BIRDS AND MAMMALSTAXONOMY AND CHARACTERIZATION
Taxonomy and Characterization class activity may be done in a variety of ways. For example, a taxonomy and characterization exercise may be undertaken after study of each of Class (Amphibians, Reptiles, Birds and Mammals.) Alternatively, the exercise may be undertaken after the four Classes have been studied. The method to adopt may be adapted depending upon situation. This can also be adapted to Georgia wildlife by selecting the animals from Georgia Wildlife Site.Objectives:
5-6 class periods (inclusive of lecture and activity)Background:
Chordates are any member of phylum Chordata. All members of phylum chordata possess certain features at some time in their life cycle, like a dorsal supporting rod called the notochord, pharyngeal apertures (gill slits), and a dorsal nerve cord running along the back. Chordate bodies consist of a body wall which encases the gut. The body is usually long and bilaterally symmetrical (right and left halves of the body similar). The mouth and sense organs are located in the anterior and the anus at the base of the tail.
The phylum Chordata is subdivided into three sub-phylums: Vertebrata or Craniata (amphibians, reptiles, birds, mamals, fishes and lampreys), Cephalocordata or Acrania (lancelets or amphioxus), and Urochordata or Tunicata (Tunicates). Tunicates are small marine animals, length ranging from 1 millimeter to 20 centimeters. Tunicates are either benthic (bottom dwelling) or pelagic (floating). Typical length range is between 1 to 5 centimeters (0.4 to 2 inches). Cephalopods are small, fishlike marine invertebrates, probably closest living relatives of vertebrates. Their size ranges from 1 to 3 centimeters. However, the vertebrates have the greatest size variation, ranging from tiny fish to the whales, the largest animal ever to have existed.
Any animal of the subphylum Vertebrata is characterized by the presence of a vertebral column or backbone. Vertebrates are unique in possessing an internal skeleton, formed of either cartilage or bone, or both. The skeleton allows vertebrates to achieve large size; most vertebrates are larger than invertebrates. Vertebrates are also characterized by a muscular system and a central nervous system partly enclosed within the backbone.
The subphylum Vertebrates is one of the best known of all groups of animals. Its members include the classes: Agnatha (primitive, jawless fishes - lampreys and hagfishes), Chondrichthyes or Selachii (cartilaginous fishes - sharks, skates, chimaeras, and rays), Osteichthyes (all bony fishes, includes the 20,000 species and more than 400 families of modern bony fishes, as well as a few primitive forms, but excludes Agnatha and Condrichthyes); Amphibia (amphibians); Reptilia (reptiles); Aves (birds); and Mammalia (mammals).Birds
Birds are warm-blooded vertebrate animals and constitute the Class Aves in the biological classification. Birds evolved from reptiles; however the scales are highly modified to feathers that cover the body. Feathers are one major characteristic that distinguishes the birds from all other animals. There are three types of feathers: flight feathers, body feathers and down feathers. Birds have oil glands which help keep the feathers waterproof. Feathers help birds adjust their body temperature. Feathers also make it possible for birds to fly. The ability to fly has permitted an almost unlimited radiation of birds, so that they are found in a wide variety of habitats and virtually everywhere on the earth, from polar ice caps to tropical rain forests. However, all animals that fly are not birds (e.g. the bat, which is a mammal) and all birds do not fly. Most birds fly, but some are flightless, they either walk/run, like ostriches or walk and swim, like penguins. The other characteristics of birds are that they have wings (a modification of front limbs); beaks but no teeth; strong and hollow bones; a pair of lungs to breathe; and powerful flight muscles. Birds are oviparous, i.e. the female lays calcareous-shelled eggs in a nest, which after a given period of incubation hatch into broods or young birds.
Birds use a lot of energy while flying and need to eat a lot of food to power their flight. Therefore, birds spend most of their time looking for food. Birds eat a varied diet like insects, worms, small or micro-invertebrates, rodents, fish, grain, plants and nectars. Some birds, like hawks, eagle and owls, are carnivores (meat eaters); some birds, like humming birds, grouse and Canada goose, are herbivores (plant eaters); while some birds, like starlings, are omnivores (like humans eat both plants and meat).
The smallest living bird is the bee hummingbird of Cuba, which weighs less than 3 grams (about 0.1 ounce) and is 6.3 cm (2.5 inches) long. The largest living bird is the flightless ostrich, which weigh 135 kilograms (300 pounds) and may stand 2.5 meters (8 feet) tall. Among the flying and extant birds, the wandering albatross has the widest wingspan, 3.5 meters (11.5 feet), and the trumpeter swan the greatest weight, 17 kilograms (38 pounds).
