair of binoculars.

Habits

a transparent lens and back onto the retina. They have far better eyesight than humans do. With plenty of light, Barn Owls found hunting during the day are able to locate their prey by sight from great distances, and to glide in for the kill.

Locating Prey Through Hearing Barn Owls have a highly-developed sense of hearing, thought to be 35 to 100 times more sensitive than our own human hearing, allowing them to hunt in almost comCompared with other birds of prey, the plete darkness. They can hear wing tips of an owl are much softer; this enables it to fly silently. squeaking, scratching or rustling through the dirt, leaves, or grass and can pinpoint the location of that sound in a second and then align their beak towards the location of their prey. Taking off from a vantage point, the Barn Owl flaps its wings silently, while swinging its feet back and forth. Then, just before its head collides with the ground and the unsuspecting prey, the owl throws its head back, thrusts its feet forward and sinks its razor sharp talons deep into the body of the prey. Because owls are typically active at night, they have a highly-developed auditory (hearing) system. The ears are located at the sides of the head, behind the eyes, and are covered by the feathers of the facial disc. It should be noted that tufts resembling ears on some species like Great Horned Owls, are not ears at all, but simply display feathers. An owl uses its unique, sensitive ears to locate prey by listening for the slightest movements through leaves, foliage, or even snow. When the owl hears a noise, it is able to tell the direction because of the minute time difference in which the sound is perceived in the left and right ear.

If the sound was to the left of the owl, the left ear would hear

Habits

it before the right ear. The owl then turns its head so the sound arrives at both ears simultaneously - then it knows the prey is right in front of it. Owls can detect a left/right time difference of about 0.00003 seconds—that’s 30 millionths of a second! An owl can also tell if the sound is higher or lower by using the asymmetrical or uneven ear openings. In a Barn Owl, the left ear opening is higher than the The asymmetrical nature of owls’ ear location on their head gives them right - so a sound coming from below amazing accuracy in locating prey. the owl’s line of sight will be louder in the right ear. The translation of left, right, up and down signals are combined instantly in the owl’s brain, and create an image of the space where the sound source is located. Studies of owl brains have revealed that the medulla (the area in the brain associated with hearing) is much more complex than in other birds. A Barn Owl’s medulla is estimated to have at least 95,000 neurons - that is three times as many as a crow. Once the owl has determined the direction of its next victim, it will fly toward it, keeping its head in line with the direction of the last sound the prey made. If the prey moves, the owl is able to make corrections mid-flight. After closing in on the prey, the owl will bring its feet forward and spread its talons in an oval pattern, and, just before striking, will thrust its legs out in front of its face and often close its eyes before the kill.

What makes an owl especially stealthy is its remarkable ability to turn its head 270 degrees, meaning by turning the head left and right, there’s no view that is out of the owl’s vision.

Habits

Talons: An Owl’s Hungry Grasp While the auditory and visual capabilities of the owl allow it to locate and pursue its prey, the feet and beak of the owl do the final work. An owl kills its prey by using its feet to crush the skull and knead the body. A Barn Owl’s feet are tipped with razor sharp claws called talons that not only keep the prey from escaping, but will kill smaller prey and help the owl hold onto larger prey. The crushing power of an owl’s talons varies according to prey size and type, and by the size of the owl. By comparison, the small, partly insectivorous Burrowing Owl (Athene cunicularia) has a grasp suited for catching insects and smaller prey while the larger Barn Owl (Tyto alba) has a greater force to grab its prey. One of the largest owls, the Great Horned Owl (Bubo virginianus), needs nearly 5X the talon strength to keep its significantly larger prey in its talons. An owl’s claws are sharp and curved. The family Tytonidae have inner and central toes of about equal length, while the family Strigidae have an inner toe that is distinctly shorter than the central one. These different characteristics allow efficiency in capturing prey specific to the different environments they inhabit.

