Wildlife

Recovery: The Miracle on Palmyra

December 15, 2015

A sooty tern colony on Palmyra Atoll. Photo © Susan White/USFWS
A sooty tern colony on Palmyra Atoll. Photo © Susan White/USFWS

No one is sure when the 618-acre wildlife paradise that had been Palmyra Atoll, a thousand miles south of Hawaiʻi, started dying. But it is believed to be one more casualty of World War II.

Palmyra sustained millions of seabirds and healthy stands of now imperiled Pisonia trees. There were at least ten species of land crabs, including the world’s largest terrestrial invertebrate — the coconut crab, which can weigh 15 pounds and live as long as a human. The land crabs maintained the plant community by dispersing seeds, breaking down organic matter and mixing soils. Seabirds did the same by bringing marine nutrients to this otherwise sterile coral atoll.

Palmyra’s native ecosystem was recovering from the U.S. Navy’s construction of bunkers, buildings, roads, piers, fuel tanks, and ammo dumps. What it couldn’t recover from was the infestation of alien black rats, presumably stowaways on Navy ships.

The rats ate the seeds of Pisonia and three other rare tree species, shutting down reproduction. They ate the land crabs, chewed the heads off baby sea turtles, feasted on seabird eggs and hatchlings and all manner of terrestrial and intertidal invertebrates.

Thus did Palmyra become one of countless islands around the globe converted by alien invaders from diversity and beauty to sameness and sterility. Ninety percent of all archipelagos are infested with alien rodents.

An aerial view of Palmyra from the east end. Photo © Graeme Gale.
An aerial view of Palmyra from the east end. Photo © Graeme Gale.

But unlike dead organisms, dead ecosystems can be brought back to life. That has happened at Palmyra. The island, a national wildlife refuge since 2001, is jointly owned and managed by The Nature Conservancy (TNC) and the U.S. Fish and Wildlife Service (USFWS). In 2011, Island Conservation (a non-profit group specializing in removing alien invaders from islands) and the USFWS partnered with TNC to rid Palmyra of rats.

Before the 1980s rodent eradication on islands this complex was unthinkable. But brodifacoum changed that. Non-anticoagulant rodenticides failed because they were so fast-acting. Rats aren’t stupid. When they saw other rats convulse and die shortly after ingesting bait they learned to avoid it. What makes brodifacoum such an effective conservation tool is that it takes a few days to work, so rodents don’t learn to associate it with danger.

Crowds of fiddler crabs. Photo © Kydd Pollock
Crowds of fiddler crabs. Photo © Kydd Pollock

Recovery of Palmyra is just starting, but already changes are spectacular. Today the refuge supports one of the few healthy tropical coastal strand forests found in the Central Pacific. Populations of two land crab species, so depressed by rats they hadn’t been previously observed, are now regularly seen. Seedlings that sprouted a few weeks after the last rat died now tower over managers’ heads. These and other healthy plants provide shelter or cover for at least 10 breeding seabird species, including the planet’s second largest colony of red-footed boobies. Researchers report dramatic increases in sooty terns, white terns, black noddies, brown noddies, and white-tailed tropicbirds. And recolonization of wedge-tailed shearwaters, blue noddies and gray-backed terns appears imminent.

A coconut crab. Photo © Island Conservation
A coconut crab. Photo © Island Conservation

“It was a wonderfully successful effort by our team,” says Evelyn Wight, senior communications manager for TNC Hawaiʻi. “It required an enormous amount of cooperation and coordination. We’re seeing native trees growing like crazy, numbers of fiddler crabs like nobody has ever seen; the ground seems to move with them.”

Refuge manager Amanda Pollock reports “population explosions” of dragonflies and crickets as well as thousands of sooty tern fledglings during each breeding season, compared with a couple of hundred during the rat years.

Sooty terns on Palmyra Atoll. Photo © Island Conservation
Sooty terns on Palmyra Atoll. Photo © Island Conservation

Unique factors made the project one of the most challenging rodent eradications ever attempted. Rats spent much time in the forest canopy. Land crabs competed with rats for poison bait, eating it like candy and with impunity. Elusive bristle-thighed curlews, which were attracted to the bait, had no such immunity. The partners undertook the effort when these migratory birds were mostly summering in Alaska. Virtually all that remained were captured and held safely in pens until the bait was no longer available — a feat some ornithologists had deemed impossible.

