Scaling back scientific Federal employees a the site worries environmentalists
Farallones — It’s for the Birds
• • • • • • • March 2025 • • • • • • •
This place is nicknamed the Devil’s Teeth or the Island of the Dead — more than 400 shipwrecks have occurred there.
The Spaniards gave it its current name, Farallon Islands, in 1603 for ‘cliffs.’ The islands are just 28-30 miles from San Francisco.
Today, the islands are considered off-limits to all but a few scientists; they are considered the Galapagos of California. But there are parts of the island that even they are not even able to visit.
Islands are more vulnerable to species extinction than any other land formation. Despite this, the island represents the largest seabird colony in the contiguous United States, representing 12 different types of birds and a total population of 300,000. The island supports half the world’s population of ashy storm petrels, for example, which is considered endangered.
Other birds on the island are western gull, Brandt’s cormorant, pelagic cormorant, double-crested cormorant, pigeon guillemot, common murre, Cassin’s auklet, tufted puffin, black oystercatcher, rhinoceros auklet, and Leach’s storm petrel.
OTHER REASONS WHY THE ISLAND IS SO IMPORTANT
The island sits beside an upwelling current caused by a dramatic 6,000-foot drop in elevation from the ocean floor. That configuration provides nutrient-rich water, making it one of only four places on Earth where it occurs. In the summer, the sun shines down on the nutrient-rich water and creates a bloom of phytoplankton, which feeds the zooplankton that feeds numerous small fish.
FUR COMPANIES
In the early 1800s, Russians descended on the island searching for fur until all the marine mammals were extinct. Adventurers from New England came before the Russians, raiding the island for pelts.
At some point, house mice (Mus musculus) gained access to the island. It is estimated that 60,000 mice are on the island. There is nowhere else in the world with more mice than the on the Farallon Island.”
EGG WAR
Then, in the 1850s, due to a shortage of chickens, the Common Murre eggs became popular. These eggs are twice the size of chicken eggs. In 1863, two dozen men attacked the Farallon Egg Company. The raid failed, but two men were killed and four were wounded from the action. Shortly after that, members of the Academy of Sciences pressured the government to end the egg collection on the island. In 1870, the Farallon Egg Company sold its rights to the land to the federal government. Egg hunting ended on the island in 1896, but it was too late — the population of the Common Murre was decimated. After President Theodore Roosevelt sanctioned the island as a National Wildlife Refuge in 1909, wildlife began to recover. Now, the 211 acres on the islands are protected. Then, in 1981, congress created the 1,279 square acre Gulf of the Farallon National Marine Sanctuary. Later, the sanctuary was increased to 2,488 square nautical miles in 2015, and the name was changed to Greater Farallon National Marine Sanctuary.
TODAY’S PREDATION ON THE ISLAND
Today, Great White Sharks hunt the large seal population. In the past, these hunts occurred nearly every day. Now, attacks occur about six times a year.
Grey whales and blue whales can be found near the island. They enjoy the multitude of krill around the islands, while the humpback whales are attracted to the large schools of anchovies and mackerel.
Burrowing owls find the thousands of mice easy prey. Unfortunately, these owls can linger and prey on the nearly extinct ashy storm petrels; half of their entire population lives on the islands alone.
CONTROLLING HOUSE MICE
At some point, house mice (Mus musculus) gained access to the island. It is estimated that 60,000 mice are on the island. There is nowhere else in the world with more mice than the on the Farallon Island. It is calculated that there is more than one mouse per square foot.
During the summer, when most of the vegetation disappears, the ashy storm petrel eggs could become the diet of the mice. A camera monitoring a bird nest spotted teeth marks from mice on the eggs, although they did not see a mouse doing the predation itself. Even researchers who claim mice don’t eat eggs have found eggshells in their stomachs.
RODENTICIDE
Previously, the US Fish and Wildlife Service (USFWS) considered dropping 1.3 metric tons of toxic rodenticide on the islands. Unfortunately, that would be poisonous to birds, mice, mammals and aquatic life. The USFWS predicts 1,000 seagulls would die if that much rodenticide is used. In this debate, it is important to realize that, unlike DDT, rodenticide pellets do not accumulate in the fatty tissue of an animal, cannot travel long distances in the air (except for bird flight), or become persistent in the environment. Another solution would be to deposit bait traps to avoid scattering the poison across the island. However, mice are territorial and do not let other mice freely travel over their territory. Traps need to be 25 meters apart to minimize that problem. Then, the traps would need to be monitored for two years. Success is determined if the rate of extermination is 100%; if not, the project is not likely to go forward.
Over 600 islands have had rodents eliminated from their environment, typically with rodenticide pellets. The Cottonwood Post advocates that this is the only alternative for rodent removal on the Farallon Islands. If nothing is done, and this disturbance continues on the island, it is possible birds will go extinct. They have done so in 75% of all the other islands affected by invasive species.
MALE CONTRACEPTION
On February 14, 2023, a new study reported a male contraception given to mice. In the test study, the male mice, just 30 minutes after receiving the contraception, were mated with females. Pregnancies were reduced by 100%. Unfortunately, this method of mice removal is believed to be impractical.
In August 2024, the Coastal Commission approved the removal of the European Mice on the island. As yet, no date has been set for the removal to take place. Yearly, the mice’s existence swings from starvation to unmanageable mice competing for limited quantities of food on the island. Cannibalism has been observed when mice become desperate for food.
With the possible extinction of several bird species on the island because of the mice, it is time for this problem to end.
ROLLBACK OF FEDERAL EMPLOYEES AT FARALLON ISLAND
Staff at the Point Blue Conservation Science, which runs the Farallon Island research team, reported on February 15th, that they are scaling back their research team on the island. Researchers will be there from mid-September to mid-March, which is when many seabirds breed. This scaling back would mean the eradication of mice on the island may need to be delayed and that unwanted human visitors on the island would proliferate, disturbing wildlife. Part of the work performed by staff also encourages the reemergence of CA native plants, as well as indigenous salamanders. Jaime Jahncke, a director at Point Blue, explained that “The Farallones are one of the most ecologically valuable sites in the US, and maintaining a year-round presence is critical to protecting wildlife, supporting conservation policies, and continuing over 55 years of groundbreaking research.” We hope Point Blue can find the strong stakeholders and the environmentalists they need to donate the funds necessary to to carry on their research.
Glenn Rogers, RLA,
President, Coalition for San Francisco Neighborhoods (CSFN)
March 2025
