Friday, March 23, 2018

Vampire Mice II: Mice changing diet, growing bigger as they attack giant seabirds


 Laysan albatross with mouse injury. Credit: USFWS.
Like characters in some horror movie, house mice are moving up the food chain and getting bigger.

They’re feeding on chicks and now adult seabirds, leaving hundreds of three-foot-tall albatrosses bleeding from their necks, heads and backs, like victims in a vampire flick.


In one case, they are also changing in size—nearly doubling in mass on one Atlantic island where they aggressively eat seabird chicks.
The lowly mouse, Mus musculus, has always been an omnivore, but they’ve never had the reputation of rats as attack rodents. That is changing on islands around the world.

The latest spooky change in their level of aggression came on  a remote Hawaiian Island: Sand Island at Midway Atoll at the remote western end of the Papahānaumokuākea Marine National Monument, which takes up all of the Northwestern Hawaiian Islands and considerable square mileage of the surrounding waters.

On Midway, mice are biting the necks of adult Laysan albatross, chewing down skin and fat and muscle, and drinking blood.  Hundreds of the big birds have been found dead, and more hundreds of abandoned nests suggest other injured parent birds may have died at sea.

Night video of the nesting areas show the tiny gray mice climbing the backs and necks of the albatrosses, repeatedly sipping at gaping wounds they have chewed into the birds’ bodies.

Mice going after big adult birds at Midway started out of the blue in 2015, and this was new. This was another step, something not seen before anywhere. Wildlife officials are now studying ways to wipe out the mouse population, before the predation gets worse.

We wrote about this at Raising Islands here

Efforts to control predation on important seabird nesting islands has previously mainly focused on rats—mainly Pacific rats and black rats, which are also known as roof rats and ship rats. But in the past two decades, mice have stepped up as serious predators of seabirds.

Mice have been caught attacking soft chicks and eggs on bird nesting islands for some time. Here is a Live Science piece on attacks at other islands. 

On Gough Island in the South Atlantic, game cameras recorded swarms of mice attacking nestlings of Tristan albatross (Diomedia dabbenena,) great puffins (Puffinus gravis) and Atlantic petrel (Pterodoma incerta.)

“One video showed up to 10 mice mauling an albatross chick and eating from three open wounds on its body,” wrote Live Science writer Jeanna Byer in 2007.
Puffins and petrels are smaller seabirds, the size of mynah birds or pigeons. Albatrosses, which can be three feet tall with wingspans of six to 11 feet, are huge.  A mouse standing up might reach four inches in height. In climbing an albatross, they are climbing a bird nine times taller than they are.
The authors of a 2012 scientific paper in Animal Conservation on that situation wrote: “mice cannot be ignored as a potential threat to island fauna, and island restoration and management plans should routinely include eradication of introduced mice.” 

Injured albatross at Midway in colony. Credit; USFWS.
A 2016 piece in Smithsonian suggests that mice, fed on a rich diet of seabird flesh, are actually changing in size—getting huge. 

They are nearly twice the weight of standard house mice. The standard house mouse is tiny, weighing only about 16 to 25 grams. On Gough, the average mouse runs more than 35 grams.

“They’re the largest and heaviest mice anywhere in the world,” said Richard Cuthbert of the Wildlife Conservation Society.

Cuthbert was the lead author of a 2016  Journal of Mammalogy  article that suggested that the bird diet is a primary cause of the change in mouse size. 

Of course it is not only adult birds that mice attack when they get established on islands. 

Wildlife officials in New Zealand have noted mice killing not only seabird chicks but native lizards, seedlings and bird eggs. New Zealand has removed rats and mice from several offshore islands.

© Jan TenBruggencate 2018

Thursday, March 22, 2018

Vampire mice killing hundreds of Laysan albatross on Hawaiian island of Midway


Bloodied albatross. USFWS photo.
The mysterious vampire mice of Midway Atoll have left hundreds of adult Laysan albatross dead, their necks torn open in garish bloody wounds.

These mice are doing something no mice anywhere else in the world are known to do.

