Hawaii’s Invasive Predator Catastrophe
By John R. Platt
It takes a lot of effort and more than a little bit of luck for researchers like André Raine to get to the remote mountaintops of Kauai, where they're working to save endangered Hawaiian seabirds from extinction.
First you need a helicopter capable of reaching sites more than 4,600 feet above sea level.
Then you need exactly the right weather to fly — and the hope that conditions don't shift, as they frequently do.
"The weather's not that great," said Raine, the project coordinator for the Kaua'i Endangered Seabird Recovery Project. "We keep going and hanging out at the helipad, waiting and watching. And then it looks like it's going to be okay but it gets fogged in, or you get up there and then you get stuck. The joys of working in a remote, inaccessible area."
The seabirds — including Newell's shearwaters (Puffinus newelli) and Hawaiian petrels (Pterodroma sandwichensis) — obviously have a much easier time getting up the tops of these mountains.
Raine holding a Hawaiian petrel chick. Courtesy Kaua'i Endangered Seabird Recovery Project
So, unfortunately, do several species of invasive predators — including feral cats, black rats and feral pigs — that have put these ground-nesting birds, and so many other native Hawaiian species, on the fast track toward extinction.
"People are always really surprised by this," Raine said, "but it doesn't matter how remote the area, or how apparently inhospitable it is to predators like cats. You're going to find cats and rats and pigs in these areas. There wasn't a single site that we work in that doesn't have all these predators, busy eating the birds."
An endangered chick in the mouth of a feral cat. Courtesy Kaua'i Endangered Seabird Recovery Project
Like many island endemics, Hawaii's bird species grew up without mammalian predators, so they're ill-adapted to the teeth and claws that arrived with human society. The cats descended from housecats, while pigs escape from agricultural sites and rats descended from stowaways on ships.
That's why the Kaua'i Endangered Seabird Recovery Project has spent the past nine years constructing fences and establishing other predator controls — work that is proving essential in giving these native birds a chance.
The first step in controlling predators is quantifying the threat.
According to a paper Raine and his colleagues published earlier this year in The Journal of Wildlife Management, introduced predators killed at least 309 endangered seabirds at six monitored breeding colonies between 2011 and 2017. That's quite a blow for each of these endangered species.
"Newell's shearwaters and Hawaiian petrels have suffered catastrophic declines over the last few decades," Raine said. "Any chick that's lost in the population is one that we can't afford to lose."
Hawaiian petrel. © Ken Chamberlain, some rights reserved (CC-BY-NC). Via iNaturalist.
The researchers took on the sad task of collecting the dead and examining the wound patterns to determine which type of predator made the kill.
Rats, it turned out, killed the most — more than 50% of mortalities — usually from entering the birds' rocky burrows and eating eggs and chicks. That dramatically slows recovery efforts, but the research shows that adult birds who've lost their chicks returned to the same burrows the following year to try again.
Pigs kill fewer birds — about 10% of all tracked mortalities — but they were the most destructive, digging up and taking out entire nests. "It's literally like someone's taken a hand grenade and stuffed it down the burrow and blown it up," Raine said. "They just eat whatever's inside."
Cats were responsible for another 35% of known deaths, and Raine says the research shows those mortalities were the worst for the long-term health of the bird species. Cats target breeding birds, taking out not just the current generation but any hope of successive generations. The seabirds are very faithful to both their burrow sites and their mates, so if a cat takes out one parent the other might not breed again for several years, if at all. (Without predation, the researchers say an amazing 98.6% percent of breeding pairs matched up again and bred each year of the study.)
And while cats in general are the most destructive, some individual cats are downright scary.
"Every now and then, you get a sort of super cat, which is really good at finding burrows and killing the birds," he said.
In one incident recounted in the paper, the seabird recovery team found images of a cat taken by nine out of 30 remote cameras on the same day. Each camera was trained at a different seabird burrow — which provided ready meals for the feral feline.
"It just shows that all you need is for a cat to get into an area for a very short period," Raine said. "When the birds are sitting in a hole in the ground, they're entirely vulnerable to predation. The cat can very easily wipe out a huge number of birds."
Raine describes another incident as "quite horrific to watch." It took place at a remote site the team can only visit about once a month during breeding season, "because it's expensive and hard to get to," he said. They arrived one day to review the site's automatic cameras and the images revealed "this one cat just wreaking havoc across the site. It goes in and kills an adult Newell's shearwater, and they next thing you know it's emerging from the same burrow with four kittens. So it uses that burrow to raise the kittens, and then we get it on camera at another burrow with the kittens, basically training them how to kill more shearwaters."
That's a tough thing to see — especially when these researchers have followed the comings and goings at these burrows for years.
