The biology of Yellow Wagtails (Motacilla flava L.) overwintering in Nigeria

• Main Author: Wood, John Brian
• Published: University of Aberdeen 1976
• Subjects: 591.7; Motacilla flava
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.477872

The English name Yellow Wagtail is commonly used to describe the polytipic species Motacilla flava. More specifically it is also used for the British breeding race M.f.flavissima, and various English names are applied to other races: e.g. Blue-headed Wagtail M.f.flava, Ashy-headed Wagtail M.f.cinereocapilla, Grey-headed Wagtail M.f.thunbergi, Black-headed Wagtail M.f.feldegg, Sykes's Wagtail M.f.beema. As the former name is ambiguous and the latter ones would be unnecessarily ponderous when describing a group of birds of several races. I have tended to use Latin epithets throughout this thesis. However, this does not allow an effective plural noun to be applied, so in addition I have used the term "Wagtails", which, unless otherwise qualified, always refers to the species Motacilla flava. This also allows a degree of variety to be introduced to the text. African savanna regions have a climate which is markedly seasonal, although these seasons do not directly correspond with those experienced in temperate regions. Nevertheless, in the regions in which this work was undertaken, the dry season occurs from about November to March and is a period of relatively severe conditions for many bird species. Consequently I bave tended to refer to this period as winter, which should be taken as synonymous with dry season. As very few studies of the overall biology of Palaearctic migrants wintering in Africa have been previously unuertaken, I have attempted to make this account as comprehensive as possible. Inevitably this makes the text rather long, and I have therefore presented as much data as possible in the form of diagrams, which allow a greater amount of information to be presented in a small space.