Mod 4 Lecture 31 - Reintroductions and Rewilding Notes

AVBS3004: Reintroductions and Rewilding

Learning Outcomes

• Define and distinguish between reintroduction and rewilding in the context of conservation biology.

• Identify the ecological, genetic, and social criteria that guide decisions around species reintroduction and rewilding projects.

• Critically evaluate case studies of successful and unsuccessful reintroduction or rewilding initiatives.

• Understand the potential risks, ethical challenges, and unintended consequences associated with reintroducing species or altering ecosystems.

• Explain how rewilding fits within broader conservation strategies.

Why?

• Biodiversity loss: 1 million species at risk of extinction (IPBES 2019).

• Habitat fragmentation, climate change, and human pressures reduce ecosystem function.

• Conservation is shifting from protecting remnants to actively restoring ecosystems.

Definitions

• Reintroduction: “the intentional movement and release of a species into an area where it once occurred but is now extinct, with the goal of re-establishing a viable, self-sustaining population.” – IUCN

• Rewilding: “large-scale restoration of ecosystems to the point where nature is allowed to take care of itself. Rewilding seeks to reinstate natural processes and, where appropriate, missing species – allowing them to shape the landscape and the habitats within.” – Rewilding Britain

Reintroductions

• Previously discussed from a captive breeding program perspective

• IUCN 2013 Guidelines:

  • Feasibility and Risk Assessment

  • Genetic and behavioral suitability

  • Socioeconomic and stakeholder considerations

IUCN Guidelines – Feasibility Assessment

• Ecological feasibility: suitability of the release site

  • Habitat quality

  • Food availability

  • Predator presence

• Threat assessment: ongoing threats to the population must be reduced to acceptable levels before release

IUCN Guidelines – Genetic and Behavioral Suitability

• Ensure genetic diversity in founder population to avoid inbreeding and maintain adaptability.

• Assess if captive individuals are behaviorally and physiologically prepared for the wild.

IUCN Guidelines – Socioeconomic and Stakeholder Considerations

• Stakeholder identification and engagement

  • Local communities

  • Government

  • Landowners

  • NGOs

• Conflict mitigation and benefit sharing

  • Anticipate possible human/wildlife conflict situations

  • Integrate benefits to the local community

IUCN Guidelines - Translocations

• Reintroduction: Into historical range (e.g., Scimitar-horned oryx)

• Reinforcement: Supplementing existing populations (e.g., Scottish wild cat)

• Assisted Colonisation: Outside historical range due to climate change (e.g., Western swamp turtle)

IUCN Guidelines

• Start with Intentional Release: Is the species being moved deliberately?

• Define the Goal:

  • Improve species status → Reintroduction or Reinforcement

  • Restore ecosystem function → Ecological Replacement

• Evaluate Species Status:

  • Extinct in the wild → Reintroduction

  • Still present → Reinforcement

• Assess Suitability of Release Site:

  • Inside historical range → Conventional translocation

  • Outside range (e.g., due to climate change) → Assisted colonization

Rewilding

• First emerged in North America in 1980s – called ‘wilderness recovery’

• Defined as ‘rewilding’ in 1992 – ‘a proposed method of preserving natural areas to connect and create habitat for all native species in North America’

• A few years on in 1998 Soulé and Noss officially defined rewilding under a ‘3C model’ in protecting Cores, Corridors, and Carnivores

• Particularly, the protection of ‘big wilderness’ and wide ranging, large animals.’

• Why large carnivores? – Keystone species whose benefits outweigh their population size.

Why rewilding?

• In response to biodiversity loss

• Even in large-scale protected areas, biological communities continue to unravel and species being lost – need more proactive approaches

• Reintroducing species that have been lost, or ‘rewilding’ aims to restore ecological balance and functions = ecological resilience

• Actively reintroducing species = classic ‘Trophic Rewilding’: emphasis on trophic cascades within ecosystems produced by apex consumers – ‘top down’ effects.

• Not just predators!

Different types of rewilding

• Trophic rewilding: restoring top-down trophic interactions and cascades via translocations

• Pleistocene rewilding: reintroducing species that were present during the Pleistocene epoch (2.6 million to 11,700 years ago) OR extinct species with domesticated descendants – i.e., Pleistocene Park, Siberia

• Passive rewilding: ‘let nature take over’ – no active management, absence of species reintroduction. Popular in Europe in natural rewilding of abandoned agri lands

• Ecological rewilding: intermediate rewilding approach, used in highly modified environments. More plant focused – active planting restoration combined with reintroductions

Rewilding in Australia

• Unlike North America and Europe, Australia does not have a strong history with rewilding work

• The unique characteristics of Australian landscapes compared to other parts of the world makes rewilding tricky

• Rewilding such as the reintroduction of large herbivores/carnivores or passive rewilding of expanses of land has not been seen in Australia

• Majority of conservation work in Australia has focused reintroduction into fenced predator-proof areas following the removal of invasive predators - 24 fenced sanctuaries to date

• Is this true ’rewilding’?

WWF rewilding in Australia

• Various rewilding projects are underway in South Australia, New South Wales, Victoria, and Tasmania, involving species like brush-tailed bettongs, platypus, eastern bettongs, eastern quolls, southern brown bandicoots, long-nosed poteroos, wombats.

Case study: beaver bombing in the UK

• Guerrilla beaver reintroductions

• Under the cover of darkness, ‘beaver black ops’ teams across Europe are illegally releasing beavers back into local waterways.

