Evidence that eradicating black Evidence that eradicating black rats rats ( ( Rattus rattus Rattus rattus ) has boosted the ) has boosted the recovery of rare reptiles and recovery of rare reptiles and seabirds on Antiguan islands. seabirds on Antiguan islands. Jenny C. Daltry Jenny C. Daltry Fauna & Flora International Fauna & Flora International Karron J. James Karron J. James , , Andrea Otto Andrea Otto , and , and Toby N. Ross Toby N. Ross Environmental Awareness Group Environmental Awareness Group Antiguan Racer Conservation Project, Antigua Antiguan Racer Conservation Project, Antigua
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Evidence that eradicating black rats ( Rattus rattus ) has boosted the
Antiguan Racer Conservation Project, Antigua. Evidence that eradicating black rats ( Rattus rattus ) has boosted the recovery of rare reptiles and seabirds on Antiguan islands. Jenny C. Daltry Fauna & Flora International Karron J. James , Andrea Otto , and Toby N. Ross - PowerPoint PPT Presentation
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Evidence that eradicating black rats Evidence that eradicating black rats
((Rattus rattusRattus rattus) has boosted the ) has boosted the
recovery of rare reptiles and recovery of rare reptiles and
seabirds on Antiguan islands.seabirds on Antiguan islands.
Jenny C. Daltry Jenny C. Daltry
Fauna & Flora InternationalFauna & Flora International
Karron J. JamesKarron J. James, , Andrea OttoAndrea Otto, and , and
Toby N. RossToby N. Ross
Environmental Awareness GroupEnvironmental Awareness Group
• Vanished from mainland Antigua after Asian mongooses were introduced (1890s).
• By 1980s, the snakes were only on Great Bird Island (8.4 hectares)
Great Bird Is.
Mark-recapture study in 1995 found 50 ± 7 individuals.Mark-recapture study in 1995 found 50 ± 7 individuals.More than 50% of the snakes had injuries consistent More than 50% of the snakes had injuries consistent with rat bites.with rat bites.
Rat eradication programme began in 1995.Rat eradication programme began in 1995.Forestry staff and NGO volunteers eradicated rats from Forestry staff and NGO volunteers eradicated rats from Great Bird Island and neighbouring islands.Great Bird Island and neighbouring islands.
• Cut grid (10x10m or 20x20m) across each island (4-6 weeks).
• Placed brodifacoum briquettes (KleratTM) on grid intersections (3 weeks).
Rat eradication programme began in 1995.Rat eradication programme began in 1995.Forestry staff and NGO volunteers eradicated rats from Forestry staff and NGO volunteers eradicated rats from Great Bird Island and neighbouring islands.Great Bird Island and neighbouring islands.
• Cut grid (10x10m or 20x20m) across each island (4-6 weeks).
• Placed brodifacoum briquettes (KleratTM) on grid intersections (3 weeks).
• 100% effective on every island.
Black Rats were eradicated from 12 islands between Black Rats were eradicated from 12 islands between 1995 and 2006.1995 and 2006.(Two islands were re-invaded by rats).(Two islands were re-invaded by rats).
Permanent bait stations in use since 2001. Permanent bait stations in use since 2001. Designed to detect and kill invading rats.Designed to detect and kill invading rats.
Antiguan Racer population more than doubled within Antiguan Racer population more than doubled within two years of eradicating rats from Great Bird Island.two years of eradicating rats from Great Bird Island.
Antiguan Racers have been re-introduced from Great Antiguan Racers have been re-introduced from Great Bird Island to 3 islands (after eradicating rats).Bird Island to 3 islands (after eradicating rats).
Seabirds and pigeon colonies have been monitored by Seabirds and pigeon colonies have been monitored by the authors and local volunteers.the authors and local volunteers.
A rapid survey was conducted in 2010 to compare A rapid survey was conducted in 2010 to compare islands with and without rats.islands with and without rats.
Anecdotal evidence that other species are more Anecdotal evidence that other species are more abundant on rat-free islands.abundant on rat-free islands.More research needed.More research needed.
1. Black rats do have seriously harmful impacts on 1. Black rats do have seriously harmful impacts on Antiguan biodiversity. Antiguan biodiversity.
2. Rats can be controlled, even in public areas, and t2. Rats can be controlled, even in public areas, and the he recovery of native species can be very rapid.recovery of native species can be very rapid.
3. Ideally, monitoring of flora and fauna should begin 3. Ideally, monitoring of flora and fauna should begin before rats are eradicated.before rats are eradicated.
4. Restoring islands also has a powerful social impact: 4. Restoring islands also has a powerful social impact: This project has motivated many people from diverse This project has motivated many people from diverse backgrounds to become conservationists.backgrounds to become conservationists.