They Simply Don’t Get It: Misguided Conservation Policies in Taiwan Continue to Promote Anole Slaughter

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A familiar face – a brown anole male from my study site in southwestern Taiwan.

For the past few years the authorities of Chiayi County, southwestern Taiwan, have paid bounties to citizens for brown anoles they collect. Every year the bounty per lizard has decreased and yet they spend their budget and the brown anole persists. This year is the same – a lower bounty – but with a slight difference; the green iguana is now also on the list. In theory, it would be ideal if the invasive lizards can be exterminated, but in reality, I am convinced, they will fail. The brown anole exists in southwestern and eastern Taiwan, and simply targeting them in one location will simply retard their dispersal to new localities (and even with the bounty in place, their distribution is extending). We recently published the results of a study in which we compared brown anole specimens from southern and eastern Taiwan, and we found that there are some variations, most likely due to adaptations to the local habitats (no surprise there!). What this means is that in Taiwan, if brown anoles can reach (either by natural dispersal or with the help of people) open disturbed habitats, with structures that can be used as perches, they will most likely adapt and establish new populations.

Me with a green iguana (Iguana iguana), that was removed by firefighters from someone’s garden in Chiayi City.

Me with a green iguana (Iguana iguana) that was removed by firefighters from someone’s garden in Chiayi City.

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A sun skink (Eutropis multifasciata) from Tainan City, southwestern Taiwan.

And then I wonder why is the brown anole singled out for extermination. Eutropis multifasciata, a relatively large invasive skink, also exists in Chiayi County. Due to its size, it has greater abilities than the brown anole to compete with and prey upon native lizards and arthropods, and yet, they are not on the list. People regard Hemidactylus frenatus, a very common gecko species in urban areas in central and southern Taiwan, as a native species, not realizing that it too is an invasive species.

Hemidactylus frenatus is a very common species in southern Taiwan, where they are often seen near external lights on the walls of buildings.

Hemidactylus frenatus is a very common species in southern Taiwan, where they are often seen near external lights on the walls of buildings.

My honest opinion is they have to accept that just like Hemidactylus frenatus, Anolis sagrei will spread in Taiwan and become a common sight in areas disturbed by humans. They will become (and in many ways already are) part of local ecosystems as competitors, predators and prey. Conservation efforts should thus rather be directed at the re-establishment and conservation of large areas of secondary forests in disturbed lowland areas of Taiwan. This would not only contribute to the conservation of native forest species, but such areas will also function as reservoirs for species like Japalura swinhonis that can compete with Anolis sagrei, as well as being barriers for its spread. People should also be encouraged to be more tolerant towards snakes, in particular non-venomous species such as Lycodon (Dinodon) rufozonatum rufozonatum, Lycodon ruhstrati ruhstrati, and Sibynophis chinensis chinensis, which can prey upon brown anoles. And, finally, an important part in the conservation efforts of native urban wildlife is to develop a better appreciation among the general public of native birds and lizards in urban gardens and parks, and to reduce the impact on these animals by their pets, especially domestic cats (Felis catus), which may prey on them.

 

Just for interest sake, here is a current list of exotic invasive lizards in Taiwan:

Anolis sagrei

Eutropis multifasciata

Hemidactylus frenatus

Iguana iguana

Lepidactylus lugubris

Physignathus cocincinus

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8 Comments

  1. Hey Gerrut, great post! Do you not consider A. carolinensis established given your 2012 report of multiple individuals (including gravid adult female)?

  2. Gerrut Norval

    Thanks James. No, I don’t think so. Apart from those mentioned in that report I have not encountered any others.

  3. Andries

    Well done Gerrut

    What about the collateral damage caused by uninformed locals, without the necessary knowledge to identify anolis lizards, targeting indigenous lizards?

    Keep up the good work

  4. Gerrut Norval

    Most of the “collectors” “catch” the brown anoles by shooting them with rubber bands. This means that mistakes are irreversible. In a project we did many years ago, students I trained, sometimes made that kind of mistake, so it is a very big possibility. But we will never know the true extent because the “unfortunate victims” will most likely simply be discarded as soon as the “collector” realizes his/her mistake. Then there is also the disturbances caused by people walking and trying to capture lizards. The lizards will learn to avoid people, but that means they will also flee when “harmless” people move through the area, and so the lizards lose time for doing what lizards do.
    If people really want to help, then they should address habitat destruction and the impact of cats on wildlife.

  5. It is not a problem of natives vs invasives, it is the deep rooted hatred of reptiles that motivates these people to kill defenseless lizards. I bet it would be more difficult to motivate the same people to kill some cute bird or mammal, especially if it wasn’t directly dangerous for agriculture and livestock. People must get it, tropical islands in main shipping routes are international hubs vulnerable to colonization by various species, mostly smallish and harmless ones. Ecosystems do change, and surely Taiwan has changed much nowadays with its large population. The same applies to reptile-hating Hawaii and other similar habitats. Some species are better adapted and survive, others will loose, regardless if they are native or not. In the case of an introduced species I see no difference for the ecosystem if the new competitor replaces an older species and continues to occupy the same nitch. Please stop this edenist modern conservationist attitude.

  6. Bennett

    Great job Gerrut!
    Your information helped me a lot for my research on dying animals. I have worked on many animals dying out but this is the first time I ever heard about killing animals in Taiwan. I was born in Taipei and I never heard of it. Your information helped me so much, Thank you

    • Eres genial Alberto, muchas gracias por tu comentario. Al visitar Toledo no olvides visitar esa iglesia convertida en pub en la que se dan conciertos, te en¡aUtarÃc.nn abrazo

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