Late at night, they climb the necks of nesting seabirds and chew through the skin, apparently feeding on the birds’ blood, skin, fat and muscle.
The albatross’ commitment to protecting their eggs is so strong that they will shake their heads, but will not leave the nests even with a predatory rodent chewing on them.

And the problem has grown since it was first spotted in 2015.

Wildlife officials assess injured Laysan albatross. Credit: USFWS
“It is horribly destructive what they do to those birds,” said Matt Brown, the U.S. Fish and Wildlife Service superintendent for the Papahānaumokuākea Marine National Monument, which includes Midway.

The Fish and Wildlife Service has teamed up with a number of agencies and now hopes to eradicate the mice, which are an alien species to Midway. Among the 10 major atolls, reefs and islets of the Northwestern Hawaiian Islands, mice only occur on Sand Island, one of the three specks of dry land within Midway Atoll.

The mice have been here at least since World War II, but the new vampirish behavior is both new to Midway and apparently new to science. Mice are known to take eggs and nestlings of seabirds elsewhere, but only on Midway do they attack large adult birds.

“This isn’t a behavior that has been observed before, although rodents have been responsible for a number of seabird extinctions and extirpations on islands,” said Megan Nagel, public affairs officer for the Fish and Wildlife Service in Honolulu.
A Fish and Wildlife Service fact sheet quoted Midway Atoll Refuge manager Bob Peyton: “The Service is working against the clock to determine how many birds have been attacked, what the rate of spread is, and how to stop the attacks. Albatrosses lay only one egg a season.” 

The proposal they’ve come up with is to try to eradicate the mice. New Zealand just completed a successful five-year effort to remove mice from the Antipodes Islands, where they were feeding on chicks and eggs of seabirds, apparently including the Wandering Albatross, whose 10 to 11-foot wingspan makes it one of the biggest of birds. 

The Midway approach will be similar to the one used at the Antipodes: a helicopter drop of toxic bait pellets during a period when the nesting seabird population is at its lowest.  That’s also similar to the technique that has been used to remove mice from more than 80 other islands and to remove rats from more than 400 islands around the world.

In Hawai`i it’s much like the system that was used to eradicate Pacific rats from Mokapu Island off Molokai and black rats from Mokoli`i off O`ahu, and which has been used to control rats at Lehua Island off Ni`ihau, a process that is still underway.
Rats were eradicated from Midway’s three islets in 1996.

The environmental assessment for the Midway mouse effort, under the name Midway Seabird Protection Project, describes the issues and the proposed solution. The public comment for the environmental assessment is open through April 20.

The helicopter would achieve a uniform islandwide distribution of specially designed bait pellets that contain the anticoagulant Brodifacoum. Some hand distribution will be employed in sensitive areas such as near the shore. The work would be done in the summer of 2019, during a period when seabirds are comparatively scarce on the island, and when dry weather limits mouse food supplies—making the grain-based bait pellets more appealing.

There are a number of reasons to use a helicopter, including assuring an even bait distribution but also foot traffic in many areas would collapse many of the thousands of nesting burrows of Bonin Petrels, which recovered strongly after rats were removed.

Similar eradication efforts on other islands have usually but not always been successful. In recent years, the success rate has gone up with improvements in technique. The environmental assessment reviews alternative approaches, and looks at the option of doing nothing at all.  The Brodifacoum bait delivered by helicopter at the right time of year, in specific amounts over time, as described in the proposal, is viewed as the best alternative.

The project is estimated to cost $3.5 million. It is not yet clear the source of that money. Many previous eradications have been funded through a combination of government funds, grants from foundations, and money from private institutions like conservation groups.

The Fish and Wildlife Service would be the lead operational agency, with technical support and assistance from Island Conservation and the Midway Restoration Partnership Group. This is a collaboration of the Fish and Wildlife Serfvice and Island Conservation as well as American Bird Conservancy, the National Wildlife Research Center of the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service, National Oceanographic and Atmospheric Agency, U.S Geological Survey and the state Office of Hawaiian Affairs.

© Jan TenBruggencate 2018
What's at risk :Midway albatross colony. Credit: USFWS.

