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Endangered Species Biodiversity
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Human Causes of Biodiversity Loss
Biodiversity: the number and variety of species on Earth - the number of species known to science is 1.6 million, most of which are insects - many scientists estimate about 13 million species on Earth BIODIVERSITY LOSS Natural Causes of Biodiversity Loss Human Causes of Biodiversity Loss World Examples Climate Change Natural Disaster Habitat destruction Hunting/Poaching Exotic Species Amazon Rainforest, Florida Panther African Elephant Purple Loosestrife, Zebra Mussels There are approximately 1.6 Million species known to scientists today, approximately are insects Although estimates vary, many scientists believe that there are bout 13 million species now living on our planet In one study in a tropical rainforest region of Indonesia, British Researchers counted the number of species of insects called hemipterans: - They found 1,690 species of hemipterans living on the ground, but only 37% of them had been known previously We still do not know how many species are alive today! Biodiversity Loss: - The human population is increasing at a rate of about 220,000 people per day - Because the population is growing so rapidly and changing the environment so dramatically, we are causing other species to become extinct at an accelerated rate - Scientists estimate that species are disappearing at least 1,000 times faster than at any other time in the last 65 million years - Evidence suggests that this dramatic increase in extinctions has largely taken place during the last century. As humans take up more and more space and deplete more resources, we destroy the habitats of other species The most common cause of extinction today is the destruction of habitats by humans Unregulated hunting and the introduction of nonnative species also contribute to extinctions Habitat Destruction: - As human populations grow we take up more space and resources and end up destroying the habitat of other species - 75% of the extinctions occurring can be attributed to habitat loss Example: Florida Panther, a kind of cougar years ago cougars ranged from Alaska to South America - because of settlement, road and canal constructions, habitat has been fragmented and destroyed - forest is primary habitat and very little is left - the only cougar population east of the Mississippi River is the Florida Panther - In 1994 only remained in the wild, making the Florida Panther one of the most endangered animals in N.A. Hunting: unregulated hunting leads to species extinction - Early 1900’s – 2 billion American Passenger Pigeons legally hunted to extinction - When first Europeans arrived to N.A. 60 million buffalo roamed the continent… by 1906 only 300 remained b/c of hunting - Today, b/c of protection laws the pop. has grown to 200, 000 Poaching: illegal hunting – African Elephants reduced in number when habitats converted to farmland and poachers killed elephant for tusks of ivory - poachers estimated to have killed half of all elephants between Exotic Species: a species not native to a particular region… can be a threat to native species, which have no natural defenses against them - Purple Loosestrife (brought from Eurasia in sheeps wool, ballast water etc.- chokes out other wetland vegetation) - Zebra Mussels (Brought from Europe in ballast water – removes plankton from water ecosystem)
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Key Terms Extinct: irreversible disappearance of a population or a species Eg. Blue Walleye Extirpated: a wildlife species that no longer exists in the wild in an area of Canada, but exists elsewhere Eg. Grizzly Bear Endangered: a species whose numbers have fallen so low that it is likely to become extinct in the near future Eg. Barn Owl Threatened: species likely to become endangered if protective measures are not taken immediately Eg. Eastern Massauga Rattlesnake Special Concern: a wildlife species that may become a threatened or an endangered species because of a combination of biological characteristics and identified threats Eg. Killer Whale
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Key Terms Con’t… CITES: Convention on International Trade in Endangered Species – offshoot of the IUCN that is responsible for limiting the sale of ivory and the killing of Elephants Eg ban on the sale of ivory worldwide Key Organizations… COSEWIC: Committee On the Status of Endangered Wildlife In Canada - is a committee of experts that assesses and designates which wild species are in some danger of disappearing from Canada WWF: World Wildlife Fund works to conserve species at risk, protect threatened habitats and address global threats CWS: Canadian Wildlife Service - Canada's national wildlife agency that handles wildlife matters that are the responsibility of the federal government
