Tag Archives: pesticides

The Marsh Pride: end of an era

Jonathan Scott: The poisoning of members of the Marsh Pride, the world’s best known lions, highlights the need for a lasting solution to human–wildlife conflict in Africa


Lioness Bibi in her prime in the Masai Mara National Reserve, Kenya. Bibi was a member of the Marsh Pride that featured in the BBC TV series “Big Cat Diary” from 1996 to 2008. Bibi died on 6 December 2015 after being poisoned along with other members of the pride. Photograph: courtesy of © Andrea Scott. All rights reserved.

Lioness Bibi in her prime in the Masai Mara National Reserve, Kenya. Bibi was a member of the Marsh Pride that featured in the BBC TV series “Big Cat Diary” from 1996 to 2008. Bibi died on 6 December 2015 after being poisoned along with other members of the pride. Photograph: courtesy of © Andrea Scott. All rights reserved.

On Sunday morning (6 December 2015) news broke of the poisoning of members of the Marsh Pride. These are the lions that Angela and I have followed since 1977 and were the stars of our “Big Cat” TV series, that documented the fascinating and often tumultuous life of the pride over a period of more than 12 years.

The Marsh Pride occupies a territory on the edge of the Masai Mara National Reserve in Kenya, one of Africa’s foremost protected areas. All members of the “big five” (lion, leopard, African elephant, African buffalo, and black rhinoceros) are found on the vast plains of the Mara, plus a wealth of other wildlife.

On Saturday night, the lions had killed cattle belonging to a family living near the reserve. In retaliation, a member of the family sprinkled pesticide onto the carcass, knowing that the lions would return. He was intentionally trying to kill them. How many lions have died as a result is still unclear.


The body of Marsh Lioness Bibi, who died from poisoning at 7.30 am on Sunday 6 December 2015, along with other members of the Marsh Pride. Masai Mara National Reserve, Kenya. Photograph: Courtesy of Patrick Reynolds

The body of Marsh Lioness Bibi, who died from poisoning at 7.30 am on Sunday 6 December 2015, along with other members of the Marsh Pride. Masai Mara National Reserve, Kenya. Photograph: Courtesy of Patrick Reynolds

I wish I could say that this was shocking news, but there is nothing shocking any more about what is happening in the Masai Mara. Tens of thousands of cattle encroach in to the Reserve every night when visitors are safely out of sight – but when the likelihood of conflict with predators such as lions and hyenas is at its greatest. This makes no sense.

This sorry state of affairs is testimony to the appalling management of the Reserve east of the river. This is a situation that has existed for at least as long as I have known the Masai Mara. Management failures contributed to the precipitous decline in the Mara’s black rhino population from an estimated 150 to 200 in the 1960s to just 11 by 1983 (it has risen again to between 30 and 40).

The BBC filmed the hugely popular TV series ‘Big Cat Diary’ in Marsh Pride territory from 1996 to 2008. Our base in the Mara was – and still is – a stone cottage at Governor’s Camp. This is a safari camp set in the heart of the reserve, in the vicinity of the glorious Musiara Marsh after which the Marsh Lions were named.

The Marsh is the heart of the Marsh Pride’s dry season territory, while to the east the intermittent watercourse known as Bila Shaka was the traditional breeding site and resting place for the pride. Bila Shaka means ‘without fail’ in Swahili, testimony that the guides could always find lions here. Not now.

Each year Governor’s Camp outfitted a special tented camp for us along the Mara River just upstream from Main Camp. The foundation of the series was that we always knew that we could find lions, leopards and cheetahs in the area on a daily basis. The Marsh Pride were at the heart of the series, and virtually never let us down.

The Marsh Pride at home in the Masai Mara National Reserve, Kenya. Photograph: courtesy of © Andrea Scott. All rights reserved.

The Marsh Pride at home in the Masai Mara National Reserve, Kenya. Photograph: courtesy of © Andrea Scott. All rights reserved.

