I've very recently become involved with monitoring a threatened bird species on the West coast. After about a dozen visits to areas where they have been positiv

I've very recently become involved with monitoring a threatened bird species on the West coast. After about a dozen visits to areas where they have been positively identified in the past few years and using active measures to attract and detect them, I finally saw one for the first time last night. At two sites where they have been positively visually identified during visits this season, the detection is below 50%. i.e. they are detected during fewer than half the site visits. All that to say that "quickly confirm[ing] in follow up visits" isn't as easy or guaranteed as one might assume - especially with a bird that seems to have a large range, sparse-if-any population, and wary nature.