On the migration and dispersal of the Cyprus wheatear Oenanthe cypriaca

Abstract

The juvenile stage is likely to play a central role in the population dynamics of migratory animals, the evolution of migration, and a species’ capacity to adapt to change. But relatively little is known about the ontogeny of migration and dispersal. In this thesis I explored migration and dispersal across the full annual cycle in the Cyprus wheatear Oenanthe cyprica – a long-distance migrant landbird – focusing on how these movements develop with age and whether they might allow adaptation to environmental change. I investigated post-fledging dispersal, the possible role of female song in dispersal, the ontogeny of migration, post-migration dispersal, and seasonally different migration routes in the context of life history evolution. I found that the post-fledging period may function to locate a first breeding territory, but only in males; pre-migration exploratory dispersal thus may contribute to early breeding the following year. Female song occurred predominantly in the pre-breeding period and may be multifunctional but was used particularly in territorial defence and mate acquisition; it may be a relatively unappreciated way to deal with the more extreme time constraints of territory and mate acquisition in migrants. Juvenile migrations became more like those of adults within a single annual cycle, suggesting that improvement in migratory behaviour occurs rapidly. Juveniles appear to make a post-first-migration dispersal on the non-breeding grounds, suggesting capacity to cope with local-scale habitat shifts. Juveniles showed
some flexibility in migration timing that may allow adaptation to advancing spring phenology. Finally, migrations were direct in autumn but detoured in spring, and may be shaped by regional wind patterns, suggesting potential for adjustment to future changes in wind conditions. Overall, these findings highlight the importance of improved efficiency of time and space use during the first-year
stage in migrant birds.

Date of Award	15 Jun 2022
Original language	English
Awarding Institution	University of St Andrews
Supervisor	Will Cresswell (Supervisor)