Movement ecology and incubation behaviour in waders

Most shorebird (or wader) species are socially monogamous, meaning that they form a pair-bond and that both the male and the female incubate the eggs and care for offspring at least for some time. In the other species, males and females do not form stable pair-bonds and offspring care is exclusively done by one sex. Studying three polygamous shorebird species (up to 60 dotterels, 60 Temminck's stints and 30 ruffs) we aim (1) to get new insight into the annual movements of dotterels and (2) to acquire data on uniparental incubation behaviour in all three species. We will use cutting-edge satellite technology (2 g, solar-powered satellite telemetry tags) to track dotterels breeding in Hardangervidda, Troms and Finnmark in Norway. The tags make up <2% of the birds’ body mass and are attached to the back of the bird using a flexible harness. We hypothesize that the polygamous female dotterels may range over wide areas in search of mates. For the first time we will also get insight into the general migration schedules of dotterels. The incubation study will explore the variation in incubation behaviour in uniparental incubators, both between and within species. Several other researchers are involved in this project outside Norway to increase the number of species and sampling localities. We will focus on how all these birds cope with varying extrinsic conditions (e.g. climate, latitude) while securing optimal conditions for the developing embryos and see if biological factors (e.g. mating system, sex of incubating bird, body condition) could explain some of the variation in behaviour. We will monitor incubation rhythm by using non-invasive temperature probes inserted into the nest cup of dotterels (normally male only incubation), Temminck’s stints (both sexes incubate, but only one per clutch) and ruffs (female only incubation). All birds in our study will be trapped and ringed with colour rings for subsequent identification and blood samples will be taken to allow certain (molecular) sex identification. All our methods are well tested in other species. Based on this, the planned experimentation is likely to have only minor impact on the birds’ welfare. The studies will likely provide data which will yield novel insight into various parts of basic avian biology. In addition, the study of dotterel movement ecology will provide data relevant for conservation, by showing where dotterels migrate and how populations are connected with each other.