Scientific Name: Monocentropus balfouri
Common Name: Socotra Island Blue Baboon
Type: Terrestrial Opportunistic Burrower
Category: Old World
Endemic Location: Socotra Island off the coast of Yemen
Body Length: 2.5” (7cm)
Diagonal Leg Span (DLS): 7” (18cm)
Urticating Hairs: No
Growth Rate: Slow
Life Expectancy: Females 12-14 years / Males 3-4 years
Recommended Experience Level: Intermediate
The Monocentropus balfouri known commonly in the hobby as the Socotra Island Blue Baboon was described by Pocock in 1897 and is an Old World Terrestrial species that is native to the island of Socotra about 150 miles east of the horn of Africa. This area has a tropical to semi desert climate with fairly moderate temperatures and rainfall. Being from this island and secluded, this species has evolved in ways unlike other tarantulas. First they have a very identifiable color pattern that makes them very recognizable. Also they are known as the most communal tarantula in the hobby as they have naturally evolved into living in close quarters in their natural habitat. Though they haven't been witnessed living communally in the wild, they are one of a very few species of tarantulas that can live communally in captivity. This species has a medium growth rate with females reaching a maximum diagonal leg span of 5-6” within a few years while males are a little bit smaller. There is some sexual dimorphism in this species but it is not the most reliable way to determine the sex of your specimen. The best way to know if you have a male or female is to examine the inside of a molt. But some have reported that once a male has its ultimate molt and is fully mature and ready to mate, its carapace will be bright blue while females will be grey or lighter blue. The reason this isn't the best method is that I have seen many reports on line from those with first hand knowledge saying their males never developed the bright blue carapace upon maturing. These spiders have a fairly mellow temperament for an Old World Tarantula. They can be very fast and are prone to bolt when startled or when they feel threatened., but in general they are relaxed and laid back, especially with other specimens in a communal set up having been observed by many keepers sharing a roach or cricket as they feed. Check out some of the videos by Tom Bigs Spiders he has put out on his M balfouri communal for more information.
This is an opportunistic burrower meaning that they will prefer to burrow down into the substrate, but they will also web up the entrance of their burrow and expand their webbing throughout their enclosure and almost seem semi arboreal like a Green Bottle Blue or Orange Baboon Tarantula. One of the amazing aspects of this species is that not only can they be kept communally, but you can keep them with other M. balfouris from different egg sacs, and there have even been multiple reports of people beginning communals by mixing slings and juveniles. It is probably best when deciding to keep specimens of different sizes together communally to make a new enclosure and move everyone into the new home as opposed to just dropping them into an enclosure that one tarantula has already settled into. And it seems that once a female has matured, if she is not already in a communal set up, she will be less likely to adjust and may not be able to co habitate peacefully with other specimens. And it is definitely not recommended to try and house a mature female and mature male together if they were not raised together in a communal set up.