"You start to really empathize with these birds, because you're watching them on the burrow cameras and you're seeing all these amazing behaviors," Raine said. "And we're tracking them as well. We're seeing that they make these incredible journeys to feed their chicks. Hawaiian petrels go towards the coast of Alaska, 11-14,000 kilometers on a feeding voyage, and then you go to the site and you find this bird that's just been shredded by an introduced predator and the chicks left to starve to death. It's quite hard to deal with."
But as difficult and dangerous as these predators can be, the research also shows that the situation is far from hopeless.
Fence Me In
Over the past decade, the Kaua'i Endangered Seabird Recovery Project and its many organizational partners have concentrated on establishing predator controls at six of their seven regularly monitored seabird breeding sites.
Again, this isn't easy to accomplish in these remote, rarely visited locations. Materials must be flown in, ungulate-proof fences built, other traps set, and pig-hunting expeditions organized. All of it must be accomplished and maintained in precarious territory full of wet vegetation, narrow ridgelines and steep canyon walls.
To make things even more difficult, the human visitors must leave the habitat as undisturbed as possible.
"If you start making trails in these areas, then you're basically just opening them up to the hordes of predators that are out there," Raine says.
But the hard work pays off.
According to the paper, fences and other controls not only keep the invasive predators out, they give the birds the opportunity to thrive.
The research team used seven years data from the six sites, from before and after predator controls were established, and projected striking results for the future of the two seabird species.
The first model looked at what would happen to each site without predator controls. It was a disaster — mostly due to cats. "We ran that for 50 years, and we found that all of the colonies dwindle toward extinction."
The paper, in what Raine acknowledges as gallows humor, calls this the CATastrophe model.
The second modeling approach incorporated data from successful breeding that took place after more extensive predator controls (fences and traps) were put in place. "We found that the populations increased over those 50 years," Raine said. Under the model, which was based on 2017 population growth rates at sites with predator controls, most sites would see a 50-60% increase over the 50-year projection, while one site more than doubled.
"It really does show that if you remove the predators, the birds will begin to recover."
This isn't the be all and end all. Hawaiian seabirds face a laundry list of additional threats, including climate change, collisions with power lines, reduced fish populations at sea, and invasive plants that change forest compositions. The models don't address those threats, which also require mitigation.
There's also another introduced predator: barn owls. Hawaii introduced barn owls in the 1960s to control rats, but — as we've seen in so many other similar examples — they quickly became a new problem. Owls only killed 12 seabirds during the study, but Raine says these newest invaders pose an increasing threat that's proven harder to control. You can build fences to protect birds, after all, but you can't prevent other birds from flying over those protections.
But this research does prove that current management techniques to protect Hawaiian seabirds from their most pressing threats — cats, rats and pigs — really do work, and that they can be applied to more locations, even by private landowners who have birds on their properties. "Although we've got seven managed sites, there are other sites on the island where the birds are still hanging on, and there's no reason to expect that these techniques wouldn't be effective at other colonies."
That's important, because some of those additional sites are on the edge.
"We're finding that these other sites are just going silent," Raine said. "With no management on them, the birds just flit away." The paper recommends predator-proof fences at all sites, as well as dedicated year-round funding for both seabird monitoring efforts and predator-control operations designed to specifically target the composition of animals at each location. The authors also suggest additional port biosecurity to prevent more invasive species from arriving, and possibly the targeted use of landscape-level toxicants to remove rats and cats.
In addition, Raine says, these techniques can be applied to other species and other island locations where invasive predators threaten ground-nesting birds.
Perhaps most importantly, the research helps show these conservationists — whose work has continued as "essential" during the pandemic — that their efforts to fight extinction in these challenging, hard-to-reach habitats are paying off.
"I remember one of our sites in particular — in fact the one I was trying to get into today — the first time I went there I found within a five-foot area a burrow that had been predated by a cat, a dead chick that had been pulled out by a rat, and a burrow that had been destroyed by a pig," Raine recounted. "Now you can go a month without even seeing predators at some of these sites because of the great work that the controllers' crews are doing."
And this raises one more issue: this work isn't just about birds. It may help heal Hawaii — the extinction capital of the world — in the process.
"I think it's really important that people understand the critical importance of seabirds as the architects of the island itself," Raine said. "They bring all those ocean nutrients up into the mountains, and their partly responsible for the watersheds that we all rely on. It's a whole ecosystem that needs to be addressed."
Reposted with permission from The Revelator.
EcoWatch Daily Newsletter
Coronavirus Shines Light on Zoos as Danger Zones for Deadly Disease Transmission Between Humans and Animals
By Marilyn Kroplick
The term "zoonotic disease" wasn't a hot topic of conversation before the novel coronavirus started spreading across the globe and upending lives. Now, people are discovering how devastating viruses that transfer from animals to humans can be. But the threat can go both ways — animals can also get sick from humans. There is no better time to reconsider the repercussions of keeping animals captive at zoos, for the sake of everyone's health.