But that all changed when the authorities decided to turn a blind eye to the incursion of cattle into the reserve, forcing the lions to move out or risk death. The Marsh Pride has always been vulnerable since its territory spreads beyond the reserve boundary. This is particularly apparent in the wet season when Musiara Marsh (and Bila Shaka at times) becomes waterlogged and the lions move to higher ground to north and east.

Each year we lose lions to poisoning or spearing by pastoralists. That was always part of life for the lions. But in the last few years the situation has escalated beyond all reason, with the Marsh Pride becoming increasingly fragmented by the influx of cattle and herdsmen. Today it would be impossible to film Big Cat Diary in the same location. What a damning fact that is.

This year the impact of livestock has been all too apparent. Huge herds of cattle would camp during the daytime along the boundary of the reserve waiting for the tourists to head in to camp. Soon the Musiara area looked like a desert and each night you could see dozens of flickering torches as the cattle were driven in to the reserve after dark.

The deep tracks leading into the reserve are testament to this, along with piles of cattle dung scattered deep inside it. And the Musiara area is not alone. Guides from other parts of the Mara have been complaining about this situation for years. But nobody seems to be able to do anything about it.

These incursions are threatening the social cohesion – and very existence – of the Marsh Pride. Earlier in the year a breakaway group of young Marsh Pride females with young cubs were forced to cross the Mara River and set up home in the Kichwa Tembo area. The older females – Bibi (17), Sienna (11) and Charm (11) – and their cubs increasingly avoided Bila Shaka and the Marsh, loitering at the fringes of their traditional territory, forced to encroach on neighbouring prides.

The pride males – Scarface and his three companions – no longer visit the Musiara area, ever since Scarface was shot in 2013. He was treated and recovered but knew better than to stay.

In the past pride males often only managed a tenure of 2 years – sometimes less – before being forced out of their pride by younger or more powerful rivals. It was not uncommon to see groups of five or six young nomadic males roaming the Musiara or Paradise area together. I have counted as many as nine travelling as a group. That was a sign of a healthy lion population with lots of dispersing sub-adults.

Now Marsh Pride males are able to remain as pride males for many more years, due to a decline in the number of young nomadic male lions vying to replace them. The scarcity of these nomadic males suggests that they are not surviving as well as in the past, due to the disturbance that lions are facing on a nightly basis in parts of the Mara from livestock and herdsmen, or from trying to survive in less optimal areas beyond the reserve boundary.

Lions are always going to kill livestock if it comes within range – and of course they will sometimes kill livestock outside the reserve and must bear the consequences when they do. The only way to prevent this happening is if there are sufficient incentives to persuade the herdsmen that lions equate to tourists – and that means a financial return.

And that is the key point. Many Masai do not think of the Masai Mara Reserve as a source of income. They often feel that it is unfair that wildlife is allowed to share their pastures, and sometimes kill their livestock, while they are not allowed to reciprocate by bringing livestock in to the Reserve during dry times.

The Masai have roamed these areas for hundreds of years, long before it was given official protection. Understandably the Masai claim the Mara as their own. The authorities urgently need to address this issue by ensuring that everyone benefits from tourism to the Mara in a truly tangible way.

There will be no safe place for the Marsh Lions until the reserve authorities decide to address all of the issues that have been debated ever since I first came to live in the Mara in 1977. Measures must be taken now to ensure an equitable distribution of revenue from the reserve to the local community, and to increase support for the wildlife conservancies created on private lands around the reserve, where cattle grazing is permitted on a rotational basis.

Within the reserve, there should be a moratorium on any further tourism development, and an embargo on grazing of livestock.

What a miracle it would be if the demise of the Marsh Pride became the catalyst for serious dialogue and change as to how the Masai Mara is managed. The Governor of Narok County, the Honorable Samuel Ole Tunai, pledged to do just that when he called a Masai Mara Stakeholders Meeting in Nairobi in September 2015.

I attended that meeting and was impressed by the number of people who made the effort to come along and by the Governor’s openness to dialogue. Since then a small group of concerned individuals drawn from all walks of life have worked to support the Governor’s initiative.

