Hi Benden - can I suggest you contact Phil Shirk- he has a lot of experience with catching and studying chameleons in East Africa:

http://www.mendeley.com/profiles/philip-shirk/

Jeff

I spent much time by searching for chamaeleons in Africa - can imagine, that any eradication effort must be frustrating issue. the glue traps suggested by Adrian Garda might work - what about trying glue ropes/lines spread in the canopy? I did not try, but might be quite easy to manipulate - also, chameleons prefer to move along smaller branches and lianas, so that lines could be effective. however, birds might get trapped too :(

Maybe a crazy idea, but trained monkeys attached to a long rope (for control) could be effective as they are intelligent and used to search for small arboreal animals.

I'd also contact Krystal A. Tolley - she's been researching chameleons for over 10 years and can be found on ResearchGate or at the South African Biodiversity Institute

I have caught a lot of chameleons in Africa and Asia. The easies way is to manually search for them during night with a strong head torch. During sleeping lthey are lightly coloured so easy to see( you probably know this allready). Most species also go to sleep on lower thin branches to avoid predators. Trapping is most likely not possible due to their limited movements and they living in bushes and trees. One idea would be to place out artifical chameleons to lure them out, them being very territorial, but still imagine this to be much less efficient than night search and it might not work.

I fully agree with Christoffer Sjöholm, The most efficient way of searching/trapping them is the night searching. It s easy and efficient. Regards, Mariano Cuadrado

I understand that these 'rainforests' you are talking about on the islands are slowly becoming ersatz ecosystems with so many peculiar non-native assemblages and change; however, what if you just accept some things. Help design the assemblage as it evolves....Use non-indigenous species assemblage evolutions to get back to good old- fashioned field ecology research, inventory and monitoring (Natural History research and citizen science). BUT we must be respectful to life as it evolves. The glue-traps (or 'lime-sticks'!!!) may catch one-two native endemic birds (that would be incongruous...). Spend more time studying the impacts of the chameleons. [By the way we have a population of African Chameloen at Yialova Pylos Greece that was probably introduced by the Romans and is now an important biodiversity issue...of course I understand the scale issue - super-alien in Hawaii].

We've been asking similar questions about several species of introduced chameleons in Florida. I'm not aware of any traps that have been tested for chameleons, and I agree with previous posters that their behavior isn't very conducive to trapping. We do a lot of sticky trapping, and it can be very effective for skinks and other terrestrial lizards, somewhat less so for arboreal lizards - also, the only arboreal sticky trapping I've seen or done involves stapling an entire glueboard to the trunk of a tree, which won't work well for chameleons. Trying to put strips of glueboard on the branches used by chameleons would be messy and time-consuming. We check glueboards every 30 min on Guam to reduce non-target bycatch/mortality. At a site that actually had native birds I'd be very concerned about use of sticky traps on branches.

In the absence of good trapping methods, we've been thinking about means of validating the efficacy of visual searching without resorting to mark-recapture. There's lots of room for brainstorming on chameleon control opportunities, I'd be happy to discuss further off-line.

Do the females of this species change to any particular color during mating season to signal readiness? If so, a small decoy of that color might help you attract males at least. The night searches sound like they might be beneficial as well. if they are high up when you spot them at night but on thin branches you might consider using an extendable pole trimmer to simply snip off the branch they are on. Good luck!

Physical models, if effective at all, would only attract one territorial individual at a time - not very useful. Sticky traps will catch lots of things you don't want to catch and very few chameleons. I agree with suggestions about night-hunting with a focused light source. I've had very good luck with this technique finding other arboreal lizards in tropical forest - they really pop out in the light. But it's still one animal at a time. Another expert to ask is Chris Anderson at Brown Univ. I think trained monkeys would be too expensive and time consuming. I suggest trained undergraduates suspended from ropes in the canopy. They can be trained in minutes and will work for nothing if you tell them it's a 'research experience'.