Habits

NOTES:

Prey

PREY prā/ noun An animal that is hunted and killed by another for food.

arn Owls have a very diverse diet. This means they have a broad selection of prey available, particularly in certain seasons. Pellets collected in various seasons will produce the bones of some of the animals shown below. There are some animals, such as small rodents, that are present in the diet all year long, but other migratory animals and insects only present themselves as a prey source during certain times of the year. Many of these prey are pests to farmers, so the Barn Owl is a welcome member of most farming communities as a natural pest controller.

Prey & Reproduction Many animals reproduce according to prey availability. In temperate climate areas where farming is common, it is not unusual to see three and four clutches of Barn Owls in a given year. Our team has observed a Central California female leaving her nest to join the male in bringing food back to her nest while the same male doubletimes with another nested female with eggs. The male’s central role during nesting season is to keep the nest(s) stocked with food so that the young can quickly develop a taste for the nutritional prey they need for survival. Because prey is ample, the overall owl population will benefit as more owls survive at a young age due to their father’s ability to supply enough food.

Variety of Prey Barn Owls have a voracious appetite. During certain times of year, they have abundant prey available. Depending on the region in which they live, the owls will have a broad choice of insects, birds, rodents, and even snakes, bats and frogs. The season that offers the most variety of prey is typically spring. During spring, while other animals are nesting and producing offspring, there are higher popula-

Prey

2 10

5 20

9 14 7

3 11

19 4 1

21 12 22

PREY KEY 1. Voles 2. Mice 3. Rats 4. Centipedes 5. Beetles

6. Red-winged Black Birds 7. Arctic Terns 8. Caterpillars 9. Chickadees 10. Bats

11. Squirrels 12. Sparrows 13. Moths 14. Lady Bugs 15. Moles 16. Grasshoppers

17. Rabbits 18. Muskrats 19. Skunk 20. Crickets 21. Perch 22. Crayfish

Prey

tions of animals and insects available. Barn Owls will often prey on their staple food source, the vole, which typically represents about 80% or more of their diet. The remainder of the Barn Owl’s diet during this season will include insects such as grasshoppers, beetles and moths and, sometimes, other birds, including small-billed black birds and cliffswallows. In drier climates, the Barn Owl has even been known to consume snakes and scorpions! Voles remain the most common food as the season changes to summer. As the nests of migrating birds (such as cliff-swallows in the Western United States) become vacated, the owl turns its attention to prey found in fields. This includes small rodents, gophers, rats and a variety of insects. It is always fascinating to find exoskeletons in owl pellets that reveal a wide variety of insects, most commonly grasshoppers, beetles and even spiders. It’s been observed by Marc Trueb, an avid Barn Owl pellet collector from Oregon, that moles surrounding and in a nest are often times not consumed as we previously thought. We’ve noticed this same behavior in spite of experts citing moles as a food item for Barn Owls. Our team has concluded that the rodent, while it can be consumed, is placed in the nest to either deter predators or be used as further insulation of the nest, since smell is apparently not a homemaking priority!

What Animal Preys on Barn Owls? Predators of the Barn Owl include opossums, raccoons and similar carnivorous mammals, as well as eagles, larger hawks and other owls. The Great Horned Owl in the Americas and the Eurasian

Prey

Eagle-Owl are noted predators of Barn Owls, though there is little evidence for predation on other wild birds by Great Horned Owls. An exception to that observation occurs when there is competition for nesting sites. When disturbed at its roosting site, an angry Barn Owl will lowers its head and sway it from side to side. The head may also be lowered and stretched forward and the wings drooped while the bird emits hisses and makes snapping noises with its beak. A defensive posture involves lying flat on the ground or crouching with wings spread out. Barn Owls are also hosts to a wide range of parasites. Fleas are present at nesting sites and, externally, the birds are attacked by feather lice and feather mites which chew the barbules of the feathers and are transferred from bird to bird by direct contact. Blood-sucking flies such as Ornithomyia avicularia are often present, moving about the owls’ plumage. Internal parasites include the fluke Strigea strigis, the tape worm Paruternia candelabraria, several species of parasitic round worm and spiny-headed worms in the genus Centrorhynchus. While predators come from the surrounding environment of the Barn Owl, there are human-caused threats as well. These include land development that encroaches on natural hunting grounds and insecticides that diminish populations. The lack of knowledge about Barn Owls and the value they bring to farming and ranching communities can potentially hurt Barn Owl populations.

