Skip navigation.
Maryland & DC 1983-1987


General Methods
Sampling & coverage of blocks

Each block consisted of 1/6 of a USGS 7.5 minute topographic quad. Many of the blocks were further divided into quarter-blocks. A total of 1269 blocks were sampled.

View blocks in the Mapping Tool >>

Coordination of coverage
Management of this project was accomplished with the help of coordinators from each county and the District of Columbia.

Breeding Evidence Codes
Code Code description  (see handbook for full description & use suggestions)
OB Category - Observed: not breeding evidence
O Species (male or female) observed within safe dates but not in breeding circumstances. This code is primarily for birds that are not believed to breed in the block.
PO Category - possible breeding evidence
X Species (male or female) observed in suitable nesting habitat during its safe dates.
PR Category - probable breeding evidence
A Agitated behavior or anxiety calls from adult.
P Pair observed in suitable nesting habitat within safe dates.
T Territorial behavior or singing male present at same location on at least 2 different days, 5 days or more apart. Territoriality can be presumed from defensive encounters between individuals of the same species, or by observing a male singing from a variety of perches within a small area.
C Courtship behavior or copulation.
N Visiting probable nest site.
B Nest building by wrens or excavation of holes by woodpeckers.
CO Category - confirmed evidence of breeding
NB Nest building by any species except wrens and woodpeckers or adults carrying nesting material.
DD Distraction display or injury feigning.
UN Used nest found. Must be carefully identified if it is to be accepted.
FL Recently fledged young or downy young. This includes dependent young only.
FS Adult carrying fecal sac.
FY Adult carrying food for young.
ON Adults entering or leaving a nest site in circumstances indicating occupied nest. To be used for nests which are too high (e.g. the tops of trees) or enclosed (e.g. chimneys) for the contents to be seen.
NE Nest with egg(s), or eggshells on the ground.
NY Nest with young seen or heard.
Habitat Codes
- - this atlas does not record habitat on the field card - -

Where this information came from
Most of the information on this page is from the project's publication or Handbook (guide for field work).
U.S. Department of the Interior || U.S. Geological Survey || Patuxent Wildlife Research Center  Laurel, MD, USA 20708-4038
This site is:
Information contained in this application does not necessarily have the endorsement of USGS.

Last updated: Site - May 2014; Content - various, depending on atlas.
Page generated on: 26-Mar-2019