Candoia: Natural History & Husbandry

The Pacific Boas

Natural History and Husbandry of Candoia

Red Candoia bibroni australis.

There are no other boas within thousands of miles. They most likely had to raft across the Pacific to get to where they now reside. Triangular shaped viper heads, up-turned snouts, no heat sensitive pits, and thick-keeled scales with flattened bodies separate them in structure. Some are semi-fossorial and some have prehensile tails. Adult sizes range from a diminutive pencil-thin 16 inches to over 7 feet with girth. They survive in the typical rainforest that most other boas do: dense undergrowth, high humidity, and lots of rain and prey. However these boas thrive equally well in dry grasslands, woodlands, plantations, and around human dwellings. The Candoia genus is like no other genus in the Boidae family. They are unique in their locality and appearance, but are overlooked in the herpetological hobby world.

Pinkish/tan Candoia bibroni australis.

Candoia are one of five Boidae genera that include the Eunectes, Epicrates, and Corallus of the Americas and the Boa that range from the Americas to Madagascar. Candoia do not possess the size of Eunectes, the iridescence of Epicrates, the bright Technicolor coloration of some Corallus, nor the popularity of the Boa genus though. Jerry Conway, one of the first hobbyist to give Candoia a real chance and the first innovator of their care, said it best; “[Candoia] are naturally beautiful…there are no ‘morphs’…no man made nonsense involved with Candoia at all…they are underdogs of the snake world…true, primitive wonders of the wild.” These boas are the hidden gems that have been sitting out in the open. They are easy to care for, the easiest to sex properly, naturally calmer than their relatives, naturally variable, and beautifully unique in the Boidae family.

Species and Subspecies

Candoia aspera

Viper boas, aka New Guinea ground boas, are the most well known species of Candoia in the herpetological world and are commonly found throughout their range. They are found on their namesake island, New Guinea, on Irian Jaya, and on hundreds of islands off the shore of Indonesia. Viper boas are short and stocky, resembling death adders, and display a lot of variation in their coloring. They run the gambit of colors and patterns including black, brown, orange, yellow, and gold, and can be blotched or banded. The most impressive individuals are fire engine red with red ventral scales. These snakes have the thickest keeled scales of all Candoia, are between 22 and 36 inches long as adults, and spend a lot of their time in their water bowls. They are also completely terrestrial and even semi-fossorial. Two subspecies are recognized: C. a. aspera (Bismarck Ground boa) and C. a. schmidti (New Guinea Ground boa).

Candoia bibroni

Two subspecies are recognized:

C. b. australis

Solomon Islands tree boas are probably the second most well known species of Candoia, although not nearly as well known as C. aspera. Solomon Islands tree boas can be found throughout the islands and will usually be found in coastal mangrove or cultivated areas. They can be quite variable in color and pattern, colored in reds, pinks, oranges, yellows, browns, grays and black. They may have blotched or splotchy patterning, uniform color, or have an almost zig-zag dorsal stripe. Along with their great display of colors and patterns, C. b. australis also have the ability to lighten and darken in color and patterning throughout the day. I’ve seen individuals change from a dark brownish-red with heavy patterning to a light pinkish-tan with faint patterning, over the course of a few hours. This species’ habits are almost completely opposite of the Viper boas’ habits. They are arboreal 90% of the time, sometimes even perched in the classic fashion of a Green Tree python. Their thin bodies lend themselves nicely to an arboreal lifestyle, where they can stretch across and move between branches with ease. Rarely you’ll spot individuals hanging out and coiled up on the ground. Males of this species range from 3 to 4 feet in length, while females rarely exceed 6 feet.

Keeled C. b. australis scales.

C. b. bibroni

Fiji Island boas are known from Fiji, Somoa, Tonga and other small Solomon Islands. These boas are mostly terrestrial, climbing little. Fiji boas are dark reddish-brown, usually with faint blotching or banding. Ventral scales on these boas are normally cream or brownish, but some rare specimens have red or orange ventrals. The largest boas of the Candoia genus, males grow to 3 or 4 feet with adult females exceeding 7 feet. Overall, little is known about Fiji boas due to their protected status throughout their range.