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By Kate Whiting
Bernice Dapaah calls bamboo "a miracle plant," because it grows so fast and absorbs carbon. But it can also work wonders for children's education and women's employment – as she's discovered.
These are the world's most bicycle-friendly cities. Statista<p>"The reason we use bamboo to manufacture bicycles is because it's found abundantly in Ghana and this is not a material we're going to import," says Dapaah, one of the World Economic Forum's Young Global Leaders.</p><p>"It's a new innovation. There were no existing bamboo bike builders in our country, so we were the first people trying to see how best we could utilize the abundant bamboo in Ghana."</p>
<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="a335b5dffdd806bd6bb4debea90c2045"><iframe lazy-loadable="true" src="https://www.youtube.com/embed/dxsb9c4HMn0?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>
Supporting Students<p>Besides encouraging Ghanaians to swap vehicles for affordable bikes, Ghana Bamboo Bikes Initiative is helping students save time on walking to school so they have more time to learn.</p><p>Each time they sell a bike, they donate a bike to a schoolchild in a rural community, who might otherwise have to walk for hours to get to school.</p><p>Dapaah knows how transformative a shorter journey to school can be to academic performance. She grew up living with her <a href="https://www.youtube.com/watch?v=sb3joGYmx9A&feature=emb_logo" target="_blank">grandpa, a forester in a rural part of the country</a>.</p><p>"We had to walk three and a half hours every day before I could go to school. He later bought me a bike, so I finished senior high and wanted to go to university."</p><p>The experience inspired her to launch Ghana Bamboo Bikes Initiative with two other students at college.</p><p>"When we started this initiative, I looked back and said, when I was young, I had to walk miles before I could get to school, and sometimes if I was late, I was punished.</p><p>"Why don't we donate bikes for students to encourage them to study and so they can have enough time to be on books."</p><p>To date, they have sold more than 3,000 road, mountain and children's bikes – and Dapaah says they plan to donate <a href="https://www.entrepreneur.com/video/350343" target="_blank">10,000 bikes to schoolchildren over five years</a>.</p>
Empowering Women<p>The enterprise is also providing local jobs. It teaches young people to build bikes, particularly women and those in rural communities, where jobs can be scarce. More than 50% of people they have trained are women.</p><p>Dapaah says they want to boost the number of people they employ to 250 over the next five years and they are looking to partner with NGOs to build a childcare facility so mothers can continue to work.</p>
Reducing Emissions<p>By promoting a cycling culture in Ghana, Dapaah says they're also committed to reducing emissions in the transport sector and contributing to the UN's Sustainable Development Goals.</p><p>"I love the idea of reusing bamboo to promote sustainable cycling. People want to go green, low-carbon, lean-energy efficient," she says.</p>
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Deforestation coupled with the rampant destruction of natural resources will soon have devastating effects on the future of society as we know it, according to two theoretical physicists who study complex systems and have concluded that greed has put us on a path to irreversible collapse within the next two to four decades, as VICE reported.
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By Kristen Pope
Melting and crumbling glaciers are largely responsible for rising sea levels, so learning more about how glaciers shrink is vital to those who hope to save coastal cities and preserve wildlife.
Groans, Creaks, Icebergs’ Calving Splashes<p>Oskar Glowacki already knew that melting glacial ice sounds like frying bacon. As ice bubbles burst, anyone nearby can hear crackling and popping, said Glowacki, a postdoctoral scholar at the Scripps Institution of Oceanography. Using hydrophones, he and other scientists now can make more nuanced measurements of how a changing climate sounds underwater, from the groans, creaks and splashes of a calving iceberg to the changes in whale songs as the ocean warms.</p><p>Glowacki recently used a pair of hydrophones to study the underwater world of glaciers, publishing his findings in <a href="https://www.the-cryosphere.net/14/1025/2020/" target="_blank">The Cryosphere</a>. He and co-author Grant B. Deane measured glacier retreat by <a href="https://yaleclimateconnections.org/2020/07/melting-glaciers-sound-like-frying-bacon/" target="_blank">recording the sounds of ice</a> – from small chunks to enormous slabs – falling off the glacier and splashing into the water.</p><p>During the summer of 2016, Glowacki's team placed two hydrophones near Hansbreen Glacier in Hornsund Fjord, Svalbard. For a month and a half, they recorded sounds, also using three time-lapse cameras to collect images – including the "drop height" (how far the ice fell into the water) – so they could compare photos to the recordings. The team created a formula to represent the relationship between the size of a piece of ice falling from a glacier and the sound it makes underwater, also accounting for the pieces of ice falling from varying heights. (Hear an example of the sound an iceberg makes while calving <a href="https://soundcloud.com/user-248456662/iceberg-calving-hansbreen-glacier" target="_blank">here</a>.)</p>
