What do we do when you report birds as rare or far out of range as this Siberian Taiga Flycatcher at Putah Creek, California, found by eBirder John Sterling, or the Ivory Gull found near New York City? Even more complex is the issue of how to deal with records of early/late migrants, or out of season records of lingering birds at local scales. Issues surrounding how to verify data like these certainly come into play when maintaining a database of records that is meant to become part of the scientific record. As with any large-scale citizen-science project open to the public, there is the possibility that erroneous data will be submitted. At eBird we consider data quality to be paramount, and we're taking every step possible to ensure that our data are the best they can be. Using advanced data vetting technology, we've developed a combination of automated filters and a network of regional editors that work together to verify eBird data. Each eBird submission, regardless of observer or location, is checked for data quality in exactly the same way.

Why worry about data quality?

A database is only as good as its weakest record. If even a few records can be deemed questionable, then the entire data set can be labeled as such. With that in mind, we should all strive to keep the eBird data as clean as possible. You can do your part by being conservative in the field and meticulous with your data entry, and we can do ours by building better connections between the eBird community and scientists.

How are records flagged?

In order to maintain data quality we have a series of filters in place that automatically flag records of rare and unusual birds--no matter who the observer! eBird flags records for review based on the values, or filter limits, set for each species in each regional filter (e.g., San Diego, California). If a count entered is greater than the filter limit set for a particular species in a particular month, the record is sent into review. Thus, a record of one Blackburnian Warbler in Ithaca, NY, in January would be flagged for review, but ten might be acceptable in May. We are constantly refining the filters, and as more data are received and we learn what people are actually seeing on the ground in each region, we adjust the filters as needed.

Records are typically flagged for the following reasons:

Rarity-a species that is rare or unusual in the region
Out of season report-a species is reported outside its normal date range in a region
High count-species count exceeds what one might expect to find in a typical day's birding in the region on a particular date

What happens to these data?

eBird has developed a network of regional editors comprised of both scientists and expert birders, knowledgeable in the distribution and abundance of birds in a particular region. This group of volunteers works together to verify records of rare birds, as well as records that are flagged for review by the automated filters. If a record cannot be supported with written details (or photos etc.) from the observer, it remains in our database, but we choose to not expose it to the public or to scientists interested in analyzing these data. Because these records remain archived in perpetuity at Cornell, scientists wishing to see the entire data set (verified and unverified) may do so. Importantly, these records also continue to appear in the original observer's personal data and lists on eBird, regardless of our reviewer's decision. This is not a judgment on the observer's ability, but a judgment on the merit of the record itself. We recognize that your records are your own, and we cannot truly know what you saw. We can only decide whether the evidence to support the record is strong enough to withstand scrutiny 100 years from now, when all of our reputations (good or bad) will long since be forgotten!

Adult Ivory Gull, Piermont, New York, 26 February 2007
^©Sean Sime

The new Review Tools

We have recently upgraded our review tools, which help our regional editors verify records. This significant improvement has made it simpler for reviewers to contact you regarding your observations. At eBird, we only use your email address for this purpose, and we are sensitive about the issue of overwhelming people with too many emails or spam. Regional editors might contact you to ask for details on any record that you are asked to "confirm" during the checklist submission process.

eBird Data Verification Email

Here is an example of an automated email that regional editors might send to you regarding one of your records:

Dear eBird user,

I am one of the regional reviewers for eBird and am writing to you about your observation of 2 Black-billed Magpies that you observed on Nov 14, 2003 from "Balboa Park", San Diego, US-CA.

When you submit a checklist to eBird, we use automated filters that compare your observations with typical totals for that month and region. If a count on your checklist exceeds the expected daily total for a species, you will then be asked to confirm the entry. Examples of flagged records are early or late arriving migrants, or counts of species that are exceptionally high. Rare birds and high counts do occur (we love seeing them as much as you do!), but in order to maintain high data quality standards we ask for further details before these observations can be accepted into the database.

We are asking for additional details on the following observation:
Species: Black-billed Magpie
Count: 2
Observation date: Nov 14, 2003
Location: Balboa Park, San Diego, US-CA
Submission ID: S2689962

The best supporting evidence for any bird record is a digital photo, which you can simply email to us. If you don't have a photo, please email any notes that you took when you saw the bird. It's often helpful to include how similar species were eliminated. Once we receive your documentation we will approve the record so that it appears in the public output. Records that lack documentation will not appear on the charts and maps, but will still appear on your personal lists.

Thanks for your understanding and any help you can provide. And, most importantly, thanks for using eBird!

Look at the Big Picture!

One must understand that the scientific community's current understanding of bird distribution is based largely on hundreds of years of verified ornithological records, many supported by specimens. When ornithologists first described the avifauna of the New World, they did so with the help of a shotgun, and sight records then were worth little or nothing--even those from the likes of Wilson and Audubon. We've come a long way since then, and with today's technology we can help observe and preserve the birds we all love. In the past science has sometimes overlooked the contributions of birders in furthering our understanding of bird migration, vagrancy, and especially field identification. However, as we challenge ourselves to become better birders by keeping detailed notes of our records, the more valuable our data become, and ultimately the more our contributions will be used to conserve birds and biodiversity.

Given today's fast-changing landscape and the wide variety of anthropogenic factors affecting bird populations (global climate change comes to mind!), now more than ever we need the help of birders in monitoring birds. These factors are potentially increasing the rate at which changes in bird distribution and abundance are taking place. Only through large-scale citizen-science efforts like eBird, BBS, and the CBC will we be able to fully understand these changes in relation to our global community. With that we ask you to participate in eBird, to understand that every observation you make is valuable, to realize that data quality is also important, and to bear with us as we continue to help narrow the gap between birding and science!

Thanks

Team eBird