Avian demography: statistics and ornithology

Avian demography is defined here as the study of the statistics of bird pop ulations. Ornithology has generated types of data - or been the first disci pline to generate them - which do not lend themselves to standard statistic al analyses. In these situations, the role of the avian demographer is to d evelop custom-built statistical methods - the analysis of primary moult is an example of a type of data needing specialised methods and this is discus sed in the final sections of the paper. Data from the Southern African Bird Atlas Project is used to present some insights into the biogeography of so uthern African birds, and to describe the 'texture' of bird distributions. The year 1998 marks, approximately, the centenary of the introduction of th e European Starling Sturnus vulgaris to Cape Town and the House Sparrow Pas ser domesticus to Durban, and the paper notes this event and these species.