Field Methods

A playback method will be used to survey Willow Tits during the pre-breeding season when the birds are territorial, and covering all potentially suitable habitat in the survey tetrad. A summary of suitable Willow Tit breeding habitat is provided at the end of the survey instructions. The playback method, using a standard (2-minute) Willow Tit call and listening for a response, has been successfully developed by the RSPB Willow Tit research project. The recording used for the survey is a combination of willow tit alarm call and song.

The call volume should be checked before surveying: the call should be audible up to 100m away from playback.

A separate tetrad map with accompanying form will be provided for each visit. The survey form should be used to record visit information, details of any Willow Tits encountered, and an overall survey summary.

Before surveying, it is best to:

  • Identify areas of potential habitat using Google Earth and OS maps and mark these up on survey sheets.
  • Create a survey route and mark the map with survey points, approximately 200m apart so all areas of potential habitat are visited and no suitable habitat is more than 100m from a survey point.

Ideally, two surveys should be carried out in each survey tetrad between mid-February and mid-April, although if you are only able to undertake one survey we will be able to use the results. If no Willow Tits are found after two visits despite there being (potentially) suitable breeding habitat in the tetrads, please consider undertaking a third visit. Once the birds are serious about excavating and nesting they become very quiet, from mid-April. Ideally, surveys should be undertaken on ‘fine’ days – if present, Willow Tits are much more likely to be detected on relatively warm days with no wind and rain. Willow Tits are more likely to respond to calls during the morning, and when not heavily overcast.

A pre-determined transect should be walked through the survey tetrad and the route taken should be marked on the OS tetrad map on the accompanying survey form, if not marked beforehand. A stop should be made every 200 metres and noted on a recording form. Playback points should be distributed so no suitable habitat is more than 100m from a point, and the location of each point should be marked on the tetrad map (as P1, P2, P3, etc).

To gain access to all potentially suitable habitat in the tetrad, it may be necessary to gain access to private land. If you are unable to gain access to all areas of suitable habitat in the tetrad, the playback point should be from the nearest public access.

At each stop the standard recording of Willow Tit call and song should be played for two minutes (this is the full length of the standard recording). A further two minutes should then be spent looking and listening for a Willow Tit response. A response is recorded if there are any Willow Tit vocalisations heard or they are seen at the survey point. If a response is achieved during playback the recording is stopped and you should move on to the next playback point.

Although the recording used contains Willow Tit calls and song, a wide range of species can sometimes respond not only Willow Tits. In particular, Marsh Tits and other tit species regularly respond.

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