Strategies of Biodiversity Conservation (Cambridge (CIE) AS Environmental Management): Revision Note

Evolutionarily Distinct and Globally Endangered species (EDGE) programme

• There are so many species that need protection that it can seem like an impossible task to decide where to allocate the limited resources available

• The EDGE programme is an initiative developed by the Zoological Society of London (ZSL):

  • It aims to prioritise and conserve evolutionarily distinct and globally endangered species

  • These species are considered to be relatively unique in terms of their evolutionary history, and face the highest risk of extinction

Selection Criteria

• EDGE species are selected based on their evolutionary distinctiveness, which measures how genetically different a species is from its closest relatives:

  • Species that have few close evolutionary relatives

  • Species that are unusual in appearance, behaviour and DNA

  • Species that represent a part of Earth's evolutionary tree that is not represented anywhere else

• They are also selected based on their conservation status, with a focus on species that are critically endangered or those facing imminent extinction:

  • The IUCN red list is used to provide information about the threat level of an evolutionarily distinct species

  • A species must be globally threatened, not just threatened on a local level

• Examples of priority EDGE species include:

  • Largetooth sawfish

  • Chinese giant salamander

  • Purple frog

Conservation Prioritisation

• The EDGE programme prioritises species with high EDGE scores, indicating their evolutionary distinctiveness, and develops conservation strategies tailored to their specific needs:

  • This may include habitat protection, anti-poaching measures, community engagement and captive breeding programmes

Community Involvement

• The EDGE programme encourages community involvement and collaboration with local stakeholders to ensure the success of conservation efforts:

  • By engaging communities living near EDGE species habitats, the programme aims to address human-wildlife conflicts, promote sustainable resource management and raise awareness about the importance of biodiversity conservation

Impact

• The EDGE programme has contributed to the conservation of numerous species worldwide, including the Hainan gibbon, Philippine eagle, and Yangtze giant softshell turtle:

  • It has achieved this by providing funding, technical support and capacity building to conservation projects focused on these species

Captive Breeding

• Captive breeding is the process of ensuring that endangered species reproduce in captivity, often in zoos, aquariums, or specialised breeding facilities:

  • The goal is to increase their population size and genetic diversity

  • Once bred, individuals may be released into their natural habitat to boost wild populations

Advantages

• Population recovery:

  • Captive breeding programmes can help recover populations of endangered species that are declining in the wild due to habitat loss, poaching or other threats

• Genetic Diversity:

  • By carefully managing breeding pairs and avoiding inbreeding, captive breeding programmes can maintain or increase the genetic diversity of endangered species

  • This reduces the risk of genetic diseases and enhances their long-term survival prospects

• Education and Awareness:

  • Zoos and aquariums with captive breeding programmes play a crucial role in educating the public about endangered species and the importance of biodiversity conservation

Challenges

• Habitat Suitability:

  • Reintroducing captive-bred individuals into the wild requires suitable habitat and conditions for their survival, including access to food, shelter and mates

  • Ensuring that release sites meet these requirements can be challenging

• Adaptation:

  • Captive-bred individuals may lack the necessary skills and behaviours to survive and reproduce in the wild, such as foraging, predator avoidance, or social interactions e.g. attracting a mate

  • This can reduce their chances of successful reintroduction

• Cost and Resources:

  • Captive breeding programmes require significant financial investment and expertise to manage breeding populations, provide appropriate care and monitor released individuals

  • This makes captive breeding a very resource-intensive process, requiring a lot of money, time and highly qualified people

Evaluation

• While captive breeding and release can be an effective conservation tool for certain species, it is not without limitations and risks:

  • Success depends on careful planning, ongoing monitoring and adaptive management to address challenges and maximise the effectiveness of conservation efforts

  • Additionally, captive breeding must be used alongside broader conservation strategies, such as habitat protection and restoration, rather than a standalone solution to biodiversity loss