FAIRFIELD, Calif. — Wildlife officials are proud of their work at the Grizzly Island Wildlife Area. Their herd of tule elk has grown to more than 100 since seven from the Owens Valley were introduced to the area in 1977. And the herd is still prospering.

River otters still swim playfully in the meandering waterways, home also to giant white sturgeon and striped bass. Eagles and hawks soar over sprawling wetlands that support millions of giant-sized jack rabbits, all wide-eyed and alert to the dangers of the territory.

Nature's ways are evident. But man's are becoming increasingly evident, too, which concerns officials.

They say rampant development results in overcrowding and pollution. Furthermore, the growing inability of hunters and fishermen to provide adequate funding for wildlife management and land acquisition makes it more difficult to protect the fragile areas.

"We have 28 million (people in California) going to 40 million by the year 2010," Director Pete Bontadelli said. "Clearly the pressures on wildlife are greater than anything we've seen before."

Given these projections, Bontadelli said the state's ability to manage existing wildlands, and the opportunity to make future land acquisitions, is becoming more restricted. In short, revenue isn't keeping up with the rising costs of wildlife management.

The grizzly bear, California's proud symbol of strength, is long gone, and officials fear more species native to the state might also become extinct. The kit fox, bald eagle, and peregrine falcon, to name a few, are endangered.

Fortunately, through bond issues over the years, Californians have helped the state set aside about 400,000 acres of precious wildlife habitat, which Bontadelli said supports many of these endangered and threatened species. He claims, however, that such land is becoming more difficult to maintain.

Another problem DFG officials might have to address in the near future involves a proposed cap on federal aid to the various states for wildlife management. If the proposal--included in the Reagan administration budget for fiscal 1990--is passed by Congress, there would be $100-million caps on both the Dingell-Johnson and Pittman-Robertson funds, federally relegated funds that support the states' wildlife agencies.