Unlocking Information About Antarctic Ice Shelf<p>Other researchers also are using hydrophones to learn more about crumbling glaciers. Bob Dziak, research oceanographer with the NOAA/Pacific Marine Environmental Laboratory <a href="https://www.pmel.noaa.gov/acoustics" target="_blank">acoustics research group</a>, captured a massive calving event of the Nansen Ice Shelf in Antarctica with a hydrophone. He published the results with colleagues in <a href="https://www.frontiersin.org/articles/10.3389/feart.2019.00183/full" target="_blank">Frontiers in Earth Science</a></p><p>On April 7, 2016, satellite images showed a massive calving event had occurred on the ice shelf. The paper described it as the "first large scale calving event in >30 years."</p><p>However, once Dziak and colleagues delved into the data from three hydrophones deployed 60 kilometers east of the ice shelf, they uncovered a series of "icequakes" from January to early March 2016. He and other researchers believe that much of the ice actually broke free in mid-January to February, but it remained in the same location until an April storm – which their paper described as the "largest low-pressure storm recorded in the previous seven months" – broke the ice free.</p><p>"We suspected that the icebergs broke apart but remained in place – kind of pinned in place – until a major storm with high winds passed through the area and, finally, it was that last push that pushed the icebergs out to sea," Dziak says.</p><p>He and his co-authors wrote that "fortuitous timing and proximity of the hydrophone deployment presented a rare opportunity to study cryogenic signals and ocean ambient sounds of a large-scale ice shelf calving and iceberg formation event."</p>
Listening to Songs of Humpback Whales<p><a href="https://www.mbari.org/" target="_blank">Monterey Bay Aquarium Research Institute</a> studies the ocean, including its acoustics. One of the institute's projects involves examining the soundscape of California's Monterey Bay, including sounds from animals, humans, weather, and geologic processes like earthquakes. The researchers once even recorded an under-sea landslide. They also focus on recording and analyzing the <a href="http://www.mbari.org/humpback-song/" target="_blank">songs of humpback whales</a>. Male humpback whales' songs can be over 15 minutes in length, and they can be repeated for long periods of time – even hours. Listening to these songs and analyzing them can provide unique insights into the lives of these complex animals.</p><p>"Any time we want to study marine mammals, sound gives us a window into their lives because they use sound for all of their essential life activities, really," says institute biological oceanographer John Ryan. "Communication, foraging, reproduction, navigation – depending on the species, of course."</p><p>Previously, scientists had thought singing occurred only during courtship and mating, but now they think whales may also use song while migrating and hunting. They know song has a crucial role in the whales' lives.</p><p>"There's a whole other dimension to humpback whale song," Ryan says. "It is a mode of cultural transmission in this species. They learn songs from each other. They share songs as a population, and when populations mix and mingle, they learn new ideas, they explore with their song, improvise, and it's a real essential part of their culture."</p>
By William S. Lynn, Arian Wallach and Francisco J. Santiago-Ávila
A number of conservationists claim cats are a zombie apocalypse for biodiversity that need to be removed from the outdoors by "any means necessary" – coded language for shooting, trapping and poisoning. Various media outlets have portrayed cats as murderous superpredators. Australia has even declared an official "war" against cats.
Faulty Scientific Reasoning<p>In our <a href="https://doi.org/10.1111/cobi.13527" target="_blank">most recent publication</a> in the journal Conservation Biology, we examine an error of reasoning that props up the moral panic over cats.</p><p>Scientists do not simply collect data and analyze the results. They also establish a logical argument to explain what they observe. Thus, the reasoning behind a factual claim is equally important to the observations used to make that claim. And it is this reasoning about cats where claims about their threat to global biodiversity founder. In our analysis, we found it happens because many scientists take specific, local studies and overgeneralize those findings to the world at large.</p><p>Even when specific studies are good overall, projecting the combined "results" onto the world at large can cause unscientific overgeneralizations, particularly when <a href="https://doi.org/10.1016/j.tree.2015.01.003" target="_blank">ecological context is ignored</a>. It is akin to pulling a quote out of context and then assuming you understand its meaning.</p>
Ways Forward<p>So how might citizens and scientists chart a way forward to a more nuanced understanding of cat ecology and conservation?</p><p>First, those examining this issue on all sides can acknowledge that both the well-being of cats and the survival of threatened species are legitimate concerns.</p><p>Second, cats, like any other predator, affect their ecological communities. Whether that impact is good or bad is a complex value judgment, not a scientific fact.</p><p>Third, there is a need for a more rigorous approach to the study of cats. Such an approach must be mindful of the importance of ecological context and avoid the pitfalls of faulty reasoning. It also means resisting <a href="https://doi.org/10.1111/cobi.13126" target="_blank">the siren call of a silver (lethal) bullet</a>.</p>
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