A puzzling case of successful double-brooding in the Little Bittern Ixobrychus m. minutus

The Little Bittern is one of the least studied heron species in its breeding range. The nominate, Palaearctic race Ixobrychus m. minutus has been generally assumed to be single-brooded only, yet detailed studies of its breeding biology and mating system are lacking. The present paper provides the first observational evidence of successful double-brooding in the nominate race of the Little Bittern and gives the first record of time-overlapping double-brooding in the species. Potential determinants of this breeding strategy as well as the frequency of its occurrence are discussed.