Yielding to pressure from animal-rights groups, the San Francisco Zoo (search) is giving up its last elephant, marking the first time in the facility's 75-history that it will be without at least one pachyderm.

The zoo's only remaining elephant is being moved to a sanctuary in the Sierra foothills after elected officials voted to require a larger compound for elephants at the seaside attraction.

The 38-year-old elephant named Lulu is the fourth animal to be relocated or to have died in the zoo's half-acre elephant compound this year.

The San Francisco County Board of Supervisors (search) said last week that elephants can only return when the zoo builds a larger elephant enclosure of at least 15 acres.

Animal-rights activists applauded the board's action.

"While no urban environment can meet the vast space requirements of elephants, the new San Francisco standards are an important first step in forcing the zoo to recognize and address the complex needs of elephants," said veterinarian Elliot Katz, president of the animal-rights group In Defense of Animals (search).

The zoo's director, Manuel Mollinedo, expects elephants to return at some point. He planned to seek bonds to help build new pens and was optimistic private donors might contribute to the project.

Animal-rights activists have sought closure of the elephant exhibit for years. The dispute intensified in April, when a 44-year-old African elephant died at the zoo. Earlier, zoo officials euthanized an 37-year-old Asian elephant because of a degenerative joint disease and other ailments.

In the wild, elephants may live 50 to 70 years.

Last month, a 38-year-old Asian elephant was moved to a 2,300-acre sanctuary in San Andreas, where zoo officials will soon relocate Lulu, an African elephant who is beset with health problems.