I am woking with FCS and would like to make maps depicting changing wildlife populations over time. I have seen this effect many times but I have no clue as to how to do it. Normally it is a semi transparent color layered over a map and it changes size and shape or color.
This is for a salmon video. We are in Alaska. Thank you, mark.

I have made animated maps using a layered Photoshop file where I import into PremPro "as a sequence" (not merged) and then use wipes on the overlay to show progress on a road (or in case of the Columbia River floods, the water/mud layer). Not exactly your application, but it can get your creative juices going.

I am woking with FCS and would like to make maps depicting changing wildlife populations over time. I have seen this effect many times but I have no clue as to how to do it. Normally it is a semi transparent color layered over a map and it changes size and shape or color.
This is for a salmon video. We are in Alaska. Thank you, mark.

What are you using for source content for the maps? Talk to a GIS person if you are using real data to make the maps. A GIS person should be able to output you a video file from that map data.

(Funny.. but I am going back to school to take GIS this fall. lol)

They have GIS here at this watershed council where I am doing the video. I will talk to them. Thanks for the suggestions.

If you want to do it direct-to-camera outside of Photoshop or NLE, - Some years back I did a B/W satellite weather photo printed on thin thermal fax paper stuck to a lexan sheet on a stand, backlit through the paper by a lamp below and a set of lamps above to light the print detail.

I used the backlit gels, cut to coastline shape under the paper on bottom side of the lexan sheet, red for the landmass and blue for the ocean. Didn't look too bad to reversal film at the time.

You might be able to lock a paper map on top of a lexan sheet on a stand and animate backlit gel pieces beneath it.

Use cooking oil or water to make the gel stick to the lexan. If you have a spare map, you may be able to soak that in cooking oil to make it more translucent and let more backlight through. Inkjet print may be ruined though.

If you have After Effects, that might be an easy way. Manipulate masks over time to illustrate your changes. Photoshop might be easier but I've never done it that way.