Saturday, March 17, 2018

Massive pesticide testing confirms: Hawai`i Surface Waters "Meet State & Federal Water Quality Standards"


Ground zero has somehow slipped away. There is no evidence of widespread pesticide contamination in Hawai`i’s surface waters, according to a thorough federal study of water resources on two islands.
That confirms similar results in separate tests from 2014 and 2016.

It would seem that HAPA, SHAKA, the Center or Food Safety can fold up their tents and go home. Their work is done. If the claims of rampant agricultural pesticide misuse were ever true, they are not true now.

The U.S. Geological Survey conducted 7,200 water tests in 2016 and 2017—one of the broadest scientific investigations ever into allegations of pesticide misuse in the Hawaiian Islands. There were 12 surface water test sites on Kaua`i and 19 on O`ahu.

Here is the state Department of Agriculture public release on USGS testing of water samples at 31 sites on Oahu and Kaua`i, for 225 different pesticides. 

“The sites included streams, ditches, canals, and a wetland– and were near or downstream of agricultural areas, developed areas, or both,” the study said.  Here is the study itself

The short version: The laboratory tests were able to detect pesticides, but all at levels below federally and state levels of concern.

Bizarrely, while the last decade of allegations of pesticide misuse have gained widespread publicity across the state, the proof that those claims were unfounded has slipped almost entirely under the radar.  

The state’s news media allocated pages upon pages of newsprint and web content to pesticide contamination allegations, but almost nothing to the actual scientific proof that these claims were were overblown.
The Garden Island newspaper on Kaua`i, dismissed the study in a brief (9 paragraph) story.  Honolulu-based media have had nothing to date. 

The new USGS study is now being repeated on O`ahu and Kaua`i, and is also being expanded to Maui and Hawai`i counties.

“This multi-year surface water study goes a long way towards assuring the citizenry of Hawaii that pesticides are continuing to be used properly,” said Scott Enright, chair of the Hawaii State Department of Agriculture.

The surface water study is not an outlier. It confirms the conclusions of several previous studies.

It supports information by a groundwater study by an independent California laboratory for the Kaua`i Department of Water Supply in 2016, which found no pesticide levels of concern in groundwater from several Kaua`i agricultural sites. Here is the RaisingIslands coverage of that study. 

That study confirms annual testing by the island’s Water Department of all its drinking water sources. Those tests can be seen here

A statewide surface water testing effort in 2014 had results along the same lines. Here is Honolulu Civil Beat’s piece on that statewide program, which found that most pesticide concerns were in urban streams, and not in agricultural areas. 

As noted above, the new USGS study did not fail to find pesticides, but where it found them they were at exceedingly low levels. Here are some of the notable findings, from the state Department of Agriculture release, including what is being done about those pesticides:

“Chlorpyrifos was detected in two Honouliuli stream samples collected during the same high-flow storm event. The highest concentration of 23.3 ng/l is below the state water quality standard of 83 ng/l and the strictest acute benchmark of 50 ng/l for the protection of freshwater invertebrates. HDOA is currently in the process of restricting the use of chlorpyrifos by reclassifying it to a restricted-use pesticide (RUP) which will allow its use by only state-certified applicators. The proposed restrictions will mirror what California has done and includes required buffer zone. These rules are anticipated to be finalized by this summer.

“Concentrations of flubendiamide in high-flow samples collected at two sites on Oahu exceeded the lowest Federal aquatic-life benchmark. Flubendiamide is an insecticide that the U.S. Environmental Protection Agency (EPA) is currently in the process of cancelling its use due to the risk to aquatic invertebrates and aquatic environments.

“Atrazine, an herbicide and established groundwater contaminant, and an RUP was detected in low-flow samples at three sites, at concentrations more than 100 times lower than the EPA maximum contaminant level for drinking water and the strictest aquatic life benchmarks. This represents a significant drop compared to the 75 percent detection rate in a 2013-14 study. The decline likely reflects the decrease in current atrazine applications and sales statewide after 2015, during the time that saw the closure of a large sugarcane plantation.

