It has come to my attention recently that I made one of the cardinal (pun intended) mistakes of data viz. I didn't get to know my data very well. I overlooked the fact that the data I received has all the types of activities, regardless of whether or not the animal being observed engaged in that activity. There was a field labeled status that informed you whether or not the animal was actually observed engaging in that specific activity. Well, I overlooked that basic information. So I went back when I had a couple of moments to spare while waiting for reports to download and fixed the viz.
Here is the accurate version...
There are far fewer birds now and I can actually size the map icons so you can get a very general idea of the number of observations for a particular location.
I was always rather pleased with this specific viz, so I am glad to have a more accurate version of it now.