A study of the relationship between the starling Sturnus vulgaris and the haematophagus mite Ornithonyssus bursa : a thesis in partial fulfilment of the requirements for the degree of Master of Science in Zoology at Massey University

Abstract

A description is given of a study of starlings breeding in 160 nest boxes over the two breeding seasons 1974-75 and 1975-76, aimed at determining productivity and some factors which possibly affect it. Changes in productivity through the season and between seasons are discussed, with particular reference to the influence of the mite Ornithonyssus bursa on nestling growth rate, weight at 15 days, mortality, blood characteristics, and lipid stores. Also the effect of mite infestations on the mean weight of nestlings from different brood sizes is discussed. The starling nestling period is described, including changes in feeding activity, growth rates, sanitation measures and behaviour patterns. Factors possibly contributing to the death of late hatching nestlings are discussed. The life cycle of 0. bursa is outlined with particular emphasis on feeding methods and their effects on the host. The behaviour of mites in response to some environmental variables is discussed briefly in relation to the effects of mites on nestlings. The seasonal pattern of 0. bursa infestation over the starling breeding season is described with particular emphasis on the proportion of nest sites infested and the degree of infestation at each of three periods in the breeding season. Several methods of mite dispersal are considered and their importance in infesting other nest sites are discussed.