Bar Charts
To learn when species most often reported, tap Bar Charts on the main Explore page, or tap the "Bar Charts" link on any Region or Hotspot page.
You can change the date range or location of the Bar Chart data by clicking the corresponding buttons at the top of the page.
From the Bar Charts tab, click the:
- Species name to visit the species page
- Map icon to see the map of eBird reports for that species
- Chart icon to get detailed histograms and line graphs of frequency and counts throughout the year
Reading Bar Charts
eBird bar charts are based on frequency: the proportion of complete checklists reporting that species within a specified date range and region.
Taller bars indicate a species is reported on a greater percentage of checklists. Thus, the taller the bar, the more likely you will encounter a species during that time of year. No bar (an empty gray box) indicates a species is not reported in that region during that time period. The current date is always marked with a vertical line.
Downloading Bar Charts
Raw frequency values can be obtained by clicking the "Download Histogram Data" link at the bottom of the bar chart. Below are the frequency "bins" that correspond to each bar height.
| Bar Height "bin" | Frequency value range |
| 9 (tallest bar) | 0.6 - 1.0 |
| 8 | 0.4 - <0.6 (e.g., 0.5999) |
| 7 | 0.3 - <0.4 |
| 6 | 0.2 - <0.3 |
| 5 | 0.1 - <0.2 |
| 4 | 0.05 - <0.1 |
| 3 | 0.01 - <0.05 |
| 2 | 0.003 - <0.01 |
| 1 (narrowest bar) | >0 - <0.003 |
| No bar | 0 |
Printing Bar Charts
Line Graphs and Histograms
eBird's line graphs and histograms (accessed by tapping the chart icon on Bar Charts) are particularly useful for comparing reporting rates across multiple species and dates.
- To add more species to the same chart: click the "Change Species" button
- To compare data for a single species across a range of years, click "Change Date" and select "Separate years (max. 5 years, 1 species)".
You can also download histogram data directly from these pages.
