ROSY BOAS

If you are a boa fan but lack the muscle power to manhandle one of the big brutes or are unable to give up half a room to provide adequate living quarters maybe you should take a closer look at the Rosy Boa. This is one of the "minis" of the boa family and rarely exceeds a meter in length with a chunky body and blunt tail. It is also undemanding and can be kept in similar conditions as North American colubrids.

Rosy Boas are found in the south western scrub land deserts of North America where the USA borders with Mexico. There is some confusion over the naming of the subspecies and a review of the genus was carried out by David Spiteri in 1993. As this review was published in the Vivarium and not a scientific journal many scientists do not recognise the new naming and continue to use the old classification. The main subspecies are:

The Mexican Rosy Boa, Lichanura Trivirgata Trivagata. This is the southern most of the species with "humbug" colouring - three dark brown stripes on a cream/grey background. One stripe along the back and one on each flank. The range of this snake is southern Baja, Sonora and southern Arizona.

The Mid-Baja Rosy Boa. Lichanura Trivirgata Saslowi (formerly Myriolepis). Possibly the most attractive and sought after of the Rosy Boas this strictly Mexican snake is from the central Baja region. Like the above this snake has three even-edged stripes ranging in colour from brown to deep cinnamon.

The Coastal Rosy Boa, Lichanura Trivirgata Roseofusca. Found along the Baja coast and north to California this is the largest of the species and may exceed one meter in length. The stripes of this variety have irregular edges and many spots which obscure the background colour. Again the stripes can vary in colour.

The Desert Rosy Boa, Lichanura Trivirgata Myriolepis (formerly Gracia). Another variable snake with irregular stripes and small spots. This is the northern most Rosy Boa, found in southern California and adjacent Arizona.

Some areas within the above regions are claimed to produce particularly attractive specimens and you will often see these referred to by their regional name ie St.Felippe or St.Gabriell. To add further to the confusion, the subspecies can interbreed and "intermediate" varieties appear for sale. These will make fine pets but are best avoided when breeding.

Fortunately keeping this snake is easier than working out its name and all the subspecies require similar treatment. They are snakes from dry scrub lands, warm in the summer but with cool winters. While a large vivarium is not required, it should be well ventilated to keep the humidity level low. To aid low humidity, I have seen it suggested that water should only be placed in the vivarium overnight once a week but I prefer to leave a small water container with the snakes at all times. On more than one occasion I have found my Rosy Boas curled up quite happily in their water container.

To allow the snake to thermoregulate a summer temperature gradient of 73o to 83o F in the vivarium will be ideal, with the heat being provided by undertank heating at one end of the vivarium. Winter hibernation of 12 weeks at around 55o F is recommended for breeding adults. Lighting is not essential but may be useful for warming the air temperature.

Rosy Boas are classed as a "burrowing" boa and in nature will be found under rocks and logs. A loose substrate several inches deep will be suitable but they can be kept on paper if provided with low hiding places at the warm and cool end of their vivarium

To breed these snakes they will need to be hibernated for three months. Give plenty of food at the end of hibernation in March and introduce the male to the female in April. If mating is successful the female boa will carry the developing embryos until August/September when 4 to 6 (sometimes more) live young will be born. The babies are chunky and can be up to 12 inches long, capable of taking fuzzy mice as their first food.

It is not always easy to get Rosy Boas to start feeding and most breeders use live food at first. As these snakes are born late in the year when their natural prey would be getting scarce it is likely that they go into hibernation and do not start to feed until the following spring. Some newly born Rosy Boas will refuse to eat and it is normal practise to hibernate these for a while and resume trying to feed after they have been brought out of hibernation. Always try to buy a snake which has started to feed to save yourself this problem (I wish I had heeded my own advise).

Once feeding has started Rosy's are avid eaters taking a fuzzy every 4 to 5 days progressing to an adult mouse every 10 days. Even defrosted mice will be struck at and constricted prior to being eaten. Initial growth is rapid and most of their length can be put on in the first year. Breeding can be attempted after two years but is better left another year.

The Rosy Boa feels different to any other snake I have held. The scales are very small and smooth giving a silky feel to a body which is soft and rubbery. Movement is slow but they will strike hard and fast once their prey has been located. In spite of this they are gentle and my snakes have never attempted to bite when handled.

I hope to report more fully on their breeding in about three years and will be happy to take any orders. In the mean time I am enjoying getting to know a fascinating little snake.