Atlas codes and definitions of criteria for breeding evidence: Ohio Breeding Bird Atlas
- Species observed in breeding season in possible nesting habitat but no other indication of breeding noted. Note : care should be used not to include migrants or vagrants in this category.
- Pair observed in suitable habitat in breeding season.
- Singing male(s) present (or breeding calls heard) on more than one date in the same place. This is a good indication that a bird has taken up residence if the dates are a week or more apart.
- Bird (or pair) apparently holding territory. In addition to territorial singing, chasing of other individuals of the same species often marks a territory.
- Courtship and display, copulation, agitated behaviour or anxiety calls from adults suggesting probable presence nearby of a nest or young; weel-developed brood-patch or cloacal protuberance on trapped adult (for banders).
- Visiting probable nest site, or nest building by wren and woodpeckers.
- Nest building or excavation of a nest hole.
- Seven or more territorial males in a block.
- Distraction display or injury feigning. Not to be confused with 24.
- Used nest found. Best limited to easy to identify nests.
- Female with egg in oviduct (for banders)
- Young recently out of the nest, not yet able to fly (including downy young of precocious species - waterfowl, shorebirds etc.). Code limited to those birds incapable of sustained flight. Gliding and fledging flights are not considered to be sustained flight.
- Adult carrying fecal sac.
- Adult(s) with food for young. Some birds (gulls, terns, raptors) continue to feed their young long after they have fledged, and even after they have moved considerable distances. Also some birds (terns, herons etc.) may carry food long distances to young in a neighboring block.
- Active nest with unidentified contents.
- Identifiable nest and eggs, adult icubating eggs, or identifiable egg shells found beneath nest. If you find a cowbird egg in a nest, it is a 38 for the cowbird, and a 38 for the identified nest owner.
- Nest with young or identifiable dead nestling(s). If you find a young cowbird with other young, it is a 39 for the cowbird, and a 39 for the identified nest owner.
Last modified 2 February 2001 / page established 24 February 1997