NATURAL HISTORY
Green Cat Snakes are actually native to our new home base here in Thailand but I have worked with them for many years now. These are a medium size, rear-fanged snake that falls within the Boiga genus. Average size for females is around 4’ and males can push into the 6’ range. They can be found India, China, Myanmar, Laos, Vietnam, Cambodia, Thailand and Malaysia but don’t range into Indonesia that I am aware of. The cyanea in the hobby do not have credible locality background information but we have been changing that. These snakes are rear fanged which basically means they have an enlarged fang towards the rear of their mouth almost underneath the eye. Different species of rear-fanged snakes can have those teeth positioned forward, directly under, or sometimes to the rear of the eye. They do have a venom gland but the delivery system is actually quite inefficient so what they do is they’ll utilize that enlarged tooth with a chewing motion and that will basically allow some of the toxin that naturally seeps into their saliva to gain access into the wound that they’re creating with that rear fang. The toxin has basically evolved to be most effective against small mammals, frogs or other reptiles and it just basically aids in subduing food and digesting food. In the wild, they eat birds, lizards, frogs, other snakes sometimes, rodents, etc. You’re gonna find these snakes in a forest or jungle setting. They can be found in humid, tropical jungles or more dry forest and they are very arboreal. They are going to be green in color. Occasionally you may come across one that is like a kind of a silvery color or a muted green color but bright green is pretty much the adult coloration. Many will have a blue chin or cheeks. Some will have silver eye color, some green eyes and other black. Babies are a red, pink, or orange color with a green head and usually by the time they’re about two years old they’re going to be green. Most adults will also have a very impressive black mouth so when gaping in a defense display, it can be quite intimidating.
CAPTIVE CARE/DIET/ACCLIMATION
Housing is pretty basic for an arboreal, tropical colubrid. Providing height and climbing branches or perches will suit these animals well. I prefer to use some type of wood bedding or substrate which helps to provide humidity. Misting or spraying is always a solid practice as it promotes movement and also drinking. In nature, rain is very normal to happen in the late afternoon or during the night so I prefer to spray also around these time periods. I provide a warm spot of about 86f and ambient can really be anything cooler as long as the animals have the option to regulate their own body temperatures. These snakes are nocturnal so lighting, in my opinion, is not really necessary. There are many schools of thought on this but I have never used lighting and never felt the need to incorporate this into my husbandry. It may be beneficial but I am still yet to find a cyanea during the day anywhere in nature.
BREEDING
As with most Boiga, cyanea are not difficult to breed. The interesting thing is that the natural range is so large and this also comes with a wide variety of weather and season. For example, the ones in my home area are enduring overnight lows in the upper 30’s and low 40’s in the winter time. The ones in the south are not experiencing anything this cold. Should you cold cycle or pass? This is difficult to answer when you don’t know where your animals came from but I never cold cycled my cyanea in the USA. Generally in captivity, I would food cycle my snakes down in the Winter and start increasing food and pairing in the Spring which also coincides with some rain systems. I always incorporate palpating for follicles as an important part of knowing when to pair my animals but they can be paired without this. The risk you run is that if animals are not in breeding mode, they may predate on eachother so you have to be careful. Normal clutch sizes are not so large with about 8 on average but can be more depending on the female. Eggs are the same as other Boiga and I tend to incubate all colubrid eggs around 80-81f and they will take roughly 110-115 days to hatch. Warmer can shorten this time period and cooler will prolong it but I feel it is better to go cooler and the babies tend to develop well.
ESTABLISHING BABIES
Establishing babies is something I would consider to be a bit more advanced compared to more commonly kept species. Some babies will readily take day-old pinky mice as first meals but that is not always the case. Some prefer lizards, some frogs, some will approve of mice scented with those food items and also birds. I always start with what I would like them to feed on and then I will take steps backwards until I find what works. Scented mice comes second and actual prey items comes third. If babies will not feed at all, I then do assist feeding with mouse tail segents and start taking those steps back to mice over time. Luckily for Boiga, chewing is part of their natural instinct to deploy their rear-fangs so the will often chew down their food when assist feeding. Once they have graduated to feeding on their own, they can have quite the appetite. I don’t like to do rodent only diets, but instead, I like to alternate between birds and rodents as they would be doing in the wild.
FINAL THOUGHTS
I think for Boiga, this is one of the better choices as I would categorize them as medium size, medium difficulty, medium price and they are the only green Boiga. We are investigating a “black-eye” variant from Northern Thailand so if we get some interesting mDNA results, we may have a second green Boiga species.