A bristle-thighed curlew. Photo © Rory Stansbury
A bristle-thighed curlew. Photo © Rory Stansbury

With these projects there is no “close enough.” If one male-female rodent pair or one pregnant female survives, you fail; and occasionally you do fail. In fact, in 2002 an eradication attempt on Palmyra by TNC and the U.S. Department of Agriculture left a few rats alive. Wildlife managers hadn’t counted on the tree-dwelling rats or the rich food supply that limited home ranges, requiring more bait stations in tighter grids.

But managers learn from failures. To lay the groundwork for the second attempt TNC and the U.S. Fish and Wildlife Service called in Island Conservation. Eradication experts from New Zealand, where brodifacoum for island recovery was first deployed, helped with implementation. Two helicopters were specially fitted and shipped to the atoll to broadcast pelletized bait specially developed by Bell Laboratories to withstand the warm, wet environment. The partners used slingshots to fire bait into trees. To keep it out of the water they devised bolas with two bait-filled bags made of biodegradable gauze on each end of a string. Suspended by a 50-foot cable from a helicopter intrepid New Zealander Pete McClelland looped the bolas over the crowns of trees, thereby acquiring the nickname “Dope on a Rope.” Bunkers and other concrete structures from the war days were hand baited.

“The whole operation was brilliant,” declares Gerry McChesney, manager of the mouse-infested Farallon National Wildlife Refuge 28 miles seaward of San Francisco and the most important seabird habitat in the contiguous states. “Amazing that it was successful. I look at Farallones recovery [in the planning stage since 2004] and it has complexities, but nothing like Palmyra.”

A baby fairy tern. Photo © Kydd Pollock
A baby fairy tern. Photo © Kydd Pollock

Jeopardizing recovery of the Farallones and other rodent-blighted islands is a pervasive mindset that assigns equal value to aliens and natives, that rejects use of all poisons in all situations, and that would sacrifice entire species to prevent limited deaths of non-target organisms (inevitable with any rodent eradication).

Environmental activist Maggie Sergio of Fairfax, California proves the old saw that one concerned citizen can make a difference. She proves also that this isn’t always a good thing. Sergio is probably the world’s busiest opponent of rodent eradication, which she publicly condemns as “inhumane.” “People are doing this to make money,” she told me. “This is insanity.”

Sergio and her allies failed to significantly disrupt Palmyra recovery but are working hard to block the Farallones effort, perhaps with some success because they’ve generated opposition from the City of San Francisco. And so far, nearly 33,000 people have signed their online petition to kill the project.

A pisonia grove. Photo © Andrew Wright
A Pisonia grove. Photo © Andrew Wright

In New Zealand Sergio’s denunciation of poisoning rodents and other invasive aliens on islands elicited this response from the Royal Forest and Bird Protection Society: “Should we allow introduced pests to kill our native species, or should we kill the pests, so that our native species can survive? Should we use the best pest control tools and techniques currently available, recognizing that they are not perfect, or should we wait for a better solution to be found and watch more of our 2,700 vulnerable native species disappear?”

Good questions. And anyone concerned about alleged cruelty of brodifacoum to alien rodents needs to view this video from Gough Island in the South Atlantic, once the most important seabird habitat on earth:

Viewer discretion advised: House mice swarm antlike over a towering Tristan albatross chick — a critically endangered species — slowly eating it alive.

This is the latest in a series called “Recovery” written by Ted Williams. He writes about fish and wildlife for national publications.