“Bromacil is an herbicide and established groundwater contaminant used almost exclusively on pineapple in Hawaii. Bromocil was detected in two areas, one of which is known to have grown pineapple.”

All but one of the samples identified at least one pesticide compound. A total of 61 different pesticides were identified across the two islands. The most commonly identified pesticide was Atrazine—either directly or from a compound that Atrazine degrades into.

Atrazine is a long-lived herbicide that was commonly used in the sugar industry, but is still used to control broadleaf weeds in agriculture today. It is the agricultural chemical most widely detected in water samples across the nation.

© Jan TenBruggencate 2018

Sunday, March 4, 2018

Aluminum tariffs, hotel taxes, electric cars and the value of complexity

Targeted taxes and added regulations always have unintended consequences.

In Hawai`i, when we pile taxes onto hotel rooms, it encourages alternative accommodations that may be able to avoid the tax—thus damaging the hotel industry.

When we regulate the heck out of taxis, it opens the door for Uber and Lyft.

Transportation fuel taxes provide an inadvertent subsidy to electric vehicles. Discussions of fixing that with a mileage tax will punish lower-income people who are forced to live where housing prices are cheaper, but who have to commute longer distances.

When President Trump announced new steel and aluminum tariffs, at first blush it seems sound. If these metals from foreign producers pay a big tax to get into the U.S., then that improves the competitiveness of metals from American producers.

But the unintended consequences are many.

Nearly a year ago, the firm NERA Economic Consulting looked into aluminum tariffs and their impact. They used an economic model from another firm, Regional Economic Models Inc. (REMI).

Among the conclusions: the higher prices from across-the-board tariffs would cost more jobs to the larger economy than they would add to the aluminum industry; and the tariffs would harm the parts of the manufacturing economy that rely on aluminum.

The study suggested that tariffs could be tweaked to actually be productive to the local economy, by targeting semi-finished aluminum products.

But, of course, that’s not what President Trump has proposed.

Tariffs and taxes are complicated. They often don’t produce the results intended.

One of the most concerning impacts of the metals tariffs is that while they may be intended to target our economic competitors, they more directly target our friends.

China is a big aluminum producer, and it has severely cut into our aluminum exports. But our biggest source of aluminum is Canada. Sixty percent of the product comes from our northern neighbor.

So it seems that an aluminum tariff could very well not harm China, but further damage Canada, which is already reeling from China’s growing exports.

Unintended consequences.

Which is a statement about complexity. Complexity breeds suspicion and misunderstanding. But complexity is almost always unavoidable in tax and tariff policy. Difficult subjects need smart people and careful consideration.

Simple solutions can sometimes be worse than no solution at all.

© Jan TenBruggencate 2018

Thursday, March 1, 2018

Fake news: A Russian agricultural disinformation campaign operates in parallel with local anti-GMO efforts and national Russian election interference

It turns out Russia hasn’t only been trying to undermine American politics, but American biotech agriculture as well.


Hawai`i has for a decade or so been a hotbed of anti-science, anti-biotech activism. Now it turns out that a Russian anti-GMO disinformation campaign has been operating in parallel, and also in parallel with Russian interfence in American elections.

A new review betrays the existence of a Russian disinformation conspiracy to undermine the West’s initiatives to use biotechnology to make food healthier, and to make agriculture more sustainable.

Researchers at Iowa State University conducted the probe into the Russian attack on agriculture.  Their paper is entitled “Sowing the seeds of skepticism: Russian state news and the anti-GMO movement.”

It turns out that many of the memes of the anti-GMO movement may be Russian plants. And the authors of the Iowa State paper pulled no punches: “Biotech news coverage in English-language Russian media fits the profile of the Russian information warfare strategy described in recent military reports.”

They suggested that the Russian anti-GMO program had one purely financial goal: to promote Russian agricultural products

 “Distinctive patterns in Russian news provide evidence that Russia is conducting a coordinated campaign to turn public opinion against genetically modified organisms. The recent branding of Russian agriculture as the ecologically clean alternative to genetically engineered foods is suggestive of an economic motive behind the information campaign against western biotechnologies,” the paper said.

