Overpopulation

Overpopulation Definition: Overpopulation, also known as overabundance, happens when a species' population grows to the point where it must be handled. It can be caused by a rise in births, a decrease in mortality, increased immigration, or resource depletion. When there is overpopulation, the available resources become insufficient for the whole population to live comfortably, if at all. This paragraph straightly gives the answer to the question, ‘’what is overpopulation.’’

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Overpopulation is largely due to developments that began with a rise in birth rates in the mid-twentieth century. Migration could also result in overcrowding in some areas. Surprisingly, an area's overpopulation may happen without a net increase in population. It can happen when a population with an export-oriented economy outgrows its carrying capacity and migration patterns remain stable. "Demographic entrapment" has been coined to describe this situation.

Well Studied Species:

Deer: The Scottish government's plan to have landowners privately eradicate the overpopulation of red deer inside the highlands has failed miserably. In the spring, Scotland's deer are hindered, emaciated, and sometimes starve. As of 2016, the herd has grown to the point that 100,000 deer will have to be culled each year just to keep the population stable.

A number of landowners have shown reluctance to comply with the statute, necessitating government action. In order to comply with landowner regulations regarding the annual cull, licenced hunters had to be hired. The annual cull costs millions of pounds of taxpayer money. To make matters worse, some landowners have used supplementary feeding at exclusive shooting blinds to make sport hunting easier.

Overpopulation may have an effect on forage plants, leading to a species' alteration of the larger ecosystem. Ecosystems in nature are highly complex. The overpopulation of deer in the United Kingdom has been attributed to legislation that makes hunting increasingly difficult, but yet another factor may be the abundance of woods, which are used by various deer species to breed and shelter. Forests and parks have resulted in Britain becoming more and more forested than it has been in modern history, potentially causing biodiversity loss, heath habitat conversion to grassland, extirpation of woodland and grassland plants due to overgrazing, and habitat structure change. Bluebells and primroses are two examples.

Deer clear the forest and decrease the number of brambles that benefit dormice and other ground-nesting birds including the dunnock, nightingale, willow warbler, marsh tit, capercaillie, willow tit, song thrush, and bullfinch. Muntjac is thought to have the greatest effect on the nightingale and European turtle dove populations. Grouse populations are suffering as a result of their collisions with deer fencing. The much more open understory produced by the deer, on the other hand, might profit redstart and wood warblers.

Birds:

Cormorant populations have an effect on aquaculture activities, recreational angling, and threatened fish populations like the schelly. Cormorants have food and winter and year-round homes in open aquaculture ponds. Cormorants have a major impact on the aquaculture industry, as a dense flock can consume an entire crop. Cormorants are supposed to generate the Mississippi catfish sector between ＄10 million and ＄25 million per year. Sharp-shooting, roost dispersal, nest destruction, and egg oiling are all traditional methods of cormorant culling.

The number of geese has often been referred to as overpopulated. Snow geese, greater white-fronted geese, Ross's geese, and several numbers of Canadian geese have all increased dramatically in the Canadian Arctic region in recent generations. Fewer snow geese populations eventually surpassed three million and are increasing at a rate of about 5% per year. Giant Canada geese have risen from the brink of extinction to become a nuisance. The typical body size has shrunk, and parasite loads gradually increased. While there are still certain bust years, Arctic geese populations had boom and bust cycles prior to the 1980s, which were believed to be dependent on the availability of food. 

Pets:

The excess of domestic pets, like dogs, cats, and exotic animals, is known as overpopulation. Six to eight million animals were taken to shelters in the United States per year, with an approximate three to four million being euthanized, with 2.7 million who are safe and available for adoption. Ever since the 1970s, when centres in the United States euthanized an estimated 12 to 20 million animals, euthanasia rates have decreased. Some animal shelters, humane societies, and rescue organisations advise animal owners to get their pets spayed or neutered to avoid unwanted and unintended litter, which can lead to this phenomenon.

Population Cycles

In the wild, rapid population growth of prey species sometimes leads to increased predator populations. Predator-prey relationships may develop cycles that are mathematically represented by Lotka–Volterra equations.

Predator population growth lags behind prey population increase in natural habitats.

After the prey population collapses, the overpopulation of predators produces mass starvation in the overall population. If fewer young lives into adulthood, the predator's population declines. This can be a better moment for wildlife managers to encourage hunters or trappers to take as many of these such animals as they need, such as lynx in Canada, but this could affect the predator's capacity to restore once the prey population starts to rapidly increase once more. These mathematical models are indeed critical in calculating the optimum sustainable yield, or the quantity of fish that can be caught in a sustainable manner in fisheries.

Predator population growth does have the impact of regulating the prey population, and this can lead to prey species evolving genetic traits that make them less vulnerable to predation.

In the absence of predators, animals are constrained by the resources available in their climate, but this does not always prevent overpopulation, at least not in the short term. A plentiful supply of resources can result in a population explosion preceded by a population collapse. Lemmings and voles, for example, have population cycles that include rapid growth followed by a decline. Snowshoe hare communities, including those of one amongst their predators, the lynx, cycle significantly. The cycles of grey wolf and moose communities in Isle Royale National Park are yet another example. These variations in mammal population dynamics are much more common in habitats observed at higher arctic latitudes for a certain explanation that is still unknown. Some insects, like locusts, go through major natural cyclic changes that farmers experience as plagues.

Introduced Species:

When trout and deer were brought into Argentina or rabbits were introduced to Australia and predators were introduced in response to try to control the rabbits, ecological disruption was common. Invasive species are introduced species that are so popular that their population grows rapidly and causes harm to fisheries, farmers, or the natural environment.

Criticism:

In natural environments, populations typically multiply before they exceed the environment's carrying capacity; once the environment's resources are depleted, populations eventually collapse. Calling this 'overpopulation,' according to the animal rights movement, is more of an ethical concern than scientific reality. Environmental systems and wildlife management are often criticised by animal rights organisations. Animal rights advocates and locals that profit from commercial hunting argue that scientists are outsiders who've been unfamiliar with wildlife problems, and therefore any animal killing is wrong.

Due to the lack of culling, hunting, or natural predators (including wolves), the use of cattle as "natural grazers" in certain European nature parks might result in an overpopulation as the cattle may not migrate, according to different case studies. Since cattle eat native plants, it does have the potential to reduce plant biodiversity.

Human Overpopulation:

Overpopulation may happen as a consequence of a rise in births, a decrease in mortality rates, and high fertility rates. It is probable for sparsely populated areas to become overpopulated if the area's ability to support life is limited or non-existent (e.g. a desert). Advocates for population moderation use topics such as quality of life and the possibility of hunger and disease to speak against increasing human overpopulation and in favour of population decline.

Effects of Overpopulation:

Below mentioned are some of the consequences of overpopulation-

1. Environmental Effects of Overpopulation

• Farming impacts

• Deforestation

• Eutrophication

• Global Warming

• Loss of Freshwater

2. Species Extinction

3. Depletion of Natural Resources.

4. Lower Life Expectancy in the Fastest Growing Countries.

5. Less Freedom, More Restrictions.

6. Increased Emergence of New Epidemics and Pandemics.

7. Increased Habitat Loss.