Ted Williams

Ted Williams detests baseball, but is as obsessed with fishing as was the "real" (or, as he much prefers, "late") Ted Williams. What he finds really discouraging is when readers meet him in person and still think he’s the frozen ballplayer. The surviving Ted writes full time on fish and wildlife issues. In addition to freelancing for national publications, he serves as Conservation Editor for Fly Rod & Reel where he contributes a regular feature-length column. More from Ted

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44 comments

  1. Go forward with your efforts at Palmyra!! Anyone who protects rats over other natural life is NUTS!

  2. Great article Ted. I lived and worked there in ’05-

    The rats would eat holes in all the coconuts, which would then catch rainwater providing the PERFECT place for mosquitoes to breed– we called them “black smokers” — little wisps of tiny black death — no rats means no black smokers–

    A worry before the eradication, because the mosquitoes having no rats to prey on, might have resorted to the birds–

  3. One great victory rescuing island ecosystems after another — it just keeps getting better, and success breeds success… wonderful. But WHY, one has to ask, should the Farallones be deprived of such ecological rescue just because some people would prefer to allow uncountable seabirds to die year after year from unnatural rodent predation than accept the same rodents to die all in one year from equally unnatural poison (after all, both are human-induced)? It’s like saying we should ban chemotherapy in cancer patients because it has nasty side-effects — would you rather die ‘naturally’ of cancer, or accept the ‘nasty’ side-effects of chemotherapy? Sure, poisoning ANYTHING isn’t nice, just as suffering the effects of serious medical treatments aren’t nice either, as in most cancer cures. But if I have cancer, I know which one I’ll choose. And I’m pretty sure Maggie Sergio would make the same choice!

  4. Very proud of the Island Conservation team which includes one of my heroes Dr Ray Nias for their great work!! This is inspiring stuff. I’ll never forget the fact I learnt studying NZ Conservation back in 1992 that just 3 possums can kill a many hundreds of years old majestic rata tree in just 2 years by eating the canopy! Bring on the brodifacoum I say!!

  5. Those who know nothing about biodiversity have no business imposing there misguided agenda on others.
    The success of Palmyra clearly illustrates that.
    Let those naysayers live with the rats and see what happens to there food supply and gardens.
    Thy will be the first to try and kill them.
    Biodiversity is the key to earths survival while there will be some mistakes along the way in repairing and preserving it on balance its much better than the alternative.

    Maybe those same people should concentrate there efforts on the people who cut down forests and spread invasive species, (those people are invasives) now that would be a good use of their time.

  6. Great work and success on Palmyra, keep it up.
    My time in the U.S. Navy on Midway Island 1964 thru 1965, hardly no harm from plastic.
    Back in 1998 and 1999 as a free lance photographer, very upsetting to witness death by plastic on birds.
    Thanks again for the hard work and effort on Palmyra.
    Best regards,
    Jerry Baldwin
    web site: jerrybaldwinimages.com

  7. I’m not really surprised that there’s a spokesperson for the rats. I guess more outraged that anyone would defend their destroying an entire already fragile ecosystem. Many declining species on that island are an important link in an entire food chain and way of life that sustains that ecosystem. They’re an invasive species on that island just as they would be considered in a big city. Do you protest outside of a pet store to stop the selling of them as food for pet snakes! Inhumanity does have its gray areas, but allowing these invasive rodents to completely bring to extinction, or to the brink of it, entire species native to that island is inhumane and intolerable. Extinction is forever. The rodents must go!

  8. Maggie Sergio doesn’t deserve the appellation ‘environmental activist’. And for all her mewling about killing rats not being ‘humane’, she doesn’t seem to have volunteered to put them up at her house.

  9. My feeling on this is to poison the rat’s out of the Farrallon Islands,these people that object to it are wrong headed and need to wake up and realize that a much more diverse habitat is better than a rat invested dead zone.

  10. Thanks for good writing and realistic solutions – and most esp. thanks for your piece a while back on the most destructive introduced animal in the West: cattle.

  11. What a wonderful story of determination to succeed against all odds! Our Landcare group (Strathallan Family Landcare) has undertaken a project to build nesting boxes and plant under-storey for the endangered Squirrel glider Petaurus norfolcencis. We also are managing several breeding pairs in captivity and are hoping for a positive result. While not quite the scale of your story, we believe ours in important to the local community and for future generations. We salute Ted Williams for his work and great writing.

  12. These folks should be applauded. I, too don’t understand the reluctance to rid the Fallarons of rodents. If Palmyra can be rid of those vermin, so could any other Island.

