Presentation on theme: "Made by Chekalkina Katya, 10-1. Endangered species An endangered species is a population of organisms which is at risk of becoming extinct because it."— Presentation transcript:
Endangered species An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters. Also it could mean that due to deforestation there may be a lack of food and/or water. The International Union for Conservation of Nature (IUCN) has calculated the percentage of endangered species as 40 percent of all organisms based on the sample of species that have been evaluated through 2006. Many nations have laws offering protection to conservation reliant species: for example, forbidding hunting, restricting land development or creating preserves. Only a few of the many species at risk of extinction actually make it to the lists and obtain legal protection. Many more species become extinct, or potentially will become extinct, without gaining public notice.
The conservation status of a species is an indicator of the likelihood of that endangered species not living. Many factors are taken into account when assessing the conservation status of a species; not simply the number remaining, but the overall increase or decrease in the population over time, breeding success rates, known threats, and so on. The IUCN Red List is the best known conservation status listing. Internationally, 199 countries have signed an accord agreeing to create Biodiversity Action Plans to protect endangered and other threatened species. In the United States this plan is usually called a species Recovery Plan.
IUCN Red List refers to a specific category of threatened species, and may include critically endangered species. IUCN Red List of Threatened Species uses the term endangered species as a specific category of imperilment, rather than as a general term. Under the IUCN Categories and Criteria, endangered species is between critically endangered and vulnerable. Also critically endangered species may also be counted as endangered species and fill all the criteria The more general term used by the IUCN for species at risk of extinction is threatened species, which also includes the less-at-risk category of vulnerable species together with endangered and critically endangered. IUCN categories include: IUCN Red List Endangered species
Question of ethics Even in the search to learn more about these species, many ecologists do not take into consideration the impact they leave on the environment and its inhabitants. It is apparent that the “quest for ecological knowledge, which is so critical for informing efforts to understand and conserve Earth’s biodiversity along with valued ecosystem goods and services, frequently raises complex ethical questions”, and there is no clear way to identify and resolve these issues. Environmentalists tend to focus on the whole ecological sphere instead of the welfare of individual animals. Focusing on such a broad view tends to diminish the value of each individual creature. "Biodiversity conservation is currently a principle goal for resource management of 11.5% of the world’s surface area."Large portions of life occur outside these protected areas and must be taken into consideration if the conservation of endangered species is going to be effective
Impact on biodiversity and endangered species In order to conserve the biodiversity of the planet, one must take into consideration the reasons why so many species are becoming endangered. “Habitat loss is the most widespread cause of species endangerment in the U.S., affecting 85% of imperiled species”.When an animal’s ecosystem is not maintained, they lose their home and are either forced to adapt to new surroundings or perish. Pollution is another factor that causes many species to become endangered, especially a large proportion of aquatic life. Also, over-exploitation, disease, and climate change have led to the endangerment of several species.
Captive breeding programs Captive breeding is the process of breeding rare or endangered species in human controlled environments with restricted settings, such as wildlife preserves, zoos and other conservation facilities. Captive breeding is meant to save species from going extinct. It is supposed to stabilize the population of the species so it is no longer at risk for disappearing. This technique has been used with success for many species for some time, with probably the oldest known such instances of captive mating being attributed to menageries of European and Asian rulers. However, captive breeding techniques are usually difficult to implement for highly mobile species like some migratory birds (e.g. cranes) and fishes (e.g. Hilsa). Additionally, if the captive breeding population is too small, inbreeding may occur due to a reduced gene pool; this may lead to the population lacking immunity to diseases.
Siberian tiger The Siberian tiger (Panthera tigris altaica), also known as the Amur, Manchurian is a subspecies of tiger which once ranged throughout Western Asia, Central Asia and eastern Russia, though it is now completely confined to the Amur-Ussuri region of Primorsky Krai and Khabarovsk Krai in far eastern Siberia, where it is now protected. It is the biggest of the eight recent tiger subspecies and the largest living felid, attaining 320 kg (710 lb) in exceptional specimens. Genetic research in 2009 revealed that the current Siberian tiger population is almost identical to the Caspian tiger, a now extinct western population once thought to have been a distinct subspecies.
Physical characteristics The pelage of the Siberian tiger is moderately thick, coarse and sparse compared to that of other felids living in the former Soviet Union. Compared to the now-extirpated westernmost populations, the Far Eastern Siberian tiger's summer and winter coats contrast sharply with other subspecies. Generally, the coat of western populations was brighter and more uniform than that of the Far Eastern populations. The summer coat is coarse, while the winter coat is denser, longer, softer, and silkier. The winter fur often appears quite shaggy on the trunk, and is markedly longer on the head, almost covering the ears. The whiskers and hair on the occiput and the top of the neck is also greatly elongated. The background colour of the winter coat is less bright and rusty compared to that of the summer coat, and tends to be more ocherous. Due to the winter fur's greater length, the stripes appear broader with less defined outlines.
The winter fur often appears quite shaggy on the trunk, and is markedly longer on the head, almost covering the ears. The whiskers and hair on the cockpit and the top of the neck is also greatly elongated. The background color of the winter coat is less bright and rusty compared to that of the summer coat, and tends to be more ocher us. Due to the winter fur's greater length, the stripes appear broader with less defined outlines.
Captivity The Siberian tiger is not very difficult to breed in captivity, but the possibility of survival for animals bred in captivity released into the wild is small. Conservation efforts that secure the wild population are therefore still imperative. If a captive bred Siberian tiger were to be released into the wild, it would lack the necessary hunting skills and starve to death. Captive bred tigers can also approach humans and villages, since they have learned to associate humans with feeding and lack the natural shyness of the wild tigers. In a worst-case scenario, the starving tigers could even become man-eaters. Since tigers must be taught how to hunt by their mothers when they are still cubs, a program that aimed to release captive bred Siberian tigers into the wild would create great difficulties.
Attacks on humans Unlike the Bengal tiger, the Siberian tiger very rarely becomes a man- eater. Several cases of attacks on humans were recorded in the 19th century, occurring usually in central Asia (excluding Turkmenistan), Kazakhstan and the Far East. Siberian tigers were historically rarely considered dangerous unless provoked, though in the lower reaches of Syr-Darya, a tiger reportedly killed a woman collecting firewood and an unarmed military officer in the June period whilst passing through reed thickets. Attacks on shepherds were recorded in the lower reaches of Ili. In the Far East, during the middle and third quarter of the 19th century, attacks on man were recorded. In 1867 on the Tsymukha River, tigers killed 21 men and injured 6 others. In China's Jilin Province, tigers reportedly attacked woodsmen and coachmen, and occasionally entering cabins and dragging out both adults and children.According to the Japanese Police Bureau in Korea, in 1928, a tiger claimed only one human victim, unlike leopards which claimed three, wild boars four and wolves 48. Only six cases were recorded in 20th century Russia of unprovoked attacks leading to man- eating behaviour. Provoked attacks are however more common, usually the result of botched attempts at capturing them.
In an incident at the San Francisco Zoo on 25 December 2007, a Siberian tiger named Tatiana escaped and killed one visitor, injuring two others. The animal was shot dead by the police. The zoo was widely criticized for maintaining only a 12½ ft (3.8m) fence around the tiger enclosure, while the international standard is 16 ft. (4.8m). The zoo subsequently erected a taller barrier topped by an electric fence. The police say that one of the victims admitted to taunting the animal.