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Coquis and EPA

2009 January 22

About the author: Lina Younes has been working for EPA since 2002 and chairs EPA’s Multilingual Communications Task Force. Prior to joining EPA, she was the Washington bureau chief for two Puerto Rican newspapers and she has worked for several government agencies.

Saludos-Greetings-Aloha to one and all in the new year.

When I wrote last May about the unwelcomed arrival of the Puerto Rican coqui frogs to Hawaiian shores, little did I know that there was going to be such a heated debate in blogosphere. Personal feelings aside, the multiple responses received motivated me to actually find out what is the Agency’s role in addressing the growth of the coqui population throughout the 50th state. After making several calls and sending some emails, I was surprised to find that EPA’s role is limited.

In fact, the Agency was asked to step in the control efforts when the State of Hawaii needed an exemption to use an unregistered product to control the coquis. EPA is involved in this issue because products sold and used as pesticides must be evaluated and approved by the Agency under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) to ensure they can be used safety and without posing any unreasonable risks to people or the environment. In this case, Hawaii has requested an emergency exemption to use an unregistered product (calcium hydroxide or hydrated lime) as a pesticide in a quarantine program to control the invasive species, the Coqui. Hawaii is concerned that the frogs pose a serious threat to both agriculture and to the native Hawaiian forest ecosystems, including endangered species. I have been informed that the Agency is in the process of reviewing this request. Currently, there is a multiagency effort to stop the spread of the coqui in Hawaii led by the Hawaii Department of Agriculture.

While I confess that this dialogue in Greenversations has been eye-opening, I still yearn for the nocturnal coqui chants I experienced in my youth. Recently a friend asked why the coquís in Hawaii seem so much louder and active than the original coquis in their natural setting. In addition to the invasive nature of the coqui in Hawaii, I think we also can attribute the contrasts largely to the differences in population density and urban sprawl. In Hawaii, the population density is 188.6 inhabitants for square mile. In Puerto Rico, it’s 1,127 inhabitants for square mile! While there are numerous groups to save the coquí in Hawaii let’s not forget the plight of the coqui in Puerto Rico.



Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

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18 Responses leave one →
  1. Haiboss permalink
    January 22, 2009

    I just stopped by your blog and thought I would say hello. I like your site design. Looking forward to reading more down the road.

  2. Lina-EPA permalink*
    January 22, 2009

    Please do! We look forward to your input to sustain a true “Greenversation”.

  3. estraka permalink
    January 26, 2009

    I think Hawaii’s issue is that Hawaii can have more frogs/area than in Puerto Rico (some estimate 3x as much). Is it possible to bring Hawaii’s population to a more livable PR level? Probably not. With a lack of predators and a lot more open space, there is no foreseeable way to contain Hawaii’s coqui population to what many Puerto Ricans are used to without total eradication or a lifelong commitment to control work. Hawaii also has the most number of endangered species in the US. With this new type of predator, we can say goodbye to such interesting inverts like the picture wing flies, happy faced spiders, native snails and the carnivorous caterpillars should these populations collide (and nothing is stopping coqui from coming into these areas). Thank you so much Lina for taking to time to research for yourself the problems we are facing with coqui. Perhaps a vacation to the Big Island would be more helpful for you research- or at the very least, fulfill your yearnings for hearing the coqui again. Aloha.

  4. Lina-EPA permalink*
    January 27, 2009

    As I’ve mentioned–this has been a learning experience. Alas, would love to visit the Hawaiian isles again–last time I went was many moons ago–pre-coqui time.

  5. Syd Singer permalink
    January 28, 2009

    I am a biochemist and medical anthropologist by training, and I have been very concerned about the coqui Frog War in Hawaii, since much damage to the environment has been done, not by the coquis, but by those wanting to kill them. And there is no science showing the coquis are a threat to the environment.

    Population densities of coquis in Hawaii have been exaggerated by those asking for funding for coqui control. Researchers (Dr. Mautz) at the U of Hawaii used a method of counting coquis that is bad science. The technique involves coming to a specific area on successive nights, finding some coquis and “marking” them, releasing these “marked” coquis, and coming back the next night to catch coquis and see the percentage of “marked” coquis. The ratio of “marked” to unmarked coquis is supposed to give an estimate of population density. However, it is important that the “marked” coquis are as easy to find on the following night as unmarked ones, or it will make it seem as though the coqui population is larger than it is. Well, the technique these researchers used for “marking” the coquis was toe clipping, which means amputation of a toe. The researchers took a pair of scissors and cut off one of the coqui’s long toes. The American Herpetological Association considers this inappropriate technique for tree frogs, and clearly it is cruel and painful to do this to frogs. It also makes these harmed frogs hide and become more difficult to find on subsequent nights, exaggerating the apparent number of coquis.

    It is also interesting to note that scientists have discovered that coquis increase the fertility of the soil, increasing plant growth. While this should be seen as a benefit, researchers invested in anti-coqui sentiment for more research grants have called this fertilization of the soil a bad thing, since it benefits non-native plants. Apparently, native trees have an advantage in poor soil. So the coquis are therefore bad, according to these people.