What Can We Do To Save Owls? Saving owls is very simple. The most important step to saving owls is to respect their natural environment by avoiding their nests during reproductive seasons. Through Kidwings’ HOOT Project, we can make a significant difference in the lives of owls with thoughtful conservation that not only helps the owl, but helps farmers who are plagued by pests!

The HOOT Project

Helping Out Owls Together You & The HOOT Project make . a difference! Conserving Owls is Good Science! Owl conservation has many beneficial aspects and outcomes. A sustained and focused conservation program promotes good stewardship, good farming practices, and it is good fun! Kidwings has enjoyed a long history of rescuing birds of prey and actively endeavors to improve the safety and welfare of birds of prey that consume pests that result in unnecessary farming costs---which makes our food cost more! Kidwings’ Helping Out Owls Together Project, affectionately known as, The HOOT Project, is the perfect program allowing you to make a difference. 1. Good Stewardship. As responsible citizens of our respective communities, we are entrusted to be good managers of our resources. Encouraging species survival is part of this important responsibility. Helping owls by providing nesting boxes offers Barn Owls protection from natural predators. This encourages healthy numbers of Barn Owls, Nature’s most effective form of natural pest control. 2. Good Farming. Helping owls thrive promotes sustainable farming practices and helps out farmers’ bottom line costs. The cost of pesticides increases every year and adds expense to efficient farming techniques. Nesting boxes encourage strong Barn Owl communities, which prey on rodents, insects and a variety of other pests that are harmful to crops. This saves farmers money and removes the need to use potentially harmful pesticides and chemicals. We can all agree, this is a win-win for everyone.

The HOOT project

3. Good Fun. Building nesting boxes is a great project for students, campers, scouts, or other community groups wanting to participate in good ecological stewardship. The process of building a nesting box and finding a suitable location for installation fosters a sense of responsibility in young people and ensures future generations of environmental stewards. Where Would I Hang a Nesting Box? Barn Owls like to be undisturbed and hidden from the view of humans and predators. If the owl can hide, it can easily become accustomed to almost any type of activity or noise and often will quietly observe human activity. Owls seem to prefer perching on wood rather than metal or stone. Well-used roost places are almost always where the owl can stay completely dry during wet weather. Given a choice of perching places, a Barn Owl almost always perches at least 10 feet above ground level. Good locations to hang boxes include high in trees on the edge of a hay or open field, in the high reaches of a barn, on the inside of a hay barn or shed, or on the outside of a structure facing an open field. Good Luck!

The HOOT Project is a great way to plug into great outcomes. Whether supporting a nesting box program in the areas the HOOT Project is working, or starting your very own HOOT project, our collaboration is making a difference. Learn more about The HOOT Project today at www.TheHOOTProject. org or at www. obdk.com. We’re Helping Out Owls Together!

Owl Pellet Lab

Owl Pellet Dissection Lab Barn Owl pellets have been chosen because these owls swallow small rodents and birds whole, and the resulting pellets generally contain the complete skeletons of their prey. Pellets begin forming within the digestive tract of an owl as soon as the prey is swallowed. Enzymatic juices break down the body tissues in the prey but leave the bony materials and hair or feathers undigested. Depending upon the prey eaten, the undigested portions may include beaks, claws, scales, or insect exoskeletons. This type of material has little nutritional value and must be “gagged” from the system. Predatory mammals such as bobcats and wolves have teeth to grind up bones and claws, and a digestive tract adapted to pass these ground parts. Owls, on the other hand, do not have teeth for grinding and cannot pass whole bone and claws through their digestive tract safely. Instead, these materials form a pellet that is surrounded with the hair or feathers of the prey consumed. The pellet is then orally expelled, or gagged, and the owl begins feeding again.

