American Birding Podcast



Google Earth / Google Map Your Christmas Count Circle!

Christmas Bird Count season is upon us, and I hope you have one or more counts to look forward to this year (if indeed you aren’t already out counting!!)   A couple of years ago I summarized how to electronically map Christmas Bird Count circles & territories over on my personal blog, BrdPics.  Here’s a boiled-down summary of how to get your CBC maps on Google Earth (free download) &/or Google Maps (online.)

I’ll start with the steps to get your map in Google Earth, summarized from a post by  Bootstrap Analysis.

  1. Get the Lat/Long coordinates of the count circle center. You can get this by hovering your pointer over the spot in Google Earth and noting the coordinates, or you can get the coordinates that are on record with Audubon through the compiler’s page (although many of these aren’t too accurate, having been estimated from paper maps lacking very good resolution. National Audobon is requesting updated count center coordinates and descriptions-see here.)
  2. If your Lat/Long is in minutes/seconds then you will need to convert them to decimal- easily done here. (Note that if you acquire the coordinates from Google Earth they will already be decimal if you set that format in the preferences- also the default setting, I think.)
  3. Link to the free KML Circle Generator, plug in your center coordinates, and set the radius to 12,070.08 meters (the equivalent of 7.5 miles.) This will return a link that you follow to download a .KML file (a map element) which will open in Google Earth as a nice circle demarking your count boundary. Right-clicking on it and selecting “Properties” (or “Get Info” on a Mac) will let you re-name it, change the color, change the thickness, change the opacity, etc. to your liking.
  4. Update:  the above link isn’t working (thanks for the heads-up, Mike!)  Try this instead:
  •  link to:
  • Input your circle’s center lat/long
  • Input your radius:  This site takes kilometers so use 12.07008 km
  • Click Draw Radius- a preview will appear on the map.
  • If all appears good, scroll down a little and click Generate KML
  • Open your downloaded .KML file in Google Earth.  Here you can edit your circle preferences such as changing the line color & thickness, selecting (or deleting) any fill color, etc.

If you want, you can use the line, polygon, and placemark tools to further divide and/or organize your circle. I also put a placemark at the count center. Now you’ve got a collection of map elements that you can save as a .KMZ file by right clicking on the folder and choosing that option.
The saved .KMZ file can be sent to others by email, shared by memory stick, or posted on a hosting site for folks to download.  Recipients clicking on it will open the map in their own Google Earth.
.KMZ files can also be opened in more sophisticated GIS software.  This can make your map very useful to other land managers interested in the data your count produces.  For example, I’ve been working with the City of Boulder Open Space & Mountain Parks to coordinate our efforts on their properties.  They were able to use my Boulder CBC .KMZ file as a layer in a map that also overlaid their properties, trails, and especially their protected areas requiring permits for special access.  They will be now able to associate count results from various territories to the specific areas where wintering birds have been found, giving more detailed analysis potential than using just the whole count circle data.

Chris Hill let me know that he uses Google Maps to set up his count circle territories, citing the ease of sharing the maps and for the potential of letting others add to the map, too. The only hitch seemed to be getting a good 7.5-mile radius circle drawn- Google Maps has line & polygon tools but not a circle generator. Curious, I did a search and it turns out that you can import any .KMZ file that Google Earth generates into Google Maps- easy directions are posted on the Google Lat Long blog. Badda-bing, badda-boom! The best of both worlds- you can work up your circle &/or territories in Google Earth, import it into Google Maps, and then share the URL with whomever. You can even embed the Google Map in your blog or other web page.


Google Earth screenshot of the Boulder CBC count circle & territories (click to enlarge.)

Zoomed-in detail of one territory (click to enlarge.)