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Internet Search on Endangered Species
Species at Risk Location in Canada Reasons for Stress Management Strategies Extinct: Blue Walleye L. Erie, L. Ontario (Extinct 1965) Overfishing, competition and agricultural run-off None Extirpated: Grizzly Bear Prairies Killing and habitat changed to farms or settlements SARA Endangered: Barn Owl S. B.C., S. ON, S. Quebec Urbanization – loss of habitat and prey species Protected by Ont. Fish and Wildlife Conservation Act Threatened: Eastern Massasauga Rattlesnake Eastern Shores of Georgian Bay and Bruce Peninsula Killing and habitat destruction/ fragmentation Special Concern: Killer Whale Pacific Ocean (offshore B.C.) Boating, toxins, fishing – reduces prey, netting Protected by Fisheries Act of Canada SARA: Canada’s Species at Risk Act was created to protect many aquatic species including fish, reptiles, marine mammals and molluscs. Find out what it means for you, especially if you are a commercial fisher, aquaculturist, recreational fisher, recreational boater, Aboriginal, scientist, researcher or involved in an activity that might impact the habitat of species at risk. The Species at Risk Act (SARA) was created to protect wildlife species from becoming extinct in two ways: * By providing for the recovery of species at risk due to human activity; and * By ensuring through sound management that species of special concern don’t become endangered or threatened. The Act became law in June It includes prohibitions against killing, harming, harassing, capturing or taking species at risk, and against destroying their critical habitats. Fish and Wildlife Conservation Act: * The Act allows MNR to protect and manage a broader range of both game species, such as moose, wild turkey and black bear, and specially protected wildlife species, such as the northern flying squirrel, the peregrine falcon and the blue spotted-salamander. In general, specially protected species may not be hunted or trapped.
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Florida Panther - Endangered
Florida panther (Puma concolor coryi) While it once ranged throughout Florida and much of the southeastern United States (from Louisiana north and east to Tennessee and the Atlantic), today there are fewer than 90 adult panthers remaining in national and state parks and nearby private lands in south Florida. The Florida panther is tawny in color with lighter fur on its lower chest, belly, and inner legs. Individuals vary in height at the shoulder from 23 to 28 inches and measure from 6 to 7 feet from nose to tip of tail. Males weigh between 100 and 150 pounds, females between 65 and 100 pounds. Panthers' tails are nearly two-thirds the length of their head and body, and help balance the body, especially during ambush pounces on prey. Solitary and elusive animals, Florida panthers are rarely observed in the wild, and they are most active at dawn and dusk. The home range of male panthers is about 200 square miles and the home range of female panthers is about 75 square miles. Panthers are strictly carnivorous, eating mostly feral hogs, white-tailed deer, raccoons, and armadillos; they may eat only once a week and sleep as much as 18 hours a day in a bed made within the shade of a palmetto thicket. The greatest threats facing today's panthers are habitat loss, vehicle collisions and disease.
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African Elephant - Threatened
Elephants continue to roam the African land, but remain under threat from poaching and habitat loss. Although poaching of elephants for their ivory has declined since the 1989 "ivory ban", it remains a widespread problem in west and central Africa. Large quantities of African ivory are still finding their way in to illegal markets in Africa and beyond in places such as Asia. A more long-term threat to the species, however, is the reduction of habitat available to elephants in the face of expanding human populations. Why is this species important? Elephants play an important role in the forest and savanna ecosystems in which they live. Many plant species are dependent on passing through an elephant's digestive tract before they can germinate; it is calculated that at least a third of tree species in west African forests rely on elephants in this way. Elephants browsing on vegetation also affect the structure of habitats and influence bush fire patterns. For example, under natural conditions, elephants make gaps through the rainforest, enabling the sunlight to enter which allows the growth of a various plant species. This in turn facilitates a more abundant and more diverse fauna of smaller animals. The influence elephants have over many plant and animal species means they are often referred to as keystone species that are vital to the long-term survival of the ecosystems in which they live.
