Glossary of Terms

Arboreal:  spend time in the tree canopy

Brachiator:  arm swinging with feet used as support.  Also includes climbing and hanging by feet.

Coelom:  a fluid-filled cavity found in an organism.  Allows for an increase in body size.

Estrus:  changes in sexually mature females that are caused by reproductive hormones.  Begins after puberty.  Humans undergo a similar cycle called the menstrual cycle.

Heterotroph:  an organism that feeds on others

Pleistocene:  most recent period of glaciations lasting from 1.65 million to 10,000 years ago.

Sexual Dimorphism:  a difference seen in male and female Orangutans.  Males are normally twice the size of their female counterparts.

Terrestrial:  spend their time on the ground

Courtesy of Wikipedia