Focusing in on eBird

There is little question that eBird, an online database of crowd-sourced bird observations, provides a remarkable resource to find birds of interest in a certain area or at a given time. Ordinary people, like me, use the eBird data to scout recently seen species in areas that I plan to visit. Researchers use the data to investigate relationships between bird abundance and climate change or seasonal weather patterns. Recently, eBird data has been fundamental in defining migration patterns for a number of bird species, and, unfortunately, the decline in bird species numbers.

Started in 2002 by the Cornell Lab of Ornithology, eBird has matured into a worldwide database.  As of December 2019, more than 500,000 eBirders (people who submit to eBird) have contributed over 737 million bird observations to the database. eBird is known as the world’s largest biodiversity-related community science project. If you are an eBirder, thanks for your contributions.  If you aren’t currently using eBird to record your bird observations, you might consider setting up a free account at the Cornell Lab website so you can begin to track your observations and add them to the global database.  You can enter data online or through a mobile device. There are even data entry kiosks at a few well-known birding areas. 

Being a bit of a data geek, I was curious about the bird observations that have been entered into eBird from the NCWAS four-county area (Chelan, Douglas, Ferry, and Okanogan). I applied to Cornell for access and was quickly granted permission to download all the data from our area. After I stored the data files on my computer, I began exploring.  Some of my initial observations are provided below.

  • There are 1,133,171 individual bird observations in the combined datasets.  The datasets include hybrid species (e.g., Coopers/Sharp-shinned) and generic designations (e.g., Accipter sp.). 
  • People have entered observations that were made prior to 2002 when eBird was created. The Chelan County data contains a few records as early as 1900. In general, though, the data records begin between 1967-69 for all four counties. 
  • There are gaps in the annual records of some of the datasets.
  • eBirder names are anonymous.  Each observer has a unique Observer ID.
  • There are 5,512 unique eBirder Observer ID’s in the database for the NCWAS four-county area. Since many people bird in more than one of the four counties, there is considerable overlap of Observer ID’s between counties.  Given that, there are 2,223 unique observers listed in the Chelan County data, 1,064 are listed in Douglas County data, 378 are listed in Ferry County data, and 1,847 are listed in Okanogan County data.  While the number of birders is a small percentage of each county’s population, there are a lot of people out looking at and counting birds.
  • 791 people entered bird observations from the four-county area into eBird in 2020.  So far in 2021, 673 observers have entered data.
  • 270 species are documented in 2020.  That is about 52 percent of the 520 species listed by the Washington Ornithological Society for Washington State. 2021 already has 260 species recorded within the four-county area.
  • The most commonly entered species in 2020 was the American Robin.  The species that were entered only one time include: American Bittern, Ferruginous Hawk, Glaucous Gull, Iceland Gull, Indigo Bunting, Ross’s Goose, Swamp Sparrow, and Willet. One might think that a single observation of a species could be an error or a prank. It is important to know that eBird uses local authorities to review data that is submitted to the database. If a reviewer thinks that an entry is suspicious or mis-coded, they will challenge the observer to provide additional support for the observation.
  • In 2020, one observer saw 223 species in the NCWAS four-county area. In that same year, 76 people saw and entered 100 or more species.

One question I had about the NCWAS area eBird data is “how many unique species are seen and documented in our area each year?”  I also wanted to see if the data showed the relative abundance of species observed each month of each year.

I analyzed the 2020 and 2021 datasets. The 2021 data includes January to early June. Complete lists of species seen, by month, in 2020 and the first half of 2021 can be found on the NCWAS website. The alphabetically arranged 2020 table is here, and the 2021 table can be seen by clicking here.

One page of the table of species recorded in 2020

You can view, download, or print the information, organized by taxonomic Family. Start by clicking here.

One of my motivations for analyzing and presenting the eBird data from our area is to encourage people to make use of eBird. I’ve learned about how the data is used to help understand our birds and what affects them. I’d like to help with the scientific understanding of the population diversity and dynamics of the bird species in our area. I think it would be great if you would join the crowd-sourcing effort by entering your bird observations into eBird.  You can start by going to www.ebird.org to create an account.  It’s free.  Any observations you enter will contribute to the global database. Each observation is important to a greater understanding of our birds.