They pretty much stay above ground all the time, except when the females lay their eggs. Is there a way that you can catch the females at that time and/or do something to destroy the eggs? That might be the most vulnerable period of their life cycle in a place where they have no no effective predators of any kind. Also, are the chameleons in areas where there are still viable native bird populations? if not, then I certainly wouldn't worry about birds getting caught in glue traps. Lastly, aren't there also invasive Dendrobates auratus in the same areas? Is there an effort to eradicate them, as well? Do you need volunteers to help?

I've seen many Jackson's caught at once in Waimea (Big Island) when landscapers trimmed shrubs and trees and threw the trimmings in the back of a truck a transported to mulching facility. As the pile of trimmings dried on the ground (days) the chameleons were easy to spot in the higher branches.

Many people complain that these chameleons, and Madagscar day geckos, are eating our native gecko. Fact is, we don't have a native gecko. The first invasive gecko came with the pioneering Polynesians. I think we're stuck with many of our new invasives, they are so well established.

I have spent much time looking for chamaeleons in West and Central Africa, and agree with a.o. Kurt Schwenk's answer above: night search is by far the best method, and glue traps present a big hazard to the rest of the wildlife, as they are not specific at all. I would suggest you to privately contact specialists like Krystal Tolley for the best methods. And, please, if you hear about an extremely efficient way to catch chameleons, don't post it here, keep it for you: there are already enough chameleons collected in the wild for the pet trade...

From my experience, Christoffer Sjöholm is correct. I have done some work with Furcifer oustaleti in Florida and we had good success with night surveys. I have had really good luck using this method, although I prefer using mountain biking lights, such as Dinotte Brand that are handheld. They are significantly brighter than almost any headlamp that you can find and allow you to see much higher up into the canopy. We typically use 20' Black Widow telescoping fishing poles to get the chameleons down from higher perches.

http://www.basspro.com/B39;n-39;M-Black-Widow-Crappie-Rod/product/27747/?hvarAID=shopping_googleproductextensions&om_mmc=shopping_googleproductextensions&kpid=27747%26adc=pg_315_11128_530bad76e4b021b76fd3b74f_39086472631

Mary had a great suggestion to use telescoping branch trimmers. This was no an option for us as we were working in agricultural fields and trimming of the trees would have been frowned upon. Unlike anoles, which are easy to knock off their perches, the chameleons often need to be coaxed onto the pole. Once this is accomplished, simply collapse the pole down to grab the chameleon.

Oh, man. I wondered when one or more of the Florida folks was going to add a comment about the Oustalet's chameleons. Long-term, coordinated volunteer efforts at manual removal do tentatively appear to be having some sort of an impact on populations, as encounter rates have declined over the term of the program. Mind you: we are working in an avocado grove where canopy height does not exceed ten meters. Moreover, the grove environment is fairly homogeneous, and while monotonous, this probably also improves our search ability.

Thanks to all for some very interesting, helpful and even entertaining answers. Where to start, I guess just to address a few recurrent themes: Jackson's chameleons don't lay eggs as most of the family does, but are instead ovoviviporous. Some suggest nocturnal manual searches. I should have mentioned that we've been spotlighting chameleons at night for many years, and despite some statements that it's "easy" and "efficient", which might be true in some parts of the world, we work in a variety of forest types, and while some of these areas are pretty easy to see and clear chameleons, others are very dense and complex with 20 m canopy ht, a couple of hours hike in, at about 1000 m elevation. We use Q-Beams with 1-3 million candlepower, have used all imaginable manner of extendable and telescoping poles, with baskets, trimmers, nets, etc. That's fine, but we are dealing with 45 chameloeons per 0.5 acre (2,000 m2). Removal is neither "easy" nor efficient", in many of the places we are working. For example in one of the natural area reserves where there are a number of endangered endemic species, a predator proof fence enclosing a 2,000 m2 plot required several thousand-man hours to manually clear. Aside from the trained monkeys, we currently plan to continue manual removal at night, but at this point I am interested in methods that might act to accumulate, or gather the beasts, bring them down from the trees, so decoys or even food source mimics have been considered, all in an effort to enhance manual collection. Glue traps are out of the question due to presence of endangered snails, birds, insects. We're conducting some trials with brightly colored female decoys with variable success. Thanks again for all the responses so far.