Another goal is simply to weaken the United States by promoting divisiveness, said Carolyn Lawrence-Dill, an ISU associate professor and co-author of the paper.

Some American anti-GMO organizations were quick to attack the study, but by impugning the motives of the authors, rather than denying the validity of the study. Indeed, Henry Rowlands of the site Sustainable Pulse, doubled down. He said the Russian news organizations are just fine, and in fact more acceptable than American media on this topic.

“The ISU researchers failed to ask the question as to why the U.S. media does not cover the GMO issue regularly, despite a growing consumer interest in and backlash against the technology. It may seem unusual to some, but on this topic the Russian media has more freedom than the U.S. media,” Rowlands said in this article on the organization’s website.  

Rowlands challenged the fairness of the paper’s authors, on grounds that Iowa State gets money from the grain industry. But that’s a stretch. Iowa state is also a leading research institution on organics.

The disinformation campaign appears to operate out of two Russian news sites, RT News and Sputniknews. Between them they used the term GMO more often than the total of five U.S. news sites across the political spectrum: Huffington Post, Fox News, CNN, Breitbart News and MSNBC.

They were RT News scare stories about GMO mosquitoes: “GMO mosquitoes could be cause of Zika outbreak.”

And this: RT News: GMO corn “contains a startling level of toxic chemicals.”

Paradoxically, RT News also had the headline, “GMO crops not harming human health, but not boosting yields.”

And from Sputnik “GMO only causes problems,” and “Mass cultivation of genetically modified crops may damage biodiversity.”

The paper makes the point that the Russians aren’t alone in opposing biotech: “High profile individuals such as Dr. Oz and organizations like the Center for Food Safety, Right to Know, Greenpeace, and the Organic Consumers Association garner considerable attention as they actively oppose the creation and release of biotech animals and crops for agricultural production, promote product boycott movements, and calls for policymakers to enact both mandatory labeling laws and outright bans.”

The Iowa paper says Russian news sites use anti-GMO “click bait,” to link stories provocatively in ways that puts biotech in a bad light. For example, a story on birth defects in mothers infected with Zika was linked to the piece on GMO mosquitos being implicated in Zika.

“These campaigns are long marches, not short sprints. Intentional misinformation campaigns can provide emotional energy and additional attention to topics deemed important for guiding public opinion well into the future,” the Iowa State paper said.

It is no secret and the Russian news organizations don’t deny that Russia’s goal is to promote its own non-genetically engineered crops. RT News admitted as much when it published this piece: “Russia looks to become leading organic food exporter as Europe sees future in GMO.”  

The Iowa State paper concludes with the assessment that Russia’s effort has multiple purposes, and that another of them to undermine science in the West.

“The threat of Russia’s misinformation campaign is not limited to sowing seeds of division in the US and Europe and bolstering Russian economic power - there is also the potential to erode public trust in science, an institutionalized pillar of western intellectual tradition. Whether their anti-science campaign will gain measurable traction remains to be seen.”

The paper has only been out for a few days, but it has already gained significant attention.

“Russia wants you to hate GMOs,” says MIT Technology Review

“Anti-GMO articles tied to Russian sites,” said the DesMoines Register

“Iowa Researchers Find Negative GMO Reporting in Russian Press,” says MSN.com.

Fake news or disinformation, a translation of the Russian word dezinformatsiya, comes from the KGB’s propaganda playbook. And it is familiar to Americans now, given our increasing knowledge of Russian interference in elections and election campaigns.

The New York Times, in a 2016 article, said “disinformation is regarded as an important aspect of Russian military doctrine, and it is being directed at political debates in target countries with far greater sophistication and volume than in the past.” 

© Jan TenBruggencate 2018

Thursday, February 8, 2018

Return to El Nino expected by summer: NOAA. Expect more hurricanes.


The central Pacific was still cooler than normal in January, but it’s warming, and national climate experts say they are seeing clear signs of a returning El Nino by mid-year.

For Hawai`i, that potentially means drier conditions during the wet season, and more and stronger hurricanes during the hurricane season.

