Bobwhite quail (Colinus virginianus) (N:9, aged 24 mo) were trained using a positive reinforcement paradigm to respond to an assigned "standard" frequency of either 1.0 or 3.5 kc/s by pressing a response key. Each S was trained in 2 phases to respond to its assigned frequency rather than to alternately presented tones of a different frequency. In every test each S discriminated its assigned frequency at greater than chance levels. Discrimination ability was poorest when delta F was at the minimum tested (0.25 kc/s). Birds whose standard frequency was 1.0 kc/s were better at the task than those trained to a 3.5-kc/s standard, especially when finer discriminations were required (Phase II). This superiority at 1.0 kc/s confirmed what was seen previously (Barton et al, J. Aud. Res., 1984, 24, 87-97) in the Bobwhite's audibility curve; it was hypothesized that the correspondence may have to do with the need for adult birds to recognize frequency variations near 1.0 kc/s that are uniquely made by immediate conspecifics rather than other members of the species. As such it may well represent a "fine tuning" of the bird's acoustic abilities.