You certainly do have a delicate problem on your hands; I always worry about how to confirm eradication when a species drops below a reasonable detection threshold (based on person-hours invested, and your thousands of person-hours for a half-acre are almost certainly not sustainable), but still maintains a sustainable breeding population. Unlike Florida, you cannot hope that you will get another freak winter like the "great freeze of 2010" to aid in the process.

It'd be nice if there was some sort of phermonal lure to bait your traps with, but you are dealing what appears to be a primarily visual species. Any behavioral cues even suggesting that females in estrous might broadcast some sort of cloacal volatile?

From my point of view, there seems to be sort of over-expectation concerning the night spotting. I know this method to be rather frustrating after spending thousands of hours by doing so. As mentioned above, it might be method of choice in poorly structured simple habitats (as in the case of the avocado grove, I experienced this repeatedly in coffee plantations in East Afica for example), but definitely not in complex natural habitats, especially in rugged terrains (as is the case in Hawaii - see Brenden's comment). Importantly, the efficiency of night spotting method varies greatly between chameleon species and habitat - some spp. sleep on leafless low lying branches and other well visible places, some do not - it is by far not universal.

Last idea - as chameleons are "visual" creatures, males might be attracted (concentrated to some degree?) by females in cages placed in exposed places. It might increase effectivity of night spotting - might be quite easy to test in the field. However, I never tried this.

Aye, also mentioned by some in the discussion - easiest and most effective way I ever experienced (in African farmlands) is vegetation trimming/clearing - chameleons try to escape after some time, making themselves visible. This might work in combination with clearing alien plants, but again, is unfavourable in shrinking native plant communities.

You might well end up by simply accepting the non-native chameleons in Hawaii. Sad but possible. Keeping fingers crossed anyway!!!

I am not a herpetologist, nor have I ever even seen a Jackson's chameleon. However, depending on your budget and the scale at which you are working, it is worth considering using trained dogs. I know that "working" dogs were able to increase detectability of brown tree snakes in Guam by orders of magnitude in the day and in the night. There are some reputable dog handlers out there, who have been training dogs to find everything from invasive plants to grizzly bear scat for conservation-focused applications. The group I know best is the non-profit: Working Dogs for Conservation out of Montana, USA.

Thanks Tammy for your answer, in collaboration with the Army Natural Resources program here on Oahu, three dogs and their trainers, from Montana (!), were flown here, housed and paid for a number of months, in an effort to test feasibility of using dogs to detect endangered tree snail predators, namely an invasive land snail. Unfortunately, despite best efforts of dogs and trainers, there did not appear to be sufficient signal from the snail. This was few years back, prior to our discovery that chameleons are now impacting native species, so we did not test chameleons with the dogs. I have thought about this possibility, and among the challenges as I see them, are the arboreal habits of the chameleons. One thought I had was that they drop their scat on the forest floor, and that likely has a distinct olfactory signature, but two problems arise there, one being how long does chameleon scat persist (it rains just about daily at many of these sites) and secondly, finding scat on the ground does not pinpoint position of the lizard, which could very well be a hundred meters from that point where scat was encountered. Due to expense and lack of success of the previous attempt to use service dogs, I think getting funding could be challenging, but still worth consideration!

"45 chameloeons per 0.5 acre" that's impressive... especially over 1000's of acres. And no chance for their prey to survive for long with that kind of pressure.

Thought.

Introduce a latent gene throughout the population whose action requires an environmental trigger. The trigger would be some form of innocuous agent that then causes the gene to express a protein that interferes with their metabolism, killing or sterilizing them, which would deplete the population. Continue to add males / females to the population with the modification to keep the gene spreading. The whole process can be repeated, with each successive round depleting the population. It may take a few years, but it would do the job.

While it may be an intensive technique, particularly in habitats like those in Hawaii, the best method for locating chameleons really is night surveys using high intensity lights. I've used it in a variety of habitats in various locations in Africa and the US with many different species and agree that it is more difficult with some species and in some habitats, but have yet to find or hear of a method that is more efficient.

Cuadrado (1998, J. Ethol. 16, 73-79.) did use models painted in different patterns to look at courtship by male Chamaeleo chamaeleon. He placed models painted in various patterns out for 4 hours in areas with unknown male presence and visited them every 30 minutes during that period. Out of 500 model placements, 59 attracted males, and models painted in female receptive coloration attracted the highest number of females.

