island eradications – Conservation Sense and Nonsense

“When the Killing’s Done” Maybe never.

I have few opportunities to read fiction because most of my time is spent trying to keep up with rapidly evolving ecological science. I was grateful for the chance to read the fictional account of island eradications on the Channel Islands because it closely relates to my interest in the planned eradication of mice on the Farallon Islands, which is still pending and as controversial as similar projects on the Channel Islands. TC Boyle’s book foretells the Farallones project as he sends a member of the fictional project team to the Farallon Islands after completion of the project on the Channel Islands.

When the Killing’s Done by TC Boyle is not entirely fictional. (1) It is impressively accurate in its description of the eradication projects themselves, but Boyle weaves a tight fictional plot around the key players who implemented the project and those who fought like hell to prevent it from happening. Like other books by Boyle that I have read, When the Killing’s Done creates intense suspense that moves the reader along at top speed. His characters are vivid and complex.

Boyle lives in Montecito, near Santa Barbara, close to the Channel Islands. No doubt he followed the projects closely as they were debated and resisted by opponents, who were primarily animal rights activists according to Boyle’s account. In interviews after the publication of the book in 2011, Boyle claimed not to have a personal opinion of the projects: “I’m not an activist in any way. With certain exceptions, I don’t think politics and art mix very well.” He sees value in both sides of the debate and the characters in his story have much in common. The antagonists are vegetarians who value nature and care deeply about the environment and the animals who live in it. I believe this common ground is also true of the adversaries in the debate about the Farallones project and others like it.

However, the ending of the book suggests that Boyle doubts the ability of humans to control nature. Although the projects on the Channel Islands were completed to the satisfaction of the land managers–National Park Service and The Nature Conservancy—the final image in Boyle’s story is of animals considered non-native on the Islands making their way to the shore of the Island. The implication is that maybe the killing is never done and that is the crux of the problem with island eradications in general and the planned mice eradication on the Farallon Islands in particular.

Rat eradication on Anacapa Island

The aerial application of rodenticide to kill rats on Anacapa Island in 2001-2002 was the first of its kind in North America. The project was also unique because it was complicated by the need to spare a population of endemic native mice on Anacapa. Over 1,000 native mice were captured before the aerial application of rodenticide and released back on the island after the poison was no longer effective.

Anacapa Island is the usual success story cited by supporters of the Farallones project where non-native mice are the target for eradication. Native mice on Anacapa were not considered a threat to birds, but non-native mice on the Farallones are, although there is no evidence that mice actually harm birds on the Farallones either. The operative word here is “native.” The mice on the Farallones are targets only because they aren’t native. The mice on Anacapa undoubtedly eat vegetation too, but that’s not considered a problem so long as they are native. The mice on Anacapa are probably an important source of food for birds, just as they on the Farallones.

If mice are not harmful to birds, there is no legitimate reason to poison them, along with untold numbers of non-target animals. The mice on the Farallones are targets only because they aren’t native.

Killing of non-target animals

Rodenticides are indiscriminate killers of warm blooded animals, including birds. An animal who eats rodenticide slowly bleeds to death. The grisly process of dying takes about 10-20 days. If poisoned mice are eaten by other animals that animal is also poisoned. It is therefore inevitable that non-target birds who are predators of mice will be killed by widespread dispersal of rodenticide pellets on the ground that can also be directly eaten by birds and other animals. This deadly sequence of events has been demonstrated many times by island eradications using rodenticides all over the world and the project on Anacapa Island is no exception.

Billboard sponsored by Raptors Are The Solution (RATS)

Raptors are the main predators of mice. Therefore, 63% of raptors on Anacapa Island (37 of 59 individual birds) were captured and either relocated or kept in captivity until the project was done, according to the first study of the project published in 2005. According to that study, “The fate of the remaining birds of prey on the island is unclear. There is evidence that some birds survived the bait application… However, three barn owls, six burrowing owls and an American kestrel either died while in captivity or were found dead on the island. The American kestrel and a burrowing owl that were captured in 2001, after the bait application, likely died from brodifacoum poisoning.” The analysis of the project considers these deaths “negligible.”