Candoia carinata

New Guinea, Pacific, or Waigeo Island tree boas are by far the smallest and most variable in pattern of the Candoia genus. C. carinata are found on low shrubbery around human dwellings and plantations. New Guinea tree boas can be found climbing or curled up on the ground, and may even be found burrowing. Individuals are usually blotched, with flowery patterning, but they can be completely striped, banded, or solid in color. Their background colors can be gray, tan, yellow, cream, or reddish-brown, with most being a mottled gray and white similar to Hyla marmorata, the Marbled tree frog. The mottled individuals are the best adapted for camouflage, blending in extremely well with tree bark. All individuals have the distinctive characteristic of a yellow-cream dorsal stripe just anterior to, and a white ventral spot posterior to, the cloaca. Adult size spans from 16 to 24 inches, becoming not much thicker than a Sharpie highlighter marker. The Waigeo Island locality is almost always brown and tan with a dark stripe running dorsally from the head all the way to the tail tip. Some specimens have a broken dorsal stripe. Waigeo Island Candoia may be a C. carinata subspecies, but to date has not been distinguished as one. Two subspecies are recognized though: C. c. carinata (Western New Guinea tree boa) and C. c. tepedeleni (Tepedelen’s tree boa).

Keeled C. carinata scales.

Candoia paulsoni

Pacific or Solomon Islands ground boas prefer dry grasslands and wooded areas, but can be found in on the ground and climbing through pineapple and coffee plantations. Background colors in this species run the gambit from red, gold, orange, tan, and bluish-brown. There have even been some leucistic C. paulsoni found.  Patterning consists of a dark dorsal zig-zag pattern from head to tail. Isabel Island (the prettiest Candoia) boas, a possible subspecies, are locality variations that usually have white base coloring with a dark dorsal striping. Similar to C. australis, C. paulsoni have the ability to darken and lighten their base color throughout the day. Adults of this species average 3 feet for males and 5 feet for females. Six subspecies are recognized: C. p. paulsoni (Solomon Ground boa), C. p. vindumi (Vindum’s Ground boa), C. p. tasmai (Tasma’s Ground boa), C. p. mcdowelli (McDowell’s Ground boa), C. p. sadlieri (Sadlier’s Ground boa), and C. p. rosadoi (Rosado’s Ground boa).

Candoia paulsoni.

C. paulsoni light (the same C. paulsoni as left).

C. paulsoni dark (the same C. paulsoni as right).

Candoia superciliosa

Palau Bevel-nosed boas are the least known species of Candoia. Until recently (within the last ten years) these boas were considered a subspecies of Candoia carinata, therefore much of the information on them refers to the New Guinea tree boa natural history. They are found on the islands of Palau and Nqeaur (Anguar island). Adapting well to disturbance, these boas live in deforested areas, as well as banana and taro plantations. As with C. carinata, they are thin, arboreal snakes with prehensile tails that can be found in low shrubbery and on the ground. Coloration in the Palau Bevel-nosed boa varies from yellow, black, and red, with patterning of dull or brightly contrasting stripes, spots, mottling, or zig-zags. These boas have the distinctive white spot situated behind the cloaca, characteristic of the New Guinea tree boa, and enlarged scales above the eye sockets. Two subspecies are currently recognized: C. s. superciliosa (Northern Belau Bevel-nosed boa) and C. s. crombiei (Ngeaur Bevel-nosed boa).

Candoia in the Herp Industry

It is a near impossibility to find captive bred-and-born individuals in the herp industry, and this does not bode well for conservation. I admit I’m not a tree-hugging conservation nut – I’ve worked for tree companies, clearing acres of land; keep dozens of snakes; and create a huge carbon imprint with all the traveling I do. I am however against the importation and exportation of hundreds of species. The animals have to suffer through the process and many die or import mites with them, infecting otherwise healthy individuals in collections. I believe that small numbers should be imported, bred, and distributed. Whatever can be done to limit deaths, decrease mites, and increase the numbers of healthy, “tame” snakes in the trade is the best option. Snakes make great pets but without conservation we cannot keep wild population numbers healthy. I would hate to see a species disappear from the wild because I wanted to put it in a tank just to look at it. With that said, almost all available Candoia are wild-caught and are usually dehydrated and may come with mites or other parasites.

With the exception of C. aspera, Candoia are naturally calm, but you want to look for an individual that looks healthy and is active when held. It is also always better to buy from a vendor that has some knowledge of the species rather than a person who can only tell you what country it was exported out of. As with all new snakes, they should be quarantined, rehydrated, and left alone until they acclimate. Once home, I’ll soak the snake in a water bath to rehydrate. This means putting the snake in a Rubbermaid container for a few hours with a few inches of clean water and a branch to use to climb out of the water to prevent drowning. After rehydrating, I’ll put new individuals in a separate room for 2 to 4 months, checking for mites and other illnesses before I merge them into the rest of the collection.

