Aromatic herbs in Corsican blue tit nests: The 'Potpourri' hypothesis

This study reports that Corsican blue tit (Parus caeruleus ogliastrae) nest s contain between one to five aromatic herb species between the onset of eg g laying till the chicks' finished growth 13 d after hatching. An herb remo val experiment during the chick stage shows that blue tits bring fresh arom atic material 1-5 d after herb removal. Nests with a series of distinct odo ur classes easily perceived by humans have never been reported in birds. A new 'Potpourri' hypothesis is proposed that may explain the functional sign ificance of this behaviour. (C) 2000 Editions scientifiques et medicales El sevier SAS.