I am mapping radio telemetry detections of shorebirds using ggmap. I want the map to depict a specific point (lat/lon) where the bird was detected. I want this depicted date of detection to be represented by a color scale. However, multiple birds are detected at the same telemetry tower (lat/lon) but at different dates. To avoid masking detections due to multiple birds being detected at the same point at different dates I would like to include a graduated point that will change size based upon the number of individuals detected. The goal is to show what date a bird was detected at a telemetry tower and how many birds were detected at that telemetry, using a color scale and graduated symbol. My thought is to have the graduated color symbol stack on itself... larger symbol on the bottom and the smallest on the top. p<-ggmap(gmap) p+geom_point(data=df.tmp,aes(recvLon,recvLat,color=as.Date(ts),size=2)+scale_fill_gradient2(low="yellow",mid="orange",high="red") I expected the map to portray the color gradient I called, but the color scale is a range of blue (dark to light)? I get no errors and the map shows a color scale of the time stamp like I want, but not the actual colors I want. Also, I do not know how to combine a graduated symbol with the color scale? *Joshua N. Barth* [[alternative HTML version deleted]]