Just call them Endangered Series — those unlucky shows whose declining ratings are killing their chances of survival. Is your favorite on the list? Here's a rundown of the programs that might get the ax to make room for next season's new shows.NBCThe West Wing has chosen Jimmy Smits and Alan Alda as candidates for a post-Bartlet White House, and NBC has reelected Wing for a seventh term, but only after Warner Bros. reportedly offered to halve the show's hefty license fee. Ad-buying executive Tim Spengler believes the political drama's appeal to upscale viewers, which makes it valuable to advertisers, convinced NBC to finance another fictional presidential campaign. Other shows in NBC's danger zone: Third Watch, Medical Investigation and American Dreams. We hear Dreams stars Will Estes and Rachel Boston have already signed on to new shows rather than wait for cancellation. ABCSoon the alphabet net's initials could stand for "Anything But Comedy." With the exception of According to Jim, all of ABC's ratings-challenged sitcoms stand a chance of getting pink-slipped. Most vulnerable are 8 Simple Rules, Less Than Perfect and Rodney. CBSFans might want to say a prayer for Joan of Arcadia. Despite heavy promotion, the spiritual drama still hasn't attracted much of a flock on Friday nights. Ditto for the aging JAG, which might spin off a new military drama starring Catherine Bell's character. If JAG does return, it will do so without costar David James Elliott. FoxThe Bernie Mac Show's ratings have perked up lately, but a fifth season could depend on the star's health. Bernie Mac suffers from the rare respiratory illness sarcoidosis, and production had to shut down last fall when he was hospitalized. Meanwhile, low-rated Jonny Zero's chances of seeing a second season are zilch. UPNKevin Hill never lived up to ratings expectations and now finds itself on shaky ground. "The first show had a lot of buzz," Spengler says. "But the story lines just didn't catch on." WBGood reviews will not keep Jack & Bobby's term from being shorter than Gerry Ford's. The show has averaged a puny 2.4 million viewers a week. Steve Harvey's Big Time Challenge also could be running out of time. For more inside info on TV's Endangered Series — like Arrested Development, for one — read the March 20 issue of TV Guide magazine.