While this method could potentially be used for T. jacksonii as well, the color and pattern displays of T. jacksonii are not as intense as in C. chamaeleon (so it would be more difficult to optimize the color pattern used), it would likely only attract males (leaving females unaccounted for), it would require significant monitoring (unless males ended up sleeping in proximity to the models, which may then still require spotlighting at night), and you're unlikely to get any concentration of animals around a single model. Also, given the habitat differences, the models may be less successful with T. jacksonii than they were for C. chamaeleon because of the reduced visibility.

Just to add a comment about using wildlife detector dogs. I have trained and am currently using a lizard detector dog, certified under New Zealand's Conservation Dogs Programme run by the Department of Conservation). She is very good at finding terrestrial lizards but tends to work with her nose to the ground. While I have no doubt that dogs could be trained to find chameleons (or other reptiles) they will be of very limited (if any) use for arboreal species because they can only effectively search to dog height. Good luck - an interesting problem!

Just make a night searching (by using a strong head lamp) . This is the easier and more effective method to search for them. I fully agree with Christoffer Sjöholm´s comment

Wow, this brings back memories ... would love to now see your current experiences in response/comparison to the Waring (2007?) report identified / predicted problems?? I remember discussing with Fern Duvall about the possibility of using Hawaii's chameleon extraction data to develop a model for sustainable harvesting of chameleons more generally, way back in early 2000!! You have/had other species of cham (Veiled & Oustaleti?) too on the islands, no? Are they a problem too? Cuadrado's work, as Chris stated, was on Common cham conducted in Southern Spain; thus, very different scenarios in terms of the cham involved and habitat being surveyed. However, I would say the most efficient system would be to maintain the good old night searching ... sorry, I know its a hard slog!! Anyway of increasing person effort by, as someone suggested previously, getting u'grad's involved or the general public - give them a hotline number to call if they come across one and don't want to handle it themselves??

Please, any chance of keeping/making available the data (search effort and cham numbers/demography, etc.) as it may well be useful to other researchers?!?!

As ecologist, we always have to think outside the box. So as crazy as it may sound, here's my suggestion. Collect a number of prey insects, connect one of their legs to a substrate (lots in a small space, perhaps 10-15 bugs in a 25 cm circumference (just making this up)), making sure that they can still move, jump, etc., then set a recording devise at 200 - 600 Hz in the same location (this is their hearing capacity) that mimics the insects call, then wait. This is sort of a natural trap, but perhaps many chameleons will be attracted in a short period of time. Good luck, its so much easier to study plants.

The sound trap might be worth a shot, but I'm not sure it would be effective over any sizable distance. Unfortunately chameleons have relatively poor auditory sensitivity, particularly to aerial sounds. This is particularly true of Trioceros jacksonii, which not only lack an external ear opening, tympanic membrane and round window (as with other chameleons), but also lack the tympanic membrane surrogate (the pterygoid plate and anterior process of the extracolumella) found in Chamaeleo species and do not experience declines in their cochlear potential when the columella is severed completely.

If their auditory stensitivity is lacking so much, are they sight hunters? Or are they feeling the vibration of their prey in the air or tree limbs? If it is known how they locate their prey and it is not just a "they wander into it" situation it might be possible to build some type of pitfall trap that could be placed into the tree canopy. Perhaps a limb that is fixed to drop them into a container if they attempt to cross it. It would be dependant on some way to attract them. Maybe a female decoy in breeding colors, something like that. Even if it didn't attract them in great numbers it sounds like any extra help would be most welcome. This would be a much less man hour intensive method.

Have you explored the idea of putting a bounty on them with the local people? If people know they can make a bit of money catching something like that it can make a good incentive, especially if you have any subsistence hunting going on in the areas infected with the chameleons.

Just a couple of ideas to consider. Good luck!

