New Tool: Explore eBird Data on Maps!

The following discussion walks through the mapping options available in eBird. For you long-time eBird users, some of this will be familiar and you may want to skip down to 'Part 2: Point Maps' to read about the new interface just released in 2009.

How to use eBird maps--Part 1: Grid Maps

To find the maps in eBird simply go to the 'View and Explore Data' tab and select the top left option 'maps: Grid or point maps for up to five species.' You will then be prompted to type a species name (or several species). If you type Ferruginous Hawk, you will get this map (Fig. 1):

Fig. 1: eBird grid map for Ferruginous Hawk for all years.

These are the eBird grid maps, which summarize frequency (darker green indicates higher frequency) in 100 x 100 km grids. The gray areas indicate regions where we have eBird data but no reports of the species; the beige and blue background colors show areas where we do not (yet) have any eBird checklists. So if you have birded on the Hudson Bay shoreline of northern Ontario, we'd love to get your data!

These maps are updated each night, so the records you just entered may take a day to show up. Please note that these maps default to show the last five years of data. To see a summary of all years, you will need to click the 'Change date' button at the top of the map: compare a map of Bewick's Wren for the last five years with the one for all years and note the complete absence of recent records in the East (that population was extirpated by about 1985.)

 Fig. 2: Grid map of Great Knot for all years

What if you notice a stray green square on a grid map and want more information? This is a question for the eBird point maps!

Part 2: Point Maps

Starting again with the Great Knot map (Fig. 2), let's say you were rightly intrigued by the light green square in West Virginia (it is tough to see in this image). If you then click "Change location" at the top of the map (see Fig. 2 above) and select "West Virginia", you will see a point map with a red balloon indicating the site of the Great Knot record. To get more information, left-click on the balloon itself and you will get the full story straight from the eBird database: two observers saw this species at Winfield Locks & Dam on 13 Aug 2007!

Fig. 3: Point map for Great Knot in West Virginia

This bird was well-photographed (only validated eBird sightings appear on the maps) and confirmed by experts. Now what if you want information on Ivory Gulls in Massachusetts? You can follow the same procedure to pull up the information for Ivory Gull and then refine the location to Massachusetts, getting the map below (Fig. 3). This is a great way to get current news on recent sightings: the most recent month's sightings are highlighted yellow. At this writing (21 Jan 2009), there are gorgeous adult Ivory Gulls in both Gloucester and Plymouth, Massachusetts! 

Fig. 4: eBird point map for Ivory Gull in Massachusetts for all years.

You will note that these maps do show the variety of spatial accuracy that eBirders use (and that we allow), since there are multiple balloons referring to a single bird. Some records may be plotted at the town or county level (we exclude state level submissions from this map), others may be plotted for the nearest hotspot or an "all encompassing hotspot" (e.g., Cape Ann), while still others may plot the precise location.

Fig. 5: eBird map of Red-footed Falcon reports for Martha's Vineyard, Massachusetts.

In 2004 North America's first Red-footed Falcon created a stir on Martha's Vineyard, spending several weeks at the Katama Airport in Edgartown. But note that eBirders that have reported this bird have not been consistent in where they plotted it. This was not because the bird moved around: it was always seen in the vicinity of the airport. The reports at the town (Edgartown) and county level (Martha's Vineyard is its own county: Dukes) are the reason for two of the out-of-place red balloons, but many others were just plotted inaccurately. With new location management tools in eBird, it is now possible to move locations relatively easily to correct these inaccurate plots. Ideally, we would want maps such as these to show a high level of spatial accuracy rather than this shotgun scatter across 10 square miles! 

A couple things to remember about these eBird point maps. First, please note that these maps are live: as soon as you enter your data, it will be shown on this map. Second, note that when two locations are plotted very close to each other, they can obscure one another. If you are looking at information for Dovekie from Gambell, Alaska, you may think that there are surprisingly few records in the one balloon visible. But when you zoom in you can see that there are several locations that obscure one another and many more records than you originally may have thought.

Fig. 6: Crested Auklets at Gambell, Alaska.

Finally, please note that we cannot list all records of some species at some locations, such as Crested Auklet from Gambell, Alaska (Fig. 3). Note that by page 3 we have listed 45 records and there are 164 more to go!

On both the grid maps and the point maps, you can explore more about the data summarized on the map by clicking the various other tabs (see Fig. 2): frequency, abundance, birds per hour, average count, and high count.

Using the bar charts to explore the maps

Another very handy way to explore the eBird database is to pull up a bar chart for an area of interest, such as Arizona and explore from there.

Fig. 7: eBird bar chart for Arizona

The Arizona bar chart displays about 515 taxa of birds and each one is highlighted blue. What happens if you click on those blue bird names? You are taken straight to the eBird point map for that species! Try it to see a map for Elegant Trogon, Five-striped Sparrow, or some other favorite Arizona bird. The great thing about exploring this way is that you can simply click the 'Back' button on your browser and be back at the bar charts and on to the next species of interest (like Painted Redstart!)

Sometimes there are personal, privacy, or concerns for sensitive-species that may mean that you would wish to exclude your records from these eBird maps. This is possible by editing the Observation Report and is discussed under eBird's Data Privacy Issues. In general, eBird data is most useful and most powerful for science and conservation when it is publically available; we leave the ultimate decision about hiding data in your hands.

How to get around on the maps

The mapping interface is not necessarily intuitive for everyone and we do field frequent questions about how to use them within eBird. When you enter data using "Find it on a map" and explore data using the eBird point maps, this is a Google Maps interface, and is essentially the same as what you get via maps.google.com. Here is a quick primer to using Google Maps most effectively.

Fig. 8: eBird point map for Thayer's Gull in Kansas for all years.

Refer to the map above for this review on how to move around the eBird Google Maps interface or left click it to pull up the map within eBird to follow along with the instructions below.

1) View type: The top right of the map gives four view options (the default is "Hybrid"). Click around and see which view you prefer.

2) Moving the map: By clicking and holding the map, you can use your mouse to scroll around on the map. Another way is to click on the arrows (left, right, up, down) at the top left corner. The center button in this array, with a bunch of arrows pointing towards the middle, returns you to the original zoom state.

3) Zooming in: There are several ways to zoom in on the map. First, you can double-click with your mouse ,which takes you roughly twice as close. Second, you can center the map on the region you want to zoom in by using the scroll bar on the left: the '+' takes you closer and the '-' zooms back out. Our favorite way to quickly zoom in is by clicking the small magnifying glass left of the scroll bar on the left side of the map. Once you have clicked this, you can click and hold your left mouse button to set the corner of a box and then when you release, the map will zoom in to a box of that size. Do not simply left-click or the map will zoom in on a very, very, very small box!

4) The balloons: On the eBird point maps, the yellow balloons show the records from the past 30 days, while the red ones show the rest of the records. Left click on any balloon to get summary information from that point. Note that for points with large amounts of data, there is a three page limit to the information. For balloons with a plus symbol (not shown above) that indicates a large number of points below; simply left-click to zoom in and see all the points.

Now that you know how to use the maps, pick some favorite species and explore what the eBird data has to show. There are certainly innumerable interesting patterns to be discovered; for example, note how closely the distribution of Prothonotary Warblers in Maryland follow rivers and streams (e.g., the Potomac, Pocomoke, and Patuxent Rivers). Enjoy!