Great bustards Otis tarda in Morocco: status in spring 1999 and evidence of a decline in recent decades

Abstract

A spring (1999) census was conducted of great bustards Otis tarda in north-western Morocco, where a poorly known population of this species occurs. Sixty-four birds were seen in four distinct areas. Adult males were seen displaying at three of these areas, indicating that they are probably traditional lek sites. No adult males were observed in the fourth area and its status as a lek site is uncertain. Two further sites were visited but no birds were seen. Two 1st-year males were seen with their mothers, demonstrating successful breeding in 1998. We argue that the small number of birds, a population sex ratio of 1 : 3.3 in favour of females, evidence for a range contraction, and probable isolation from other great bustard populations mean that this population is now extremely endangered and will decline to extinction unless conservation measures are implemented immediately