Mountain Horned Dragons
(Acanthosaura species) by Marcia Bradley
Acanthosaura species are medium sized arboreal lizards that range from Burma, Thailand, western Malaysia, Indonesia, Cambodia, Laos, Vietnam, and southern China. With adequate research and preparation prior to acquisition, the Mountain Horned Dragons (MHDs) are delightful animals with a wonderful temperament. Unfortunately, most of the MHDs available in today's pet trade are wild caught, usually carrying a heavy parasite load, stressed, and in poor health. With proper care and medication however, it is possible to get these animals established. It is my hope that this page will help MHD keepers to recognize the potential problems and provide the needed treatment and care so that they can enjoy these beautiful animals. Please pay special attention to the health section below.
The species most often seen in the current pet trade are A. capra, A. crucigera, and A. armata. Mine are all Acanthosaura capra as are most of the imports in the United States. There are a few Acanthosaura crucigera but these seem to be less common. There are some breeders in Europe working with Acanthosaura armata and Acanthosaura crucigera as well as Acanthosaura capra so I will give a very brief description of each here.
Total length male, 275-305 mm or 11-12 inches, females, 250-270 mm or 10-10 1/2 inches.
A. armata has long spines on the curve of the eyebrows and occiput that reach almost the height of the nape crest. The dorsal crest is initially the same height as the nape crest. There may or may not be a small break between the dorsal and nape crest. Armata has a small throat pouch. The back colors are varying shades of greens and browns and the lighter underside can be green, brown or reddish. Armata is found at altitudes ranging from 0-750 meters.
Total length 305 mm or 12 inches
A. capra is lacking spines on the occiput. The tall nape crest is separated from the dorsal crest. Both consist of lanceolate scales (having shape of lance-head, especially tapering at each end), the bases of which are broader than in the other A. species. The predominant back colors are olive or brown. Color changes with mood. They show a lot of yellow when sleeping and get very dark when stressed. Capra has a large throat pouch which has streaking of rust, and yellow when extended.
Total length male,259-262 mm or 10 inches, females, 212-237 mm or 8.5 - 9 inches.
A. crucigera is the smallest and reportedly the most aggressive species of the genus. There are spines on the nape and Occiput. A wide gap separates the dorsal crest from the taller nape crest. Crucigera is recognized by the pronounced dark brown or black cross on their nape. The colors of the crucigera vary considerably.
Total length male, 190-276 mm or 7 1/2-11 inches, females, 195-264 mm or 7 1/2-10 1/2 inches.
A. lepidogaster has short spines on the curve of the eyebrows and occiput. The dorsal crest is interrupted in the nape or is continuous with very short, closely spaced scales.
These are pretty sketchy descriptions but I have included pictures to help differentiate the species. There are a couple of good books on Agamid Lizards that you can use to help you determine species. Also, you can submit pictures to the Mountain and Tree Dragons forum on the kingsnake.com's Mountain and Tree Dragon Forum and chances are that someone there can help with identification.
Mountain Horned Dragons are charming animals that tolerate being handled fairly well. I have high hopes for the captive bred being very tame since the wild caught MHDs are so easily handled. At first, make the sessions short and friendly. Don't stress your animal. If it becomes flighty and try to jump and run from you, put it back in its enclosure and try again another day.
MHDs are a fairly inactive and calm lizard. It is not unusual to find them hanging out on a branch with all four legs hanging totally limp! Activity is pretty much confined to courtship, feeding, defecating, and visiting the water. Initially the new MHD can be expected to spend most of it's time sitting and will probably run and hide when you approach, but once the MHD is acclimated it should prove to be a docile lizard that is easy to handle.
Males seem to be more docile than females. Young MHDs tend to be a bit more flighty and aggressive than older animals but calm down with regular handling. Females will also be more aggressive when gravid, often hissing, kicking with her back legs, whipping her tail, and swinging her head to hit at you.
