Byrd back on the Senate floor

Sen. Byrd returned to the Senate Thursday.

(CNN) – Sen. Robert Byrd made a surprise visit back to the Senate Thursday, a month after the 90-year-old Democrat fell in his West Virginia home.

Byrd was greeted warmly by many of his Senate colleagues and used a wheelchair and a walker to move around.

Byrd is Senate president pro tempore, a position that makes him third in line for the presidency, behind Vice President Dick Cheney and House Speaker Nancy Pelosi.