2018 LEBANON COUNTY ENVIROTHON ELEMENTARY & MIDDLE SCHOOL WILDLIFE OBJECTIVES BACKYARD WILDLIFE

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1 2018 LEBANON COUNTY ENVIROTHON ELEMENTARY & MIDDLE SCHOOL WILDLIFE OBJECTIVES BACKYARD WILDLIFE WILDLIFE OBJECTIVES-ROTATION 2/4 ESSENTIAL TOPICS I. Knowledge of Backyard Birds & Mammals a. Backyard wildlife species identification b. Natural history of backyard wildlife species c. Habitat/ecosystem types and associated wildlife II. Understanding Wildlife Ecology a. Survival requirements of backyard species and how they are met b. Ecosystem dynamics: Predator-prey relationships Energy flow-food chain, food web, food pyramid Succession (how a biological community evolves over time) c. Adaptations III. Conservation and Management of Wildlife a. Wildlife Management b. Improving/managing habitat for wildlife IV. Issues Involving Wildlife and Society a. Endangered and threatened species b. Habitat loss and fragmentation c. Impact of declining habitat d. Managing/planning for people and wildlife e. Non-native species; invasive species; introduced species 1

2 Envirothon Students will be able to: LEARNING OBJECTIVES 1. Knowledge of Backyard Species a. Describe various roles of wildlife species in their ecosystems and be able to cite examples. b. Identify species from mounted specimens, pelts, skulls, pictures, or silhouettes. c. Describe ways habitat can be managed/improved for specific species. 2. Understanding Backyard Wildlife Ecology a. Identify basic needs required by backyard species. b. Identify, describe, and explain specific anatomical, physiological and/or behavioral adaptations of species to the environment and how they help the animals survive. (i.e. hibernation, defense posturing, venomous, etc.). c. Describe predator-prey relationships, discuss physical adaptations of predator vs. prey species, and be able to cite examples. d. Describe and be able to model food chains, food webs, and be able to cite examples. e. Describe factors that limit or enhance population growth. f. Define and explain terms associated with wildlife biology and wildlife populations. 3. Conservation and Management of Wildlife a. Describe the role of the PA Game Commission as the state agency responsible for the protection and management of wild birds and mammals, and their habitat of Pennsylvania. b. Describe ways each person can help in the protection, conservation management, and enhancement of wildlife populations. 4. Issues Involving Backyard Wildlife Species & Society a. Describe what makes one species more prone to becoming endangered than other species. b. Define and be familiar with the terms in the vocabulary list. c. Distinguish between native, non-native, and invasive species. Explain the impact of non-natives on natives. d. Describe the main causes that have led to the depleted populations and describe measures being taken to help their recovery. e. Describe major causes of habitat loss in Pennsylvania and how habitat loss affects wildlife. BACKYARD WILDLIFE SPECIES - IDENTIFICATION STUDY LIST Gray Squirrel Little Brown Bat Mallard* American Robin* Opossum Striped Skunk Cooper s Hawk* Gray Catbird* White-Footed Mouse White-Tailed Deer Eastern Screech Owl* Northern Mockingbird* Norway Rat Raccoon Northern Flicker* European Starling* Southern Flying Squirrel Eastern Chipmunk English Sparrow* Northern Cardinal* Feral House Cat Short-Tailed Shrew House Wren* Ruby-Throated Hummingbird* *Must know calls - please refer to the PA Ethon- PA Bird Songs CD or download the PA Ethon app. 2

3 2018 LEBANON COUNTY ENVIROTHON ELEMENTAY & MIDDLE SCHOOL WILDLIFE VOCABULARY 1. Adaptation: the process of making adjustments to the environment. Two examples include the opposable thumb of the opossum or the ability of the gray fox to climb trees. 2. Arboreal: living in or often found in trees, of or relating to trees. 3. Big Game: term for larger hunted species in Pennsylvania this includes deer, elk, bear, and wild turkey. The enforcement of big game laws is an important part of the PA Game Commission s responsibilities. 4. Biodiversity: a term used to represent the variety of life forms in a given area. 5. Browse: to eat twigs and leaves from woody plants (method used by deer and elk to feed). 6. Carnivore: a meat eater. 7. Carrion: the flesh of dead animals. 8. Conservation: the use of natural resources in a way that assures their continuing availability for future generations. 9. Department of Environmental Protection (DEP): state agency responsible for environmental laws regarding pollution, water, air quality, and drilling. 10. Department of Conservation and Natural Resources (DCNR): state agency responsible for the management of Pennsylvania s state parks and forests. 11. Diurnal: active by daylight; opposite of nocturnal. 12. Endangered: an endangered species is one which is in danger of extinction throughout all or a large part of its range. 13. Extinction: the condition of having been removed from existence. An animal or plant facing extinction is one in danger of vanishing from our world. 14. Feral: referring to domesticated animals gone wild; e.g., feral cats. 3