MHDs are tree dwellers and will want to find high places to perch. Don't be surprised when your MHD runs to the top of your head! I wouldn't make it a habit to "wear" your MHD out when you go places as this is too stressful, but once they are used to being handled they will sit on your shoulder for long periods without moving. Often when it's time to put the MHD back in its enclosure the MHD will run up your arm instead of going back into the enclosure. I have heard many keepers make the comment that their MHD doesn't want to go back because it wants to be social. I think in reality that the MHD is trying to find the tallest perch, which is usually you not that branch in the enclosure! I have found that if I place my hand with the MHD under a branch, the MHD will grasp the branch and run up it instead of my arm. If this doesn't work position the front of the dragon on a branch and lower your hand. Usually it will grasp the branch.
Always make sure you wash your hands thoroughly before handling your MHD and ALWAYS remember to thoroughly sanitize your hands after handling any reptile to avoid transfer of any bacteria that may be unhealthy to humans!
Unfortunately, the dragons that are sold in pet stores are almost always wild caught and are usually stressed and in poor health. The females are often laden with eggs and many die eggbound or shortly after laying their eggs. It is not uncommon to find your new Mountain Horned Dragon is spending most of the time on the floor of his enclosure not eating or taking water. I know from my experiences that it is possible to help them recover from such poor condition, but it takes a lot of time, work, the help of a vet, and dedication. Once recovered, they are a wonderful, docile animal.
Your first priority should be to find a vet who is familiar with small reptiles. Once you have located a reliable vet, find a fresh fecal sample and have it checked for parasites. It is almost a guarantee that these will be found have high gut load of various flukes, nematodes, worms, and other parasites. Bacterial infection is also a possibility. These can usually be determined through a fecal exam. If fresh feces is not available because your MHD has not been eating, it will be necessary to take the MHD to the vet. They can do a cloacal smear where they swab the cloacia for a sample to determine what parasites are present. Though examination your vet can also evaluate your MHDs overall condition and determine if it is dehydrated.
While treating for parasites I recommend using paper towels or newspaper for substrate so that you can keep the enclosure clean and sanitized. If you have a gravid female who has parasites, you will need to use a soil type substrate, but make sure you change it frequently to avoid re-infecting the MHDs. I also recommend raising the temps to 80-82F while caring for a sick MHD.
While treating for parasites the MHD will possibly have to be force fed and hydrated. I would give some pediolyte or one of the reptile electrolyte drops. Don't over-do it, just enough to fill the mouth a couple of times a day. You can also try soaking your MHD in warm water or pediolyte. This is most easily done if you use something like a critter keeper that has a lid so your MHD can't climb or jump out. Use lukewarm water, and remove the MHD when the water starts to cool. If you put a towel around the container so he can't see out he will stay a little calmer and this will help to reduce the stress.
My vet showed me how to administer medication, fluids, and food the first visit I had. She put the lizard on the front of her shirt and while holding it with one hand so it wouldn't run, she held the bulb of the medicine dropper in her teeth, and gently pulled down on the dewlap. When the dragon opened its mouth, she leaned her face closer and bit the bulb dispensing the drops into its mouth. Although MHDs can bite, they don't usually, and it isn't too hard to get them to open their mouths. Many will open their mouths and hiss when touched on the top of their head or by touching the corners of their mouth and this makes it much easier to administer the medication. If all else fails in getting your MHD to open its mouth, enlist the help of another person to hold the animal and open its mouth while you dispense the medicine.
A nutritious food for force feeding is high protein strained meat baby food mixed with a little mashed banana and powdered vitamins and thinned with fruit juice or pediolyte or Gatorade. To feed the baby food mixture, use the same methods as described for administering medications. Once the MHD begins to show a little more vigor, start introducing insects. Place an insect in his mouth to get him to eat. If he pushes them out with his tongue, continue to feed the meat mixture until he starts taking at least part of the insect. Eventually he will begin eating the insects when offered. It can take a lot of time to complete this process and get the MHD eating on his own. It is possible to bring these animals back around when they are pretty ill but it takes a lot of time and persistence and the help of a 'good' qualified vet. Remember though, by the time it is obvious that a reptile is ill it is already near death. It is best to have your reptile checked as soon as you get it home and follow up with periodic fecal exams to keep him healthy.
