Figure 1.

Patterns of feeding activity of house sparrows under constant conditions after exposure to different photoperiods. (A) Activity recordings of two representative birds from the LD 8/16 group (Left) and from the LD 16/8 group (Right) during the last 3 days of synchronization (LD) and during the first week in continuous darkness (DD). (B) Mean (±SEM; n = 6) daily feeding activity times during the first week in DD. (C) Mean (±SEM) duration of daily feeding activity (α) during the first week in DD. (D) Mean (±SEM) period (τ) during the first week in DD. ***, P < 0.001; black bars, LD 8/16 group; open bars, LD 16/8 group.