Boa constrictor Page

The report about the Tarahumara Mountain Boas was made by our friend Gus Rentfro

www.RioBravoReptiles.com

We appreciate his consent to publish it on our website. We bought 2.2 of these dwarfish Boas from Gus and
we are looking forward obtaining them after the import-/export paperwork is done.

Locality

Sierra Tarahumara lies in the northern state of Chihuahua, Mexico. This vast area of high peaks, forested plateaus and deeply eroded riparian canyons is sometimes referred to as Mexico’s rugged “Western Mother Mountains”. High above the harsh desert floor at elevations over 4000’ are the Ponderosa pine forests. It is here where these “dwarf” boas (B. constrictor ssp.) originated.

Tarahumara Moutain Boa

Sexual matured female

photo courtesy Gus Rentfro

History in culture

A researcher from the University of Arizona (UA) brought back a single pair of these boas in the early to mid 1990’s. That pair made their way into the private sector where soon after an Arizona collector bred them. That first breeding resulted in a single live male. In the 1998/1999 season they bred again, ten babies with a high male ratio were born. Rio Bravo Reptiles did acquire a male/female pair of these boas in early 2001 from an associate here in Texas. By the winter of ‘02 the 3-1/2 year old boas had grown to 37” in length. This year (2002) both myself and Graham Criglow of Bryan, TX successfully produced healthy litters of Tarahumara dwarf boas. Amazingly, both litters (9&10 respectively), were born the morning of July 3rd. Whether this is simple coincidence or driven by something in their genetic makeup is unknown. Prior to these breedings there existed only the original 13 animals (1.1 WC original pair, 1.0 1st breeding baby and 0.0.10 2nd breeding babies) in our hobby. The pair maintained here and those held by Mr. Criglow are the only Tarahumara boas known to have been kept together and bred pure for their unique locality.

Tarahumara Moutain Boa

Sexual matured female and
her babies

photo courtesy Gus Rentfro

What is a dwarf Boa?

Genetics and food availability combine to determine the adult size of boas in captivity. A locality or form could be considered dwarf if individuals reach sexual maturity and give viable young without complication at a significantly smaller size and mass. Mainland populations of Boa constrictor properly managed mature in 3-5 years at 5 to 6 feet in length, depending upon the subspecies and to a lesser extent the locality. The imperator sub-species generally will mature earlier at a somewhat smaller size than the B. c. constritor. Some insular forms (Corn Is. as an example) can and do breed successfully at lengths just over 40”. The Tarahumara boas bred and gave birth while still less than 38” long.

Tarahumara Moutain Boa

cb 2002 by Gus Rentfro

Amazing are the black head markings which are
similar to Boa c. longicauda

It is not known how large the Tarahumara boas would become if fed aggressively over a period of years. However, in my experience other mainland forms of Boa managed similarly would have attained lengths of 5 feet or more in the same period of time. And deliberately rationing food to keep Boas small inhibits their ability to reproduce.