How does one do it if the nest site hasn't yet been identified?
They're here, there and everywhere and so, well ... swift!
I assume you are referring to the swift inventory. Counting swifts can be tricky if you have a large flock that are zooming around as they do in their screaming parties. It is basically a case of making a best estimate of these groups if you are finding it difficult to be exact, an informed guess is still useful. If the flocks are truly huge then try counting them in multiples of 5 or 10.
With the nesting site recording, only record the ones that you know are definitely using a nest, which should be a little easier!
Warden Intern at Otmoor.