Madagascar Tree Boas

MADAGASCAR TREE BOAS
Sanzinia madagascariensis volontony   
By Douglas Taylor

SCOPE
This caresheet is for the Mandarin Phase/Western subspecies of the Madagascar Tree Boa or Sanzinia. I'll cover the general husbandry that I've used and the breeding strategy employed for successful reproduction. This is not intended as the final word on care and breeding of Sanzinia.

This caresheet is based on my experience with the 2.2 that I have and the clutches of babies they have produced for me. It may be better called a “report” than a “caresheet”. I got my original breeding pair in late 1998, a second male in late 1999 and a small female in early 2001. They were all adults or young adults so I don't have any experience raising the babies to adulthood.

You will see some pictures of the Green Phase, or Sanzinia madagascariensis madagascariesis. These are pictures of a pair that were under my care for a short time. I do have a young pair of Green phase animals, but I have neither raised them to adulthood or had any reproduction from them. As such, a caresheet would be a bit premature.

A green phase or S.m.madagascariensis posing in good Tree Boa form
TAXONOMY

The name "Sanzinia" comes from an early explorer and catalouguer of Madagascar by the name of R. Sanzin. Early references to these snakes called them "Sanzin's Tree Boa".

A recent paper by Miguel Vences and Frank Glaw conclude that the Eastern (Green Phase) and the Western (Mandarin Phase) are distinct enough to deserve subspecific classification and perhaps future reclassification as distinct species. The Green Phase is now considered Sanzinia madagascariensis madagascariensis and the Mandarin Phase is now Sanzinia madagascariensis volontony. Volontony means "Earth Colored". If I understand the name, it means Earth Colored Sanzinia from Madagascar. To read more, click this link Sanzinia reclassification

ARBOREAL?
Madagascar Tree Boa is something of an odd name in that they aren't nearly as arboreal as the other arboreal boids. Emerald Tree Boas and Amazon Tree Boas are certainly more arboreal; spending most of their lives perched on branches. My MTB's seem to spend most of the time on the ground, taking advantage of climbing opportunities when they are out looking for food. Usually they are found in a hidebox.

The babies climb and hang out on branches more than the adults. My adult males, who are smaller than the female, spend more time perched on shelves in the cages or climbing around. They do this much more than the larger females. Females can be found perched on high spots, just not as often. This leads me to conclude that the tendency to climb has a lot to do with overall size. All of my animals can span impressive distances and I'm sure they would be marvelous climbers.

Wild specimens are frequently found high in trees and Compared to the other Madagascan Boas, Acrantophis madagascarensis and Acrantophis dumerili, they are much more likely to be found in trees, so maybe “Tree Boa” isn't too much of a misnomer.

SIZE

Mandarin Madagascar Tree Boas are medium sized boas. They are from the western side of the island of Madagascar and also a small island off Madagascar called Nosy Be. They are larger and more robust than the Green Eastern subspecies. Mine range from 6 feet and about 7 lbs for the males to over 8 feet and 12-15 lbs for the females. There are reports of individual females reaching up to 30 lbs. I would guess that mine are about average size for the subspecies. Greens don't get as large.

ATTITUDE

MTB's have an undeserved reputation for being quick to bite. Mine are all very pleasant animals. The babies usually are quick to strike during the first week after birth, but soon become as calm as the adults. All of the breeders of MTB's that I have talked to say the same thing, that MTB's are generally calm and mellow captives.

They hold on very tightly when held. This makes them easy to hold, but sometimes hard to get back into the cage. This also can lead to you thinking the animal is holding tightly on your arm and when you look away, he's stretched out and has his head and neck around your computer monitor and he's trying to pull it off the desk.

HOUSING

The caging requirements for MTB's can be as elaborate or spartan as you wish to make them. Give them the chance to climb and they will take advantage of the opportunity. They do not need fancy cages to do well. I have cages without any climbing available and some cages with shelves and such. All of the snakes do well.

A hide box is important and will be used daily. I use an opaque plastic container with damp peat moss.

I use shaved aspen as a substrate. Butcher paper, newspaper, paper towels, terry cloth, peat moss or whatever type of substrate you prefer is probably just fine with an MTB. As always, NEVER use cedar shavings for anything but starting a fire.

The size of the cages I have used range from 4'x18”x18” for males to 4'x3'x2' for females.

TEMPERATURES AND HUMIDITY

From the first of April until about October 31st, I just keep the cages at 65-70 at night and 75-80 in the day. The cage will get a bit warmer during the day if the female is gravid. If she isn't gravid, I let it go like the males cages. I cover winter temperatures in the “Breeding” section.

For humidity I just keep a large water dish in the cage. It seems to be enough. I also keep a humidity box in the female's cage. They seem to tolerate a wide range of temperatures and humidity. The babies have been kept at room temperature without any sort of external heat and they are doing fine.

In a nutshell, they don't need much heat to do well, quite unlike any other arboreal. In fact, I'm finding them to be almost as easy to keep as any snake I've had.

FEEDING

Yummy

My experience with MTB's and their feeding habits was frustrating at first, but with a little experience and research, became quite tolerable. I was used to feeding Eastern Indigos, which are absolute eating machines. MTB's eat when they want, and that isn't often. They have slow, efficient metabolisms and they just don't need to eat a lot.

My males usually begin eating sometime around April and will eat about once a month, sometimes more, sometimes less, until about October. In October, they quit eating, especially if a female is nearby, and they have less interest in food until daytime and temperatures increase again. Males, once adults, don't need more than 6-8 medium sized meals per year. If the male is looking too skinny, toss a few extra meals his way. Fat males are ugly and poor breeders.

