Conservation of endangered species
CIE A-Level BiologyΒ· 19.3 Conservation of endangered speciesΒ· 25 min read
1. In Situ Conservationβ β ββββ± 8 min
In Situ Conservation
The conservation of species in their natural habitat, involving active management of the ecosystem to maintain and protect wild populations.
Example:
Protection of black rhinos in South Africa's Kruger National Park
In situ is the preferred long-term conservation strategy for most endangered species. It maintains the species' natural behaviour, ecological interactions, and evolutionary adaptations within their native environment, and also protects the entire ecosystem, benefiting all co-existing species.
A small population of endemic lion tamarins lives only in a fragmented patch of Atlantic rainforest in Brazil. Outline how in situ conservation could protect this population.
- 1
- First, grant legal protection to the forest fragment to stop further deforestation and development.
- 2
- Create wildlife corridors to connect the fragment to larger intact forest areas, improving gene flow between isolated populations.
- 3
- Control invasive species that outcompete tamarins for food or habitat, and regularly monitor population size and health.
- 4
- Educate local communities to encourage participation in conservation and reduce human-wildlife conflict.
Exam tip:
Always mention the benefit of protecting the entire ecosystem when evaluating in situ conservation for 3+ mark questions.
2. Ex Situ Conservationβ β β βββ± 7 min
Ex Situ Conservation
Conservation of endangered species outside their natural habitat, used as an emergency backup when in situ conservation is no longer feasible.
Example:
Seed storage in the Svalbard Global Seed Vault, captive giant panda breeding in zoos
Ex situ conservation is used for species on the brink of extinction. It allows controlled breeding to increase population size, and supports research into species biology and threats. For plants, common approaches are botanical gardens and seed banks; for animals, captive breeding and frozen gamete storage (frozen zoos).
Explain why seed banks are an effective ex situ conservation method for endangered plants.
- 1
- Seeds are stored at cool, low-humidity temperatures, remaining viable for decades or centuries.
- 2
- Thousands of seed samples can be stored in a small space, making seed banks very cost-effective.
- 3
- Seeds preserve the full genetic diversity of the species, and can be reintroduced to restored natural habitats if the species goes extinct in the wild.
- 4
- A key limitation is that seeds from many tropical plant species cannot survive drying and freezing, so alternative methods are required.
Exam tip:
When comparing ex situ to in situ, always note that ex situ does not protect the natural habitat or broader ecosystem.
3. International Conservation Agreementsβ β β βββ± 8 min
Endangered species conservation requires global cooperation because species often cross national borders, and illegal wildlife trade is a transnational issue. The two key agreements you need for CIE are CITES and the Rio Convention on Biological Diversity.
CITES
An international agreement that regulates and restricts international trade in endangered species and their products to prevent overexploitation.
Example:
CITES bans international trade in African elephant ivory to reduce poaching
Evaluate the effectiveness of CITES in protecting endangered species.
- 1
Advantages:
- 2
- Signed by over 180 countries, creating a global framework for regulating wildlife trade.
- 3
- Has successfully reduced legal trade in many high-risk products like whale meat and ivory.
- 4
Disadvantages:
- 5
- Enforcement is weak in many countries, so illegal trade continues due to high black market prices.
- 6
- Does not address habitat loss, the main threat to most endangered species.
- 7
Conclusion: CITES is a useful complementary tool but must be combined with other strategies to be effective.
Exam tip:
For 6-mark extended response questions, you must include both advantages and limitations to gain full marks.
4. Captive Breeding and Reintroductionβ β β βββ± 7 min
Captive breeding is an ex situ strategy designed to increase population size of species that are nearly extinct in the wild. The end goal is to reintroduce captive-bred individuals back into protected natural habitats. Key steps in successful programmes include:
Maintaining a studbook to track the pedigree of all captive individuals to avoid inbreeding
Using assisted reproduction (artificial insemination, embryo transfer) to increase breeding success
Gradually acclimating captive-bred individuals to wild conditions before release
Monitoring the reintroduced population after release to track survival and breeding
Explain why inbreeding is a major problem in small captive populations.
- 1
- Small captive populations have very low genetic diversity, so closely related individuals often breed.
- 2
- Inbreeding increases the frequency of homozygous recessive harmful alleles, leading to reduced fertility, higher infant mortality, and lower disease resistance, a condition called inbreeding depression.
- 3
- Careful studbook management and exchanging individuals between zoos increases genetic diversity and reduces this risk.
5. Common Pitfalls
Wrong move:
Claiming ex situ conservation is always better than in situ conservation.
Why:
Ex situ is only a last resort when in situ is not feasible, and in situ has far greater long-term benefits. Examiners expect you to recognize in situ is the preferred approach.
Correct move:
State that in situ is the preferred first strategy, while ex situ acts as an important backup for critically endangered species.
Wrong move:
Confusing the role of CITES with the Rio Convention on Biological Diversity.
Why:
Students regularly mix up the core functions of the two key international agreements.
Correct move:
Remember: CITES regulates international trade in endangered species, while the Rio Convention focuses on sustainable use of biodiversity and habitat protection.
Wrong move:
Thinking in situ conservation is just leaving the habitat untouched.
Why:
In situ conservation requires active management, not just legal protection. Passive preservation is not the same as modern in situ conservation.
Correct move:
Include specific active management actions (corridors, invasive control, community engagement) when describing in situ conservation.
Wrong move:
Forgetting that seed banks conserve more than just endangered plants.
Why:
Students often only mention endangered species and miss the additional role of seed banks for agriculture.
Correct move:
Mention that seed banks also preserve genetic diversity of crop wild relatives for future crop improvement and food security.
6. Quick Reference Cheatsheet
Strategy | Type | Key Benefits | Key Limitations |
|---|---|---|---|
National Parks / Reserves | In Situ | Protects habitat + entire ecosystem, maintains natural behaviour | Conflicts with local communities, vulnerable to climate change |
Captive Breeding (Zoos) | Ex Situ | Increases population of critically endangered species, enables public education | Risk of inbreeding depression, high cost, reintroduction often fails |
Seed Banks | Ex Situ | Low cost, preserves genetic diversity, long-term storage | Not all seeds are storable, does not protect natural habitat |
CITES | International Agreement | Reduces illegal wildlife trade, enables global cooperation | Weak enforcement in many countries, does not stop habitat loss |
7. Frequently Asked
What is the difference between conservation and preservation?
Conservation is the active management of biodiversity to allow sustainable use of resources, while preservation protects ecosystems from any human interference entirely.
Do I need to include examples in exam answers for this topic?
Yes, CIE examiners expect specific named examples (e.g. Svalbard Seed Bank, Kruger National Park) to gain full marks for extended response questions.
When this came up on past exams
AI-estimated based on syllabus patterns β cross-check with official past papers for accuracy. Use only as revision-focus signals.
- 2022 Β· 22
Compare in situ vs ex situ conservation
- 2023 Β· 12
Discuss role of CITES in species protection
Going deeper
What's Next
Conservation of endangered species builds on your understanding of threats to biodiversity and connects to many other topics in the CIE 9700 syllabus. Modern conservation increasingly uses genetic technologies like DNA profiling to monitor genetic diversity in small populations, and assess the success of reintroduction programmes. This subtopic also links closely to discussions of the ecological and economic reasons for maintaining biodiversity, which is a common theme for extended response questions. Mastering the comparison between in situ and ex situ strategies is critical for high marks in paper 2 and paper 4.