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Good practice Imported

Falkland Islands Offshore Rat Eradication Programme

Falkland Islands (Malvinas) · Stanley · See the Falkland Islands (Malvinas) profile

Evidence: Quasi-experimental Top 81% 33/100 · Ask Evidence Copilot about this practice

Since 2001, Falklands Conservation and partners have cleared invasive Norway rats from 65 islands (~6,500 ha) for under £250,000; a peer-reviewed study found bird species richness on cleared islands matches historically rat-free islands within 1–11 years.

65 islands
Islands cleared of Norway rats (2001-2019)
~6,500 ha
Total area cleared
under 250,000 GBP
Cumulative programme cost (2001-2019)
2,070 ha
Largest island cleared (Bleaker Island) (2019)
230 islands
Islands surveyed in peer-reviewed study
1-11 years
Species-richness convergence window with historically rat-free islands
26 islands
Cleared islands re-invaded within five years (within 5 years)
Falkland Islands Offshore Rat Eradication Programme

Details

Maturity
Established
Promoter
Falklands Conservation / Wildlife Conservation Society
Period
2001–2019
Keywords
invasive rodent eradication, seabird & passerine conservation, island biosecurity

Context

The Falkland Islands' offshore archipelago hosts globally important seabird and passerine populations, including the endemic Cobb's wren (Troglodytes cobbi), but introduced Norway rats (Rattus norvegicus) devastate ground-nesting birds on invaded islands.

Objectives

From 2001, Falklands Conservation, the Wildlife Conservation Society (owner of Steeple Jason Island) and local landowners engaged New Zealand rodent-eradication specialist Derek Brown to run a rolling programme of island-by-island rat eradications using bait stations and trapping.

Activities

Between 2001 and 2019, the programme cleared Norway rats from 65 islands totalling roughly 6,500 hectares, ranging from under 1 hectare up to the 2,070-hectare Bleaker Island (cleared in 2019), for a cumulative cost of under £250,000, one of the most cost-efficient island-eradication records documented globally.

Results

A peer-reviewed study (Tabak et al., Journal of Animal Ecology, 2015) surveyed 230 Falkland islands -- 85 still holding rats, 108 historically rat-free, and 37 post-eradication -- and found that passerine species richness on eradicated islands converged with that of historically rat-free islands within just 1-11 years, with strong recoveries of vulnerable species such as Cobb's wren and the blackish cinclodes.

Conclusions

26 additional islands that were cleared became re-invaded within five years, underscoring the need for sustained biosecurity monitoring, and two larger islands remain untreated because the terrain requires costlier helicopter-based operations.

Implementation
Indicative cost
Low (< €50k) — A cumulative cost of under £250,000 for 65 islands (~6,500 ha) over 18 years is explicitly documented as one of the most cost-efficient island-eradication records globally -- rated low cost band.
Time to results
Long (> 3 years) — The programme ran from 2001 to 2019 (18 years) as a rolling, incremental rollout, with ongoing biosecurity monitoring still needed given re-invasion of 26 islands -- rated long timeline.
Staffing & skills
Falklands Conservation (NGO), Wildlife Conservation Society (landowner, Steeple Jason Island), Local private landowners, New Zealand rodent-eradication specialist (Derek Brown)

Conditions for success

  • Engagement of an experienced, specialist eradication practitioner (Derek Brown) with a proven bait-station/trapping methodology
  • Partnership across NGOs and private landowners enabling an island-by-island rollout
  • Rolling, incremental approach kept cumulative costs low

Common failure modes

  • 26 cleared islands were re-invaded within five years, indicating insufficient sustained biosecurity monitoring in some cases
  • Two larger islands remain untreated because the terrain requires costlier helicopter-based operations, leaving gaps in coverage

Where it fits

Governance type
NGO- and private-landowner-led, decentralised (no single statutory authority)
Scale
archipelago-wide, island-by-island (65 islands, ~6,500 ha)
Income level
high-income (UK Overseas Territory)

Commonly funded by

Philanthropic / foundation funding

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Data sources

Where this practice's information was retrieved from, and when.

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