Environment : Notes about your surroundings.

BLUEBIRDS: For two years now, Dick Purvis has been working to ensure that Orange County’s western bluebirds have places to nest. The birds used to have easy access to the woodpecker holes where they build their nests, but since the introduction of two non-native bird species to the United States--the house sparrow from England and the European starling--bluebirds have been losing out in the competition for suitable nesting sites. Dwindling habitat is another factor: bluebirds prefer moist, open savanna with scattered trees.

Purvis, a volunteer from the local Sea and Sage chapter of the National Audubon Society, has placed more than 100 nest boxes throughout the county in the past two years. So far he has been “delighted” with his success: In 1987, 25 pairs of western bluebirds nested in his boxes (many nesting twice), up from eight pairs in 1986. The secret is that the entrance holes to the boxes are large enough to accommodate the bluebirds but too small for the starlings. Two of Purvis’ most successful areas are Green River Golf Course east of Yorba Linda and the Holy Sepulcher Cemetery in Orange, landscaped areas that simulate the birds’ natural habitats.

The bluebirds are nesting now, and Purvis expects to have a 1988 count in a few weeks. He fears that the dry winter may have cut down the number of bluebirds in the county this season. “But you never know,” he added. “I could be surprised.”