A Watergate legend, former senator Sam Ervin, yesterday spent his seventh day in Grace Hospital in Morganton, N.C., where he is being treated for a persistent high fever. The 88-year-old Ervin, who suffers from an array of ailments, including cancer, reportedly is alert and feeling better in spite of the fever. No decision on when he will be able to return home will be made until doctors are able to deal with the stubborn fever . . .

Actress Elizabeth Taylor was released from St. John's Hospital in Santa Monica, Calif., yesterday after being treated for her back problems. The hospital refused to say more about her ailment . . .

Villagers in Ireland, concerned that a Bruce Springsteen concert may cause the same sort of rioting that broke out last year at a Bob Dylan concert, have voted against giving permission for Springsteen's show. The open-air concert had been planned for sometime in June on the grounds of Slane Castle, 30 miles north of Dublin. . .

Sixty members of the "My One and Only" cast and crew showed up for a party in their honor at the Black Horse Tavern late last week, including the stars, Sandy Duncan and Tommy Tune. After they ate, the cast put on a small show, dancing energetically throughout the room. That is, everyone but Tune, who works pretty hard in the show, and who undoubtedly had had enough dancing for the evening . . .

A sex survey has been taken in France and the finding is that most of those interviewed said they enjoyed their lovemaking on an average of two to five times a week. Most of the men complained, however, that that wasn't frequent enough. The best statistic was that half of those questioned refused to answer how often was often enough, aware obviously that sex is something you do not discuss with strangers, or a gentleman never tells . . .