Strategies of Biodiversity Conservation (Cambridge (CIE) AS Environmental Management)

Revision Note

Alistair Marjot

Written by: Alistair Marjot

Reviewed by: Bridgette Barrett

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

Evolutionary tree showing how the platypus can be considered to be a EDGE species
The platypus (species "A") can be considered to be an EDGE species as it is evolutionarily distinct from rabbits (species 'E') and rats (species 'F'), which have a more recent common ancestor — the platypus is a unique and iconic egg laying mammal that is the only living representative of its family and genus

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

Photo of a Chinese giant salamander
The Chinese giant salamander is both evolutionarily distinct and globally endangered, and is a focal species for the EDGE programme (CC BY-SA 4.0, via Wikimedia Commons)

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

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Alistair Marjot

Author: Alistair Marjot

Expertise: Biology & Environmental Systems and Societies

Alistair graduated from Oxford University with a degree in Biological Sciences. He has taught GCSE/IGCSE Biology, as well as Biology and Environmental Systems & Societies for the International Baccalaureate Diploma Programme. While teaching in Oxford, Alistair completed his MA Education as Head of Department for Environmental Systems & Societies. Alistair has continued to pursue his interests in ecology and environmental science, recently gaining an MSc in Wildlife Biology & Conservation with Edinburgh Napier University.

Bridgette Barrett

Author: Bridgette Barrett

Expertise: Geography Lead

After graduating with a degree in Geography, Bridgette completed a PGCE over 25 years ago. She later gained an MA Learning, Technology and Education from the University of Nottingham focussing on online learning. At a time when the study of geography has never been more important, Bridgette is passionate about creating content which supports students in achieving their potential in geography and builds their confidence.