(see handbook for full description & use suggestions)
PO Category - possible breeding evidence
Species (male or female) observed in suitable nesting habitat during its breeding season.
PR Category - probable breeding evidence
Singing male present (or breeding calls heard) on more than one date in the same place.
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, or agitated behavior or anxiety calls from adults suggesting probable presence of nest or young nearby; brood patch on trapped female or cloacal protuberance on trapped male.
Visiting probable nest site.
Nest building by wrens or excavation of holes by woodpeckers.
CO Category - confirmed evidence of breeding
Distraction display or injury feigning; coition.
Nest building by any species except wrens and woodpeckers.
Used nest found. Must be carefully identified if it is to be accepted.
Female with egg in oviduct. (For banders.)
Recently fledged young (of altricial species) incapable of sustained flight or downy young (of precocial species) restricted to the natal area by dependance on adults or limited mobility.
Adult carrying fecal sac.
Adult carrying food for young.
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.
Nest with egg(s), undisturbed nest with a bird in incubation posture, eggshells found below nest, or identifiable dead nestling(s).
Nest with young or downy young of waterfowl, quail, waders, etc.