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Purple Loosestrife - Exotic Species
Purple loosestrife was introduced to the northeastern U.S. and Canada in the 1800s, for ornamental and medicinal uses. It is still widely sold as an ornamental, except in states such as Minnesota, Wisconsin, and Illinois where regulations now prohibit its sale, purchase and distribution. ECOLOGICAL THREAT Purple loosestrife adapts readily to natural and disturbed wetlands. As it establishes and expands, it outcompetes and replaces native grasses, sedges, and other flowering plants that provide a higher quality source of nutrition for wildlife. The highly invasive nature of purple loosestrife allows it to form dense, homogeneous stands that restrict native wetland plant species, including some federally endangered orchids, and reduce habitat for waterfowl.
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Zebra Mussel - Exotic Species
Zebra mussels (Dreissena polymorpha) - are small, fingernail-sized mussels native to the Caspian Sea region of Asia. They are believed to have been transported to the Great Lakes via ballast water from a transoceanic vessel. The ballast water, taken on in a freshwater European port was subsequently discharged into Lake St. Clair, near Detroit, where the mussel was discovered in 1988. Since that time, they have spread rapidly to all of the Great Lakes, the Mississippi River, and are showing up in waterways in many states. Dangers of Zebra Mussels Biggest concern, once zebra mussels get into a lake, there is no known remedy that works 100% effectively. Another factor in the rapid spread of zebra mussels is the reproductive rate of a female zebra mussel. Spawning generally occurs in the spring and can continue through the summer until fall. Over the course of a year, a female zebra mussel can produce up to one million eggs. These develop into microscopic, free-swimming larvae called veligers that begin to form shells. At about three weeks, they begin to firmly attach themselves to submerged rocks, dock pilings, boat hulls, water intake pipes, and any other solid object.
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Blue Walleye - Extinct The blue walleye (Sander vitreus glaucus), previously erroneously called the blue pike, was a subspecies of the walleye that went extinct in the 1960s. Until the middle of the 20th century, it was a commercially valuable fish with about a half million tonnes being landed during the period from about 1880 to the late 1950s, when the populations collapsed. The fish was endemic to lakes Erie and Ontario of the Great Lakes region of North America, including the inter-connecting Niagara River, but most especially to Lake Erie where it sometimes represented more than 50% of the commercial catch. The subspecies was apparently extirpated by about 1965 through a combination of anthropogenic eutrophication, overfishing and competition with the introduced rainbow smelt, Osmerus mordax. The subspecies is now considered extinct. There are occasional reports of blue walleye being caught from waters in the Great Lakes basin. This is due to the fact that many yellow walleye populations also contain a colour variant with a bluish colour.
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Grizzly Bear - Extirpated
Status History: The species was considered a single unit and designated Not at Risk in April Split into two populations in April 1991 (Prairie population and Northwestern population). The Prairie population was designated Extirpated in April Status re-examined and confirmed in May 2000 and in May Last assessment based on an update status report. The effects of Grizzly Bears on their environment are wide and varied. They disperse the seeds of berries and plants that they feed on, and scavengers benefit from incompletely consumed salmon where Grizzly Bears feed. Nitrogen, derived from feeding on salmon, is redistributed on land through the urine and feces of the bears. Wolves and Grizzly Bears compete with each other for live prey and carcasses, and will steal food from each other. Reasons for extirpation The last members of the Grizzly Bear Prairie population disappeared from the Cypress Hills area of Saskatchewan and Alberta around The extirpation of this population resulted from the killing of Grizzly Bears by humans, and conversion of the natural habitat to agricultural, residential, and urban areas.
