Golden-cheeked warbler · presence/absence protocol
Six steps, drawn from the U.S. Fish and Wildlife Service's requirements. Every rule shown in gold is quoted from the protocol, not paraphrased.
The survey starts in the dark. Detection depends almost entirely on song, and golden-cheeked warblers sing hardest in the first hours after dawn — so the biologist is in position before the birds start.
Survey times must start no earlier than 30 minutes before sunrise.The season, one site
Five visits minimum, no two within any five-day period — and a visit lost to weather does not count, so it has to be made up inside the same eleven weeks.