The Class Aves is comprised of 29 orders, 146 families and approximately 9,600 living species of birds. (Some 1,000 extinct species of birds have been identified from fossils.) Twenty of these living orders occur in Georgia: Gaviiformes (Loons), Podicipediformes (Grebes), Procellariiformis (Petrels, Shearwaters, and Storm Petrels), Pelicaniformes (Pelicans, Anhingas and Cormorants), Ciconiiformes (Herons, Egret, Storks, Ibis, Bitterns, and Vulture), Anseriformes (Ducks and Geese), Falconiformes (Falcons, Hawks, Eagles and Ospreys), Galliformes (Turkeys, Quail, Pheasant and Bobwhite), Gruiformes (Cranes, Rails, Limpkins, Gallinule and Coots), Charadriiformes (Shorebirds, Gulls), Columbiformes ((Pigeons and Doves), Psittaciformis (Parrots, Parakeets and Macaws), Cuculiformes (Cuckoos and Ani), Strigiformes (Owls), Caprimulgiformes (Nighthawks, Nightjars, and Goatsuckers), Apodiformes (Hummingbirds and Swifts), Coraciiformes (Kingfishers and Rollers), Piciformes (Woodpeckers and Toucans), Passeriformes (Perching birds - Fly catchers, Martins, Jays, Wrens, Ravens, Crows, and Warblers), and Phoenicopteriformes. The Order Passeriformes is the largest order with approximately 5,700 species worldwide, and it is also the largest order in Georgia.
Birds have perhaps been related to humans in some way since their origins. Wild birds and eggs have been a human food source from time immemorial, and are still a food source in many societies. Feathers of birds have been used for decoration by many societies since early times. With the development of agrarian human cultures several bird species have been domesticated for food (chickens, ducks and geese) and to carry messages (pigeons). Also, birds of prey, like hawks, are trained and used for hunting rodents and birds. Birds play an important role in the natural control of insect pests, in the dispersal of seeds, and the pollination of flowering plants (for instance by nectar-eating humming birds.) In modern culture the hunting of waterfowl, quail, grouse, doves and other game birds has become a popular form of sport and industry. Many birds such as finches, canaries, parrots and mynahs are also kept as pets.
With the rise of agriculture, humans' relationship with birds has become more complex. Birds have become serious avian pests to fruits and grains. In North America various species of blackbirds (family Icteridae) are serious pests in grain fields. Birds are also a hazard to flying airplanes: bird collisions cost millions of dollars annually and pose a safety risk to people flying in airplanes. Though most avian diseases do not infect humans, birds are carriers of some diseases that do. For example ornithosis (psittocosis) is caused by viruses transmitted directly to humans from pigeons, parrots and a variety of other birds. Encephalitis, an inflammation of the brain, is another serious disease, which is transmitted from birds to humans via biting arthropods (insects), including mosquitoes. Wild birds may also act as reservoirs of diseases that adversely affect domesticated birds.
However, humankind's impact on birds is increasingly aggravated with increasing human population and modernization. As a result of human action, since 1680, some 60 species of birds are known to have become extinct and an even larger number of bird species is now in danger of becoming extinct. The reasons for extinction and endangering are all human-made. They are: pollution, pesticide application, destruction and fragmentation of natural habitats, and introduction of exotic animals and diseases along with them. Therefore, humans, as the most intelligent and powerful species on earth, should bear the responsibility for their protection and conservation and maintenance of overall ecological balance.Mammals
Mammals are a group of vertebrate (animals with backbone) animals belonging to class Mammalia. Mammals are especially characterized by the presence of mammary glands (a modification of sweat glands) in the females that secrete milk to nurse babies. In addition to the characteristic milk glands, mammals have hair on their bodies (although in many whales the hair has secondarily disappeared in the fetal stage.) Mammals are a warm-blooded animal (endothermic), which means they are able to regulate and maintain a constant body temperature when the external temperature either becomes hot or cold. Mammals have limbs, but never more than four. Limbs may be of different kinds, viz. arms, legs wings, flippers or fins. Mammals breathe with lungs, taking in oxygen and giving out carbon dioxide.
The class Mammalia has a world-wide distribution, and has tremendous diversity in both habits and forms. Every major habitat is inhabited by mammals that swim, fly, glide, burrow, or climb. Living modern-day mammals range from tiny pygmy shrew (1.2 - 2.7 gm) and bumblebee bat (about 2gm) to the largest of all animals that has ever lived, the blue whale, which reaches a length of more than 100 feet and weighs 150 tons. It is estimated that there are about 5,000 living species of mammals. They are divided into 120 families, 26 orders (there is no consensus among biologists) and three subclasses. Of the 26 orders, species from 10 orders are found in Georgia; the inclusion of humans (Primates) makes it eleven. They are: Didelmorphia (pouched mammals), Insectivora (shrews and moles), Chiroptera (bats), Xenartha (armadillos), Carnivora (flesh or meat eating), Cetacea (whales and dolphins), Rodentia (gnawing mammals such as mice and squirrels), Lagomorpha (rabbits), Sirenia (manatees), and Artiodactyla (even-toed hoofed mammals such as deer and swine). It is estimated that about 400 species of mammals are found in North America. Sixty-nine terrestrial mammals are found in Georgia.