We can only hope that we are about to witness tangible steps towards securing the future of this iconic landscape and its magnificent wildlife.


Paula Kahumbu writes: This is an edited version of an article written by Jonathan and Angela Scott and published on their blog on 7 December 2015. Jonathan and his wife Angie are award winning authors and internationally renowned wildlife photographers. My sincere thanks to Jonathan and Angela for permission to publish the article here.

Responding to a tip-off from visitors, the Kenya Wildlife Service and local authorities acted swiftly to bring the culprits to court, while the David Sheldrick Wildlife Trust and other local conservation organisations were prompt to treat the affected lions. But despite this veterinary support three lions have already died. At the time of writing, another four are still sick. The condition of others is not known.

Kenya has never before charged a person with poisoning wildlife, even though it is a frequent crime that has devastating effects on populations of lions, vultures and other predators.

However in this case the new Wildlife Crime Prosecution Unit has moved quickly to charge the suspects of this crime with offences against endangered wildlife species under Section 92 of the 2013 Wildlife Act, which could result in a fine of Ksh 20 million (USD 200,000) and/or life imprisonment.

This is another welcome sign that Kenyan courts are now taking wildlife crimes seriously. As Jonathan eloquently argues, this needs to be backed up by action to address the root causes of wildlife crime, inspired by the vision of a common future for people and wildlife


Details and photos of lions poisoned in Masai Mara

On the 25th of April investigators discovered three dead  lions near Lemek in the Masai Mara ecosystem which occurred on the 22nd of April 2010. The lions lay dead in a traditional homestead where they had been poisoned by eating a cow laced with pesticides by a Masai family. A lioness had died about 5-10 meters away from the cow carcass. The carcasses of a juvenile male and second lioness lay some 30m away. There were piles of dead flies around the cow carcass and the lions had not yet been scavenged. KWS arrested a local man who admitted that he had poisoned the lions with his neighbors. He produced a container that contained pink powder, which he had used to poison the lion. The same pink coloring was visible on the laced meat of the cow carcass used for the poisoning.  KWS have sent samples of the lion carcasses and the pink substance have been sent for toxicological tests to confirm what pesticide was used.

lion poisoned Masai Mara

The suspect confirmed that the cow carcass that was laced belonged to him and other family members, and that it had been killed by lions when his herd’s boy was grazing livestock. The suspect was taken to the police by KWS but despite the admission of guilt and evidence provided, he was released shortly thereafter. According to sources who wish to remain anonymous, a local politician intervened on his behalf.

Lion poisoning 2nd female-1small

This incident brings to 8 the number of confirmed poisoning cases of lions in recent weeks in southern Kenya, the other five occurring near the Amboseli National Park. In their National Conservation and Management strategy for Lions and Hyenas, the Kenya Wildlife Service state that “poisoning is perhaps the greatest threat to predators and scavenging birds” and reveal that Kenya’s lion population has declined to fewer than 2,000 individuals and estimates that only 1,970 individuals remain.  KWS confirm that 2010 has started off badly for lions – in addition to 8 confirmed poisonings, more than 10 other lions have been killed in other circumstances; A lion was shot in or near Buffalo Springs Reserve, Samburu District, by local police, while others have been speared near Amboseli  National Park.

lion poisoning (Cow) small

In response to this incident, Richard Leakey the Chairman of WildlifeDirect has again called for the government to take action “The future of tourism in Kenya is at risk if dangerous pesticides used to kill lions like Carbofuran (sold locally as Furadan) remain on the market and cases of abuse are not followed up and culprits are set free time and time again. The Kenyan government must show it’s seriousness and take swift action on availability of deadly pesticides like Furadan and the enforcement of the law in obvious incidents of pesticide abuse such as this. Failing this Kenya’s lions go extinct in a matter of years which will cause a catastrophic loss in potential tourism revenues ” .