Thanks for the discussion and ideas, keep 'em coming. Chameleons are highly visual species, areas of most concern on Oahu are remote, off limits to public, pitfall traps, like glue traps and poison baits are out of the question due to concerns of non-target impacts, due to presence of lots of rare and endangered taxa, plus arboreal habits. We're getting ready to test female decoys of various designs and sizes. The basic design is simply 2-d painted an appropriate courtship bright green, with some "eye-catching" shiny fringe made of mylar on one of the designs, along the lines of trout flies, only a lot bigger so that they can be seen from afar. The Cuadrado study showed however that best case decoy scenario is attraction males only, and one at a time (they are territorial so just don't gather in groups, unfortunately), but this might at least help reduce their numbers in key areas. The other field test we'll run this summer is reproductive females in cages. That's about all we have to work with at present.

Attracting only males is not optimal but the more males you can remove from the population the fewer offspring that will be produced. If they are territorial, how do they establish territories? If territory is based on scent markers, have you thought of using scent to "herd" them? If you could combine that with the female decoy or caged female you might have a better chance of gathering more males into a tighter area. It would still be one at a time removal but it sounds like one at a time is as good as it's going to get.

Actually I was thinking about "pitfall" traps that could be designed around your lures up in the canopy to minimize the chance of anything else happening into them but of course there would still be some risk.

I don't know how it is in Oahu but here "off limits to public" only means they sneak in. If you see any sign of people coming into the area secretly, they might be an ally in working to get rid of the chameleons. With a bit of education about what and why they could be helpful.

Dear Brendan, greetings.

I had been mulling over your vexing reptile issues for a while.

It did occur to me, that although expensive and time consuming and you had access to some very dexterous, willing and clever vets; it might be possible to sterilize(Chemically or invasive surgery) enough male chameleons and introduce them into zones where populations are light.

As predation is non existent ,these males will become dominant with age and may prevent fertile males from the chance of mating. Seeding populations of - Tse-Tse flys, goats and grey squirrels etc particularly in closed ecosystems has proved successful elsewhere in reducing population numbers.

Myself and other Bee keepers in Britain use Queen Bee pheromones as bait to attract swarms and it may be possible to extract female chameleon pheromones to attract males.

Depending on the sensibilities of the human population and legislation in your country, it might be possible to use air rifles, according to best practice, to help reduce further rises in chameleon numbers in control areas and monitoring results. Paying a bounty, dead or alive, doesn't sound such a bad idea. I would like to the think that the gravity of this particular problem trumps the squeamish feelings that many folk have for their fellow creatures.

I am a native Kenyan and am well aware of the aversion that many Africans have, of anything to do with these animals, however this might not be the case with other nationalities, and I know from experience, that the species concerned has some merit as an addition to the table..Good luck with your endeavours, kind regards, Jim Storrar.

How about setting snares along branches? Unsure whether catching non-target birds would be a problem....maybe experiment at least with some captive "chams"? Snares for feet and or heads?

Females release pheromones from the mental, axillary and inguineal glands.  Perhaps these could be synthesized or extracted to produce baits for males but this would likely be a long and difficult process.  Attempts to reduce males by this is and other methods would probably not be very productive anyway since females mate with multiple males and can store sperm for prolonged periods for fertilization of eggs if mates are unavailable.  Night collection using flashlights and poles etc. has been used with great success by collectors for the pet trade and may be the most practical - and labor intensive method.  It's use may be justified in the most sensitive environments where endangered snail species etc. are at risk.  Outside those areas the impacts of chameleons on native invertebrate populations have been questioned and these costly control efforts may be difficult to justify.  In my greenhouse areas near Naalehu on Hawaii Island there are few native insects and the lizards are beneficial eating roaches, centipedes and other undesirable invasives.

@Edward Harry Rau;  really interested to read that Cham's are having an indirectly positive affect on native invert's by eating less desirable / introduced ones ... am I reading that correctly?  If so, do you have any publications/reports/data on that or is this personal observations / anecdotal?   