• Ecosystem engineers, or keystone species: fell trees, build dams, create wetland – ideal habitat for other wildlife.

• A healthy wetland systems beavers create can sequester large amounts of carbon and slow water flow, protecting from floods and droughts.

Case study: beaver bombing in the UK - Backlash:

• Ecologists: “Who cleans up the bill for illegal anonymous rogue rewilding if things go wrong?”

• Could increase the chances of conflicts between humans and wildlife, spread disease and actively harm biodiversity by introducing the wrong animals into the wrong environments

• Making decisions based on personal bias rather than ecological expertise

• Beavers are capable of destroying valuable trees, eating crops and flooding farmland.

• In Tayside, Scotland, where beavers were illegally introduced around 2006, farmers shot the animals on sight.

Backlash to rewilding

• Examples of backlash to rewilding efforts include a fatal bear attack in Italy, leading to political issues; Swiss farmers protesting rising wolf numbers; and a Dutch rewilding experiment resulting in animal starvation.

Conservation framework

1. Define the problem: What is causing the problem?

2. Set goals: Set specific targets; What is desirable?

3. Evaluate management options: Cost: benefit analysis; What will work in this population?; What is acceptable?

4. Manage: Record what you do

5. Monitor outcomes: Report

6. Evaluate success

Rewilding: stakeholder engagement is the key to success

• Conservation framework: Stakeholders

• What is a stakeholder in conservation management?

  • An individual/group/organization with an interest in a conservation initiative that can either affect or be affected by it
    *Different people may have different opinions on what is causing the problem, what the goals should be, what management should be done (if any)

Stakeholder Considerations

• Positive: Acknowledge conflict, Work cooperatively, Adopt sensitive behaviors, Listen & openly communicate

• Negative: Avoid behaviors that give rise to risk, Recognise interdependence of efforts, Acknowledge & monitor

• Remember: everyone’s opinions are valid

Urban rewilding

• Most extensive biodiversity loss occurring right in our backyards

• By 2050 ~ 70% of the world’s expected 10 billion inhabitants are expected to live in urban areas, a 20% increase on what we see today

• In Australia, 90% already live in cities

• Globally, urban footprints are expanding on average twice as fast than their populations – massive fragmentation

• In the US, in the next 20 years total urban land cover will surpass national and state parks and private reserve areas combined

• But, cities are often built in biodiversity ‘hotspots’

Urban rewilding - challenges

• Narrative that urban environments are of little conservation value

• Misconceptions about the ability of species to persist in urban environments – i.e. remnant habitats not suitable

• Means most conservation efforts place premise on protecting areas of ’wilderness’ or controlled remote areas (fenced sanctuaries)

• Exclude urban areas assigning low conservation value a priority

• Very few global examples of rewilding in cities globally

• IPBES global report on biodiversity loss (2018): major indirect driver of biodiversity decline is peoples lack of connection with nature

Urban rewilding – extinction of experience

• Ideas of ’wilderness’ that position nature and humanity as separate = undervalue in urban areas

• People in cities becoming more and more disconnected with nature

• ‘Extinction of experience’ or ‘biological impoverishment’ = disinterested in conservation

• How can you value what you cannot see?

• ‘Collective ignorance leads to collective indifference’

• US: more likely to ID corporate logos than native plant species, teens in LA more likely to correctly ID a weapon by its sound, than native birds

• Need to ‘re-connect’ people, urban areas are the best place for it! - Need to empower, not scare

• Plus, many physical and mental benefits of being in greenspace

Urban rewilding – a bold conservation approach

• A lot work being down to restore parklands and reserves around Sydney BUT vegetation focused

• Support complex set of plants and recreated habitats, but many urban areas contain increasingly simplified animal communities, or many invasives

• ‘Field of dreams’ hypothesis

• ‘Restored’ ecosystems in cities typically comprise revegetated urban landscapes – heavily fragmented, natural recolonisation of species unlikely

• Need a more proactive approach – active species reintroduction, or ‘rewilding’

• Improve ecosystem function, avert future declines

• Large opportunities for people to engagement with nature!

Urban rewilding – peregrine falcon

• Significant population crash in USA from 1950 – 1970 due to DDT (Rachel Carsons ‘Silent Spring’)

• Between 1974 – 1999 over 5102 falcons released over the US, now over 3000 breeding pairs

• ‘Hack boxes’ on buildings

• Most successful release sites in cities – abundant prey, fewer predators / competitors, ample next sites

• Now closely watched and well-loved in cities

• Live cams on nests worldwide, even in Melbourne

Urban rewilding – Eurasian red squirrel

• Widely distributed in Eurasia, large declines in cities due to habitat loss

• Reintroduction of 24 individuals in 1997 in two urban parks across two cities in Portugal

• Population now thriving, spread to other parks

• Groups and school classes that come and observe the squirrels

• Considered an important tool of environmental education by urban park managers and other stakeholders

Urban rewilding – North Island kākā

• Rare on mainland NZ due to habitat loss, invasive predation

• Separate releases of 14 juveniles across 2002 and 2007 into a predator proof sanctuary ‘Zealandia’, Wellington. Birds moved outside the fence into surrounded urban land

• Population now thriving in Wellington City

• Support of the local community was essential to the success of the program

• Allowed the Wellington community to learn about and become engaged with conservation

• But, increasing human – kākā conflict: locals reporting feeding damage to trees, buildings, and outdoor furniture, costing NZ$3000$$$3000$$ to repair