Reasons why predators are endangered 1 – Lack of prey

| July 9, 2013 | Reply

Predators need prey. An eagle, a cat or a shark cannot survive without a regular and sufficient food supply. Although some reptiles can live for months without food, mammals like Lions or Leopard and birds like Golden Eagles or Great Horned Owls need regular food (not every day but they cannot live without eating for several months).

Unfortunately many prey species are also endangered as many predators.

For example, the Hog Deer from Asia – which is eaten by Tigers, Leopards and Dholes – is now classified as Endangered by the IUCN – that is the same category as the Tiger is in.

The European Rabbit is now classified as Near Threatened because of a sometimes dramatic decline in the last decades. It is ironic that the species is considered a pest and an invasive species in many countries around the world but on the Iberian Peninsula where the European Rabbit evolved it is now a threatened species. This is not only of serious concern because of the European Rabbit itself but the species is also an import prey of the Critically Endangered Iberian Lynx and the Vulnerable Spanish Imperial Eagle. The diet of the Iberian Lynx can be more than 80% rabbits and the Spanish Imperial Eagle also favors this prey species – although it also hunts other animals like Red Partridges. The European Rabbit declined due to diseases, habitat destruction and overhunting.

In Africa, bushmeat hunting can dramatically reduce the prey of Leopards, for example River Hogs and forest dwelling antelope species (see this press release by Panthera (PDF).
It is possible that other predators like African Crowned Eagles (who prey on monkeys and small antelopes) are also negatively affected by the hunting of their prey species.

The lack of prey can lead to the following problems for predators:

  • They simply starve. Without regular food the animals either leave a certain area or starve.
  • If they leave, they may have to enter a territory of another member of the same species (or another dangerous predator, e.g. a Leopard entering a Tiger territory) which may result in the death of the predator.
  • When natural prey gets rare, many predators like large cats will attack more livestock which brings them into conflict with people. This will often lead to the killing of the predator.
  • Less offspring. If the females cannot get sufficient food they may give birth so smaller litters (or lay less eggs in the case of birds). And the already smaller number of young are then threatened themselves if the female (in mammals) or both parents (in birds) cannot find and kill enough prey.

If we want to protect and conserve predators like Tigers, Jaguars or Martial Eagles, we also need to protect their prey. Of course the prey species themselves are as much worth saving as the predators.

Saving many of the prey species is not easy and they face – among others – the following threats:

  • Lack of habitat: The ongoing destruction of habitat around the world is a serious threat for many prey species like deer, monkeys, birds or fish.
  • Conflict with livestock: Many species like deer or antelopes often compete with livestock leading to the killing of the wild animals.
  • Overhunting: As already mentioned above in the bushmeat example, overhunting is a serious threat to many species. Overhunting, often combined with habitat destruction or deterioration can lead to rapid population decline and even extinction – at least locally.
  • Diseases: When wild animals come into contact with domestic animals, diseases can jump over to the wild animals and seriously reduce their population

Conservation of enough prey for predators involves a serious of different strategies, incl:

  • Protection of habitat: Large areas of suitable habitat needs to be protected or managed in a way that wild animals like deer, antelopes, rabbits or birds can live there.
  • Hunting must be reduced to a sustainable level. Local people need alternatives to hunting wild animals.
  • More research: For many animals we don’t even know the current population numbers or trends. More research is definitely needed here to learn about a possible decline. Also, research into the ecology of the prey animals is needed to implement sound conservation strategies.
  • Reintroduction: If the habitat is still suitable and former threats are gone, locally extinct species can be reintroduced.

The relationship between predators and prey is among the most fascinating topics in ecology and we still have a long way to go to fully understand it – if this is even possible.
The arms race between predators and prey is also one of the most fascination topics in evolution.

We must work hard to protect both predators and prey so that ecological processes and evolution through natural selection can continue.

Category: conservation

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