evidoria

← Back to browse

Good practice

Redonda Ecosystem Reserve — Rat and Goat Eradication (Antigua and Barbuda)

Antigua and Barbuda · Redonda · See the Antigua and Barbuda profile

Goat and rat eradication (2016–2018) on the barren islet of Redonda triggered a peer-reviewed sixfold+ rebound in an endemic ground lizard and a >2,000% rise in vegetation biomass, leading Antigua and Barbuda to designate a 30,000-hectare land-and-sea reserve in 2023.

60 goats
Feral goats removed (Nov 2016–Apr 2017)
112–147 individuals/ha
Redonda ground lizard density (2012 baseline) (2012)
935.3 individuals/ha
Redonda ground lizard density (2019) (2019)
~13-fold
Redonda ground dragon (anole) population increase (since 2017)
>5-fold
Invertebrate abundance increase
>2,000 %
Vegetation biomass increase
17 species
Plant species richness (before)
~90 species
Plant species richness (after)
15 species
Land bird species recolonized
30000 hectares
Redonda Ecosystem Reserve area (designated 18 August 2023)
~180 km²
Coral reef area within reserve (designated 18 August 2023)
Redonda Ecosystem Reserve — Rat and Goat Eradication (Antigua and Barbuda)

Details

Maturity
Established
Promoter
Environmental Awareness Group (EAG) / Fauna & Flora International / Government of Antigua and Barbuda
Period
2016-present
Keywords
island restoration, invasive species eradication, marine protected area, endemic reptiles

Context

Redonda is a small, uninhabited volcanic islet (~150 hectares) belonging to Antigua and Barbuda. Goats were introduced during the 19th-century phosphate-mining era, and black rats established later, stripping vegetation until the island was reduced to bare rock, a 'moonscape'. This pressure from invasive species threatened endemic reptiles, including the Redonda ground lizard and the Redonda ground dragon (anole).

Objectives

The programme aimed to remove invasive goats and rats from Redonda to halt vegetation loss and allow the islet's ecosystem, including its endemic reptile species, to recover.

Activities

Between November 2016 and April 2017, the Environmental Awareness Group (EAG), Fauna & Flora International, New Zealand technical contractor Wildlife Management International, the Government of Antigua and Barbuda, and funders including Re:wild, the Darwin Initiative, USAID and the National Fish and Wildlife Foundation removed about 60 feral goats. Rat eradication using brodifacoum bait ran from February to April 2017, and the island was declared rat-free in July 2018.

Results

A peer-reviewed study in Integrative Zoology (2021) documented Redonda ground lizard density rising from roughly 112–147 individuals per hectare in 2012 to 935.3 individuals per hectare in 2019, while the endemic Redonda ground dragon increased roughly 13-fold since 2017 and invertebrates rose more than fivefold. Vegetation biomass grew by over 2,000%, and plant species richness rose from 17 to about 90 species; fifteen land bird species recolonized the island. On 18 August 2023, Antigua and Barbuda designated the Redonda Ecosystem Reserve, roughly 30,000 hectares of land and sea including a coral reef of about 180 square kilometres, the largest marine protected area in the Eastern Caribbean.

Conclusions

No programme cost figures have been published, land crab recovery was reported only qualitatively without a percentage figure, and long-term funding for continued monitoring is not fully secured. The peer-reviewed study itself flags possible weather and observer bias in its visual-census methods, so results should be read as a strong but imperfect ecological monitoring record.

Implementation

Indicative cost
Medium (€50k–€500k)
Time to results
Long (> 3 years)
Staffing & skills
Environmental Awareness Group (EAG) — lead local NGO delivery team, Fauna & Flora International — international conservation partner, Wildlife Management International (New Zealand) — specialist technical contractor for the eradication operation, Government of Antigua and Barbuda — designating authority and government partner

Conditions for success

  • Small, uninhabited islet (~150 ha) reducing reinvasion risk and eradication complexity
  • Coordinated multi-partner delivery combining a local NGO, an international conservation organisation and a specialist eradication contractor
  • Diversified international funding base (Re:wild, Darwin Initiative, USAID, National Fish and Wildlife Foundation)
  • Post-eradication peer-reviewed ecological monitoring to document recovery and support the case for reserve designation
  • Government follow-through with formal legal designation of a large protected reserve

Common failure modes

  • Long-term funding for continued monitoring is not fully secured
  • Visual-census monitoring methods are flagged by the peer-reviewed study itself as subject to possible weather and observer bias
  • Land crab population recovery was only reported qualitatively, without quantified data

Data sources

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

Attachments

Similar practices you may find useful