[Biology Class Notes] on Endangered Species Pdf

An endangered species is a living thing that is in danger of becoming extinct more so as a result of human action. Endangered species are those that are in danger of becoming extinct or are already extinct, in other words extinction-threatened species. The destruction or pollution of a species’ native environment is one of the most important factors in its endangerment or extinction. Overhunting can be considered as deliberate extinction of species. Endangered species are species that were formerly native to a region but have seen their population decline from 50% to 5%.

Species Become Endangered due to Two Tactors:

Natural disasters can result in habitat destruction. For example, dinosaurs have been extinct for 65 million years. The hot, dry environment of the Cretaceous period abruptly altered, most likely as a result of an asteroid impact. As a result of the asteroid’s collision, debris was thrown into the atmosphere, decreasing the quantity of heat and light reaching the Earth’s surface. The dinosaurs couldn’t adjust to their new, cooler environment. Dinosaurs became extinct after becoming endangered.

Habitat loss can be exacerbated by human activity. The habitat of native organisms is reduced as a result of development for housing, industry, and agriculture. Increased contact between wild animals and humans can also be a result of habitat loss. People may have increased exposure to wild species when development puts them closer to a species’ range. Poisonous plants and fungi are likely to spread closer to people’s homes and schools. There are also increasing sightings of wild animals.

This can occur in many different ways. Indirectly, development can endanger species. Other organisms may use some species, such as tropical forests fig trees, as a habitat. Species that rely on tree habitats may become endangered as a result of tree destruction.

As a species’ range expands, it’s possible that habitat will be lost. Hundreds of square kilometres are covered by many creatures.

Genetic variety refers to the diversity found within a species. It’s why people’s hair might be blond, red, brown, or black. Species can adapt to changes in the environment due to genetic variation. In general, the larger a species’ population, the greater its genetic diversity.

Natural selection can result in a drop in genetic variation. Cheetahs are an endangered African and Asian species. There is virtually little genetic diversity among these large cats. Cheetahs went through a long period of inbreeding during the previous ice age, according to biologists. 

As a result, there are very few genetic differences amongst cheetahs. Fewer cheetahs reach maturity because they are unable to adapt to changes in the environment as quickly as other animals. Cheetahs are also considerably harder to procreate in captivity than other large cats like lions.

Many animal species have been decimated as a result of overhunting and overfishing. A breeding pair consists of two adult individuals of the species that are not related and are capable of producing healthy offspring. As the number of breeding couples diminishes, genetic variation decreases.

Population Reduction Rate

When a species’ population has decreased by 50% to 70%, it is considered endangered. This decrease is assessed over a period of ten years or three generations, whichever comes first. When a species’ population has fallen by at least 70% and the reason for the loss is recognized, it is designated as endangered. When a species’ population has fallen by at least 50% and the cause of the reduction is unknown, it is designated as endangered.

Geographic Range

The range of an endangered species is less than 5,000 km² (1,930 square miles). The range of endangered species’ area of occupancy is fewer than 500 km² (193 square miles).

Population Size

A species is deemed endangered when there are fewer than 2,500 mature individuals. A species is classed as endangered when its population drops by at least 20% in less than five years or two generations.

Endangered Species Examples

Siberian Sturgeon:

The Siberian sturgeon (Acipenser baerii) is a huge fish found in Russia’s Siberian rivers and lakes. The Siberian sturgeon is a type of benthic fish. The Siberian sturgeon is a threatened species since its population has decreased by 50 to 80 percent in the last 60 years (three generations of sturgeon). This reduction is due to overfishing, poaching, and dam construction.

()

Tahiti Reed Warbler:

On the Pacific island of Tahiti, the Tahiti reed warbler (Acrocephalus caffer) is a songbird. Because of its limited number, it is classified as an endangered species. The bird can only be found on a single island, implying that its range and range of occurrence are quite limited. Human activities have also put the Tahiti reed warbler at risk. Miconia is a non-native tropical weed that has encroached on most of Tahiti’s original flora.

()

Critically Endangered Species

Transcaucasian Racerunner:

The Transcaucasian racerunner (Eremias pleskei) is a lizard found in Armenia, Azerbaijan, Iran, and Turkey on the Armenian Plateau. The Transcaucasian racerunner is a severely endangered species due to a massive population drop of more than 80% in the last ten years.

()

White Ferula Mushroom:

The white ferula mushroom (Pleurotus nebrodensis) is a fungus that is critically threatened. Because its range is smaller than 100 square kilometres, the mushroom is highly threatened (39 square miles). It can only be found in the Mediterranean Sea, in the northern section of the Italian island of Sicily. 

()

Importance of Endangered Species

The Endangered Species Act (ESA) controls the endangered species list at the federal level. Congress approved the Endangered Species Act (ESA) in 1973. Protecting endangered species (species that are likely to become extinct throughout all or a major portion of their range), threatened species (species that are likely to become endangered in the near future), and important habitat is the responsibility of the federal government under the ESA (areas vital to the survival of endangered or threatened species).

Plant and animal species are protected both domestically and internationally under the Endangered Species Act. When a species is protected under the ESA, it is referred to as a “listed” species. Many more species, known as “candidate” species, are being investigated for possible protection under the ESA.

The Endangered Species Act is crucial because it protects our native fish, plants, and other endangered wildlife from extinction. They’re gone for good, and there’s no way to get them back. Because the effects will be felt throughout the food chain, even the loss of a single species can have severe consequences for the rest of the ecosystem. 

The benefits of preserving threatened and
endangered species are immeasurable, ranging from offering solutions for terrible diseases to sustaining natural ecosystems and enhancing the general quality of life.

Conservation of Endangered Species 

Find out which Species in your Area are on the Endangered List:

This is the first step towards becoming aware of your surroundings and sharing that awareness with others. There will be endangered species in almost every location. If you know which species are endangered, you can inform those around you so that they can take steps to ensure that these animals’ lives are not threatened.

Give your Time to Help Conserve the Animals in your Area:

Important species are frequently found at wildlife refuges, parks, and other locations. Volunteering at one of these locations to help safeguard the animals is a great way to help.

Toxic Herbicides and Insecticides should not be Used:

Many people want to do everything they can to have a beautiful lawn or garden, yet many herbicides and pesticides are terrible pollutants that harm the ecosystem severely. Find alternate ways to keep your lawn and garden growing without harming the environment or negatively impacting local wildlife.

Reduced Water Consumption:

Droughts are affecting many areas, and wasting water exacerbates the problem. Reduce your water consumption so that more water is available for the animals.

List of Endangered Species of Animals

Did you know?

Humans are too responsible for the extinction of 99 percent of the world’s species.

Over a quarter of all bird species are endangered or on the verge of extinction. Twenty percent of animals are on the verge of extinction. Invertebrates, such as butterflies, worms, and mollusks, make up 97 percent of all species on the Earth. A third of them are on the verge of extinction.