4 15. Food Chain: the transfer of food energy from the source in plants through a series of animals, with repeated eating and being eaten. 16. Furbearers: legal designation for mammals which may be managed, trapped, and hunted only under regulations of the PA Game Commission. Furbearers include raccoons, foxes, coyotes, opossums, skunks, weasels, fishers, mink, muskrat, and bobcats. 17. Game Animal: legal designation for animals which may be managed and hunted only under the regulations of the PA Game Commission. Small game in PA include pheasants, ruffed grouse, quail, cottontail rabbits, squirrels, and groundhogs 18. Habitat: the arrangement of food, water, shelter, and space suitable to the needs of wildlife. 19. Habitat fragmentation: The partitioning of larger habitats into smaller more isolated parcels, usually as a result of development. Fragmentation of habitat can negatively affect the abundance and diversity of plants and animals in an area. 20. Herbivore: a plant eater. 21. Hibernation (hibernate): to spend the winter sleeping or resting. 22. Insectivore: an insect eater. 23. Invasive (species): a plant or animal species that has the ability to significantly displace desirable or native species. 24. Litter: a group of young animals that are born at a single time. 25. Marsupial: a type of animal (such as a kangaroo or an opossum) that carries its babies in a pocket of skin on the mother's stomach. 26. Migratory: in wildlife, birds or other animals which make annual migrations; i.e., travel great distances in seasonal movements. 27. Mustelid: a mammal of the weasel family (Mustelidae), distinguished by having a long body, short legs, and musky scent glands under the tail. 28. Native: a plant or animal species that was produced, grew, or originated in a certain region. 29. Nocturnal: active by night; the opposite of diurnal. 30. Nongame: all wildlife species which are not commonly hunted, killed, or consumed by humans, such as songbirds and birds of prey. 4

5 31. Non-native: in conservation terms, an organism that has been introduced into a new area. 32. Omnivore: an animal that eats both plant and animal materials. 33. Ornithology/Ornithologist: a branch of science that deals with the study of birds/someone who studies birds. 34. Pennsylvania Fish and Boat Commission (PFBC): the state agency responsible for the management and protection of fish, amphibians, and reptiles. Also enforces boating and fishing regulations. 35. Pennsylvania Game Commission (PGC): the state agency responsible for the protection and management of the wild birds and mammals. Enforces all hunting and trapping regulations. 36. Plumage: the feathers that cover the body of a bird. 37. Pollution: harmful substances deposited in the air, water, or land, leading to a state of dirtiness, impurity, and unhealthiness. 38. Predator: an animal that kills and eats other animals. 39. Prey: animals that are killed and eaten by other animals. 40. Rabies: a very serious and often fatal disease that affects mammals (such as dogs) and that can be passed on to people if an infected animal bites them. 41. Reintroduction: a wildlife management technique where a species is reintroduced or brought back into historic range; replanting of animals in areas where they had become extinct. In Pennsylvania, the Game Commission has reintroduced bald eagles, osprey, elk, fishers, and river otters. 42. Renewable Resource: Living resources, such as plants and animals, which have the capacity to replace themselves when conditions for survival are favorable. 43. Rodent: a small animal (such as a mouse, rat, or squirrel) that has sharp front teeth. 44. Scavenger: an animal that feeds on carrion, dead plant material, or garbage. 45. Threatened: in wildlife terms, a species present in its range but in danger because of a decline in numbers. 36. Venomous: capable of putting poison or venom into another animal's body usually by biting or stinging it. 5

