Activity information related to area

[wbazant]

On the live site, there is a 'foraging range' setting for a user, which then allows showing activity in that particular place. We could carry it forward to the beta site, but activity information for an area could be more generally useful.

Information on when activity happened is useful for understanding the map, especially that the site is ten years old, and locations change. Given an area, a user might like to:

• view summary stats similar to the counts of types
• filter on activity dates
• order the list by last edit date

Not necessarily something to try solve right now, but we can start collecting ideas!