The player uses a random mix of swift calls and pauses to sound more like a real colony, helping curious swifts notice potential nesting spots while being gentler for neighbours too.
Swifts are most likely to investigate nest sites on calm, warm mornings and evenings from late April to July, especially in May.
Good conditions are 12°C+, low rain, and light to moderate wind, when insects are active and swifts are feeding.
For best results, place a small Bluetooth speaker near your swift brick or nest box at a moderate, natural sounding volume.
