Aaron Koelker’s map of map turtles is one of our favorite examples of how shape can influence and enhance a map. For our next Behind the Map, we spoke with Koelker, a member of the Geospatial Services team at New York’s Office of Information Technology Services, to learn how he transformed an idea into a memorable visual experience.
Maps.com: What inspired you to create this unique and creative map?
Koelker: I got the idea for a map turtle map several years ago while on a visit to the Flint RiverQuarium in Albany, Georgia. They had a Barbour’s map turtle on exhibit there and some info about their limited range and vulnerability. As one might expect, a turtle that both looks like a map and is named after maps immediately resonated with someone like me, a mapmaker. I also like puns, and sensed potential.
But it wasn’t until a couple years later, when I happened to be reading about the “World Turtle” and the expression “turtles all the way down”—for some reason or another—that the idea clicked. The plan was to make a giant visual pun, with a turtle carrying the world(s) on its back and having hexagons within hexagons for a repeating, turtles-all-the-way effect. I hoped the overall layout would be amusingly memorable and catch the reader’s attention long enough for them to learn a bit about the turtles.
Maps.com: How did you build this map? Were there any notable tools and techniques?
Koelker: The map was primarily made using ArcGIS Pro and Inkscape (an open-source vector graphics program similar to Adobe Illustrator). The individual maps (or small multiples) were created in ArcGIS Pro, while the surrounding turtle design and text were done in Inkscape. The range data was created manually, as I couldn’t find consistent data for each species in a convenient digital format. Thankfully, I came across a book (and free PDF) from the IUCN Turtle Taxonomy Working Group that inventoried turtles around the world, and which had images with ranges for each. So, I quickly georeferenced each image in ArcGIS Pro and manually selected the overlapping bins within a hexagon grid I generated—not terribly accurate, but good enough for this case, given the small scale and relatively large bins.
The hexagonal frame for each map was done right within an ArcGIS Pro layout by using the Polygon frame option instead of the default Rectangle when inserting a map frame. The turtle shell and skulls were drawn manually (lots of clicking!), and the background texture is a Turing pattern created using a repeating series of filters. You can do this in any image editing software like Adobe Photoshop or GIMP by rendering a basic cloud pattern, then using a series of High Pass, Threshold, and Gaussian Blur filters over and over again until the pattern emerges. Like magic!
Maps.com: Did you encounter any unexpected challenges along the way?
Koelker: Early in the process, I needed to know how many species of map turtle there were so that I could plan the number of maps and the shape of the shell, but it was surprisingly difficult to get an exact count. There were so many different online papers, ebooks, and articles available to me that you’d expect it to be easy, but these sources often seemed to contradict each other on counts and names. Some species had multiple common names or names used only regionally; others were referred to as subspecies in one text and an independent species in another.
Wikipedia, after everything, does have the right answer if you happen to look there (fourteen), but I would be remiss if I relied on Wikipedia to have the final say on anything. My eventual savior was not online, but at a local library—a book dedicated entirely to map turtles, which isn’t available in a digital format. I think I was the first person to ever borrow it! So even with ebooks being so commonplace now, don’t forget to still check out your local library for those hidden research gems that you can’t find anywhere else.
Maps.com: If you could change or tweak this map, are there any updates you’d make?
Koelker: While I am overall happy with this map as both a novelty and a fun experiment—I do think it has some big flaws. The readability isn’t quite there, and in hindsight, it sacrifices a bit too much functionality for the sake of the form. If I attempted it again, I would try to find a better balance between the two.
The idea of the shell layout is what appealed to me most, but a lot of the map ranges within are a bit too small to read without getting quite close—even when the map is printed at its original 24″ x 36″ size. I tried experimenting with different scales and extents for each map, depending on the distribution of the species, but then it became difficult to tell which geographic regions were being shown, and it ruined the overall effect of the shell pattern. I was really attached to the “hexagons within hexagons” idea at the time, but I think it would probably benefit the map to ditch them for something else that’s easier to read from a distance.
Maps.com: How did you get into mapmaking?
Koelker: I think maps have become a sort of crossroad for a lot of other things I’ve always been interested in. I’ve had a creative itch since I was a kid and have spent most of my free time drawing things, building things, or thinking about stories. And I’ve always had an interest in history, geography, conservation, and science. Maps are a useful outlet for all of those things, and I like that they can be just as creative or moving as any other art form, while having an added element of functional practicality that appeals to me. It feels good making something that someone might consider hanging on a wall, but which also has the power to teach and inform.
Maps.com: Do you have a favorite map?
I’m too indecisive to choose an all-time favorite map, but I’ll point out one of many that I admire: The Ribbon Map of the Father of Waters, by Coloney Fairchild & Co (1866). It’s just 2.75 inches wide but nearly 11 feet long, and winds up into a small container meant for tourists cruising the Mississippi River, covering everything from the Gulf of Mexico to just north of Ft. Ripley, Minnesota.
In one sense, I kind of just love the absurdity of it, but I also appreciate how it retains so much accuracy and detail at one scale while being almost totally decoupled from real-world geography at another. The Mississippi is nowhere near that straight, but for this use case, it doesn’t matter, since your only perspective (on the boat) is relative to moving up or down the river. In that way, it’s sort of similar to modern transit maps, except with the added benefit of retaining some of those extra geographics details you can follow along with from the boat, such as distinct river bends, islands, and confluences. I like the idea so much that I’ve made a few ribbon maps of my own that are inspired by this one and others.
Maps.com: What’s up next in terms of your mapping projects?
I’ve just moved to upstate New York, so my recent projects have mostly been excuses to learn more about what’s around me and my new home. I’m in the middle of a couple of projects at the moment. One is a map of historic canals in upstate New York. The Erie Canal is, of course, the big one here that everybody knows, but you can find the remnants and impact of other canals all over. This part of the state was pretty much built on them.
The other project is a story about glacial refugia (places where a population of organisms could survive through harsh, ice-age conditions) and a rare, local plant here that survived through them. I’m experimenting with a watercolor style on that one. Both projects have been a great excuse to drive around and explore new places and do some in-person research.
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Aaron Koelker
Aaron Koelker originally hails from Florida but is currently living in Ithaca, New York, where he recently joined the New York State Office of Information Technology Services Geospatial Services team. When not making maps, he’s either pursuing some other creative outlet or pretending he can fly-fish.
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