Endangered species and how to conserve themSpec 20.4.3, 20.4.4, 20.4.8
In short
An endangered species is at risk of dying out, and an extinct species has no individuals left alive. Causes include climate change, habitat destruction, hunting, overharvesting, pollution and introduced species. Endangered species are conserved by monitoring and protecting species and habitats, education, captive breeding programmes and seed banks. Artificial insemination and IVF help captive breeding.
An endangered species is at risk of dying out. A species is extinct when no individuals are left alive anywhere.
Why organisms become endangered or extinct
| Cause | Explanation |
|---|---|
| Climate change | Habitats change too quickly for species to adapt or move |
| Habitat destruction | Loss of food, shelter and breeding sites |
| Hunting | Animals are killed for meat, fur, horns or tusks faster than they reproduce |
| Overharvesting | Plants or animals are collected or caught faster than they can be replaced |
| Pollution | Poisons or waste make habitats unsuitable or kill organisms |
| Introduced species | A non-native species may compete with, prey on or spread disease to native species |
How endangered species can be conserved
- Monitoring and protecting species and habitats: populations are counted, and reserves and laws protect the animals and their habitats.
- Education: people are taught why species matter, so they support conservation.
- Captive breeding programmes: animals are bred in zoos and reserves, and young may be released into the wild.
- Seed banks: seeds of rare plants are stored at low temperature so that plants can be grown later if the wild population dies out.
Supplement (what this means)
Supplement: only for the Extended papers (2 and 4). Core students can skip it. What the labels meanArtificial insemination and IVF in captive breeding
Supplement (what this means)
Supplement: only for the Extended papers (2 and 4). Core students can skip it. What the labels mean- Artificial insemination (AI): sperm is collected from a male and placed into the female by a technician. It allows breeding between animals in different zoos without moving them, and helps animals that will not mate naturally.
- In vitro fertilisation (IVF): eggs are fertilised by sperm outside the body in a laboratory. The embryos are placed into the female, or into a surrogate female, to develop. This produces more offspring than natural mating.
- With both methods, conservationists can choose parents that are not closely related, which helps to keep genetic variation in the captive population.
Captive breeding programmes alone do not save a species. The habitat must also be protected so that the animals can be released.
Written and checked against the Cambridge IGCSE Biology (0610) specification · Updated October 2026