A SPECIAL REPORT: BIRDS

LONG GONE: Orange County is a hot spot for birders, thanks in part to its location along the Pacific Flyway migration route. Bird counts have turned up more than 200 species in a single day. . . . But some once-common breeding birds have been forced out by, among other things, development. Fresh-water marshes and streams were especially hard hit, and such birds as the willow flycatcher and the yellow-billed cuckoo long ago stopped breeding here. But last year, a pair of least Bell’s vireos nested in Irvine, the first to nest here in years. . . . Another bird that was once seen in Orange County but no more: the California condor.