6 WILDLIFE STUDY GUIDE BACKYARD MAMMALS: GRAY SQUIRREL: Pennsylvania s most common squirrel. Adults weigh 1 to 1.5 lbs. and are 18 to 20 long; about half this length is a broad, bushy tail. Albinism (white coloration) is rare but melanism (black coloration) is fairly common. Once, black phase gray squirrels were found statewide; today they occur most often in the northcentral counties. These herbivores feed mostly on mast; acorns, hickory nuts, walnuts, and beechnuts. Other foods include berries, mushrooms, pine seeds, dogwood, wild cherry and black gum fruits, and corn. Gray squirrels are diurnal. Hawks, owls, foxes, and tree-climbing snakes kill young squirrels, but adults are not easily taken. Predator effect is therefore low; the food source is the key to population numbers. Maximum life span can reach 10 years, but few live more than three years. Gray squirrels breed in late winter or early spring. Often they will produce a second litter in July or August. OPOSSUM: The opossum is one of the world s oldest species of mammal, and the only marsupial on the North American continent. The opossum is common in wooded areas throughout PA. At birth, opossums are about the size of a honeybee and continue their growth in the pouch of the mother s abdomen. Most members of the marsupial family come from South America and Australia. The opossum s relatives date back 90 million years. However, the opossum didn t appear in North America until less than a million years ago. The name comes from the Algonquin Native American word apasum, meaning, white animal. An opossum has a long pointed snout with 50 teeth; more than any North American mammal and has small dark eyes and rounded bare ears. Their feet have five toes, each with a claw, except the first toe of each hind foot, which is long and works like a thumb. They will, when threatened, play dead for a few minutes to a few hours. An omnivore and scavenger without food preferences, the opossum can be found in different habitats including cities, towns, and neighborhoods. In Pennsylvania it is classified as a furbearer. 6

7 WHITE-FOOTED MOUSE: Found statewide, this handsome nocturnal mouse may be the most abundant rodent in Pennsylvania. The coat is reddish brown above, white on the belly and feet. The white-footed mouse nests in stone walls, rock crevices, under old boards, and in woodchuck burrows, beehives, tree cavities, and the abandoned nests of squirrels and birds. They do not dig burrows but use the runways of other small mammals. This mouse is very agile and can climb trees. White-footed mice consume about a third of their bodyweight daily. Primarily herbivores, this mouse eats seeds, nuts, berries, fungi, plant matter, insects (namely caterpillars and ground beetles), centipedes, snails, and small birds and mice. They cache food in autumn, carrying seeds in their cheek pouches to chambers beneath logs and stumps. This species average three to four litters per year with each litter consisting of 3-7 young apiece. Females can reproduce at 2 months old. NORWAY RAT: The Norway rat is in length, including a naked, scaly 6 to 9 tail. This Old World rodent s fur is thin, coarse, reddish to grayish brown above and paler below. This non-native species arrived from Europe aboard ships around Today it is found statewide, and ranges across North and Central America. Extremely adaptable, they live in and under barns and farm buildings, in city sewers and dumps, along streams and rivers, marshes, and open fields. Although mainly nocturnal, rats also move about and feed during the day. Omnivorous, they eat anything they can find or subdue, including fish, eggs, vegetables, grain, fruit, nuts, garden crops, carrion, and garbage. They kill poultry, snakes, and wild birds; in local areas, rats may wipe out native birds and mammals, especially ground-nesting birds. Rats carry many diseases, including rabies, typhus, and bubonic plague. SOUTHERN FLYING SQUIRREL: The southern flying squirrel is found throughout Pennsylvania and is slightly smaller than the closely related Northern Flying Squirrel. Adults are 8 to 10 long, including a 3 to 5 tail. Weights range from 1.5 to 3 ounces. Their soft fur is grayish brown on the back and pearly white on the belly. The large, dark eyes are adapted for nocturnal activity. Flying squirrels are arboreal although they will still feed on the ground. They feature a loose fold of skin along their belly that when stretched forms an airfoil they can glide with up to 40 yards. Flying squirrels eat nuts; seeds; winter bud from Hemlock trees, fruits berries and fungi. But, as omnivores, they also feed on moths, beetles, spiders, birds and their eggs, small mice, and shrews. Owls and house cats are major predators and foxes, coyotes, weasels, skunks, raccoons, and black rat snakes also take them. Their life span is estimated at 5 years. 7