  13. Get rid of species not native to an environment! Continue to save native species. I believe it’s pretty obvious!!

  14. Thank you for this hopeful information. And thank you for intervening. I saved the lovely photo of salt-spray coated leaves and the blue crab.

  15. We need to replace our natural systems & eradicate the pests. They can thrive where they began.

  16. So glad the destruction of the mice is over! My hope is that we, as the human race, find more ways to retrieve the mess and horror we have caused. Whether by accident or by idiots on purpose. Thank you, Thank you, Thank you!

  17. I am an avid wildlife, environmental activist who defends all species of nature, and love all animals (I am vegan), but I commend all those involved in eradicating these ruthless rats to preserve various species. It is amazing how intelligent the rats are, but they are considered vermin for a reason.

  18. I agree that the rats on Palmyra had to go. But we tend to be selective when talking about alien creatures causing damage to a ecosystem. Here in Olympic National Park of Washington the debate continues (I think) on how to rid the mountains of the mountain goat, “introduced” decades ago before the Park was established. Many who fully agree that the rats of Palmyra ought to have been eradicated are not so eager to rid ONP of the goats (including me). Is the goat more worthy of living than the “lowly and to many loathsome” rat? The point being that we humans must in many cases take responsibility for what we wreak on the environment.

  19. Kill the rodents it is more important to protect the native species. Anyone who has ever. Lived with rats, as I do in the woodlands of Washington state,knows you have to be tough to protect your home and wildlife.

  20. Humans are an amazingly complex species, creating wonderful inventions and inserting ourselves into nearly every habitat worldwide. Unfortunately, we’re also causing tremendously difficult-to-solve problems along with our “progress”. That some would oppose removing non-native predators that are destroying ecosystems shouldn’t surprise, but… Yes, all creatures may be viewed as “God’s making”, but those are well-established elsewhere. These endangered critters have nowhere else to go, and humans caused this problem, so our obligation is to eliminate the problems, atoning for short-sightedness! Great work on Palmyra, and good luck on the Farallones going forward.

  21. This rodent eradication sounds Wonderful ! Having some forestry background, I can well appreciate the difficulties (to put it mildly!) of trying to re-balance the human-created imbalance of nature. Moreover, as in any major conflict, the few are sacrificed for the many.

    Nor do I have any regrets about the rats. In my lab work, I came to know and respect -Yes, and to Like these intelligent and social creatures. And, yes, they have their place – in their native, natural habitat with its natural checks and balances.

    My only concern -and a grave one – is that we may extend the definition of “pest” or “vermin”to Any Creature which, because of human stupidity, has come to represent real – or imagined – threats to other creatures on some peoples ‘ (read: special interests) “good list. ” Something like the slaughter of wolves in the U.S. west, (where poisons and traps – horribly inhumane methods) are used to in part “protect” the Elk as well as sheep etc.

    But,this being said, the Recovery certainly is a really great accomplishment whose method should be Wisely employed in other ravaged ecosystems.

    Congratulations!

  22. Last I checked nice and rats are not on the endangered list!! Ok some species in some far off hill probably is but really you want to argue that over the health of the pacific????

  23. I say kill the rats & mice. The mice eating on the albatross chick is gross. The mice deserve to die.

  24. I am heartened by your work to save islands and native species.
    Here in Phoenix, Arizona we have “roof rats,” which seem to be an offshoot of Norway rats. I’m afraid to poison them, as advised/demanded by some HOA’s, because I can hear owls hooting at night. If the owls eat rats that ingest poison, won’t they die, too? I won’t use poison in my yard even thought I know the problem exists right here in my grapefruit and tangelo trees.
    Do you have any other suggestions for me?

  25. Very impressive…keep up the excellent work. The rats have to go! One question, is there a concern about shorbirds ingesting invertebrates ( like sandhoppers) that have consumed brodifacoum which could possibly cause secondary poisoning?

  26. I’m a 52 year old Swiss screw machinist. I have been for some 34 years. I ran a room of 117 machines as a Leadman. I do not have any experience with such an effort as saving even a small piece of our planet earth. But….. If there is any way that one can make a living. I would be so honored to help. I can get just about anything done, somehow or other. So if your in need, look me up. My name is Patrick. PEACE !!!

