Conservation Case Studies (DP IB Environmental Systems & Societies (ESS))

Extinct, Critically Endangered & Improving Species

Extinct species

• Passenger Pigeon (Ectopistes migratorius):

  • The Passenger pigeon was once one of the most abundant bird species in North America, numbering in the billions of individuals

  • However, due to overhunting and habitat destruction, the passenger pigeon went extinct in the early 20th century

  • The hunting of these birds for meat, as well as the destruction of their forest habitats, led to a sharp decline in their numbers

  • By the late 1800s, the species was in serious decline, and despite some attempts at conservation, it went extinct in 1914

• Tasmanian Tiger (Thylacinus cynocephalus):

  • The Thylacine, also known as the Tasmanian Tiger or Tasmanian Wolf, was a carnivorous marsupial that once inhabited the Australian island of Tasmania

  • Human activity such as hunting, habitat loss and disease transmission by introduced species caused their population to decline

  • The last known Tasmanian tiger died in captivity in 1936, marking the extinction of the species

Critically endangered species

Sumatran Orangutan (Pongo abelii):

• The Sumatran orangutan is one of three species of orangutan and is found only on the Indonesian island of Sumatra

• Habitat destruction and fragmentation due to logging, conversion of forests to agriculture, and infrastructure development have been the primary causes of its decline

• In addition, illegal hunting and capture of orangutans for the pet trade have also contributed to their decline

• The Sumatran orangutan is now critically endangered, with only around 14 000 individuals remaining in the wild

• Black rhinoceros (Diceros bicornis):

  • The black rhinoceros is a large mammal native to Africa and is critically endangered due to poaching for their horns, habitat loss, and civil unrest in the countries of their range

  • Their population has declined by over 90% since the 1960s, and there are currently only around 3 000 mature individuals remaining in the wild

  • Conservation efforts such as anti-poaching patrols, habitat restoration and captive breeding programs are underway to try to save this species from extinction

Improving species

Southern white rhinoceros (Ceratotherium simum):

• The Southern white rhinoceros was once on the brink of extinction due to poaching for their horns, with only a handful of individuals surviving in the wild in South Africa in the early 20th century

• However, conservation efforts including increased law enforcement, habitat protection, and captive breeding programs have helped their population recover to over 18 000 individuals today

• While they are still threatened by poaching and habitat loss, the Southern white rhinoceros' conservation status has greatly improved thanks to human intervention

• Bald eagle (Haliaeetus leucocephalus):

  • The bald eagle is a bird of prey native to North America and was once on the brink of extinction due to habitat destruction, hunting, and pesticide use, which caused eggshell thinning and reproductive failure

  • Conservation efforts such as habitat protection, captive breeding programs, and the banning of harmful pesticides like DDT have helped their population recover from less than 500 pairs in the 1960s to over 10 000 pairs today

  • The bald eagle's conservation status has greatly improved thanks to human intervention