The RSPB has launched a national pilot survey in a Lincolnshire town to learn more about swift populations and tackle the decline in their numbers.
People in Boston are being asked to report where swifts are nesting
The group is concerned that a combination of home improvements and conversion of old buildings is destroying the nest sites of the birds.
It wants people in Boston to report where swifts are nesting and how many have been seen in flocks this summer.
The initiative could then be extended across the country.
A spokesperson for the RSPB said: "We would also like to get some idea of the numbers of swifts seen to use as a baseline to calculate declines in future years."
Survey forms can be downloaded from the organisation's website.