Conservationists in Kenya warn that carbofuran is the most widely used pestsicide to kill wildlife pests such as lions and leopards in the country. It is also used in pesticide fishing and hunting of birds for human consumption. Carbofuran is a neurotoxin that is deadly to fish, birds in irrigation schemes, cats and even humans.  Due to it’s toxicity and negative impacts, carbofuran is not permitted for use in agriculture in the European Union and use in USA where it is manufactured, was recently revoked after the Environmental Protection Agency (EPA) found it unsafe for users, consumers and wildlife. After incidents of lion poisoning in Kenya became public in 2008, the manufacturers of Furadan, FMC withdrew the product from Kenyan shelves. However, carbofuran is not banned and Furadan can still be found in some places, and the active ingredient carbofuran occurs in other over-the-counter pesticides.

Lion Death Map  Masai Mara

WildlifeDirect is a conservation charity registered in USA and Kenya, and based in Nairobi. We enable conservationists at the front lines to tell their stories and raise awareness about their work through over 80 blogs from the field on the website platform http://wildlifedirect.org.  The Chairman of WildlifeDirect is Dr. Richard Leakey and the Executive Director is Dr. Paula Kahumbu. Visit http://wildlifedirect.org for more information

Furadan: WildlifeDirect is campaigning for the de-registration or total ban on the active ingredient of Furadan, carbofuran in Kenya due to the threats it poses to users, consumers and wildlife. This pesticide threatens the survival of lions, vultures, fish species and many other mammals and birds In Kenya. Furadan is produced in USA by FMC and is sold locally by Juanco SPS as an agricultural insecticide.  For more information on our campaign against wildlife poisoning visit http://stopwildlifepoisoning.wildlifedirect.org

KWS is the government body responsible for wildlife conservation in Kenya.  For more information visit http://www.kws.org

For other photographs or more information please contact Paula Kahumbu [email protected], or call 0722685106, or 020 2602463

Carbofuran the most widely used poison in USA

A Kentucky man has pleaded guilty to poisoning migratory raptors using Furadan and has been fined US$ 5,000 for the offence. He admitted to lacing a turkey carcasses with Furadan to poison coyotes and ended up killing migratory birds, three red-tailed hawks and three vultures,

According to federal agent Jim Gale.

“Furadan is the most widely misused pesticide documented during wildlife poisoning investigations in the United States,” he said. “During the past 10 years Furadan has been documented in 26 investigations in Kentucky alone.”

The threat to Kenya’s lions by Furadan remains a high priority due to the growing human lion conflict resulting from the drought. Scientist are on high alert and have warned us that they expect a surge in killings.

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Childs death to Furadan not an isolated case

After WildlifeDirect spoke to the father of 3 year old Kimutai last week there has been a flurry of media regarding this case. National Geographic also interviewed the childs father and the manufacturers of Furadan, FMC claim to be conducting their own investigations . This is not the first time that a human being has died from ingesting  deadly amounts of carbofuran, however it is the first time that it has gained media attention and a response from FMC in Kenya.

No reporting or under reporting of pesticide poisoning suggest this is probably not an isolated case

According to our sources in Uganda, a young man died in Uganda after ingesting Furadan last year. Although reported to FMC, we are told that FMC apparently have not responded to that incident. In the case of Kimutai the story reached the media because of a coincidence – the father knew a journalist who happened to be aware of the campaign to ban carbofuran in Kenya. Kimutai’s father told me that he fears that thousands of others may have been affected and have simply not reported the incidents. In rural Kenya autopsies are not conducted – and so the evidence trail ends.

A report compiled by the international crop research institute ICIPE states that 97.5% of Kenyan green bean farmers use pesticides and all are purchased in AgroVet stores.  The ICIPE report also claims that

“A fairly high proportion (about 21%) of farmers reported having visited clinics for treatment for maladies related to pesticide usage.” 

