1955 Aphelocoma coerulescens Oct 19 Queens Rd., Berkeley, Calif. Locally established pair present from Fairlawn past home, down the draw across and below Queens Rd.; center of activity is in Chapanal Island below Queens Rd. Today, calling heard indicating presence of roving individual(s) almost certainly 1st-year birds. Chase of such an intruder seen to begin below Queens Rd and to proceed up hill into eucalypts just above Fairlawn. Intruder followed by occupant (σ, judging by size), the two proceeding in flights of 50-75 feet, the occupant flying forward and displacing the intruder each time it stopped and even keeping close behind so that the intruder rarely had a moment to rest. This chasing and displacing of the intruder occurred over at least 1/2 m just with the chaser stopping and calling into eucalypts just above Fairlawn. Female (smaller, weaker r higher pitched voice) followed, calling also and perching along Fairlawn. Oct 25 Strange joy calls above Fairlawn: occupant joy present below home flew up to post-top along Fairlawn, calling in flight and from post-top. No encounter followed. Fairlawn evidently marks approx. upper limits of the territory of this pair.