“Tarzan” Oscar winner Phil Collins, 50, and his third wife, Swiss-born Orianne Collins, 28, have had their first child together, the star’s publicist announced in London on Tuesday. Nicholas Grev Austin was born Saturday in Geneva, Switzerland, where his parents (who have been married for two years) now live. “It is difficult to express just how happy Orianne and I are with the arrival of little Nicholas,” said Collins, whose 1999 “You’ll Be in My Heart” took the Academy Award for best song. His spokeswoman said that British rocker is currently working on a studio album and a new animated feature for Disney. Collins is also father to Simon, Joley and Lily, by his first two marriages.