Using the Checklist of Birds of the Mid-Atlantic Area

The Checklist of Birds of the Mid-Atlantic Area was created to assist birders in the broader Mid-Atlantic area, including but reaching well beyond Northern Virginia.  It replaces the Audubon Society of Northern Virginia Mid-Atlantic checklist published in 2006.

The checklist will print on 8.5 x 11 size paper.  Printed copies are available from the ASNV office, info@audubonva.org.  

The checklist is based on the official state lists for the jurisdictions covered, as well as eBird data. These sources provide the most comprehensive information about birds that occur in the Mid-Atlantic area, and which species are introduced, rare, or accidental.  Read further for details on the checklist. 

What area is covered by the checklist?  The Mid-Atlantic checklist covers the District of Columbia and the states of Delaware, Maryland and Virginia. 

Rare species.  The checklist shows an asterisk * for some species, indicating that the species is rare in the Mid-Atlantic area. This information is based on eBird data about the frequency with which the species has been reported and should be taken as a guide, not as definitive.  Also, birders should expect to find the species in appropriate habitats. They are not likely to find ducks in dry grassland habitats, for example, except for birds flying over.

Introduced species.  Any species denoted with (I) is an introduced species. It is not native to the region, but was brought to the area and is sustaining a wild population. This group includes a number of European species introduced to the United States that have become familiar and well established, such as the House Sparrow and European Starling.

Accidental species. The main checklist is followed by a shorter list of species that are accidental or vagrants in the Mid-Atlantic area.  Accidental species are those that have been observed only a very few times. A vagrant is a bird that has strayed far out of its expected range, for example, blown in by a storm.

What are official state lists? The ornithological societies in each state provide the official list of birds found in the state, as determined by the state records committee.

These societies include the Virginia Ornithological Society, the Delmarva Ornithological Society, and the Maryland Ornithological Society. The Maryland society provides lists for both Maryland and the District of Columbia.

What is eBird? eBird is an online real-time checklist program www.ebird.org supported by the Cornell Laboratory of Ornithology at Cornell University. As a “citizen science” tool, eBird’s data are comprised of reports entered by thousands of individual birders about the birds they have seen or heard, the number of individual birds, and the location, time and date of the observation. For the Mid-Atlantic list, we used eBird data for 2005-2015, which included nearly 700,000 reports from birders in our region.

This information allowed us to see what species have been found in the region and how abundant they are. Details on how we developed the checklist are available here.

Using eBird.  ANSV encourages you to enter your observations in eBird.  Your sightings will become part of the eBird database that is used in scientific analyses of trends in bird population levels, distributions and migration patterns, as well as for projects like our checklist.  The analysis of bird populations is critical to understanding how birds are being impacted by habitat change, climate change, and other conditions, and in developing conservation practices and habitat protection and restoration efforts.  You can set up a free eBird account at www.ebird.org. You also can download the eBird app to your smart phone and enter your lists while in the field. eBird will help you track your personal bird list, such as your life list. 

Limitations of eBird data. While eBird data are an invaluable resource, they do have some limitations.

eBird is based on what individual birders have reported. That is, it tells us what birds were observed during the times and at the places where birders go. This is a different type of data than would be found during a survey using a formal protocol where coverage and timing can be planned. 

Some locations are heavily birded, others are not. Some locations, such as parks and refuges, may have nocturnal or other species that are not observed because the locations are not open when these birds may be active. The result is that the frequency data for such species, for example owls, may be lower than what would be found with more formal data sources.

Also, when a rare bird shows up in our region, many birders go to see it and enter reports in eBird.  The result is a lot of reports for 1 or 2 individual birds.  In preparing our checklist, we looked at the individual reports where we thought this might be the situation, and adjusted as needed.

Who compiled this checklist?  The checklist was developed by a team led by Dixie Sommers with input from Tom Blackburn, Greg Butcher, Greg Fleming and Laura McDonald.