Learning UML 2.0

Colophon

The animal appearing on the cover of Learning UML 2.0 is a gorilla (Gorilla gorilla). Despite its reputation for aggression, the gorilla is generally shy and inoffensive, rising to an erect position and beating its chest only when provoked or threatened. This behavior is meant to intimidate intruders rather than harm them. However, if the family group is attacked, male gorillas will risk death to protect their young. Gorillas are the largest and most powerful of the apes, with females weighing up to 200 pounds and males up to 400 pounds.

Gorillas are socially flexible, meaning their social structure is not set in stone. Troops can number as many as 30 individuals but are more often comprised of 6 or 7, including one silverback (mature male), a few females, and their young. In her lifetime, a female gorilla gives birth to about three offspring, which remain in her care until they are three or four years old. Offspring stay with their troop until they reach sexual maturity—about nine years old—at which time they generally start or join another troop.

Populations of gorillas are decreasing due to human encroachment and hunting. Scientists estimate that there are roughly 50,000 gorillas left in the wild in Africa, most of which are western lowland gorillas—only about 600 are mountain gorillas. Most countries have passed laws protecting gorillas, but enforcement is difficult in remote jungles where people survive by hunting. Tourism now generates a great deal of money in Rwanda, ...