  27. Eradication is the way forward.tha person opposing this is not bring practical. Rats and mice also brings disease. The ill effect of the poison outweighs the negative impact on the environment by these marauding rats. So onward toward rat eradication when and where necessary.so what if some people are making money .not all organisations can contribute pro bono.

  28. I am an environmentalist, humanist, naturalist …but a rat is a rat. They have “plagued ” the world’s societies for thousands of years…no better or useful than cockroaches and just as prolific at reproducing Bye-bye rats.

  29. I applaud this project and hope it can be used elsewhere as conditions allow. The world has become littered with invasive species, introduced with the best of intentions, or with abysmal ignorance. It seems unrealistic to plan to eliminate all of them, but in isolated environments it can and should be done.

  30. Mr. Williams looks like and writes like what I know as a real fisherman. My uncle Frank Carroll was a friend of Ted Williams ,the ball player during the time he was stationed at Bronson Field in Pensacola, Fl. He taught Ted how to throw a cast net and probably a lot more about fishing than that as Uncle Frank was probably the best that ever lived. Ted was said to be just a bit arrogant and abrasive and my uncle liked his cousin, Dick Williams better. I learned a lot about fishing from Uncle Frank growing up. Fishing was certainly better then than today around here. Most of the problems stem from overdevelopment and the exploiting of petroleum offshore in the Gulf. What I am most proud of about my uncle was his work helping to preserve some of the Panhandle beaches pushing quietly behind the scene to create National Seashore here. My childhood beach is now preserved, surrounded by some of the ugliest concrete condo canyons in the world. I rarely go there now because you have to pass by these eyesores to get there. The Nature Conservacy attempted to save Gulf State Park land across the state line in Alabama but was rejected by the crooked political machine and their spurious privatization scheme. As a result, the park has been secretly carved up and sold off to be slowly developed in a gradual, inexorable squeeze that nobody will notice until nothing is left. I applaud the Nature Conservacy’s attempt but we must be ever vigilant in the endless struggle against the mindless destruction spawned by those blinded by avarice and greed and a total disregard for the gifts that nature bestows upon us all.
    After a life traveling and working my way around the world, I try to live today the way I was raised -as a farmer, subsistence fishing and hunting on the side. I never kill more than I will eat (something more people should consider) and often make gyotaku prints of notable catches, something I’ve gotten proficient at doing , learning during eight years working and living in Japan and the twenty-some years back here at home. I might be of service to the Nature Conservacy in this capacity as I have done work for Dauphin Island Sea Lab and even have a couple of prints in the Museum of Natural History , British Museum in London, England. I wonder if the Conservacy might consider the usefulness of recording catches of fish caught for research purposes as a baseline for future comparison in both pristine and over-exploited fisheries. Gyotaku is the most accurate technique to do this but is difficult to do well without long experience.
    I offer my services without charge, voluntarily. Obtained images might even be useful for advertising or promotional purposes.

  31. This is encouraging and an amazing feat! I hope people of common sense rule in the Farallones rodent extermination issue. I’d love to see somebody take on feral pigs in the United States.

  32. This is a wonderfully heartening story and everyone involved is to be congratulated. However, it saddens me greatly that with all the massive problems we face in repairing our planet and its native wildlife and plants we also have to combat these misguided cretins. We actually have people in Australia who would protect introduced feral foxes, cats, dogs, rabbits et all of which have decimated our wildlife such that we have lost more species then any other continent on our planet. I cannot help but feel that we should lock these folks in a dark room with starving mice and rats just on the off-chance they might change their minds.

  33. Rats, feral cats and dogs, mongooses, wild hogs and goats and sheep, wild horses, … Humans …. So much constant rampant destruction of natural ecosystems.
    It is so hard to understand – let alone sympathize in any way with – the clueless protectors of these evil unnatural plagues. Shame on them. May they itch all over.

  34. Thank you for the dedication and effort you have put in. One of your supporters told me about this on facebook and i am more than happy to help spread the word for you. I am the admin of the facebook page called Animals Air Land and Sea. Your supporter has posted this article to the visitors section and i am going to share it to the main page for you. I will keep on reposting it for you too. If there is anything else i can do to help, please feel free to message my page.