Breeding Nightjar Monitoring Protocol

This survey has two elements, firstly a transect based survey, followed by a static survey once broad territories have been established. Both are carried out using standard methods derived from the BTOs Common Bird Census (CBC). 
For the transect survey, at least three visits should be made to the site at dusk between late May and July. Surveyors should follow a route which takes them within 100m of all suitable breeding habitat. As the survey is carried out after dusk, it is highly recommended that surveyors recce the site in the daytime to familiarise themselves with the terrain and route. 

Sightings of the target species within 100m at a right angle to the transect line are recorded using BTO species and activity codes, whereby birds seen in flight, calling or churring/displaying are drawn on a map of the site. Males should be located by sight and their location recorded as accurately as possible (GPS can aid with this). For Nightjar, churring males are a good proxy for an individual territory. 

Estimates of how many territories are being held can be made from assumptions around how many individual churring or displaying males were seen and judged to be separate from each other. Males churring within 30 seconds of each other but located 400m apart should be dotted-lined as separate males.

From this estimate, areas can be prioritised for the static survey which should take place in late July. The survey should last for 60 minutes. Here, surveyors should space themselves out evenly across areas where Nightjar have been recorded in the previous surveys, providing good coverage and in place to start the survey 20 minutes after sunset. Any churring males should be recorded using standard BTO activity codes, however, rather than using the species code NJ, surveyors should record birds as A, B, C, D etc, along with the time that this record was made. This enables a final assessment to be made of how many territories are occupied.