Cost-effective estimates of Water Rail Rallusa quaticus breeding population size

Aims: To propose a rapid and cost-effective method to obtain reliable population estimates of Rallus aquaticus. Location: Northern Italy. Methods: Optimal period and effectiveness of playback use were investigated through dedicated surveys. Results: Playback use resulted in a greatly enhanced detection rate; the use of broadcasted vocalizations during end of March -April could allow rapid and effective estimates of number of territories. Conclusion: Water Rail censuses should be undertaken using playback song, between the end of March and the first half of April, the period which proved to be the best both in Italy and UK and provided high detection rates associated with a low risk of including winter migrants.