Restoring the Farallon Islands
December 11, 2021
We are at a critical moment in safeguarding the future of the Farallon Islands ecosystem and the wildlife that depend on it. The US Fish and Wildlife Service, our partners in managing the islands, have a significant opportunity for ecological restoration: the eradication of the invasive house mouse from the Farallon Islands. Point Blue would like to voice our strong support for this project.
View the recording of a webinar we participated in hosted by the Marin Audubon Society (below) to hear from the experts themselves.
Just over fifty years ago, biologists from Point Blue Conservation Science (known then as Point Reyes Bird Observatory) landed on the Farallon Islands for the first time. We have maintained a continuous presence on the islands ever since: 24 hours a day, 365 days a year. A year after arriving, the South Farallon Islands became part of the Farallon Islands National Wildlife Refuge and we entered into a unique, long-term partnership with the U.S. Fish and Wildlife Service (USFWS) to become stewards of the island and to provide baseline monitoring of the islands populations. Our role on the islands is simple: we use our expertise in biology, ecology, and conservation to provide rigorous science to the Service, helping them make decisions that will ensure a healthy ecosystem on the islands for generations to come.
Referred to by some as “California’s Galapagos,” the Farallones host the largest seabird breeding colony in the contiguous United States and 25% percent of California’s breeding seabirds (more than 300,000 individuals of 13 species). Before human-caused disturbances, more than one million seabirds bred at the Farallones. Over the last 40 years, the USFWS has strived to restore the Farallones by removing invasive plants and animals that have negatively impacted the island ecosystem. As an example, introduced, invasive cats and rabbits were removed in the 1970’s with positive ecological responses including the return of breeding rhinoceros auklets after a long absence.
Today, the invasive house mouse is the last invasive vertebrate remaining on the Farallones. Introduced by sailing vessels, likely in the 19th century, these mice exist on the islands in plague-like levels–at times reaching as many 1,270 mice per hectare, one of the highest observed densities in the world. The presence of invasive house mice is negatively impacting the Ashy Storm-petrel, other seabirds, Burrowing Owls, Farallon arboreal salamanders, Farallon camel crickets, and the islands’ vegetation. Threats to the rare and threatened Ashy Storm-petrel’s declining population are of particular concern.
Thirteen years ago, the USFWS began a thorough review of available options to remove mice from the island. In the spring of 2019, the Service published one of the most thorough and scientifically rigorous Environmental Impact Statements on record, extensively referencing original, peer-reviewed science by Point Blue. The final product represents over a decade of careful study, with a final report of 322 pages supported by an appendix 577 pages long. Before publishing the final EIS document, USFWS reviewed each of the 553 public comments that were made on the draft EIS and addressed all substantive comments in its final report.
Invasive rodent removals have been successfully completed on nearly 700 islands worldwide. Land managers have successfully eradicated house mice from more than 60 islands worldwide. Nearly all of these successful projects utilized techniques like those proposed for the South Farallon Islands house mouse eradication.
The Farallon Islands are a world-famous local treasure. The USFWS has a unique opportunity in this moment to take a giant step forward in restoring the island’s fragile ecosystem and protecting the many species that rely on it. We applaud the USFWS for their careful, transparent process and their commitment to science-based decision making. Based on our fifty years of experience studying birds and other wildlife on the islands, we strongly support the conclusions of the Service’s EIS.
Addressing misinformation and misleading statements
Point Blue is aware that critics of this project have been spreading misinformation and misleading statements. Please visit this page where we clarify some of the important issues regarding the proposed project.
Selected Point Blue Science Contributions
Over the 50+ years that Point Blue scientists have been living on and studying the Farallon Islands, our original science has produced numerous peer-reviewed papers. Some of these have been used by the US Fish and Wildlife Service in the preparation of their Final Environmental Impact Statement and in the planning of this proposed restoration action. These include (but are not limited to) the following publications and reports:
- Projecting impacts of a mortality event on a Western gull population. Nur et al. Published in Ecosphere (2021)
- Removing invasive mice will benefit storm-petrels through reduced owl predation. Nur et al. Published in Ecosphere. (2019)
- Burrowing Owl diet on Southeast Farallon Island, California. Chandler et al. Published in Journal of Raptor Research (2016)
- Non-lethal hazing can protect gulls from exposure to rodenticide. Warzybok et al. Report to the Oiled Wildlife Care Network (2013)
More information about the project including a FAQ, photos and videos, and official documentation from the USFWS can be found at the project website: www.RestoreTheFarallones.org.