Feb 11. 3 mi. ESE Del Valle. a few feet to the E of me. Then the bird flew across the path in a NW direction and began to sing. I fired at it twice with .38 without apparent concern to the bird. A third shot brought it down (712, 5?). No other thrice noted immediately afterward. After 10:30 I worked back up Drion Creek to point where I had taken 709. Further search revealed no trace of a second titmouse so I started up tributary. A squabble between 2 pairs of chickadees was in progress and beyond them a thrice scolded. I approached and fired with a .38. The bird flew W and I tried a load of 10's -- bird worked down the tributary, scolding. I followed to Drion Creek where I heard scold and saw 2 thrice fly back up tributary as I maneuvered for a shot. I followed again and caught up with a scolding thrice. I whistled and it answered and appeared excited although never fluttering wings. I waited to see other bird but never located it. Meanwhile enthusiasm of singer waned and I lost track of it. I left area at 11:20. Titsmouse singing from base of hill as I drove up. I worked along the level "mesa" top after 11:45 - growth of deciduous oaks, junipers elms; titsmouse singing from several scattered points. The grove of deciduous oaks and elms and of junipers lay at the W end of an open pasture. The grove was a narrow fringe at the W edge of the mesa and