    The fact is, coquis are wonderful to have. I help manage the Hawaiian Coqui Frog Sanctuary and Nature Preserve, and we appreciate our fruit trees being fertilized by coquis. They also help limit our insect pest problems. And we love their nocturnal serenade. Nights without them feel eerie and empty.

  6. Syd Singer permalink
    January 28, 2009

    One more point. I find the anti-coqui rhetoric disturbing from another perspective. The government of Hawaii is denigrating the coqui, and only speak ill of them. They say nothing positive at all about these frogs, and have created public hatred and fear for the sound of frogs chirping. Chirping frogs are not a noise nuisance. They are part of the sounds of nature. And coquis, in particular, are not as loud or shrill as some tree frogs can be. There is a good reason why these are the national animals of Puerto Rico.

    In Hawaii there have been past eradication efforts against crickets and myna birds and other singing birds, mostly because some people feel disturbed by the sound. To me, this is a major human problem — intolerance for nature. We need to welcome and appreciate the sounds of nature, for these sounds will become increasingly rare with increased deforestation and pollution.

    I feel blessed to have the sound of the coqui added to the other sounds of nature — animals, insects, whales, and the surf. It is a symphony of nature, and for me, an avowed nature lover who grew up in New York City, listening to this symphony on my piece of Paradise in Hawaii is one of my greatest joys.

  7. Lina-EPA permalink*
    January 29, 2009

    Dr. Singer–Gracias. Mahlo.

  8. Larry permalink
    January 30, 2009

    as someone who lived in puerto rico for 4 years and now have had coqui’s in our back yard in hawaii for 2 years i can say there is no difference in the sound level between the two islands. the frogs in my forested back yard are as “loud” as they were in the forested areas i visited in puerto rico. the frogs were not this “loud” at out home in puerto rico but there was no forest around us, just other houses and grass and we were 50 yards from the ocean. but when we went up to friend’s houses where the forest came right up to the house, the coqui symphony sounded no different there than it does here in hawaii every night. the frog is the same it’s the people’s attitude that differs between the islands.

  9. Lina-EPA permalink*
    January 30, 2009

    In response to some of the questions I’ve received on this blog–EPA received Hawaii’s application requesting an exemption in May, 2008. EPA published said application and opened it to public comments in the Federal Registar as of July 30, 2008. For more information, see the docket at

  10. Lina-EPA permalink*
    February 2, 2009

    Thanks for sharing. Since I haven’t lived the Hawaiian coquí experience, I cannot compare, but there is no doubt that the attitudes are more than oceans apart!

  11. estraka permalink
    February 3, 2009

    It’s not just the people and the culture that makes the frogs a nuisance in Hawaii- it’s also the environment. We have a ripe environment for the coqui to proliferate beyond that which is found in PR- no predators, plentiful food items and fewer frog parasites. Hawaii’s environment also has many rare insects that will be easy prey for the frogs- unique types of insects to any other in the world including a spider species with happy faces on them and beautiful flies with elaborate designs on their wings that they use in a courtship dance. All life is sacred, but how do you choose which life is more sacred?

  12. Lina-EPA permalink*
    February 4, 2009

    That’s a very tough question. We can’t play God, but does Mother Nature make the choice? Is the ecosystem too fragile to adjust?
    I don’t know the answers. Thoughts anyone?

  13. estraka permalink
    February 5, 2009

    Aloha Lina,
    It’s kind of an open ended question- philosophical and theological. But this answer can also be answered by most scientists involved in invasive species ecology and conservation, especially in Hawaii or other island ecosystems. If you’re really interested in whether or not the ecosystem can adjust in time (adapt or evolve), you should contact someone directly rather than listen to a commenter on your blog :) My opinion is that there is ample evidence that Hawaiian species would not be able to adapt quickly enough to survive such a voracious predator such as the coqui frog. many native species are highly adapted to only certain types of habitat and by either directly preying upon them, competing with them for food or even changing the habitat around them (eg by adding nutrients to the soil), a species could be decimated. But, for all you know, I could be basing my knowledge on something I made up in cyberworld :)

  14. Lina-EPA permalink*
    February 9, 2009

    Hola from DC, Estraka

    BTW–In this other EPA blog entry–
    We’re starting to have a discussion about invasives. You’re right, it is a more complex subject than that which you normaly find in blog exchanges, but I think it’s a good Greenversation which we should keep going.

  15. Kookee permalink
    July 7, 2009

    “Live and Let Live” …”Only the strong survive”…build a herpetarium in the drier Kona side of the big island to raise these and other endangered frogs under a controlled environment. Jobs, real helpful research by world class biologist who I’d say would “thrive” here with our unique flora and fauna at their fingertips, and let’s not forget the diving, bring your scuba gear.

  16. lyounes permalink*
    July 7, 2009

    Nice suggestion. What a better place for some “green” jobs? Aloha

  17. Kookee permalink
    July 14, 2009

    Lina, Have they had a ruling on the 6% hydrated lime yet?

  18. Doris permalink
    June 26, 2014

    Coquíes are in danger of extinction in Puerto Rico and actually two of them are already extinct – the Coquí Dorado and the Coquí Palmeado. Hawaiians don’t have to kill the Coquí frog, send all the Coquí frogs to Puerto Rico, please, we love that frog.

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