The female's feeding behavior is different. Due to their increased size and extra needs due to reproduction, females will eat once or twice a month, year round. They will eat a little bit less in the winter, but shouldn't have any trouble digesting even in the coldest months. One of my females has even eaten when the lows dropped near 60! When a female is gravid, she loses all interest in food and will refuse all food offered until she has dropped her babies and had a post-lay shed.

They also seem a little sensitive about being held and later eating. I avoid handling them if I plan to feed them soon. They are nocturnal feeders and are normally more willing to accept prey at night than in the day. The males almost never accept food for me during the day. I just feed them at night now.

BREEDING

Madagascar Tree Boas have a reputation of being tough to breed. I agree with this to an extent. They may not reproduce annually. I breed mine every other year with a rest year in between. They have slow metabolisms and take quite a while to build up the energy reserves they need for reproduction. I suspect that reproduction happens every 2nd or 3rd year in most cases. Large females may produce more often.

They like to mate, a lot. I have seen mating every month of the year. But successful mating does not guarantee reproduction. It just means the snakes are having a good time. I expect that the best time to put the pair together is around November and separate them around early February. Some breeders, myself included, feel that multiple males help with reproduction.

I put the males together in the same cage as the female. The males will ignore her and wrestle. I pull out the “loser” and leave the “winner” (the one I want to mate with the female) in the cage with the female. I've never seen anything other than “wrestling” behavior. I keep an eye on them to make sure that they aren't actually biting each other.

This is the hardest part. If I plan on the pair actually reproducing, in November I drop the Night Time Lows (NTL's) to around 60f. I let the temps drop that low for 2 months. During this time I let the Daytime Highs (DTH's) get to about 70f. For about a week in late December I might let the NTL's get as low as 55f and with the DTH's no higher than 70. To bring them out of the winter months, I return the temps back to normal, except that the female's basking area temperature will be much warmer, around 90-100f. The rest of her cage will be just a little warmer than normal.

Mandarin phase female showing lighter non-gravid colors

These temperatures are really low and it's hard for snake keepers to allow the temp's to drop so low because of fear of respiratory infections and such. One could always drop the temps and if the snakes appear ill affected by it, turn the heat back on.

If the female is gravid, she'll let you know. First, she'll begin to bask. My females never basks unless gravid. Second, gravid MTB females darken significantly, presumably to better absorb heat. They remain darker until after they drop the babies. Then after the babies are delivered, the female sheds the dark colors off. The female will drop the babies around July. Most of the breeders I contacted agreed that the birth coincided with the arrival of a large storm front. Watch for babies when a storm comes!

Here's a gravid female showing the darkening of colors

Gravid females usually refuse to eat during the entire gestation. My female refused to eat from October of 1999 until August of 2000, about 2 weeks after she had her babies. In 2002, the gravid female fasted for 9 months. Once she dropped and shed, she ate every 3-7 days and regained most all of her lost mass. Having a snake go 8-9 months without eating can be a difficult time for the keeper.

The males may also refuse to eat through most of this time, especially if there is a female in the same room, but should be willing to eat once April rolls around. Mine don't seem to be ill affected by a 4-7 month fast.

HATCHLINGS

The babies will probably be quick to strike at first, but should calm down once in hand. They quickly lose the defensive strike behavior. Newborn MTB's will probably want medium sized fuzzy mice right away and will accept thawed prey soon. I keep my babies at room temperatures, with no extra heat. They come out at night and love to climb around.

SEXING

I use a somewhat controversial method to sex my MTB's. I look at the spurs. If they are visible, it's a male. If there is little to nothing for spurs, I consider it female.

A male showing prominent spurs

A female showing the lack of prominent spurs

CAST IRON SNAKES

In the past few years, I've made a few mistakes with caging, temperatures, and humidity, whatever. They have always come out of it just fine. The first year I had them, I kept them more like emeralds with higher temperatures and humidity, even misting them daily. They were fine except that they didn't reproduce that year.

Another time, I put damp peat moss in the hide box of one of the male's. I didn't check into his cage for probably 3-4 weeks. When I did, I realized he was sitting in a muddy mess. I had put way too much water in the box. I checked him out and there was nothing wrong with him, even though he had sat in a puddle for almost a month.

At night, one of my males will climb onto his basking lights and unscrew them. Regardless of all the goof ups I've made, they have continued to prove they are “Cast Iron” snakes.

The females love to soak. They will spend days or weeks at a time soaking. There has never been any skin problems. At first I thought it was because it was too warm, but she would stay in the water even at night when it was much cooler. So perhaps this "Tree Boa" is "Semi-Aquatic". Perhaps it is something related to ovulation.

CONCLUSION
Madagascar Tree Boas are, overall, a very easy snake to keep. They tolerate handling, don't need a lot of heat, don't need a lot of feeding, don't have any unusual requirements and don't get too big. They have neat markings, come in a few colors and sizes and have the coolest looking HEAD of any boa. I think that as they become more common and cheaper, that they will be seen as a good “first boid”. Hopefully more breeders will have success with these snakes and more people will begin to be able to enjoy keeping them.

I want to thank David Tracer, Dr Adolf Maas DVM, Rene Voss, Steve Hammack, Joe Dembinski, Ken Counts, John Hollister, Terry Lilly, Bobby Pruett, Ron Huffaker, and any Mad' Tree Boa breeders I may have forgotten, who have been willing to share information about care and keeping of Sanzinia madagascariensis.

tonkashouse@comcast.net

206-240-4057

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