A total of 94 seed-eating birds were also found dead after the poison drop. Most were song birds, but an additional 6 birds were too decomposed to identify the species. The study notes that these collateral kills were consistent with other similar projects.

Western Gull on Channel Islands. NPS photo

The study makes no mention of gulls that were undoubtedly killed by the project. Gulls are omnivorous scavengers for whom dead and dying mice are ideal food, preferable to dive bombing for French fries on your picnic table. According to the National Park Service, “Western gulls are the most abundant breeding seabird in the Channel Islands National Park, with a population estimated at more than 15,000.” Shortly after the poison drop, dead seabirds washed up on the shore near the Santa Barbara harbor. UC Santa Barbara’s daily newspaper said, “…a strong correlation exists between the National Park Service’s most recent airdrop of pesticide on Anacapa Island and the dead birds.”

In other words, those who implemented the eradication project on Anacapa are probably not telling the full story about the death of non-target birds. The death of hundreds of gulls is anticipated by the promoters of the project on the Farallones. If the organization that implements the project is the same organization that monitors and reports on the project (as was the case for the projects on the Channel Islands), we may never know the actual impact on the birds living on the Farallones.

Those who promote these poisonous projects justify the death of non-target birds by saying they are “incidental” and have no lasting impact on the species population. They will apply for and receive “incidental take permits” in advance of the Farallones project that will satisfy legal requirements of the Migratory Bird Treaty Act and the Endangered Species Act. The lawsuit that was filed to prevent the Anacapa project was overturned on those grounds.

The killing is never done

Rat eradication on Anacapa and pig eradication on Santa Cruz (where over 5,000 pigs were shot by sharpshooters and 54 Golden Eagles were removed because they were predators of endemic foxes) are the focus of TC Boyle’s masterful book. Both were implemented and considered successful by the organizations that implemented the projects. Although land managers are no longer killing animals (to our knowledge) in the Channel Islands they are waging a continuous war on non-native plants by spraying them with herbicide. When we visited Santa Cruz Island in 2010, we witnessed the application of Garlon on non-native fennel.

Roundup (glyphosate) has been used 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. Given that these islands are not far from the California coast and are visited by thousands of migratory birds every year, we must expect that the arrival of new plants to the islands will be continuous: seeds are eaten and carried by birds; seeds are carried by birds in their feathers and feet; wind and storms carry seeds to the islands, etc.

The Environmental Protection Agency recently published a Biological Evaluation of glyphosate products. EPA reports that glyphosate is “likely to adversely affect” 93% of legally protected endangered and threatened plants and animals. That finding applies equally to all plants and animals, whether they are legally protected or not because the physiological processes of species in the same order are similar.

The Environmental Impact Statement for the Farallones project accuses mice of eating vegetation, although far more vegetation is probably killed by herbicides. Non-native vegetation arrives on the Farallones partly because birds eat it and carry it to the Farallones. Animals do not care if edible vegetation is native. Nativism is a human prejudice not shared by animals who seek food and shelter wherever they can find it.

The constant poisoning of plants is perhaps a trivial consideration in comparison to the futility of trying to eradicate mice. Although rats have been successfully (leaving aside the death of non-target animals) eradicated by some projects, attempts to eradicate mice have been significantly less successful.

A study of 139 attempted eradications on 107 Mediterranean islands in eight countries, with Greece, Italy, and Spain accounting for the highest number found that eradication projects targeted 13 mammal species. The black rat was the target of over 75% of the known attempted eradications in the Mediterranean Basin; other species targeted were feral goat, house mouse, European rabbit, and domestic cat. The most widely used technique was poisoning (77% of all eradications), followed by trapping (15%) and hunting (4%). Techniques were largely target-specific.

The average failure rate of the projects was about 11%, but success was defined only as the death of animals living on the islands at the time of the project. However, this percentage varied according to species. The failure rate of house mouse eradication was 75%. Reinvasion occurred after 15% of eradications considered initially successful.