The Enclosure should be a minimum of 130 cm (4feet) high, 100 cm (3 feet) long, and 50 cm (1.5 feet) deep. If keeping more than one Mountain Horned Dragon (MHD) this should be increased to allow each to establish his own territory.
MHDs require a shady rainforest setup with flowing filtered water. Provide thick vertical branches and plenty of foliage in order for them to feel comfortable. Since these are territorial animals you should keep no more than one male per enclosure. Several females can be kept together with each male as long as there are adequate vertical branches so that each may stake out his/her own branch.
It is recommended that MHDs be provided a large area of moving water where they can drink and swim. They will not pay attention to water unless it is moving, therefore there should be a pump/filter combination, a waterfall, or at the very least an air stone to keep the water moving. A waterfall system or a stream is the best type of "water bowl" for MHDs.
The humidity should be 70-80%. Water and humidity are extremely important, as MHDs will dehydrate easily if proper moisture is not provided or if they are not visiting the water area. There are several methods that will help in obtaining the proper humidity levels. You can use a fogger set on a timer to produce fog at dawn and dusk. The animals really seem to respond well to this and have fewer problems with sheds. Misting daily is also beneficial in increasing humidity and improving sheds. Use of high humidity plants such as pothos, some of the dracaenas, ferns, bromeliads, orchids, and other epiphytic plants will also help to maintain the needed humidity and provide hiding places for the MHDs. Try to choose sturdy plants as the MHDs will climb anything they can.
There are several good types of bedding that are good for this setup. The shredded coconut bedding is excellent as it holds the moisture well without getting muddy or overly soggy. This is what I have had the best results with. Some keepers have used bark with good results, but this is more difficult for the MHDs to dig in. You can also use potting soil that is free of perlite, foam pellets, and fertilizer, but this will produce a lot of mud if you keep it too wet. MHDs love to dig and these types of soil help increase the humidity.
The Mountain Horned Dragon needs daytime temps in low 70's to low 80's Fahrenheit. I recommend plus/minus 78F daytime temperature and plus/minus 72F at night. Temperature should never exceed 84F and I would not allow mine to drop below 70F. Although many people set up all reptile tanks with a heat rock, it is not needed for MHDs as they are tree dwellers and won't use a heat rock. Likewise a basking light is not necessary as MHDs live in the forest and would only be getting filtered light in nature.
There has been some debate between some keepers concerning the need for a UVB bulb since these animal are forest dwellers, but I believe that a good UVB bulb should be used to make sure they can produce the needed vitamin D3.
Mountain Horned Dragons are completely insectivorous and will eat most of the commonly available feeder insects. Adults will eat dusted superworms, crickets, roaches, silkworm pupae, moths, and earth worms with the silkworm pupae and earth worms being their favorites.
My MHDs actually feed best on earth worms, which can be purchased pretty inexpensively at any bait shop. I offer one every day. I feed earth worms by dangling the worm in front of the dragon or on the branch in front of it. If they are interested they will start smacking and licking their lips. My males eat an earth worm every other day or so but my females eat at least one daily. The best part about earth worms is that they are rich in Calcium so you won't have to worry so much about dusting with calcium, just an occasional sprinkle. When I first started breeding there were problems with the shell of the eggs being deficient in calcium, but since I have started feeding earth worms the eggs are all well calcified. For variety I continue to offer crickets and other insects dusted with Sticky Tongue Farms Miner-All I (indoor formula).
My experience has been that the males become amorous sometime in July. If he is with the females at this time you will see courting behavior. Both the male and female will display extending their gular pouch, raising themselves with the male bobbing his head and shoulders up and down while hissing. The male will chase the female around the enclosure until she accepts him. Like most other lizards, there is some biting involved and it is not uncommon for the female to lose horns or crest scales. If the male becomes overly aggressive it is best to separate them.
No special cycling or other preparation is necessary to encourage breeding. As long as you provide the proper health care and environment and are sure you have a male and a female that are sexually mature, breeding should occur. Mountain Horned Dragons are sexually mature at 18 months of age, about 4 inches snout to vent length.