With such a high rates of maladies associated with pesticides one would expect the regulations to be stringently enforced. They are not. Kimutai was buried without an autopsy being conducted and according to his father, no record of the pesticide poisoning was forwarded to higher government offices. It seems that Kimutai represents an incident that never got recorded even as a statistic, even FMC cannot be sure that he died of Furadan poisoning. There were no tests, no documentation and apparently no death certificate. We agree with his father believes that this lack of reporting may be concealing a serious problem in farmlands across Kenya.

What does the Furadan label actually communicate?

 I have been asking people to read the Furadan label and tell me what it means

Furadan carbofuran label

Furadan label carbofuran

Two people have told me that it is a pest killer  for any form of pest from insects to rats to lions – this they know from recognizing the packaging and from previous experience. Two people thought it was a dusting powder for dogs against ticks – indeed the packaging for tick powder is in an identical container and may explain why Maasai herdsmen are trying to use Furadan on sheep. At half the price it’s a simple economic decision.

One person thought it was for malaria – the yellow square with x in side it is apparently a symbol used on malaria medicine.

None of the 5 people asked thought it was a deadly toxin. They associate a skull and cross bones with that.  None of the people I interviewed could explain what the six symbols in yellow at the bottom meant. Before I share with you recordings of farmers trying to explain – please send me your thoughts – what do you think the 7 symbols in yellow boxes at the bottom of the label mean?

Status of Furadan Buy-sback in Kenya 

We can also confirm that while the availability of Furadan  in Kenya is down, it is by no means gone from the Agrovet outlets. I personally visited several Agrovets in and around Nairobi and can confirm that it cannot be found anywhere near the headquarters of Juanco, the Kenyan distributor. Most Agrovets said they thought it has been banned by the government, however they admitted that it could be found in certain Nairobi stores, in major seed outlets and in up country Agrovets.

We have just received a report that it is available in Eldoret, a major agricultural town in central Kenya.  WildlifeDirect has been collaborating with FMC on reporting the presence of Furadan in Kenya but we remain dismayed at the lack of information regarding how much Furadan has been bought back, from where, where it has been taken or how it will be disposed. We have had no response to a series of emails to FMC on these issues. Our greatest fear is that tons of the product may have simply been moved to  border towns just outside of Kenya where we know the Agrovet stores are fully stocked with the deadly pesticide.

Ban Carbofuran in Kenya and Africa to save people and wildlife 

WildlifeDirect and other conservation organizations in Africa are proud to be associated with National Geographics Derek Joubert who says “We need to use whatever networks we’ve got, whatever political power we’ve got, to impose on FMC to pull this product out of Africa—that’s the bottom line.”

Saving the last lions


This article is in today’s Washington Post and is written by a good friend of WildlfeDirect, Dereck Joubert

Tuesday, October 13, 2009

Just 50 years ago there were close to a half-million lions in Africa — about 450,000 in all. Today there are between 16,000 and 23,000. And yet, unlike elephants (a far more numerous species), lions have no protection under the international accord governing such matters.

Big cats are in trouble everywhere. The number of tigers has dipped below 3,000. Indeed, as we look at the lion population today, it’s the shadow of the tiger’s history that scares me most. Tiger bones are used extensively in the East for medicines and mythological (read nonsense) cures for ailments or limp libidos, and the demand is increasing. A growing demand and a disappearing supply is a formula for disaster.

The solution we are seeing play out is a switch from tiger bones to lion bones, which can be easily sold off as tiger bones. It’s ironic that the most famous animal in Africa, perhaps in the world, can’t even be poached on its own value but only as a “mock tiger.”

This week the Convention on International Trade in Endangered Species (CITES) is meeting to decide whether lions, whose numbers have declined by 50 percent in the past 20 years, are worthy of protection under Appendix I to the convention: the listing of the most endangered animals. The problem is that the safari hunting industry and buyers in Asia are opposing it, because such a decree would limit what they can do with the trophies. Fact: Appendix I does not mean you can’t shoot a lion — it means you can’t import the skin to hang on the wall. And the answer to the question we are asked a thousand times is: Yes, you can still go to Africa to kill a lion.

