Island Conservation is releasing a request for information from companies that can supply aerial application services for the removal of invasive rats from Savana Island, U.S. Virgin Islands

Resources: Request for Information

Savana Island, U.S. Virgin Islands is one of the few islands within the Puerto Rico Geographic Bank that can serve as a refuge to introduce a native population of the Endangered Virgin Islands Tree Boa (VI boa). However, invasive rats are a major threats to the VI boa, predating juveniles and adults. By removing invasive rats from Savana Island, we will create a safe refuge for a new population of the VI boa, contribute to the delisting criteria for the species recovery, build additional capacity within local partners for similar projects in the region, and demonstrate that drones can be safely used in the U.S. to manage or eradicate invasive species. This is part of a joint project between Island Conservation, the U.S Fish and Wildlife Service (USFWS), the U.S Virgin Islands (DPNR-DFW) and the U.S Department of Agriculture to restore Savana Island as a safe refuge for the Endangered Virgin Islands Tree Boa and improve the resilience of an important Caribbean Island ecosystem. 

To complete the restoration project, Island Conservation is seeking information from companies that can supply aerial application services using an uncrewed aerial system (UAS) or helicopter equipped with a dispersal system capable of evenly distributing conservation bait pellets to target invasive rats on Savana Island. The project is funded by US federal government and likely private funding sources. We are currently completing project planning and regulatory compliance with a planned implementation of March-April 2024. This request for information is intended to inform the project about the availability and constraints of current aerial broadcast service providers and will inform a request for proposals request anticipated on April 15^th, 2023.  

Given the size of Savana Island and challenging terrain, an eradication most likely requires the use of aerial broadcast application methods applying bait via an underslung or attached bait spreader bucket. Both helicopter and uncrewed aerial systems (UAS) have been used to successfully eradication invasive rodents from islands, however a UAS-based rodent eradication has not yet occurred within U.S. sovereign territory. We seek information from aerial service providers to identify feasible and cost-efficient service solutions for the project  

Innovation and increasing accessibility to technology are transforming our world and the ways in which we conserve and sustain it. As leaders in invasive species eradication, Island Conservation has spent the past 26 years developing, implementing, adapting, and refining the processes and methods necessary to protect endangered island wildlife and benefit island communities.

Innovative drone technology was recently used to restore Kamaka Island, French Polynesia as part of an ongoing initiative by Island Conservation to refine and reduce the cost of conservation technology. With Kamaka Island free of predatory invasive rats, Island Conservation expects birds from the nearby source populations to repopulate the island, reestablishing Kamaka as the seabird-driven ecosystem it once was. Seabirds are critical connectors between land and sea, producing important nutrients that fertilize the surrounding marine life. 

Drones were first used remove invasive rats in the Galapagos from North Seymour Island and the Mosquera Islet in 2019. The islands were declared rat-free in 2021. Free of invasive rodents, Seymour Norte Island and Mosquera Islet will be able to recover; endemic and native plants and animals will be able to fulfill their ecological roles, guaranteeing the hatching of nests and survival of birds and reptiles, including Galapagos Land Iguanas, Blue-footed Boobies, Frigatebirds, and Swallowed-tailed Gulls (the only nocturnal gull on the planet). Restoration also contributes to protecting the habitat of the Lava Gull, one of the rarest species of gulls in the world, categorized as Vulnerable by the International Union for Conservation of Nature (IUCN).

Why Islands?

Islands represent both a unique conservation need and opportunity. Islands total only a small fraction of our planet’s land area and host a disproportionately higher rate of extinction and endangerment per unit area than continents. For this reason, investing limited conservation funds on islands provides a high return on investment.

• There are ~465,000 islands in the world, yet they comprise just 5.3% of the Earth’s terrestrial area.
• Islands have been epicenters for extinctions: Islands have hosted 75% of known bird, mammal, amphibian and reptile extinctions since 1500.
• Islands provide critical refuges for highly-threatened species, currently supporting 36% of bird, mammal, amphibian and reptile species that are classified as Critically Endangered on the IUCN Red List.

Invasive alien species are a major driver of species extinctions on islands, particularly invasive mammals.

• Many islands’ species are threatened as a direct consequence of invasive alien species, particularly invasive mammals. Invasive cats and rats are the most damaging invasive species known on islands.
• Invasive species devour eggs, young and even adults of native animals and plants, spread invasive seeds, and destroy vegetation.

Islands offer hope that we can prevent extinctions and protect biodiversity.

• Eradication of invasive mammals from islands is a proven conservation tool.
• More than 1,200 invasive mammal eradications have been attempted on islands worldwide, with an average success rate of 85%.
• Larger more remote and technically challenging islands are being successfully cleared of invasive species populations each year.
• Many of these investments have resulted in remarkable stories of restoration success, including the recovery of globally threatened species.
• Protecting island wildlife and improving the resiliency and sustainability of natural and cultural resources for island communities will require innovative new tools to increase the scale, scope, and pace of restoration to match the magnitude of this conservation challenge.

Island Conservation is a science-based nonprofit conservation organization committed to protecting island species and ecosystems. Island Conservation’s mission is to prevent extinctions by removing invasive species from islands.

Featured photo: Endangered Virgin Islands Tree Boa Credit: Jan Paul Zegarra