Needs List, Cartogram Style

By josh • Maps for Birders • 28 Apr 2015

About a year ago I began futzing around with using chloropleth mapping to explore eBird data and had the thought that it might be fun to visualize where I need to go to find life birds within the ABA area.  I had a general idea that these birds would be to my south and west, but that’s pretty predictable because nearly everything is to my south and west!

I divided the ABA area into ‘birding regions’, which are a subjective melange of political boundaries, geophysical regions, and ecological regions.  My general idea was that these would be common sense areas that you might try to bird on a single trip.  Some (I’m looking at you, boreal forest, taiga, and tundra…) don’t fit that criteria well, but it seemed silly to create unnatural divisions in vast places like the taiga portion of the Northwest Territories.  Apologies if I’ve divided your part of the world in a nonsensical way- some places were easier than others.  I also added two Pacific waters pelagic regions and three in the Atlantic waters.

This was fairly tedious work, but I got a lot of practice using ArcMap editing tools, and now that I have the regions defined I can use them for other things.  Plus, it’s easy to see how this map can be dynamic as my needs list changes.

Then, using eBird data and range maps from Sibley and Cornell, I assigned a value of Code 1 and Code 2 species regularly (commonly? it’s relative to the species, really) found in each region.  I assigned a color ramp to symbolize how many potential life birds I might find in each birding region, ranging from green (as few as 0 lifers) to red (presently as many as 80 potential lifers).

Turns out there were few surprises, though the differences between regions were perhaps more extreme than I was expecting.  Well known birding destinations where I’ve spent little or no time, like southeast Arizona (80), south Texas (66), and the southern California coast (58) are responsible for the biggest numbers.  Three regions of Coastal Alaska are also not surprising.  I was intrigued, however, by how many species I need in the cordillera regions of Colorado and Montana, a few prairie regions like central North Dakota and southeast Alberta, and the Mississippi Delta region of Louisiana.  Now I just need to convince my family what a wonderful city Tucson is, and how much they’ll love the beaches around Harlingen!


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