The Killing Fields: The Rhino Poaching Crisis #IronViz

Note: This is a detailed post about the creation of my entry into the second 2017 Iron Viz feeder. In the post, I detail my thought processes, how I created various components, etc. If you’re not interested in all this, then feel free to jump to the end where you can find the final visualization.

Iron Viz Safari
It’s Iron Viz time again and the theme of this year’s second feeder competition is “Safari.” When I (and most of us in the Tableau community) think of visualizations involving plants and animals, I immediately think of the amazing animal vizzes of Jonni Walker. His work is just so incredible and his passion for animals is obvious. I’ve personally made a couple of attempts to create similar animal visualizations, creating one tardigradesand one on quokkas(I haven’t formally published this one yet but will soon), so I felt like I had a bit of practice here. I personally like what Jonni does in spotlighting a specific species, often one that is endangered. So, it made sense to do something similar for the Iron Viz competition.

Unlike this year’s first feeder, finding a topic didn’t take me long. Within a few hours of the announcement, I had decided that I would try to bring attention to the problem of rhino poaching in Africa. One of the first things I started doing was looking at images of rhinos which had fallen victim to poachers. I saw image after image like this one from the website, Lowvelder.

As I looked at these images, I grew increasingly disgusted that someone could do such a thing. At that point, I decided a couple things. First, the viz needed to be somewhat in-your-face—I could not shy away from graphic images like these because including them would help to show the reality of this crisis. In fact, images like these needed to play a key role in the viz. Second, this needed to be more than just a data visualization, but a call-to-action.

The Bloody Bar Chart
One of the first data sets I found showed the total number of African rhinos killed by poachers over the past decade or so. I immediately thought of the following infographic by Simon Scarr, which I first saw on Andy Cotgreave’s blog.

The point of the deep red down-facing bar chart was to create a feeling of dripping blood. I personally thought this would lend itself well to my viz. A quickly gave it a try but, unfortunately, I didn’t have nearly as much data as the above and it didn’t have the same effect. I then tried something else, drawing lines for each year going from zero to the total number of rhinos killed in that year (essentially a bar chart), but I sized the lines so that they started out wider at the top, then thinned out towards the bottom. It was definitely starting to look like blood, but still needed something more. For inspiration, I Googled “dripping blood” and saw this on a free clipart site:

This was just what I needed. From here, I cut off the ends of one of the blood drops and converted it to a custom shape. I then plotted the custom shape on the end of each bar. It looked great, but the top of the blood still wasn’t quite right. It was far too uniform and didn’t have the irregularities you’d expect of dripping fluid. So, finally, I did some additional photoshop work, turning the above image into a background image for the chart. The final version looks like this:

At this point, I felt it looked quite a bit like dripping blood. Of course, it’s probably a little dramatic, but as I noted above, the viz needed to be a bit in-your-face, and I felt that this would both grab the viewer’s attention and express the seriousness of the subject matter.

Population Data
At this point, I had spent way too much time on the “bloody bar chart,” and didn’t have a single other element of the viz complete, so I returned to looking for data. The IUCN Red List provided lots of great information about rhino populations over time, as well as information about their Red List designations (endangered, critically endangered, etc.). This allowed me to create two additional elements. First, I created a timeline showing the population of white and black rhinos over time.

Second was a map of Africa with bubbles indicating the rhino population in each country. For this, I used a satellite map from Mapbox. Unfortunately, I ran into a couple of problems here. First, I really wanted to show Africa only, without the Middle East, Europe, etc. Second, the water in the satellite map is various shades of blue and, no matter what I did with my viz’s background color, I could not get it to transition smoothly to the map. So, I decided to deploy a trick I’d used in other visualizations. I saved the map as an image, then, using an image editor, changed the water to black and stripped away all land except Africa. I then recorded the x and y coordinates of each African country I needed to plot. Finally, I changed my chart so that it used a background image (instead of background map) and x,y coordinates (instead of latitude and longitude). The result looks like this:

Horn Seizures
At this point, the viz was shaping up nicely, but I realized that it failed to explain the drivers for poaching. So, after doing some research, I realized that much of the demand is being created by countries like Vietnam, China, and Hong Kong where people use rhino horns in medicines, believing that they can cure just about anything. So, I began looking for data on rhino horn seizures, in hopes that it might give some additional insight to the countries involved. I eventually found a comprehensive data set on the Environmental Investigation Agency’s website which documented all known horn seizures over the past decade or so. For this data, I decided that a simple line chart and bar chart would work perfectly. The line chart shows kilograms of rhino horns seized over time and the bar chart shows kilograms seized by country (top 10 countries only). To highlight the prevalence of Asian countries, I colored the bars by continent.

Image Carousel
As noted earlier, I wanted to show some of the images that had so disgusted me. I remember seeing both Jonni Walker, Pooja Gandhi, and Adam Crahen use an “image carousel” at the bottom of some of their visualizations, so I reached out to Jonni to see how it was done. He graciously pointed me in the direction of a site called Cincopa, which allows you to easily create image & video slideshows, then provides a simple method to embed them. I uploaded my images and added the resulting image carousel to the viz. Clicking on an image will display a larger version.

Big A%$ Numbers
A recent trend I’ve been seeing a lot of is Big A%$ Numbers (BANs) to callout key metrics. I also noticed that Jonni Walker uses these heavily in his animal vizzes. So, I decided that would definitely be helpful. I picked a handful of key metrics then placed them in appropriate places on the viz. Here’s an example:

Call to Action
As I noted earlier, I wanted this viz to be a sort of call-to-action, so I felt it was really important to spotlight some organizations working on behalf of African rhinos and to give viewers a chance to take action. After doing some research and looking into non-profit groups’ histories and charity ratings, I chose to spotlight three of them, International Rhino Foundation, African Wildlife Foundation, and Save the Rhino. Clicking on the logos will take you to each organization’s website.

Finishing Touches
With all my major elements in place, the last steps were to add images, add text, arrange the components in a compelling way, and various other final touches. After completing these, I still needed a title. I finally came up with “The Killing Fields,” playing off the name of the 1984 film about the Khmer Rouge regime in Cambodia.

I’ve written enough, so here’s the final visualization. It works fairly well as an infographic, but the full visualization has some additional interactive components that help to provide further information and context. You can click on the image to explore the full visualization.  

Special Thanks to Jonni Walker
Before I end this post, I wanted to give special thanks to Jonni Walker. Not only did his incredible animal visualizations serve as inspiration for my own viz (and likely many others who will be entering this competition), but he also willing shared his knowledge, design tricks, data sources, and advice throughout the build of the viz. Without him, this viz could never have come together as well as it did.

Ken Flerlage, June 17, 2017


  1. This is brilliant Ken. I glanced at it when it was first released but now have had the time to review the viz and read the blog. There are just so many parts and so many tricks employed; it's beautiful, informative and has a nice flow.

    The standard for IronViz will have to be extraordinary for this to not be a serious contender. Great work!

    1. Thanks Charlie. I tried to up my game for this one and feel really happy with the result. Crossing my fingers!!

  2. Ken, its a great visualization. You have raised the bar too high for starters like me. And showed how great visualizations are done. Thanks for sharing.

    1. Thanks Vinod, but I'm still pretty new to this myself. My first ever Tableau visualization was just 1 year ago. So keep working with it!!

  3. Which font did you used for the title?. Thanks for the blog.

    1. The font is called "Scorched Earth". See

  4. Thanks for sharing Ken. How did you create the shape for line chart?

  5. Is Cincopa a free tool? Thanks for the viz Ken.


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