(Image: This chart shows how water temperature at the Pacific equator differed from normal over the past year. The big blue area at right represents the cooler water associated with the La Nina that seems to be ending. Credit: NOAA.)

The warming trend was documented in the latest report today (Feb. 8, 2018) from the Climate Prediction Center, National Centers for Environmental Prediction, National Weather Service and the International Research Center for Climate and Society.

The report confirmed that, for now, La Nina conditions are still in place, which forecasts in Hawai`i wetter weather and fewer named storms. For the Mainland, it suggests warmer weather and less rain across the southern states and cooler temperatures and more precipitation across the north.

“The atmospheric conditions over the tropical Pacific Ocean… reflected La Niña, with suppressed convection near and east of the International Date Line and enhanced convection around Indonesia.  Also, the low-level trade winds remained stronger than average over the western and central Pacific, while upper-level winds were anomalously westerly. 

“Overall, the ocean and atmosphere system remained consistent with La Niña,” the report said.

But most of the climate models used in the tracking of El Nino-La Nina cycles predict the mild warming seen in January will strengthen through the next few months, leading to neutral conditions by the period from March to May, and to full El Nino conditions by fall.

The report says that the various computerized models that predict climate trends don’t all agree with the forecast, but that on average, they clearly suggest the warming trend.

The way in which La Nina and El Nino impact storm formation in the Pacific is complex. In terms of La Nina, here’s what NOAA said in a 2016 statement.

 “La Niña typically suppresses central Pacific hurricane activity by increasing the wind shear and causing an irregular sinking motion in the atmosphere, both of which suppress storms from forming and intensifying.”

That was in place during the 2017 hurricane season. There were actually more storms than normal last year—18 named storms, 9 of which were hurricanes—but most were weak and did not last long.

But during the last active El Nino, the Pacific was a hotbed for tropical cyclones big enough to get names. In the El Nino year of 2015, there were 26 named storms, of which 16 were hurricanes. Hawai`i was spared a direct hit that year.

It was the second most active hurricane season on record. The last time there was more hurricane activity in the Pacific was in 1992, the year Hurricane Iniki hit Kauai head-on.
This latest El Nino-La Nina climate report updates the one we published last month

© 2018 Jan TenBruggencate

Thursday, January 11, 2018

Wet La Nina winter shifting, to a stormy summer?


Hawai`i’s wettish winter could continue, as the current La Nina climate cycle is expected to last through the winter.

That’s the latest assessment (January 11, 2018) from NOAA’s Climate Prediction Center and the International Research Institute for Climate and Society.


Long-term prediction of climate cycles is problematic, but most climate models seem to suggest that we could shift into El Nino by mid-summer. If that holds true, it could result an more tropical storms and hurricanes later this year than normal.


La Nina and El Nino are two major climate cycles affecting weather conditions in the Pacific. La Nina has cooler water in the equatorial central Pacific and El Nino has warmer waters.

Generally, for Hawaiian islands, El Nino conditions are associated with dry winters and stronger and more frequent hurricanes June to November. La Nina—which we’re now in—tend to have fewer storms from June to November and wetter winters.

Have you noticed a lot of strong tradewinds recently? La Nina conditions are also associated with stronger low-level tradewinds.

The new report suggests that La Nina conditions continued through the end of 2017 and are expected to persist through the rest of the winter, while weakening. After that, conditions should drift toward a neutral condition for the spring. And the models seem to indicate a continued shift toward El Nino as the summer progresses.

El Nino/La Nina conditions don’t only impact the climate of the Pacific, but are also associated with rainfall and temperature patterns on the Mainland.

Based on the latest climate models, “The outlooks generally favor above-average temperatures and below-median precipitation across the southern tier of the United States, and below-average temperatures and above-median precipitation across the northern tier of the United States.”

Since central Pacific ocean water temperatures are a key indicator of El Nino and La Nina cycles, the climate agencies have computerized models that track where they think water temperature is going. There are many such models, but as shown below, most of them are showing water warming into the summer months.

