BREEDING CODE is based on increasing importance of breeding status:
| Species Observed | |
|---|---|
| O | Species observed in its breeding season but not in suitable nesting habitat, or species soaring high overhead, or a colonially nesting species not in the nesting colony. |
|
Possible Breeding = PO |
|
| SH | Species observed in breeding season in suitable nesting habitat |
| SM | Singing male present |
|
Probable Breeding= PR |
|
| S | Seven of more territorial males observed on at least two days, a week or more apart during the breeding season. |
| P | Pair observed in suitable habitat |
| T | Bird or pair on territory, or singing mail present on more than one date |
| C | Courtship Behavior |
| V | Visiting probable nest site, or nest building by wrens or woodpeckers |
| A | Agitated behavior or anxiety calls |
| B | Brood patch or cloacal protuberance |
| N | Nest-building or excavation of nest hole |
|
Confirmed breeding = CO |
|
| SE | Seven or more territorial males observed only once in the breeding season. |
| DD | Distraction display |
| NU | Used nest or egg shells |
| FE | Female with eggs in oviduct |
| FY | Fledged young or downy young |
| ON | Occupied nest (adults entering or leaving, contents unidentified) |
| FS | Adults with fecal sac or food for young |
| NE | Nest with eggs |
| NY | Nest with young, or identified dead nestling |