These snakes will take your breath away. Literally.

1. Physical characteristics Boidae. Average size snake (20 inch. at birth, 8-13 feet as adults). Females

generally larger than males ( 6-8 feet long as adults). Mature boa = 60 pounds.

Colour =depend on their environment. Colours:, brown, grey, cream and red, with dark cross bands. Helps them to camouflage.

Other Boidaes have obvious heat-sensing pits to find warm-blooded prey. Boas have less obvious heat-sensing scales.

Aglyphous teeth – fangs don’t carry venom. Teeth similar in size, point towards back of the mouth.

Constrict and suffocate their prey. 2 equal lungs instead of 1. Pelvic spurs on each side of the vent (remains of hind legs).

2. Habitat Tropical forests due to humidity, temperature, natural cover and

abundance of prey. Near the edges of the rainforest. Semi-desert conditions, burrows of mammals, open savannahs and cultivated fields as well. Accomplished swimmers, but don't go to the water – terrestrial and arboreal.

Boa constrictors and their subspecies found in:o Central America: Mexico, Belize, El Salvador, Costa Rica and Panama. o South America: Columbia, Peru, Brazil (mostly in the Amazon

rainforest), Bolivia and Uruguay, among others.o Some subspecies found on Pacific coasts and many Caribbean islands

(Lesser Antilles, Trinidad, Dominica and St. Lucia, as well as some islands off the coast of Belize and Honduras).

3. Diet Cells in their lips that help them to sense heat. Ambush hunters

(wait quietly for prey to pass by). Size influences types of prey it can swallow. Small animals at

daylight and dusk: monkeys, rats and other rodents, birds, small reptiles (e.g. lizards) and even wild pigs. Ability to climb trees and live on the ground= increases hunting range.

Favourite meal = bat, which they will (hunted by hanging from tree branches near cave mouths). Grab the bat as it tries to enter the cave, then constrict it to death. Digestion of a large meal = an entire week.

4. Lifecycle Nocturnal(daytime only to get heat). Most subspecies alone, only

associating with other snakes during mating. Few Dominican subspecies that live in dens together. Females attract males by emitting a pheromone. Male fertilizes female's eggs internally and female gives birth to live offspring.

Ovoviviparous – incubate their young internally for 5-8months. Average litter size= 25 (record= +60).

Babies (tiny adults) independent from birth. Childhood: danger of being eaten. Maturity= three years old.

Moult skin regularly throughout lives to accommodate body growth and to get rid of parasites. The new skin has already formed beneath the old.

Adults = few natural predators. National Geographic: 20 -30 years in the wild.

5. Risk factors Deforestation & pollution of rivers. Exotic pet trade. Predation from other animals (e.g. jaguars). Human hunt to trade

their exotic, fine, ornate snake skin or just to kill them. Some endangered (most have protected status). Most populations not under threat of immediate extinction.  

Cold weather (freeze to death because of cold blood).

6. Measures for protectionRespecting their environment: not to cut down so many

trees, not to construct any buildings, etc. Avoid poaching. Free although they do well in captivity.

7. Interesting facts Boas have a strong sense of smell and good eyesight. Boas are said to be the most beautifully colored of all snakes. The boa constrictor can unhook its jaws wide enough to swallow a whole

monkey headfirst. In South America, some households keep boa constrictors to control

vermin.  When it's time for boas to mate, a group of males will wrestle in a group

with a female for up to two weeks until one of them wins or until the female chooses one of them.

Boas generally prefer to leave people alone unless they are directly attacked.

Boas only go hunting for food, not for sport.

A presentation made by Andrés Rodríguez (1º D)

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