CITES needs a country to sponsor the motion for lion protection. We can’t, so far, get one to put its hand up first, to take on the issue and save lions. No one will risk offending big safari hunting lobbies. It would seem that many are just not thinking this through. Extinction threatens by the year 2020. Then there will be no lions to hunt, or to protect.

(Meanwhile another ominous development poses a further threat to wildlife. A pesticide is being used by poachers to kill lions and many other animals. Sprinkled on meat, it kills lions, hyenas, vultures and other creatures in minutes).

We don’t have much time. The biggest threat isn’t hunters, poachers or poison makers — it is our own complacency, the lazy hope that someone else is taking care of the great beasts of Africa.

Lions and other large predators are disappearing even as we learn more about the collapse of entire ecosystems. The $200 billion a year reaped from ecotourism will be lost, causing suffering among communities all over Africa that rely on this trade.

As explorers in residence at National Geographic, my wife, Beverly, and I are calling on everyone with even a remote interest in big cats, or in Africa, to make sure that these wild systems keep working well. Scientists, conservationists — everyone — must come together, work together and support this effort now: the Big Cats Initiative. It’s a movement that doesn’t want to exclude a single soul or leave out any idea on how to reduce the conflict. We have a short window of time in which we can remedy this. It is closing very rapidly.

Dereck Joubert and his wife, Beverly Joubert, are National Geographic explorers in residence. They have spent years making films and writing about the big cats of Africa. To view some of their photos and films, visit http://www.wildlifeconservationfilms.com. For more information, visit http://www.nationalgeographic.com/bigcats.

Research Suggests EPA Standard for Pesticide Safety Overlooks Poisons’ Long-term Effects

We received this press release from the good people at the University of Pittsburgh news section. I think it’s a wake-up call to government agencies charged with regulating pesticides. This gross oversight on the part of the EPA should scare you and make you ask yourself: ‘who is safe these days?’

The dangers that pesticides pose to wildlife is immense and although the researchers in this report used only amphibians, we can all imagine what implication these poisons would have on large mammals and other species. I am particularly reminded of the danger already posed by Furadan on lions and other predators, birds of prey and scavengers. Maybe you need to read along and see this for yourself, for these poisons are not only a danger to wildlife, but also to humans.

August 12, 2009
Contact:   Morgan Kelly
[412-624-4356 (office); 412-897-1400 (cell); [email protected]]

Pitt Research Suggests EPA Standard for Pesticide Safety Overlooks Poisons’
Long-term Effects

Environmental Toxicology and Chemistry article reports “lag effect,”
revealing that harmful effects can remain hidden until after EPA’s four-day
direct exposure test

PITTSBURGH-The four-day testing period the U.S. Environmental Protection
Agency (EPA) commonly uses to determine safe levels of pesticide exposure
for humans and animals could fail to account for the toxins’ long-term
effects, University of Pittsburgh researchers report in the September
edition of Environmental Toxicology and Chemistry.

The team found that the highly toxic pesticide endosulfan-a neurotoxin
banned in several nations but still used extensively in U.S. agriculture-can
exhibit a “lag effect” with the fallout from exposure not surfacing until
after direct contact has ended. Lead author Devin Jones, a recent Pitt
biological sciences graduate, conducted the experiment under Rick Relyea, an
associate professor of biological sciences in Pitt’s School of Arts and
Sciences, with collaboration from Pitt post-doctoral researcher John
Hammond. The paper is available on Pitt’s Web site at

The team exposed nine species of frog and toad tadpoles to endosulfan levels
“expected and found in nature” for the EPA’s required four-day period, then
moved the tadpoles to clean water for an additional four days, Jones
reported. Although endosulfan was ultimately toxic to all species, three
species of tadpole showed no significant sensitivity to the chemical until
after they were transferred to fresh water. Within four days of being moved,
up to 97 percent of leopard frog tadpoles perished along with up to 50
percent of spring peeper and American toad tadpoles.

