Green tree python (Morelia viridis)

Next to the "redtail boa" (Boa c. constrictor), the green tree python is one of the most desired boids in herpetoculture. These two species have enough fans to be considered ‘cult snakes’.

Morelia (or even Chondropython) viridis is a feast for the eyes, and a living room enclosure housing this species is the most beautiful decoration that an enthusiastic snake keeper could wish for.

Unlike most other constrictor snakes, the green tree python does not feel the need to hide. It is always coiling around a branch at a visible spot, preying on passing birds (which are admittedly less abundant in captivity than they are in the wild).

Unfortunately, even this species has its catch. Being an inhabitant of the rain forest, it requires a relatively high humidity (at least 75%), which naturally promotes bacterial growth in the enclosure. Death resulting from bacterial infections is not a rare occurrence in Morelia viridis. Furthermore, due to the small size of the hatchlings, gender determination by probing is not recommended until the animals reach juvenile age. When acquiring hatchling green tree pythons, you can never be absolutely sure in regards to their gender.
Those lucky enough to breed this species must be prepared to force-feed a good part of the young, as these often refuse to feed on their own.

It should also be mentioned that Morelia viridis lays eggs. Egg-layers are not for everybody. Many breeders (including ourselves) prefer boas, since they give birth to live young. .

Emerald tree boa (Corallus Caninnus)

This also an arboreal snake looks very similar to the green tree python. The emerald tree boa lies exactly like Morelia viridis visibly coiled around a branch, and also has a large fan community.
However, the emerald tree boa is also notorious for its extremely long teeth, as well as mouth rot, which is a frequent occurrence in this species, along with the regurgitation syndrome. The ladder means that the eaten prey item is regurgitated after 3-6 days. The potential causes for this are numerous and reach from bacterial infection of the digestive track to stress. We will target this issue in more detail later on.
The problems mentioned above occur mainly in wild-caught specimen, though captive-bred animals are not spared completely. The high humidity that these animals require, and the subsequent favorable conditions for bacterial growth in the enclosure play an important role again.
In contrast to the green tree python, the emerald tree boa gives birth to live young. The emerald tree boa is therefore a better choice for those people that do not like “egg-layers”, but yet would like a green snake.

It should be mentioned that both the green tree python and the emerald tree boa are unsuitable for people looking for a “pet snake”, just as a bicycle is for a fish.

Madagascar ground boa (Acrantophis madagascariensis) and Dumerils boa (Acranthophis dumerili)

These snakes are (as the name implies) from Madagascar, are listed as a Cites-I species, and are relatively undemanding animals that are very hardy. They are therefore also suitable for beginners of boid husbandry.
Yet, this recommendation is not entirely without concern, since some of the newborn Acrantophis dumerili are picky feeders, as they would prefer birds or fellow mates as prey. A cautious approach is therefore needed when housing several young of various sizes in one enclosure. In addition, and in contrast to most other boids, the Dumerils boa tends to pass urine and urinary calculus almost daily, and is therefore a bit more demanding in maintenance than is the case with most other boids.

There is nothing really negative to say about its northern relative, Acrantophis madagascariensis, except maybe that it grows to be significantly larger and stronger than the Dumerils boa, which on average grows to around two meters (over 6.5ft) in length. Specimens of three meters (10ft) are no rarity in Acrantophis madagascariensis. Interesting is also the gestation period of the Madagascar ground boa: It lasts 9 months.

Boa constrictor

We now finally get to our favorite snakes. It is really worthwhile to elaborate on this species.

First off, it is to be said that even the Boa constrictors cannot be recommended all-inclusive. There are about 10 Boa constrictor subspecies, of which some can give a person new to the keeping of boids a difficult time.

This refers mostly to the so-called "redtail boas", the Boa c. constrictor from the distribution areas of Suriname and Guyana, to name the most important ones. However, especially these “redtail boas” are, along with the tree pythons, among the most desired and most beautiful snakes kept in captivity.

Boa c. constrictor neonates are notoriously known to regurgitate over-sized prey items. The term for this is “regurgitation syndrome”. We have previously mentioned this, and will deal with this topic in more detail later on.

But don’t worry: If the owner of a redtail boa is able to implement a moderate feeding schedule, then there won’t be any problems with the animal.

Similar is valid for Boa c. occidentalis (Argentine boa). This subspecies of Boa constrictor is also prone to the regurgitation syndrome.

Many boa fans are enthusiastic about the Boa c. amarali, a very pretty form that occurs in Bolivia and Brazil. The Bolivian form is trouble-free, however, the high fatality rate among animals of the “Danish bloodline”, the so-called “silverbacks” from the region of Sao Paolo/Brazil sticks out.

Almost all of the specimen of this form that are available in Europe originate from the bloodline of a Danish breeder. Unfortunately, these animals appear to be highly delicate. The “regurgitation syndrome” is even more common in neonates of this bloodline than it is in the so-called “redtail boas”. Many of the “silverbacks” that were raised despite major difficulties later died from bacterial infections or due to other causes that are not normally lethal (for instance, when changing owners). We do not know, as to what degree the inbreeding may play a role in this.

We had always assumed that the „silverback amarali“ on average do not get larger than about 1,60m (a little over 5ft). After a trip to the United States in 2000, the author had to revise his opinion. He was there confronted with specimen, compared to which mature amarali from the “Danish bloodline” would have appeared to be yearlings.

A conversation with Joe Terry, the „Father of amarali“ (he is known as an absolute authority in regards to Boa c. amarali, and first bred this subspecies in captivity), yielded the fact that there are actually two types of “silverbacks”, one of which gets relatively large (about 2.5m; over 8ft) and is very hardy. We have acquired those animals in the U.S., and can confirm these findings through our experience thus far. Of course, there are also healthy specimens that reached an impressive size among the “silverbacks” that are bred here in Europe. However, to be clear, these are exceptions.