It is not uncommon for MHDs to be imported gravid so it is important to make sure your MHD is getting adequate calcium from the beginning. Don't be caught off guard thinking you have juveniles! An animal with 4-5 inch snout to vent length is sexually mature. I bought a juvenile that began to look bloated while I still had her in quarantine. I took her to my vet for a second checkup for parasites. She did a fecal exam and found that the female had worms. The vet and I though that this was why she was bloated. We began treatment with Panacur. A week later I noticed that she was no longer bloated looking and instead she looked lumpy. Eggs were obvious when I palpated her so I quickly put some bed-a-beast in the tank. Just two days later she laid 10 beautiful eggs.
Mountain Horned Dragons are pretty secretive, so chances are you won't know if they do mate until the female starts getting fat and then lumpy, however, displaying and head bobbing is a good indication of courtship! If you know what you are doing, MHDs are fairly easy to palpate to check for eggs.
The first clutch of eggs will be laid four months after mating. Subsequent clutches may be laid 2 to 3 months after the first clutch. The first year I bred MHDs my two females laid four clutches each, the first 4 months after mating and the subsequent 3 clutches each 2 to 3 months later. The second breeding season my young female who was purchased gravid produced two clutches. My older female have each produced two clutches and it is too soon to tell if they are done or not. The male was removed after I was sure they had mated to prevent over-breeding. Since they have produced multiple fertile clutches from only one breeding, I am fairly certain that they retain sperm.
From what I have read from others working with these animals there have been clutches laid in May, and then from late October through February. So it seems there is a long laying period. My first breeding season Darla laid her eggs on 10/28/99, 1/18/00, 3/29/00, and unfortunately she died gravid and I removed her last clutch of eggs 6/20/00, Dixie laid on 1/4/00, 3/11/00, 5/6/00, and 6/28/00. The second season is still in progress, but so far Darcy laid on 10/8/00 and 1/27/01, Daphne laid on 11/19/00, and 1/27/01, and Dixie laid on 12/23/00 and 3/17/01.
When the female is close to her due date, she will most likely stop eating and just lay around until it is time to dig her nest. I have a young adult that ate right up until the last few days before laying, but my other females quit eating a week to ten days before laying. Quite often the female will sit and soak in the water for several days before beginning to dig her nest.
Make sure you have provided moist substrate that the female can easily dig her nest in. If the substrate is deep enough, she will dig a hole 4-5 inches deep. If the substrate is not that deep, she will dig a tunnel. Often they will lay the eggs under or against a rock, flowerpot, or the edge the water pan. Digging can take a couple of days, or up to a week depending on the female. Once she has dug the hole to her satisfaction she will back in and layer the eggs in the hole. Then she will fill the nest back in a layer at a time packing it by ramming her head against the soil. A young female laying her first clutch will usually only produce 9 or 10 eggs, but I have had one female who laid 19 eggs in her very first clutch. I have had females who have had problems with their eyes becoming stuck shut after laying due to soil getting in their eyes. I have found this easy to remedy by flushing the eye with warm sterile water.
Once the female has left the nesting site, carefully remove the eggs without turning them over. Place the eggs in moist vermiculite in deli cups or Rubbermaid type sandwich containers. The only luck I have had with incubating MHD eggs has been to keep them at 66°-74F with a humidity of 70-80%.
I have had good luck incubating the eggs at 70-75F. They have hatched in 169 to 175 days at this temperature range. Do not turn the eggs like you would for birds, they must stay same side up until they hatch. Place moist vermiculite in a sandwich container or deli cup with pinholes in the top or sides for air. The vermiculite should be moist but not soggy. If you can squeeze water out, it is too wet. If you have a scale that weighs in grams, the best way to mix the vermiculite is equal weights of vermiculite and water. You want just enough vermiculite to keep the eggs off the bottom of the container and to cover them half deep. Make indentations for the eggs and place them in the vermiculite. Loosely place the cover over the container. I don't snap mine on because it is too easy to upset the eggs trying to pry it off!