8 FERAL HOUSE CAT: Domestic cats originated from the European and African Wild Cat. The domestic cat is now considered a separate species. These non-native cats were introduced worldwide mainly by colonists from Europe. It has been estimated that between 2 to 4 million rural free ranging cats are in Pennsylvania. There is no doubt that these free ranging cats kill wildlife and a lot of it. Nationwide, rural cats probably kill over a billion small mammals and hundreds of millions of birds each year. These feral cats outnumber native predators and when present in large numbers, cats can reduce the amount of prey for wild predators like hawks, owls, and weasels. An example of how cat populations affect wildlife, consider that in 1989 a cat discovered and killed the last king rail (a Pennsylvania endangered bird) known to be born in Pennsylvania. Worldwide, cats may have been involved in the extinction of more bird species than any other cause except habitat destruction. LITTLE BROWN BAT: Bats are the only mammals that fly. Their wings are thin membranes of skin stretched from fore to hind leg, and from hind legs to tail. Their long slender finger bones act as supports, stretching the skin tight for flying and fold the wings alongside the body. All Pennsylvania bats are insectivores and belong to the common or evening bat family. The little brown bat is Pennsylvania s most common bat and is found statewide. The little brown bat makes several feeding flights each night, and is capable of eating 1200 insects a night. After hibernation, females gather in summer roosting colonies of just a few to 100 or more in attics, barns, sheds, and other dark, hot areas. Males are solitary, roosting in hollow trees, under loose bark, behind loose shingles, and in rocks. This species has been hit hard with White Nose Syndrome (WNS), a fungus that has killed a significant part of the population. WNS is believed to have come to New York State from Europe; it disturbs bats during hibernation causing them to burn up their fat reserves and thereby prevents successful hibernation. 8

9 STRIPED SKUNK: The striped skunk belongs to the mustelid family, which includes weasels, minks, and otters. Widespread, the striped skunk is found on all of the lower 48 states. Striped skunks are omnivores. What they eat depends on where they live. In summer they feed heavily on insects even digging out bee nests and hives eating the bees as they fly out. Small-cone shaped holes in the yard often show where skunks were digging for grubs. In fall and winter they eat fruit like wild grapes and cherries, but also small mammals, mast, and carrion. Musk, an oily, yellowish liquid can be shot by a skunk up to twelve feet. This is designed to keep predators at a distance. Skunks do not hibernate. Along with groundhogs, raccoons, squirrels and other wildlife the skunk does well where humans have cleared land or driven out large predators. Skunks can live in a neighborhood for years unseen because they are nocturnal but perhaps not unsmelled. The great-horned owl is a common predator of skunk in Pennsylvania. WHITE-TAILED DEER: The state mammal, the white-tailed deer is an herbivore. However, deer don t eat like cows (grazers) but are browsers. That means they eat a wide variety of plants. In one Pennsylvania study, biologists checked the stomach contents of road-killed deer and discovered over 100 different plants deer had eaten. That means when too many deer are present they can destroy their habitat. This is called exceeding the habitat s carrying capacity. In neighborhoods, deer can destroy lawns, shrubs, and gardens. In 2012, Chronic Wasting Disease (CWD) was discovered in a captive deer on a farm in Adams County. CWD is a brain and nervous system disease found in deer and elk in certain geographic areas of North America. This disease attacks the brains of infected deer and elk and results in death of the animal. The Game Commission has responded by declaring parts of Adams and York Counties as a Disease Management Area (DMA). This will require all successful hunters in this DMA to have their deer checked for CWD. This will allow the Game Commission to monitor and determine if CWD has spread to the wild deer population. 9