I didn't mean to suggest that their consumption of undesirable invasive species in my greenhouse was evidence for a positive effect on native inverts in the wild.  But in environments where other invasives such ants, centipedes, spiders, snails, roaches, smaller lizards etc. that prey on or compete with native inverts are becoming dominant preferential consumption of the invasives by the chams in could have an indirectly positive effect.  That is speculation but I have observed the chams eating some of the introduced invasive species mentioned.  There is one study by Holland et al. DOI 10.1007/s10531-009-9773-5 of the stomach contents of chams collected from native and pristine forests on Oahu confirming predation on native inverts but I'm not aware of any similar studies in disturbed environments where introduced species are becoming dominant.  McKeown 1996 cited in Holland also confirmed that chams consume a wide variety of introduced species.

Edward - Chameleons do not have mental, axillary or inguinal glands. Further, there is little evidence that chameleons rely much on pheromones at all to attract each other. Their nasal cavities, nasal capsule, and olfactory nerves and branches are all reduced or otherwise poorly developed, and while the formation of the vomeronasal organ is variable in chameleons, the members of the genus Trioceros that have been examined have been reported to completely lack this organ. As a result, chameleons are considered microsmatic at best, and the presence and functionality of the vomeronasal organ is doubtful in this species.

Christopher - Thanks for correcting this.  The information came from a book article citation to Wright KM. Breeding and neonatal care.  In: Girling SJ, Raiti P eds. BVSA Manual of Reptiles 2nd ed.  Gloucester: British Small Animal Veterinary Association.  I did not have access to this publication and it may have been misquoted.

As you were interested in Chameleons, I'm just wondering if any of you have or know of any data sets / papers on the mortality rates of chameleons in the wild?

Thanks Christopher, right you are, chams lack not only these anatomical structures but there have not been any peer-reviewed accounts of production, use, or detection of pheromones, much less any other olfactory activity in reproduction, to my knowledge.  We all need to keep in mind the importance of *peer reviewed sources* rather than take what we read from the grey literature, internet accounts, and pet care manuals. 

Sorry Edward Harry Rau, but I am afraid I would urge increased caution re: your post, while potentially well-intentioned, is rife with fundamental mistaken "facts".

There have been no scientific studies documenting any "beneficial effects" of invasive chameleons in the Hawaiian Islands, or any where else for that matter. 

They don't feed on centipedes or ants, likely have zero impact on roaches, etc. b/c their diet is highly diverse (a number of studies have shown this, let me know if you need references) and they cannot put a dent in the reproductive rates or geographic scope of these invasive arthropods.

Jackson's chameleons have not been shown to store sperm , nor do they "lay eggs". 

They are ovoviviporous, and give live birth.

We have been nocturnally, manually spotlighting chameleons for over a decade in conservation sensitive forests and Natural Area Reserves for over a decade, and while this may be "highly effective", for the "pet trade", the pet trade  and control eradication for conservation have wildly different objectives and therefore probably shouldn't be compared.  Manual removal is simply our only conservation control option at this point, until some science-based attraction/trapping  strategy and or technology is devised.

I would finish by noting that surprisingly little information on impacts of invasive species in Hawaii has been published.  Amazingly, there are 32 established reptiles and amphibians alone, not to mention the hoards of mammals, insects, spiders and birds, in the islands, and only a couple of recent papers on impacts of ONE species (Jackson's cham)(oh yes and a little bit of work on the coqui frog).

to this end we have collected and dissection several  dozen introduced birds from native habitat, and are currently assessing range of prey items from gut contents, as well as bullfrogs, wrinkled frogs, and skinks, but there is still an enormous amount of work to be done!

Hi Angus, I have not come across anything along these lines.  In Kenya there are a couple of natural predators, one is a raptor, the other an arboreal snake, but of course in Hawaii we don't have natural predators for chams.  I see them on roads occasionally, as road kill, but we don't have a way to quantify mortality.

Hello Brenden, I hope that you and your team had success with the chameleon project. My family and I will be visiting Oahu in May and my son, 5 years old is captivated by reptiles including chameleons. I was wondering if your trapping project remains ongoing and if we might be able to see the work in action, perhaps assist in some capacity for a day or two and experience Chameleons up close? It would be a wonderful experience for us if there might be an opportunity to visit and assist in some capacity. If you have contacts that have chameleonsome available please let me know. We may wish to obtain a permit and bring one home with us as well. Thanks kindly very much in advance for your reply. Happy New Year! Andrew