The annual Swift Survey has been running since 2009, gathering information on where swifts are nesting across the UK. \xa0Swift numbers are 53 per cent down over the last 30 years and data from the survey, coupled with some ground breaking research in Northern Ireland, is providing clues to why this might be happening. On this episode of Nature\u2019s Voice Jane Markham talks to RSPB Northern Ireland\u2019s senior conservation scientist Kendrew Colhoun about using GPS tracking \u2013 a world first on a bird so small -\xa0 and to Guy Anderson about how your sightings can contribute to this year\u2019s survey.