Point Blue has maintained a year-round presence on the Farallons that will be curtailed in 2025 due to the loss of funding, leaving the island vulnerable to unauthorized visitors and activities in the winter. It will reduce the ability to monitor wildlife populations and maintain long-term datasets that identify trends in wildlife populations.
So, what is the good news? For the moment, the plan to aerial broadcast nearly 2 tons of rodenticide bait on the islands to kill harmless house mice has been abandoned because it cannot be financed. A brief reminder of why that is good news:
- Thousands of non-target birds and marine animals are likely to have been killed by eating the bait directly or by eating poisoned house mice. The plan and its Environmental Impact Statement (which has not been certified), predict 1,100 collateral deaths of Western gulls. Delayed and inadequate reporting of non-target deaths by similar projects suggest numbers may be greater.
- House mice on the Farallons do not need to be eradicated because there is no evidence that they harm birds on the Farallons. The only evidence of mice eating bird chicks of which I am aware were albatross chicks, a naive species that spends their life in the air except to nest in a few places in the Southern Hemisphere, but not on the Farallons. Native mice live unmolested on other off-shore islands in California. Native mice were removed from Anacapa Island prior to the rodenticide drop to kill rats and were returned after the drop. House mice on the Farallons are targeted solely because they are non-native (and anecdotally because they are an annoyance to research staff who stay in dilapidated housing from which mice cannot be excluded).
- The bizarre explanation for killing house mice is that they attract a small population of burrowing owls, who allegedly eat bird chicks. The burrowing owls could be removed from the Farallons, as Golden Eagles were removed from Santa Cruz Island to save the Channel Island Fox.
More Good News
It seems likely that the budget cut will also reduce the application of herbicides on the islands to kill non-native vegetation. Roundup (glyphosate) has been used by Point Blue Conservation on the Farallon Islands every year since 1988. Between 2001-2005, an average of 226 gallons of herbicide were used annually (5.4 gallons per acre per year), according to the annual report of the Farallon National Wildlife Refuge. (1)
63%-80% of the vegetation on the Farallons is non-native. (2) The non-native vegetation that is being needlessly sprayed with herbicide was brought to the islands by birds who ate them elsewhere and/or by wind and ocean currents. They cannot be eradicated because they cannot be excluded from an open ecosystem, just as house mice cannot be excluded from a dilapidated building. They are useful to wildlife and it is pointless to contaminate the ecosystem with herbicide.
House mice on the Farallons are also accused of eating rare insects and competing with rare salamanders for food. The study of the diet of mice on the Farallons (2) reports that mice also eat insects when vegetation becomes scarce in the fall. If useful non-native vegetation weren’t being killed, there would be more food for all animals on the islands, including house mice, who prefer vegetation to insects.
In Conclusion
I am not in a position to evaluate the over-all impact of cuts in the budget to the National Wildlife Refuge System. It seems likely that the overall impact on our refuges is negative. I can only evaluate the impact on the only wildlife refuge system that I know well enough to say that the budget cut will be a reprieve for wildlife on the Farallon Islands because it is likely to reduce the unnecessary use of herbicides and it will spare the entire ecosystem from the planned aerial broadcast of anti-coagulant rodenticide bait.
I am one of thousands of people who have vocally opposed the planned rodenticide drop for over 10 years. We cannot claim credit for this reprieve. The budget cut was not a surgical removal of the poison drop. Rather it was a hatchet job. That should not prevent us from celebrating the good fortune of the animals who will be spared.
Going Forward
I do not consider the issue of island eradications with rodenticides resolved, but I am grateful for a delay on the Farallon Islands. The drop is likely to happen if private funding can be found for it and the federal budget for wildlife refuges could be increased in the future.
I always have hope that those who believe non-native plants and animals are harmful will come to their senses one day. Non-native plants and animals are integral members of the food web. As newcomers, they represent new opportunities for natural selection to find the adaptations needed to survive in our changed and changing environment. We hope that US Fish and Wildlife Service will be deprived of the funding to continue their crusade against house mice long enough to figure this out. They are smart, highly educated, and well-meaning people. Surely they will figure it out eventually, hopefully in time to save wildlife on the Farallons.
Here are the articles about the mouse eradication project on the Farallons that I have published. They provide more details about the damage done by other island eradications around the world:
The mouse eradication project on the Farallon Islands: The "con" in conservation
Island eradications in the Bay Area rear their ugly head again
It's time to comment on the deadly project on the Farallon Islands
“When the Killing’s Done” Maybe never
Deadly Dogma: Revisiting the unnecessary project on the Farallon Islands
EPA's biological evaluation of rodenticides is green wash for island eradications
References:
(1)https://drive.google.com/file/d/1XoPcS104SeOUIyfbPT_NbardctNyWAgs/view
(2) https://www.biorxiv.org/content/10.1101/2022.02.23.481645v1.full
Sources for this article:
https://www.sfchronicle.com/climate/article/farallon-islands-research-19444987.php
https://www.pointblue.org/our-work/oceans/support-our-national-wildlife-refuges/
https://www.marinij.com/2024/06/04/farallon-islands-wildlife-research-is-in-trouble-2/