Disposition

C. carinata.

Almost all Candoia are hesitant to bite, and if they do it is only to test what you are.  C. b. australis rarely ever bite unless you’re restraining them. C. carinata will bite for the same reason, but are so small they can barely bite around a pinky finger. C. b. bibroni and C. paulsoni bite when unsettled, but most will sit still for a cage cleaning as long as they don’t have to be moved too much. Contrary to all the other Candoia species, C. aspera can be downright mean sometimes. They are by far the most bitey of all the Candoia and can be pretty cage defensive. As with all snakes though, captive bred will always be more docile and wild caught can be worked with and handled often to calm them down.

Morphs

Until the end of 2011, there were no known morphs within the Candoia genus other than a one-of-a-kind leucistic C. paulsoni Jerry Conway had been working with. Recently, there have been several albino projects popping up. Albinos Unlimited Inc. announced their importation of a wild-caught, albino C. aspera. If all goes well, there should be het albinos entering the hobby within the next couple of years if the trait proves to be recessive. There is also another private hobbyist that is currently working with possible het albino Isabel Island ground boas (C. paulsoni) and hypomelanistic Candoia sp. Another private hobbyist is working on producing calico C. aspera, from a dark male with random orange and white splotches. Lastly, although I haven’t heard of any proven lines of hypos, there are some hypo C. carinata, C. aspera, and C. b. australis floating around in private collections.

Husbandry

Housing & Humidity

Adults can be kept in simple 20 to 50-gallon aquariums, dependent on size. C. paulsoni and C. bibroni will utilize larger enclosures, while the more diminutive species will be comfortable in smaller tanks. The tanks should have secure tops since Candoia are quite inquisitive and will surely test their enclosures for escape routes. Large water bowls are also a must to allow the snakes to soak. C. aspera can often be found soaking in their bowls throughout the day.

C. b. australis.

Humidity should be kept between 50 and 80% with daytime temperatures around 85^oF. A temperature gradient should be created using a heat lamp or outside-of-the-tank heating mat, with the hot spot at 90^oF. Nighttime temperatures should not drop below the mid-70s. The cage should also be misted 2 or 3 times a week to allow the snakes to drink water off of the sides and help with shedding. A healthy Candoia will shed about once every two months.

Within the tank there should be plenty of branches to climb on and a couple of hides at different heights.  Arboreal species, such as C. b. australis and C. carinata, are better housed in taller terrariums where they can climb upwards. The more terrestrial species, such as C. paulsoni and C. aspera, can be housed is shorter terrariums where a thick layer of substrate is provided to burrow into. Many people prefer Aspen tree shavings, but I particularly like Zoo Med Repti Bark (fir tree pieces) for their control of “snake smell” and their ability to hold moisture. Candoia are all ambush predators and will use the branches to wait in a coiled “S,” burrow and wait for prey to come by, or sit by the entrance of their hide and strike when prey is in range.

Feeding Your Adult Candoia

Adults should be fed once every three weeks. They have a fairly slow metabolism and can go off feed for months without losing large amounts of weight. Most will eat more often – my adults will eat two adult mice every 15 to 20 days, but you need to watch that they do not become overweight. Also, if it is a new acquisition, wait at least one week before offering food. This time allows the snake to acclimate, without which it can become stressed and go off feed permanently.

Since Candoia are nocturnal, hunting mostly at night, appropriate sized prey should be offered after dark. Food items should only be slightly larger than the width of the snake. If the food item is a lot larger, regurgitation problems may occur. Another way to ensure that proper digestion takes place is to make slits in the skin of the food item to aid with speeding up digestion.

C. carinata in strike position.

Most adult Candoia will readily accept rodents, but there are exceptions. C. b. australis and C. b. bibroni will eat rodents, but many favor birds (chicks and quail are favorites). C. carinata and C. paulsoni may be picky and only eat anoles or tree frogs (Hemidactylus frenatus and Hyla cinera are the easiest to obtain). I’d imagine C. superciliosa follows suit since they are so similar to C. carinata. Viper boas, C. aspera, are the easiest to feed, with most individuals readily accepting frozen/thawed rodents. This is understandable though, as Viper boas are the most terrestrial of all the Candoia species and consume more rodents in the wild than their counterparts.

Breeding

Start cooling your Candoia in early November, gradually dropping the temperature 2 to 3^oF a week until it reaches 68^oF at night, keeping the daytime temperature around 83^oF. This should last for two months before increasing the temperatures back to normal. Once the cooling period is done, introduce the males into the females’ enclosures. Males should be at least 3 years old, while females should be at least 4 years old. I’m in no rush when it comes to breeding because it is not worth possibly stressing a snake that is too young.