10 RACCOON: A medium-sized mammal, the raccoon is a New World animal, found only in Central and North America. Raccoons range in size from 28 to 38 inches, which includes a 10-inch tail, and weigh 10 to 30 pounds. There are records of raccoons weighing as much as 40 pounds but this is very rare in the wild. Raccoons are found throughout PA, most often near sources of water (lakes, streams, etc.) As an omnivore, they adapt well to people and some raccoons live in cities and neighborhoods where they den in storm drains and attics and raid garbage cans and pet food. Raccoons are the most common carrier of rabies. Agencies including the Game Commission, the Department of Health, and the Department of Agriculture combined on the Oral Raccoon Rabies Vaccination (ORV) Program. This program places bait that contains a vaccine that prevents raccoons from getting rabies. Laboratories tested more than 5,500 specimens last year, and of those, 428 tested positive. In Pennsylvania the number of rabies EASTERN CHIPMUNK: A small rodent found throughout Pennsylvania, the eastern chipmunk is a member of the squirrel family. Chipmunks are omnivorous, feeding on nuts, seeds, mushrooms, berries, bird eggs, insects, snails, earthworms, millipedes, salamanders, and more! In the fall, chipmunks cache winter food, storing it in their burrows. Unlike true hibernators, chipmunks do not enter winter with a thick layer of fat. Instead they survive winter by going underground to live on stored food until spring. Perfect chipmunk habitat is open woods with plenty of stumps and logs. Overall, habitat is shrinking as shopping centers, housing developments, and highways cover once open land. Chipmunks can adapt to some change. Unfortunately, many other wildlife species cannot. SHORT-TAILED SHREW: One of the most common shrews and most abundant mammals on the Eastern US. Active day or night, this insectivore eats insects, worms, snails, salamanders, small snakes, mice, songbirds, other shrews, carrion, and vegetable matter. This shrew has poor eyesight, a fair sense of smell, and good hearing and touch. It has slightly venomous saliva but lacks a good way to inject it. So the venom must get in through cuts caused by the shrew s sharp teeth. The venom slows down or kills warm-blooded prey. Shrews are short lived, most short-tailed shrew live for twenty months or less. Foxes, dogs, bobcats, skunk, weasels, hawks, owls, and snakes prey upon the shorttailed shrew. 10

11 PART II: BACKYARD WILDLIFE BACKYARD BIRDS: WILDLIFE OBJECTIVES-ROTATION 2/4 MALLARD: The drake (male duck) is readily identified by a metallic green head and neck, yellow bill, narrow white color, chestnut breast. Black central tail feathers curl up. Hen (female) feature mottled plumage; look for orange bill marked with black. The familiar and common duck, found in city parks, suburbs, farm fields including water bodies of various sizes. Commonly hybridizes particularly with the American Black Duck. People should refrain from feeding these ducks to keep them wild and reduce the possibility of passing diseases when birds are overly concentrated. COOPER S HAWK: Distinguished from Sharp-shinned hawk by its longer, rounded tail & larger head. A member of the Accipiter family of hawks. They prey largely on songbirds & some small mammals. Often hunts near bird feeders. During breeding season has a regular feeding route where it hunts for common, medium-sized birds such as Mourning doves, jays, and starlings. Will perch on telephone poles. Named in 1828 after William Cooper, a New York naturalist. In Pennsylvania, many migrating hawks follow ridges paralleling the Allegheny Plateau, climbing high on thermals (a current of warm air) that rise along these ridges. Hawk Mountain, near Kempton in southeastern Pennsylvania, is a famous spot to observe migrating hawks. EASTERN SCREECH OWL: Common in a wide variety of habitats: woodlots, forests, swamps, orchards, parks, and suburban gardens. Nocturnal; best located and identified by voice. Two typical calls: a series of quavering whistles, descending in pitch; and a long single trill, all on one pitch. Eats mice, insects, amphibians, and birds. May feed in neighborhoods on insects attracted to street lamps. Occurs in red or gray morphs, or color phases. Sometimes seen in daylight at nest or roosting in tree hole or nest box. Nest box plans can be found on the Pennsylvania Game Commission s web-page at 11

