My colleague Paul Donald has recently written this commentary which is a précis of his (and others) previous work discussing skewed sex ratios in adult birds.
The implications for bird populations where one sex heavily outnumbers the other in adult populations are obvious, but what are the possible causes?
Additionally, for those of us who take part in atlassing and surveying work, what significance is there now to recording ' singing males'?
Currently, we consider the presence of a singing male on territory within suitable habitat as evidence of probable breeding. Paul's theory has certainly caused me to think again about my perception of what constitutes breeding evidence.
Paul's previous paper (again published in Ibis) can be found here.
ATB,
DOM
Leave only footprints, kill only time.