Of most concern, explained Relyea, is that tadpoles and other amphibians are
famously sensitive to pollutants and considered an environmental indicator
species. The EPA does not require testing on amphibians to determine
pesticide safety, but Relyea previously found that endosulfan is 1,000-times
more lethal to amphibians than other pesticides. Yet, he said, if the
powerful insecticide cannot kill one the world’s most susceptible species in
four days, then the four-day test period may not adequately gauge the
long-term effects on larger, less-sensitive species.

“When a pesticide’s toxic effect takes more than four days to appear, it
raises serious concerns about making regulatory decisions based on standard
four-day tests for any organism,” Relyea said. “For most pesticides, we
assume that animals will die during the period of exposure, but we do not
expect substantial death after the exposure has ended. Even if EPA
regulations required testing on amphibians, our research demonstrates that
the standard four-day toxicity test would have dramatically underestimated
the lethal impact of endosulfan on even this notably sensitive species.”

Andrew Blaustein, a professor in Oregon State University’s nationally ranked
Department of Zoology, who is familiar with the Pitt study, said the results
raise concerns about standards for other chemicals and the delayed dangers
that might be overlooked. Some of the frog eggs the Pitt team used had been
collected by Blaustein’s students for an earlier unrelated experiment, but
he had no direct role in the current research.

“The results are somewhat alarming because standards for assessing the
impacts of contaminants are usually based on short-term studies that may be
insufficient in revealing the true impact,” Blaustein said. “The
implications of this study go beyond a single pesticide and its effect on
amphibians. Many other animals and humans may indeed be affected similarly.”

Tadpoles in the Pitt project spent four days in 0.5 liters of water
containing endosulfan concentrations of 2, 6, 7, 35, 60, and 296
parts-per-billion (ppb), levels consistent with those found in nature. The
team cites estimates from Australia-where endosulfan is widely used-that the
pesticide can reach 700 ppb when sprayed as close as 10 meters from the
ponds amphibians typically call home and 4 ppb when sprayed within 200
meters. The EPA estimates that surface drinking water can have chronic
endosulfan levels of 0.5 to 1.5 ppb and acute concentrations of 4.5 to 23.9 ppb.

Leopard frogs, spring peepers, and American toads fared well during the
experiment’s first four days, but once they were in clean water, the death
rate spiked for animals previously exposed to 35 and 60 ppb. Although the
other six species did not experience the lag effect, the initial doses of
endosulfan were still devastating at very low concentrations. Grey and
Pacific tree frogs, Western toads, and Cascades frogs began dying in large
numbers from doses as low as 7 ppb, while the same amount killed all green
frog and bullfrog tadpoles.

The endosulfan findings build on a 10-year effort by Relyea to understand
the potential links between the global decline in amphibians, routine
pesticide use, and the possible threat to humans in the future.

A second paper by Relyea and Jones also in the current Environmental
Toxicology and Chemistry expands on one of Relyea’s most notable
investigations, a series of findings published in Ecological Applications in
2005 indicating that the popular weed-killer Roundup® is “extremely lethal”
to amphibians in concentrations found in the environment. The latest work
determined the toxicity of Roundup Original Max for a wider group of larval
amphibians, including nine frog and toad species and four salamander
species. The report is available on Pitt’s Web site at

In November 2008, Relyea reported in Oecologia that the world’s 10 most
popular pesticides-which have been detected in nature-combine to create
“cocktails of contaminants” that can destroy amphibian populations, even if
the concentration of each individual chemical is within levels considered
safe to humans and animals. The mixture killed 99 percent of leopard frog
tadpoles and endosulfan alone killed 84 percent.

A month earlier, Relyea published a paper in Ecological Applications
reporting that gradual amounts of malathion-the most popular insecticide in
the United States-too small to directly kill developing leopard frog
tadpoles instead sparked a biological chain reaction that deprived them of
their primary food source. As a result, nearly half the tadpoles in the
experiment did not reach maturity and would have died in nature.

News releases about Relyea’s previous work are available on Pitt’s Web site
at http://www.news.pitt.edu