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Barn Owl - Endangered Reason for Designation: This owl occurs in very small and declining numbers in eastern Canada. It is limited by loss and degradation of wetlands and agricultural habitats, and by severe winters at the northern edge of its range. Status History: The species was considered a single unit and designated Special Concern in April In April 1999, the Western and Eastern populations were assessed separately. The Eastern population was designated Endangered. Status re-examined and confirmed in May Last assessment based on an existing status report. Threats The main factor limiting the Barn Owl is the loss of habitat and of prey species, mainly due to the conversion of pasture into sites for row crops, and urbanization. Barn Owls are also susceptible to cold, and severe winters can reduce the population size. Pesticides and chemicals in the environment can cause reproductive problems and the death of birds; the use of chemicals to kill rodents has led to the poisoning of many Barn Owls.
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Eastern Massasauga Rattlesnake - Threatened
In Canada, the Massasauga is found in four separate localities of unequal size, all in Ontario. In central Ontario, it is found along the eastern shores of Georgian Bay and on the Bruce Peninsula. In southwestern Ontario, it is found only in an area near Windsor and in the Wainfleet Bog on the northeast shore of Lake Erie. The Ontario population is estimated to be between and snakes, with less than 100 individuals judged to be living in each of the two southwestern Ontario populations. Habitat Although Massasaugas use strikingly different habitats across their range — from tall grass prairie to cedar bogs to shorelines — all habitats share distinctive characteristics. The snakes need sufficient protection from predators and the elements, so the habitat cannot be too open, but they also require access to spots where they can get warm enough to effectively digest their food and reproduce. Granite rock tables in the Georgian Bay area and brush piles in the Ojibway prairie provide snakes with similar hot spots to bask in. Sufficient moisuture is apparently key to surviving the winter, and the hibernacula (overwintering sites) of Massasaugas are often associated with wetlands or small, wet depressions in the terrain. Threats The greatest threat to the Massasauga is habitat destruction and fragmentation. Greater development also results in an increase in the number of snakes accidentally killed on roadways. The deliberate killing of snakes by humans is also a significant threat to Massasaugas in Canada. The low population numbers at the two sites in southwestern Ontario make these populations vulnerable to becoming extirpated as a result of a chance event. Protection The Massasauga is protected under the federal Species at Risk Act (SARA). More information about SARA, including how it protects individual species, is available in the Species at Risk Act: A Guide. The Massasauga is listed as a "specially protected reptile" under the Ontario Fish and Wildlife Conservation Act, which makes it illegal for it to be killed, trapped, held in captivity, or traded without a permit. The Canada National Parks Act protects Massasaugas and their habitat within the boundaries of two national parks, Georgian Bay Islands and Bruce Peninsula.
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Killer Whale - Special Concern
Threats Given their low population sizes and low potential rates of growth, Killer Whales are potentially at risk from anthropogenic (human-related) influences including immunotoxic effects of persistent toxic chemicals, and reduction in prey availability, possibly competing with fisheries for prey. Organochlorine concentrations in their tissues appear to be similar to those of the northern resident population.The offshore population lives on or near the major offshore routes for oil tankers.Fishing boat/human interactions include direct takes (whaling, culling), live-capture fisheries, entanglement in fishing gear, collisions with vessels, and exposure to oil spills. Although the largest fisheries of whales were discontinued in the early 1980s and 1990s, small numbers are probably still taken.It is also possible that the large and growing commercial and recreational whale watching industry on the west coast may be having an impact, though such impacts are as yet unclear. Among the natural factors that may be limiting the whale's populations are periodic events such as mass strandings or entrapments in narrow inlets or ice, which have the potential to drastically reduce numbers locally. Protection The Killer Whale Northeast Pacific offshore population is protected under the federal Species at Risk Act (SARA). More information about SARA, including how it protects individual species, is available in the Species at Risk Act: A Guide. Legislation to protect the Killer Whale in Canadian waters was first introduced in 1970, under British Columbia's Wildlife Act. In 1982, the species became included in regulations under the Fisheries Act of Canada.
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