You will need the following items in order to conduct a Barn Owl Discovery Kit Pellet Lab: OBDK Bone Identification Charts Pencil Clean sheet of paper Two probes Tweezers Magnifying glass Paper towels Antibacterial wipes White glue Tub of water diluted bleach

To To To To To To

aid in prey identification record findings place extracted bones on loosen fur from bones extract bones away from fur identify bone type

To To To To

absorb excess water sanitize work station secure bleached bones to bone chart whiten extracted bones

Owl Pellet Lab

Scientists and teachers take advantage of this unique process by collecting these pellets and examining their contents. Since owls are not very selective feeders, these pellets can be used in a variety of instructional settings. The contents are a direct indication of what an owl has fed on. A one-year study of a particular Barn Owl revealed the following diet: 1,407 mice, 143 rats, 7 bats, 5 young rabbits, 375 house sparrows, 23 starlings, 54 other birds, 2 lizards, 174 frogs, 25 moths, and 52 crickets.

Owl Pellet Lab

Esophagus

Pellet Formation

Glandular Stomach Muscular Stomach

Intestines

Prey is positioned head-first in the beak.

Vent

Barn Owls do not have teeth to chew prey. Some large prey may be torn into smaller pieces before they are swallowed, but usually the Barn Owl will swallow them whole, in one bite. This is how Barn Owls eat shrews, mice, voles, and most rates. Since owls do not have teeth, the bones cannot be ground into small pieces that pass through the body. Instead, the prey is completely broken apart by chemicals in the stomach called enzymes. Along with pressure from the stomach muscles, this separates the fleshy portions from the bone and hair. Muscular parts in the stomach prevent the bones and hair from going any further, but they allow the digested, fleshy portions to enter the intestine. This is where the nutrients are collected and sent to the rest of the body. These nutrients include proteins, carbohydrates, vitamins, and water- all of the things that an owl needs to make energy and continue living.

2. Prey is swallowed and passes through the esophagus.

3. Prey enters the glandular stomach.

Owl Pellet Lab

Enzymes break down the prey and nutrients pass through the muscular stomach.

Some of the digested material that enters the intestine is not needed. This material, along with other waste collected throughout the body, is ejected from the vent. This pasty, white material is known as urea. It is very rich in nitrogen and is similar to urine in mammals, only thicker. The bones and hair that were left in the stomach must also be expelled. This is done through the mouth. Since the bones are no longer surrounded by flesh, they could get stuck in the throat. To prevent this, the stomach packs the bones in the hair. This slick, soft package is then regurgitated as what we call an owl pellet.

5. Nutrients are absorbed into the body from the intestine. Hair is pressed around the bones of the prey.

6. Waste is excreted through the vent.

The pellet is orally expelled.

Owl Pellet Lab

Constructing a Food Web Animals that eat other organisms for energy and growth are called consumers. There are three consumer levels found in a food web: primary, secondary and tertiary. Primary consumers are usually herbivores; they feed on photosynthetic products such as grass and seeds. Secondary consumers gulp down primary consumers. And tertiary consumers (carnivores) devour secondary consumers and are usually found at the top of the food chain. Here is an example of a food web including the Barn Owl.

EXERCISE 1: What other carnivores and herbivores would you add to the food web? Listing these others, construct a food web, with the Barn Owl at the top.

Owl Pellet Lab

What’s on the Outside? Before you dissect the pellet, examine the outside of the pellet for clues to where it was gathered. Pellets are collected from a variety of places around the country. Use the chart below to see if you can determine where the Barn Owl might have gagged your pellet.

What you might find: Milo Seeds → Grain → Dirt → Hay or Straw → Feathers → Pine needles →

Where owl gagged the pellet: Open sheds Grain elevator Cut banks and under trees Barns and hay sheds Man-made nesting boxes Under evergreen trees

EXERCISE 2: 1. On your piece of paper, write down the clues that might indicate where your pellet was gathered. 2. Can you identify other items stuck to the outside of the pellet?

