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A vulnerable species is any kind of species that is at risk of becoming extinct. Often species are vulnerable because they lose their homes. Vulnerable species are those that have a steady drop in population over time. Finally, these species will likely become endangered or extinct if threats to their survival aren’t fixed.


Vulnerable Species- a group of organisms at a high risk of going extinct. The extinction of vulnerable species can occur after several years.

Endangered Species- any organism that is at a very high risk of becoming extinct. Endangered species can go extinct after a few years


The International Union for the Conservation of Nature (IUCN) has a list of things known to make a species vulnerable. Species must meet the following requirements before they are “vulnerable.” (Research from National Geographic)

vulnerable species criteria
  1. Population Reduction Rate

  • A species is vulnerable when there is a 30% or greater decline in its population. 
  • There are two ways scientists track populations. First, they can track the population reduction rate over a decade (10-year period). Second, they can measure over three generations of the species (grandparents, parents, children). 
  • When the population of a species declines by 30% and the cause is not known, the species is vulnerable. For example, if there are 4000 bears in a forest and the number declines to 2800 from a new disease, the bears are “vulnerable.” 
  • A 50% decline in a species population from a  known cause also makes a species “vulnerable.” For example, if the population of the 4000 bears reaches 2000 due to hunting activities. Then the bears are “vulnerable.”
  1. Reduction in the Extent of Occurrence

  • In Biology, a species’ “extent of occurrence” means the smallest place where a species can live and how many live there. These places are defined on a map.
  • A species is vulnerable when its extent of occurrence is less than 7,722 total square miles.
  • Additionally, a species is vulnerable if the population does not exist in more than ten places.
  • Loss of habitat causes a smaller extent of occurrence.
  1. Population Size of Mature Individuals

  • A species is vulnerable if the population of mature individuals is less than 10,000.
  • A species is also vulnerable when there is a 10% or more loss in the population in 10 years. 
  • The number of mature adult animals in a habitat can fall quickly or slowly.
  1. Restricted Population

  • Population restriction is when there are fewer adult animals in a habitat. Loss of habitats also causes population restrictions.
  • Vulnerable species have an area they live in that is less than 8 square miles.
  • A species is vulnerable when there are 1,000 or fewer adult animals in a place they normally live.
  • Species that are restricted are at risk of becoming endangered.
  1. High Likelihood of Extinction

  • A species is vulnerable if there is a 10% or greater chance of it going extinct within a period of 100 years.
  • Scientific research is the only way to know the extinction rate of a species.
  • If vulnerable species are not helped they are likely to become endangered. Endangered species are more likely to go extinct than vulnerable species.


A large number of animal species in the wild are considered vulnerable. This is due to harmful human activities. Currently, about 5,000 animal species are vulnerable: (Research from AZ animals)

examples of vulnerable species


  • The cheetah is the world’s fastest land animal. Cheetahs can go from 0-60 mph in just three seconds.
  • The population size of cheetahs in the wild is about 7,000. Habitat loss is the biggest threat to the cheetah population. Cheetahs are also hunted and killed by humans.
  • 79% of the cheetah habitats in the wild have less than 100 adult cheetahs.

Wandering Albatross

  • The Wandering Albatross has the widest wingspan of all living birds. On average, Albatrosses have an 11-foot wingspan.
  • Out of the 22 Albatross species, 7 are vulnerable. The population of these birds is falling due to fishing activities that harm them.
  • As of now, there are only about 25,000 Wandering Albatross in the wild.

Polar Bears

  • The main threat to polar bears is climate change. Global warming is causing the arctic ice to melt. The ice in these regions is important to polar bears. 
  • Polar bears use ice to hunt, travel and find mates.  Currently, there are around 25,000 polar bears in the world.
  • Some Scientists think polar bears will go extinct within the next 30 years.


  • The IUCN lists lions as a vulnerable species. In fact, lions are endangered in some African countries.
  • Their numbers are falling quickly as a result of human-lion conflicts and habitat loss.
  • The population size of lions in the wild is about 20,000.

Snow Leopard

  • Snow leopards are mainly found in Europe.
  • The population of snow leopards is falling due to habitat loss and hunting.
  • There are about 5,000 snow leopards left in the wild.


The Philippines is one of the most biodiverse places in the world. Some of the plant and animal species in the Philippines are not anywhere else on the planet. (Research from Mongabay)

Philippines and species
  • Many animal species in the Philippines are vulnerable or endangered.
  • The IUCN says more than 400 animal species in the area are vulnerable.
  • Poaching, or illegal hunting, is the main problem. Animals are also losing their habitats due to deforestation. Deforestation is the cutting down of trees. 
  • The Palawan fruit bat, Gray’s monitor, Philippine porcupine, and Sarangani Tiger are some examples of vulnerable species in the Philippines.


There have been many species that have died out over time. Extinction is a slow process that can take hundreds or even thousands of years to happen. It all starts with a species’ vulnerability and then gets worse until it’s in real danger.

It is only possible to save vulnerable species if we act quickly to change the unfavorable conditions that threaten their existence. This is what you need to do to help animals and their habitats.

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