Over-ocean flocking by Pacific dunlins. Graphical summary of over-ocean flocking observations by DD made in January, 2006. Columns are successive days, with time given on the y-axis. The horizontal line in each column gives the time of high tide, and the shaded portion indicates the duration of over-ocean flocking. Further details in the text.
Ydenberg et al. BMC Ecology 2010 10:1 doi:10.1186/1472-6785-10-1