How can overpopulation affect a species

Ten thousand years ago, the mass, the weight, all of the humans on the earth, plus all our pets, plus all the livestock we keep to feed ourselves, was 0. The rest of the mammals — elephants and tigers and rhinos and whales and kangaroos etc — made up Since the Year , around the world, more than species of bird have become extinct. One in 8 species is now at risk of worldwide extinction, and bird species are critically endangered.

One in two mammals are shrinking in number, and nearly one in four species is at risk of extinction. More than species are critically endangered, including land icons such as the African mountain gorilla and the Sumatran orangutan, and sea icons such as whales, dolphins and seals. Examples include the Wedge-tailed Shearwater — waters of the Great Barrier Reef which are too warm for its preferred food; the Fairy Tern, whose nests are now destroyed by foxes due to falling water levels in the drought stricken Murray, and the Mallee Emu Wren has lost more than half its population in 10 years to bushfires and drought.

Donate Now Subscribe. Recent News:. Staff Spotlight: Ronald Ahirirwe October 22, Latest eNews view all Newsletters view all Annual Report view all. Current World Population 7,,, Net Growth During Your Visit 0. You can make a big difference. Clinic Monitoring. More than 27, people used a Planned Parenthood widget from East Los High 's website in the first month of broadcast.

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Tell Us Your Story. Learn More. Donate Now. As the number of people increases, so does the demand for food, water and other resources. The harmful emissions produced by factories and vehicles cause environmental damage, such as climate change. In a particular place, over population can also be caused by an influx of people forced into the area due to war, famine or other disasters making their previous home uninhabitable. Climate Change is causing an increase in the number of hurricanes and floods and is likely to cause many more people to become displaced in the future.

Overcrowding leads to further demand for limited resources and this, in turn, can lead to more conflict and warfare. As humans seek out more resources, they take over land that was once the habitat of other species leading to huge biodiversity loss. Animal overpopulation occurs when an ecosystem is unable to support the existing wildlife because there are too many of a given species.

The environment suffers due to the strain from the natural activities of the overpopulated species. The results can be devastating as animals scrape for food and wander into unnatural habitats in search of something to eat. Disease is also a factor as the ecosystem makes a final attempt to regain a natural balance and order. Overpopulated animal species lead difficult lives with limited resources. Lack of food occurs when there is a breakdown in the food chain due to overpopulation.

This is typically a cause-and-effect relationship. For example, in ecosystems where carnivores die out or become extinct, herbivores begin to grow in numbers. Without the balance achieved from the predator-prey relationship, overpopulated herbivores will compete for the same plant species, causing scarcity, or wiping out the plant species entirely.

This unnatural balance damages the ecosystem and food chain. When too many of the same animal compete for a similar food source, many die from starvation. Others are forced to leave their natural habitats in search of food. When overpopulated animals are starving, their innate survival instincts cause them to wander into unnatural places in search of food.