I keep my containers of eggs in a Styrofoam box that I got from a pet shop. It's one that was used for shipping tropical fish in. I have 3 females that are laying this year and have had 3 clutches of 16 or more from 2 and one clutch of 10 from the other, so I need a pretty large box. You should be able to use a small Styrofoam cooler if you only have one or two clutches. I place a bowl of water in the box with the container of eggs to keep it a little humid. Place the incubation box in a spot where the temperature will stay in the desired range and where the box will be undisturbed. I purchased an indoor/outdoor digital thermometer that records the min and max temp. It has a thin cord with a probe on the end and I place the probe in the egg box and then I can check the temps without opening the box.
You should open the box and lift the lid of each egg container to get a fresh air exchange and to check for moldy or failed eggs. If the eggs are not fertile, they will dent, get slimy and turn dark. If they are fertile, in about 3 months you should be able to see the developing babies in the eggs when candled. You can candle the eggs with a bright penlight flashlight. It is really awesome!
Shortly before the eggs pip, they will begin to sweat and shrink. The center egg in this picture pipped the next morning. It is important to closely monitor at this time, as the baby will need plenty of oxygen while hatching. Do not leave the new hatchling in the incubation box as it could suffocate.
Incubation can take anywhere from 140 to 190 days depending on incubation temperatures. The new hatchling will be 2 1/2 to 3 1/2 inches long and weigh only 1 to 2 grams. Once the baby has emerged from the egg move it to a tall sterile container containing something to climb on and use moist paper towels as substrate. I find that a one-gallon jar with holes in the lid will work nicely for the first few days. I would keep them in this setup until the yolk sac is completely absorbed. Once the yolk sac is absorbed the babies can be moved to a tank that is set up like that of the adults. I use a ten or twenty gallon aquarium with about one inch of shredded coconut fiber bedding heavily planted with parlor palms and other upright plants for the babies to climb on. Just as with the adults you should also provide some small vertical pieces of branch for them to climb on.
I recommend misting the babies to encourage drinking. They will usually get their first drink from droplets of water on the side of the aquarium, a branch, or a leaf. Once they are interested in water, it is much easier to keep them drinking I use a small shallow dish with a rough surface for their water so they can easily climb in and out. A dripper set up over the water dish will create movement and attract them to the water. In no time the babies are splashing and drinking in the dish.
Offer the babies small insects, pinhead crickets, small mealworms, ½ inch long silkworms, and small earth worms. I have found small red wigglers that get no more than 2 inches long that are sold for aquarium fish. These are perfect for the babies and don't require cool temperatures like normal earth worms so they can be added to the substrate where the babies can dig and catch them at will. For the babies I make sure the insects are not only well gut loaded, but I also dust with Sticky Tongue Farms Miner-All I (indoor formula).
***This Caresheet is the property of Marcia Bradley and FroggieB Dragons. Feel free to use this caresheet or to link to it from your web page. No part of this Caresheet is to be copied in any form without the explicit permission of its owner. ***
Agamid Lizards by Ulrich Manthey and Norbert Schuster
Agamid Lizards: Keeping and Breeding them in captivity David J. Zoffer
This page last updated May 21, 2001.
Thanks to Joseph from Penang Butterfly Farm for permission to use their photo of Acanthosaura armata.
Thanks to Sebastian for permission to use his photos of A. lepidogaster.
Thanks to Cheyanne Day of Spitfire Reptiles for lending her support and advice.
Thanks to all of the participants of the Mountain and Tree Dragon Forum on Kingsnake.com for sharing information, questions, and for caring about these wonderful animals.
Thanks to Dan H. for Skywalker, Stumpy, Daniela and Teddy, a group of WC juveniles that he trusted to my care.
Thanks to Lucy T. for entrusting me with Cedar and Spunky, both beautiful adult females.
And most of all, Thanks to my husband for tolerating my obsession!
Without all of the above people, this caresheet would not have been written and I would not have had so much opportunity to learn about these wonderful animals. Thanks again to you all!