Breeding Codes

Possible

habitat - Species encountered in suitable nesting habitat during its breeding season such as a Virginia Rail in a marsh. This code would also be used when you hear a male singing in a likely nesting area on only one occasion.

Probable

Mult. singing - Multiple (5 or more) singing or territorial birds of a species detected within same block on the same day.  Most species listed as (M) can be upgraded to (S) during a later visit.

Singing male - Singing male present at same location on at least two dates 7 or more days apart.

Pair in habitat - Pair observed in suitable nesting habitat during the breeding season.

Territory - Permanent Territory presumed through defense of breeding territory by fighting or chasing individuals of same species.

Courtship - Courtship behavior such as transfer of food, displays, or copulation between a male and female.

Nest site - This code applies when a bird is observed visiting the same likely nest site repeatedly, but which provides insufficient behavior for upgrading to Confirmed. Especially useful for cavity nesters or for a shrub-nesting species that flies into the same thicket and disappears on several occasions.

Agitated - Agitated behavior or anxiety calls from adults usually indicate a nest site or young in the vicinity.

Building nest - Nest building by wrens or excavation of cavities by woodpeckers.

Confirmed

Physiological E - Physiological Evidence of breeding based on bird in the hand such as a highly vascularized swollen incubation (brood) patch or an egg in the oviduct. Used primarily by bird-banders.

Carrying Nest - Bird seen carrying nesting material such as sticks, grass, mud, cobwebs, etc.

Nest Building - Nest building seen at the actual nest site, except wrens and woodpeckers (see under Probable code "Building Nest").

Dist. Display - Distraction Displays, defense of unknown nest or young, or injury feigning. Killdeers may give a "broken wing" act, a Red-winged blackbird may dive at you near the nest site, or an Ovenbird may run about with wings fluttering.

Used Nest - Used nest or eggshells found. Unless carefully identified, use this only for unmistakable eggshells and nests that were used during the Atlas period.

Occupied Nest - Occupied nest indicated by adult entering or leaving nest site in circumstances indicating an occupied nest, including those in high trees, cliffs, cavities, and chimneys where the contents of the nest and incubating or brooding adult cannot be seen.

Fledged young - Recently fledged young or downy young. This includes dependent young only. Be cautious of species that range widely soon after fledging..

Feeding Young - Adult bird carrying food for young or feeding recently fledged young. Note: Some adults carry food a long distance or may be engaged in courtship feeding. One of the best signs to look for is the repeated carrying of food in the same direction.

Fecal Sac - Adult bird seen carrying fecal sac. Many passerine adults keep their nests clean by carrying membranous, white fecal sacs away from the nest.

Nest with Eggs - Nest with eggs or eggshells on ground.

Nest with Young - Nest with young seen or heard.