Report number 139 from Kvismare Bird Observatory:
Does song reflect age and viability? A comparison between two populations of the great reed warbler Acrocephalus arundinaceus.
Forstmeier W, Hasselquist D, Bensch S, Leisler B
Article in journal
Behavioural Ecology & Sociobiology . 2006. Volume 59, page(s) 634-643.