MULTIPLE MALES, MULTIPLE MALES, MULTIPLE MALES!!! When breeding Candoia you need to use three to four males per female. I’m not saying that one or two males won’t work, but the odds of successful mating greatly increase when three or more males are used. Of course, you need to carefully watch since “wrestling,” a series of twisting and constricting motions, may occur between the males and you don’t want any of them being injured. After a little competition has occurred, you can select the winner. If you may see that a male has paired off with a female, pull the other males out. Copulation may take place for a couple weeks, upon which the female will become noticeably swollen. At this point I leave the male with the female for another week before taking him out to ensure that the female is gravid. Most of my Candoia will breed throughout January.

Gestation lasts up to 9 months in Candoia, during which the female may go off feed for weeks or even a couple of months. If your female remains feeding, smaller prey items than normal should be offered to prevent regurgitation. During this period, many females avoid the heat source while gravid, so care should be taken to ensure a heat gradient throughout the enclosure. Since gestation lasts so long and females may go off feed during much of the pregnancy, they should only be bred once every 2 years. Giving them a year off allows them to recoup the lost body weight and get back to breeding size without being stressed.

Neonate Care

Candoia, like all boas, are viviparous. They give birth to anywhere from 2 to over 70 live little worms. For the most part, neonate care is identical across the Candoia genus; it is just a matter as to how many babies you need to care for. 

With smaller litters, C. carinata produce 2 to 6 offspring. Producing intermediate size litters, C. bibroni and C. aspera will give you 3 to 35 offspring. The largest litters of Candoia come from C. paulsoni, with 20 to upwards of 80 young, and C. superciliosa, with 12 to 50 young. There are outliers to these averages, as litter size is extremely dependent on the size, age, and health of the individuals.

C. b. australis.

Once the Candoia neonates are born, you can sex them immediately by looking for spurs. Males have spurs and females don’t - they cannot get any easier to distinguish. You’ll want to house them individually in small enclosures as cannibalism has been reported among baby Candoia. The size will be dependent on the species, but generally a 5–gallon aquarium is enough space. You just need to make sure the holes aren’t big enough for the neonates to escape. Housing neonates on paper towels makes it easy to clean and ensures that no wood chips or debris will be accidentally eaten. Temperatures should be a few degrees cooler during the day than what is provided for adults, maxing out around 86^oF. As always, a temperature gradient should be provided as much as possible in a small enclosure so the snakes can thermoregulate. Humidity should be kept between 50% and 70%, with cage misting 2 to 3 times a week and a water bowl deep enough to soak in. A small hide and some climbing branches complete the enclosures, providing the neonates with a place of security and a location to wait for prey.

The neonates will shed their skin immediately after birth, but you should not feed them for at least two weeks. At this time, small pinky mice can be offered. Most neonates, especially C. b. australis and C. carinata, will refuse this first offering of pinky mice. Some neonates may be too small to comfortably eat a pinky mouse. C. carinata are born about as long as a pinky finger and as thin as a piece of string. Since Candoia feed on lizards in the wild, gecko tails can be used to start them feeding. You could also start them feeding using mice tails and assist feeding methods, but I would strongly suggest this method only for an experienced keeper. After feeding on gecko tails for two cycles (every two weeks), no food should be offered for three weeks and a lizard-scented pinky mouse should then be offered. This usually does the trick in starting the neonates on mice.  In some cases, the neonates will still refuse and will have to continue to be fed with geckos. Other feeding success has been reported with earthworms, minnows, and even tuna fish.

Inhabiting hundreds of islands in the South Pacific, new species may be waiting to be discovered, the same way Candoia are waiting to be discovered in the herp-keeping hobby. Now is the time to start keeping the more interesting species.  Instead of following the crowd of people that are surrounding ball python morphs, become a more well-versed keeper. Add a Candoia to your collection. Help stop the importation of animals by adding captive bred individuals to the hobby. Who knows, you may even find a new morph… hey it made ball pythons popular!

Keeled scales of a C. paulsoni.

References:

Conway, J. (June 27, 2009). The Candoia Page: Boas of the South Pacific. Retrieved September 2011 from: http://www.kingsnake.com/candoia/

Mattison, C. (2007). The New Encyclopedia of Snakes. Princeton, New Jersey: Princeton University Press.

O’Shea, Marc. (2007). Boas and Pythons of the World. Princeton, New Jersey: Princeton University Press.