Study area is a polygon feature class showing the extent of where most of the bird sightings were recorded and then used in the atlas. A few rare species have been included as well that go beyond this area.

Sidney Island Shorebird Surveys transects area feature.

Rare species is a point feature class containing rare species sightings.

Grids surveyed is a polygon feature class containing the 5’ latitude by 5’ longitude grid cells surveyed for all seasons combined including the grids that were surveyed but where no species were seen. In order to produce maps for a specific season a selection for these grids must be performed.

Survey points is a point feature class containing transects and observations completed in 2011.

Average grid cell density is a polygon feature class containing the average density value for each grid cell per species/groups and season.

This polygon outlines the basic area included in the survey counts. This area is the best approximation of the mudflat that can be surveyed from shore and is exposed at tide tide height of 3.5 m, based on tidal predictions at Point Atkinson, British Columbia.

Survey transects is a line feature class containing transects completed in 2011.