Owl Pellet Lab

What’s on the Inside? EXERCISE 3: Label a clean sheet of paper for each pellet you dissect, for example, pellet one, pellet two, etc. Note: If you find that the pellets do not come apart easily, you can soak them in warm water to soften them. Using the probes provided, begin to loosen the hair of the owl pellet. As bones are uncovered, carefully remove them using your tweezers and place them onto a properly labeled sheet of paper. Take extra care to keep skulls intact and near the mandibles (see Owl Brand Discovery Kit Bone Identification Charts). Continue to extract bones from the hair of the prey. Once you have found all the bones, you can begin identifying them by comparing them to the illustrations on the charts provided.

Owl Pellet Lab

Bleaching & Mounting the Bones to your Owl Brand Bone Identification Charts

EXERCISE 4: 1. Keep the bones from each prey item separate by setting each set onto a separate clean (labeled) sheet of paper. 2. Place the bones into a tub of diluted bleach to whiten them. (Bleaching is Optional) 3. After the bones have been cleaned, set them onto a separate dry paper towel. 4. Using a magnifying glass and the Owl Brand Discovery Kits Bone Identification Charts, try to identify the type of skeleton that was found in your owl pellet. 5. Use white glue to attach the bones to the correct Bone Identification Chart.

Bone Identification

BIRD

CLAVICLE

MANDIBLE

SKULL (top view) ULNA FEMUR

FIBULA RADIUS TIBIO TARSUS

SCAPULA

PELVIS

HUMERUS

Bone Identification

MOLE

Scaparus orarius

MANDIBLE

CLAVICLE

FIBULA

HUMERUS SKULL (top view)

TIBIA FEMUR PELVIS

SCAPULA

Bone Identification

MOUSE Microtus

CLAVICLE

SKULL (top view) SKULL (side view)

FEMUR

FIBULA

RADIUS

TIBIA

SCAPULA

ULNA

HUMERUS PELVIS

Bone Identification

RAT

Microtus CLAVICLE

SKULL (side view)

FEMUR

FIBULA RADIUS TIBIA

SKULL (top view)

ULNA

HUMERUS

SCAPULA PELVIS

Bone Identification

SHREW

Sorex vagrans

MANDIBLE

CLAVICLE ULNA RADIUS SKULL (top view) HUMERUS

TIBIA FIBULA

FEMUR PELVIS SCAPULA

Bone Identification

VOLE

Microtus

CLAVICLE

FIBULA

TIBIA

MANDIBLE SKULL (top view)

RADIUS HUMERUS

ULNA

FEMUR PELVIS SCAPULA

Learn about

Barn Owls: Habitat, Habits and Prey Since 1996, the Owl Brand family has produced resources that are instrumental to teaching about the subject of Barn Owls, their habitat, habits, and prey. OBDK Explores Barn Owls: Habitat, Habits, & Prey is the 7th edition of the original Owl Brand Kits Discovery Guide and not only gaining in valuable information, but in popularity too! Choose from a selection of books, videos, online guides, and more at our other websites: Learn About Iconic Species like Owls www.Kidwings.com Find Science Labs . www.OBDK.com Learn About Saving Owls . www.theHOOTproject.org Meet Wolves Up Close . www.WolfCenter.org

Find us on Contact Us Email: chris@obdk.com Mail: OBDK.com, 3029 69th Ave W, Suite H, University Place, WA 98466

FB.com/Owl Bra nd FB.com/ WolfCenter FB.com/ TheHootProject FB.com/ SherlockBonesMysteryLab

2021 Barn Owl Habitat, Habits, and Prey Teacher's Guide

Articles inside

Exercise 4 – Bleaching & Mounting Bones to the Charts

Exercise 3 – What’s on the Inside?

Exercise 2 – What’s on the Outside?

Exercise 1 – Constructing a Food Web

Pellet Formation Chart

You and the HOOT Project Make a Difference

Eyes of a Hunter

What Can We Do To Save Barn Owls?

What Animal Preys on Barn Owls?

Talons: An Owl’s Hungry Grasp

The Perfect Hunter

Locating Prey Through Hearing

The Perfect Homemaker

What Do We Learn From Great Horned Owls?

Which Owls Do We Explore?

Where Do Barn Owls Live?

Barn Owls & Vantage Points?

How to Use This Guide

Owl Basics

Why Do We Explore Owls?

Let’s Get A Couple Things Straight