The three sub-classes or types of mammals are monotremes, marsupials, and placental. The monotremes are egg-laying mammals, for example echidnas and duck-billed platypus. Except for monotremes, all mammals are viviparous (i.e. give birth to live young). Marsupials are characterized by pouch in the female members, where they raise and nurse their extremely immature-born babies (for example possums, kangaroos and koalas.) In placental mammals young ones are born at a relatively advanced stage (more advanced than marsupial or monotremes). Before birth, the young are nourished through the placenta, an organ that attaches the fetus to the mother's uterus to deliver oxygen and nutrients. Most mammals are placental, for example humans, cats, dogs, and horses. Mammals may also be classified based upon their diet: herbivores (plant eaters - e.g. deer, beavers, cows, pandas and others); carnivores (meat-eaters - e.g. wolves, cats, foxes, tigers and others); omnivores (eat plants and meat - e.g. humans, some bears and others); and insectivores (eat insects - e.g. anteaters, pangolins and others).
Both wild and domesticated mammals are interlocked with human development and history. Primitive to modern human societies have been dependent upon other mammals for food and clothing (leather, fur). Mammals are hunted and/or domesticated to provide a source of protein and a means of transportation and heavy work as well. Many mammal species like non-human primates (monkeys and apes), European rabbits, guinea pigs, gerbils and others are used as laboratory animals for the study of human-related physiology, psychology, and a variety of diseases. Today hunting, primarily for sport, of various mammalians like rodents, lagomorphs, carnivores and ungulates is a multibillion-dollar industry. It is estimated that more than 2 million deer are harvested annually by licensed hunters in the US alone. Besides meat and pelt, special parts of mammals have been important to human societies. Horns of rhinoceroses are used in concocting potions, ivory from elephants and walruses is highly prized, and ambergris, a substance regurgitated by sperm whales, was widely used as a base for perfumes (it is now substituted by synthesized compounds.) As a result, some of these species have been hunted nearly to extinction.
Mammals can be a source of problems for humans. Rats and mice now occur virtually all over the world and each year cause substantial damage and economic loss. Herbivore mammals eat or trample planted crops and compete with domesticated livestock for food, and carnivores sometimes prey on domestic herds. Mammals are also important reservoirs or agents of a variety of diseases that afflict humans, such as plague, yellow fever, rabies, hemorrhagic fever, Rocky Mountain spotted fever to name a few. The annual economic cost resulting from mammal-borne diseases in humans and their domestic stock is incalculable.
Many mammals, especially large ones that competed with humans for food or space, or were specially sought for food or trade, have been extirpated entirely or exist today only in parks and zoos; and many others are in danger of extinction. Human encroachment into habitat once available to other mammal species is another factor contributing to their endangerment. Realizing the ecological and aesthetic value of other mammal species, humans in recent times have started expending resources to conserve the vanishing species, setting aside natural areas to establish zoological parks and gardens. These gardens and parks now provide outdoor laboratories that attract millions of visitors and provide means by which present and future generations of humans can appreciate and study other kinds of mammals.
Hanging in the Habitat: A Game about Animals in an Urban Habitat. Games are on BlueJay, Squirrel, Salamander and Garter Snake.
Endangered Species Unscramble Game
Endangered Species Matching Game
Risky Critters (Game on wildlife and endangered species)
Internet Resources on Chordata:
Encyclopaedia Brittanica Chordate Site
Encyclopaedia Brittanica Vertebrate Site
Glossary on Animals + Links to Animals related web site
A Useful site on Amphibians, Animal, Bird, Fish, Game, glossary, Mammal, Reptile, and Internet link resources
Critter Corner (Amphibians, Birds, Fish, Insects, Other Invertebrates, Mammals, Reptiles, Habitats, Endangered species, Alien Invaders - Wisconsin state related)
All about Nature (animals - natural history and descriptions, biome): A very useful site - a must source for teachers)
Georgia Birds (Georgia Wildlife Web)
All About Birds
Encyclopaedia Brittanica Bird Site
Protected Birds of Georgia
Wild Bird Photography Library Arranged by Species
Georgia Mammals (Georgia Wildlife Web)
All About Mammals
Encyclopaedia Brittanica Mammal site
Georgia Conservancy, Mammal Site (pdf)
Protected mammals of Georgia
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