12 NORTHERN FLICKER: The Northern Flicker is a large, brown woodpecker with a black-scalloped plumage. It feeds on the ground, probing for ants, which are 45% of its diet; also catches insects in air and eats fruits, berries, and seeds. Will visit bird feeders. When they fly you ll see a flash of color in the wings yellow if you re in the East, red if you re in the West and a bright white flash on the rump. In the East, the morph or color phase most commonly observed is the Yellow-shafted variety. Fairly common in open forest, parks, and gardens. Flickers winter principally in the Southern United States. ENGLISH HOUSE SPARROW: This non-native, invasive species can be found in urban areas, parks, and open farmland. Introduced from England in the middle of the 19 th century. Aggressively competes with our native cavity-nesting species of birds for nest spots. They will kill adult birds, nestlings, and eggs of other species in order to take over a birdhouse or cavity. Forages on the ground and foliage for insects, spiders, small fruit, weed seeds, waste grain, and crumbs. Nest of straw, weeds, trash, grass, lined with feathers, placed in any natural or constructed cavity, such as a birdhouse, under eves of house, in signs or nooks of commercial buildings. HOUSE WREN: Plump little bird with short tail often cocked; upper parts unstreaked and grayish brown. Nest of twigs lined with grass, rootlets, and feathers placed in a wide variety of cavities. Prefers woods edges in rural and suburban areas. These birds feed on insects, spiders, millipedes, and snails. The species breeds across southern Canada and the United States. Individuals from the East, winter mainly in Georgia and Florida. The oldest house wren on record lived seven years, but most individuals probably only survive for a year of two. Ornithologists believe the species has been expanding southward since European settlement began; this house wren benefits from forest fragmentation and does well in town and residential areas. AMERICAN ROBIN: Hops about on lawns, meadows, and golf courses looking for earthworms. Also eats insects, fruit, and berries. Occasionally comes to feeders for fruit. Nest of grasses and middle layer of mud, lined with fine grasses, placed on a horizontal limb of shrub, tree, or on a building ledge. Both parents feed the young. In fall, migrates south often in waves of hundreds or thousands in evenly spaced flight, which is strong and direct. Some winter as far South as Guatemala. In Pennsylvania, the American robin is thought to be the most abundant bird species. 12

13 GRAY CATBIRD: All gray with a black cap. Feeds on the ground and in foliage, eating various insects, as well as spiders, wild grapes, and berries. Both sexes give the meow call in alarm situations. This songbird is a neo-tropical migrant wintering in coastal Southeast and Central America. Featuring a variety of calls, the ability comes from the structure of the syrinx, or voice box, whose two sides operate independently, letting the bird sing with two voices at the same time. Catbirds destroy eggs and nestlings of other species, including wood pewees, robins, and sparrows; biologists don t know whether this behavior represents an attack on competitors or a feeding strategy. NORTHERN MOCKINGBIRD: White wing patches flash in flight. Calls are a mixture of original and imitative phrases, each repeated several times. Found in a variety of habitats, including towns. Nest of twigs, plant stems, mosses, cloth string, and dry leaves lined with rootlets and gasses. Feeds on the ground and in foliage, eating various insects, spiders, snails, crayfish, lizards, small snakes, and wild fruits and berries. May occasionally come to birdfeeders for raisins, other fruit, bread, and suet. Mockingbirds often sing at night. EUROPEAN STARLING: A short-tailed, stocky blackbird, in , starlings were introduced into New York City from Europe. Since then they have spread across North America. Starlings aggressively compete with native species of birds for nesting cavities. To reduce competition from starlings for birdhouses, make sure the entrance hole is 1 ½ inches or less in diameter, since this is too small for starlings to enter. Outside nesting season, usually seen in large flocks. Forages on the ground for insects, spiders, earthworms, garbage, salamanders, snails, weed seeds, and berries. Comes to feeders for seeds and suet. NORTHERN CARDINAL: The male is bright red with black around the base of the bill with a large crest. Females are buffy below; grayish brown above, with reddish bill. Feeds by hopping around on the ground, gleaning food from low shrubbery and trees. Eats insects, spiders, wild fruits and berries, weed seeds. A favorite at birdfeeders, where it prefers sunflower seed, safflower seed, and cracked corn. Nests in shrubs near open areas, woods, and suburban yards. Nonmigratory, this species has extended its range northward (probably due to feeding) during the 20 th Century. A common call; it is loud, liquid whistling with many variations, including cheer, cheer, cheer. 13

