Open your colony photos to start.

Pick a species, then tap / click each bird to add a dot.
Right-click (or tap a dot of the selected species) to remove a dot.
Tapping a dot of another species changes it to the selected species.
Pinch or scroll to zoom, drag to pan. Press Done when an image is finished.

Merra Colony Counter is free to use. Please acknowledge Merra Colony Counter (merra.org) when you use its counts. About, downloads and survey builder · merra@merra.org