The bottom line shows months in three-month periods. The dynamic average shifts from negative to positive temperatures in May-June-July (MJJ)



Forecasts of sea surface temperature (SST) anomalies for the Niño 3.4 region (5°N-5°S, 120°W-170°W). Figure updated 18 December 2017. Credit: NOAA.



© Jan TenBruggencate 2018









Figure 6. Forecasts of sea surface temperature (SST) anomalies for the Niño 3.4 region (5°N-5°S, 120°W-170°W). Figure updated 18 December 2017.





Figure 6. Forecasts of sea surface temperature (SST) anomalies for the Niño 3.4 region (5°N-5°S, 120°W-170°W). Figure updated 18 December 2017.


Wednesday, January 3, 2018

Rats detected at Lehua, four months after major eradication effort

Rat control team on Lehua. Credit: DLNR
Rats are back at Lehua, or more likely, a few Pacific rats survive after a major effort to eradicate them during the late summer.


Wildlife management teams were on the island yesterday to better understand the extent of the rat presence and to establish extensive bait and trapping measures in the area where they were seen. They have not abandoned efforts to completely eradicate invasive rats from the small island.

The Lehua rat control project is designed to remove a major predator of the many species of seabirds that nest on the small island north of Ni`ihau. The island has been populated by Pacific rats at least for the past century. It is a state seabird sanctuary.

Pacific rats prey on eggs and chicks of many species, and they also damage the environment by eating seeds and seedlings of plants that otherwise would provide cover and nesting habitat for the birds.

This statement about the rat control project was released yesterday by the state Department of Land and Natural Resources:

Lehua's steep terrain. Credit: DLNR
“The invasive Pacific rat is a voracious predator on the eggs, chicks and even adult birds that currently breed and nest on remote Lehua. The restoration project team has stated repeatedly that the project will not be considered a success unless every invasive rat is removed from the ecosystem, and that will take a full year after the final application to say for sure. The goal of the Lehua Island Restoration Project is to provide safe, predator-free breeding habitat for native seabirds and other species so they may thrive again.”

Numerous motion detection cameras and human surveys of the island after the final delivery of diphacinone rat bait in September 2017 detected no rat presence. But camera memory cards collected in December revealed at least two rats near the summit of the island in late November.

The rats spotted on the camera cards are believed to be Pacific rats, the species that was abundant on the island before the eradication effort in August and September, although a positive identification from fuzzy black and white photos was not possible.

The team sent to the island yesterday included members from Island Conservation (IC), the state Division of Forestry and Wildlife and the Kaua‘i Endangered Seabird Recovery Project (KESRP.) 
The teams have installed a range of measures to attempt to assess whether there are more of the predators present on the island. A total of 134 monitoring devices have been placed on the island, including traps, tracking tunnels with ink pads to detect footprints, wax chewing blocks, bait stations and motion-detection cameras.
Many of the cameras are aimed specifically at seabird nests and burrows as part of the KESRP program, but will identify rat presence as well.

Rats have been eradicated from dozens of islands around the globe, and most eradications work the first time. However, a significant percentage has required repeat control efforts. In the case of Lehua, one theory was that winds at the top of Lehua blew rodenticide pellets away from the top of the ridge, allowing a few rats to survive there, while rodents elsewhere on the island were controlled.

“After seeing these two rats on camera, we collected, immediately reviewed, and noted locations of any additional images the cameras may have picked up,” said Mele Khalsa, of Island Conservation. A review of all other camera records identified no other rat photos.

“While we are clearly disappointed to see evidence of two rats on the island, we are very lucky our partners (KESRP) were able to detect them. We knew from the beginning there was the possibility that a few rats could linger. Now it’s important to address this,” said Suzanne Case, chair of the state Board of Land and Natural Resources.

The rat eradication program has been intensely controversial, largely over the fear that toxic baits could impact the marine environment. Tests on fish found around the island immediately after the bait distribution could not show that the rodenticide was an issue, and tests on the livers of pilot whales that stranded on Kaua`i a month later showed no presence of diphacinone.

Since the two rat detections were in the central part of the island, the current effort should not impact the coastline of Lehua.


© Jan TenBruggencate 2017