The proposed project on the Farallon Islands is a dead end in many ways. It will kill many non-target animals. It will probably not be successful in the short run or the long run. Every time it is repeated it will kill more animals. Furthermore, it is pointless because mice do not harm birds on the Farallon islands.

T.C. Boyle, When the Killing’s Done, Viking, 2011.

The Grand Delusion: Controlling Nature

“This is a book about people trying to solve problems created by people trying to solve problems.”

Elizabeth Kolbert’s earlier book, The Sixth Extinction was ground-breaking, not because it described the consequences of climate change in the 21^st Century, but because it put modern climate change into the context of similar events in the past 500 million years of life on Earth. Although the current episode of climate change is man-made, five previous mass extinctions were natural events. What past extinction events have in common with the sixth extinction is the inevitable consequence of such changes in climate: when the climate changes, all life on Earth changes with it. Plants and animals will adapt, change, or they will go extinct as they have for 500 million years. (1)

Kolbert’s new book, Under a White Sky, turns the page on this cataclysmic event in the Earth’s history to focus on the efforts being made to control nature to address environmental problems, including climate change. To say that Kolbert is skeptical of those efforts is to understate her critical evaluation of them.

Controlling Nature

In 1990, I was introduced to the human delusion that we can control nature by John McPhee’s The Control of Nature. His book had a profound influence on my thinking about nature. It was the basis for my belief that attempts to turn back the botanical clock to 500 years ago to a pre-settlement landscape, mistakenly believed to be pristine, are futile, misguided, and often damaging. Kolbert’s latest book is written from the same perspective as McPhee’s seminal work and she gives him credit for his pioneering work.

McPhee’s book predicted the catastrophic flooding of New Orleans by hurricane Katrina in 2005. Human engineering of the Mississippi River for over 100 years set the stage for that disaster. New Orleans sits at the Gulf end of the Mississippi River. Historically, the river flowed from Minnesota to the Gulf, accumulating sediment along its way and depositing it as it entered the Gulf, fanning out into streams and swamps that created the Mississippi Delta. The labyrinth of land and marsh created by the sediment deposited by the river created a barrier that protected New Orleans from storms.

However, the uncontrolled and episodic flow of the river caused periodic flooding that was not convenient for the human inhabitants of New Orleans and the Delta community. So, the flow of the river was controlled by levees and pumps were used to return water from the land to the river. Sediment from the river could no longer replenish the land because it was confined to the constrained river, which put the human engineers onto a never-ending treadmill of building higher levees and bigger pumps. It was inevitable that the river would eventually overwhelm the defenses built by the engineers and so it did during Katrina in 2005.

Kolbert updates this untenable situation in the Mississippi Delta in her new book. The underlying cause, as told by McPhee is recapped by Kolbert. Then new manmade environmental issues are added to the catastrophic circumstances that will inevitably doom the human inhabitants. Rising sea levels caused by climate change are one factor. The incursion of salt water into fresh water swamps killed vegetation that acts as a buffer during storms. Oil and gas exploration and extraction in the Delta has caused the land to drop further.

Many Delta communities and some neighborhoods in New Orleans have been abandoned because they are essentially underwater. Since Katrina, no serious effort has been made to change the approach to the issues. Bigger, more powerful pumps have been built and levees have been made higher and stronger. No one is seriously considering the need to relocate New Orleans or surrounding communities to higher ground. The delusion that humans can outsmart the river continues.

A comedy of errors

Kolbert introduces the many projects that are trying to solve problems that were created by bad decisions made earlier by other humans with a quote from Albert Einstein: “We cannot solve our problems with the same thinking we used when we created them.” These wise words from a wise man are clearly not being heeded by the masterminds of the projects Kolbert describes in her book:

High on the list of projects in which society is heavily investing is the attempt to prevent carp from entering the Great Lakes from the Mississippi River. After many different approaches were tried and failed, the current strategy is an electrified fence separating the Chicago River (connecting to the Mississippi River) from Lake Michigan that kills untold thousands of fish every day. This deadly project is the end stage of previous bad decisions. A link between Lake Michigan and the Mississippi River was created by a massive engineering project that reversed the flow of the Chicago River in 1887. Later, carp was introduced to the Mississippi River from China as biological control to address pollution issues. One species of carp was introduced to control aquatic weeds and another carp species was introduced to consume nutrients in sewage ponds. Kolbert says such biological controls became popular after Silent Spring was published because Rachel Carson considered pesticides a curse and biological control a panacea. (Which is not to say that pesticides aren’t a curse.) In other words, we traded one problem for another.
Island eradications of introduced mammals such as rats and mice are also popular projects (with some people). Genetic engineering is being aggressively pursued as a possible substitute for the rodenticides that are being used for these projects. These projects have the potential to drive an entire species into extinction or alter their physiology such that they could become killers or prevent them from being killers. Kolbert buys a genetic engineering kit for $209 from a young entrepreneur in Oakland that enables her to make E.coli cells resistant to an antibiotic. E.coli is a deadly bacteria that can be fatal if untreated by antibiotics. In other words, anyone with $209 can turn bacteria into killers with no special training or equipment. What could possibly go wrong, Kolbert asks rhetorically.

The promise and threat of geoengineering

Kolbert visits several different geoengineering projects that are trying to prevent the consequences of climate change without reducing greenhouse gas emissions, the underlying cause of climate change. One such project is turning CO₂ into stone. Apparently it CAN be done, but to do it on a scale that would actually prevent climate change would be to devote much of the surface of the Earth to that purpose.

Kolbert visits a project that believes injecting aerosols into the atmosphere to block the sun is the best bet to stop climate change. The proposal strikes Kolbert as both preposterous and dangerous. The researcher detects her skepticism and retorts, “People think of all the bad examples of environmental modification. They forget all the ones that are more or less working. There’s a weed, tamarisk, originally from Egypt. It’s spread all around the desert Southwest and has been destructive. After a bunch of trials, they imported some bug that eats the tamarisk, and apparently it’s kind of working.”

Tamarisk defoliation along Colorado River, near Needles, California

In fact, the introduced tamarisk beetle is working too well. It has spread far beyond the regions where it was introduced and produced wastelands of dead trees in Arizona and Southern California. Since one of the rarest desert birds depends upon tamarisk there isn’t much to celebrate about this over-achiever beetle.

Compounding the problem

Instead of addressing the source of environmental issues, we compound them by creating new problems with our theoretical “fixes.” The native plant movement, in their zeal to save native plants, sprays herbicides that kill as many native plants as non-native plants and poison the soil while doing so, stunting all new growth, both native and non-native.

I share Kolbert’s skepticism about the projects she describes for the same reasons she gives. Every “fix” has the potential to create new problems that could be more disastrous than the problems they are meant to resolve. And the resources used to develop new techniques such as massive geoengineering projects could be used instead to address the underlying cause of the problem, which is the greenhouse gas emissions causing climate change. We don’t want to give up our fossil-fuel driven economy, so instead we conjure up even more damaging ways to ameliorate the inconveniences of climate change. It’s a fantasy that prolongs and exacerbates the consequences of climate change.

Finally, let’s give Kolbert the last word: “This has been a book about people trying to solve problems created by people trying to solve problems…Geoengineering may be ‘entirely crazy and quite disconcerting,’ but if it could slow the melting of the Greenland ice sheet, or take some of ‘the pain and suffering away,’ or help prevent no-longer-fully-natural ecosystems from collapsing, doesn’t it have to be considered?…But to imagine that ‘dimming the fucking sun’ could be less dangerous than not dimming it, you have to imagine not only that the technology will work according to plan but it will be deployed according to plan. And that’s a lot of imagining…But let’s just say the record here isn’t strong.” (2)

Thank you, Elizabeth Kolbert, for calling out the grand delusions of humans who mistakenly believe it is possible to control nature to avoid inconveniencing human society.

Elizabeth Kolbert, The Sixth Extinction, Henry Holt and Co., 2014
Elizabeth Kolbert, Under a White Sky, Crown New York, 2021