14 RUBY-THROATED HUMMINGBIRD: The only breeding hummingbird east of the Mississippi River. Eats flower nectar, insects, spiders, sap from sap-sucker-drilled holes. Comes to hummingbird feeders. Do not use red-colored water in feeders since research indicates the dyes are not good for these unique birds. Ruby-throated hummingbirds are fairly common in parts of the range; found in gardens and woodland edges. With global warming, plentiful feeders, and late-blooming sage, more are showing up in the North and a few attempt to over-winter. 14

15 PART III: BACKYARD WILDLIFE SKULLS: WILDLIFE OBJECTIVES-ROTATION 2/4 NOTES: CAT (CARNIVORE) DEER (HERBIVORE) 15

16 NOTES: 16

17 17 WILDLIFE OBJECTIVES-ROTATION 2/4 All skulls are made of bone. Bone is one of those amazing materials that is both rigidly strong but flexible. Bone gives support and size to animals as different as an elephant or a mouse. Bone helps a wolf run and support a bear when it stands. Bone grows as the animal grows and can also heal themselves when they break. Bone like skulls, are made of composite material. One material is apatite or calcium phosphate, which gives bone its strength. The other material is collagen, which gives bone its flexibility. Teeth can be very helpful in identifying animal skulls. There are usually four types of teeth found in most mammal skulls: incisors, canines, premolars and molars. Incisors located in the front of the mouth, between canine teeth (if there are canine teeth). Used for nipping or pulling at food. A deer uses its lower incisors to yank leaves off a tree. Canines usually larger than incisors and located to the sides of the incisors. They are often long, curved and sharp conical teeth used for piercing. A coyote would use its canine teeth to tear the flesh or crush the bones of a jackrabbit. Pre-molars located behind the canines. Pre-molars can be sharp for grasping or tearing meat or flat for grinding plant food. A bear eats both animals and plants. The pre-molars of a bear are somewhat flat with a sharp edge to them. Molars located behind the pre-molars. These are larger than the pre-molars and used for crushing both animals and plants. The molars of an elk are large and flat. The molars of a cougar are large and sharp. The shape of the teeth in a skull can help you determine the animal s diet and whether it was an herbivore, an omnivore or a carnivore. Animals that feed on plants are called herbivores. The teeth of herbivores are usually flat or beveled so they can pull and grind the plants that they eat. Omnivores usually feed on both plants and animals. The teeth of omnivores show a combination of sharp canines, moderately sharp molars, beveled incisors and flat molars. Almost all the teeth of carnivores have sharp edges that help them to tear at their food. The location of the eye sockets on a skull can help you decide if the animal was a prey species or a predator. Predators (generally carnivores and omnivores) have large eye sockets placed so the eyes look forward and the vision of both eyes overlap. When the vision of both eyes overlap the animal has

18 binocular vision. Binocular vision gives you depth perception. Depth perception helps the animal gauge how far it must leap or how fast it must run in order to catch its prey. Prey species (such as herbivores and some omnivores) have eye sockets on the sides of their head. This gives them monocular vision. Monocular vision allows them to watch for an approaching predator from almost every direction. Most prey species (the herbivores) also have eye sockets located relatively far from their mouths and nostrils. This allows them to bury their mouth in deep grass while grazing or stick their mouth into thick brush while browsing and still be able to watch for predators. Sometimes it s hard to identify an animal s skull from a picture. Here are some tips to help you: In pictures, all skulls look like the same size. When real skulls are placed in front of you it will be clear that they are from animals of very different sizes. Put the skulls into categories. 1. Try to identify your skull according to size. First think of the animals on your study list. Which animal is the largest? Which animal is the smallest? Keep in mind that not all black bear skulls are from an adult bear. For example, in most cases a bat skull will be smaller than a fisher skull and a fisher skull will be smaller than a black bear skull. 2. Try to identify your skull according to teeth. Locate the incisors, the canines, the pre-molars and the molars on your skull. Ask yourself if the teeth are flat or sharp? Or are the teeth a combination of both flat and sharp? Is your skull from an omnivore on your study list? Is it from a carnivore? Or is it an herbivore? 3. Try to identify your skull according to eye sockets. Which of the animals on your study list are predators? Which are prey species? Look at the placement of the eye sockets to help you decide if you are looking at the skull of an animal that has binocular vision or monocular vision or a bit of both. 18