The role of dietary quality in nestling growth: an experimental PUFA supplementation study in Alpine swifts

Climate change is reshaping insect communities worldwide, with important consequences for insectivorous birds. While many aerial insectivores have experienced population declines, Alpine swifts show a contrasting pattern, with increasing populations and faster nestling growth over the past 25 years despite evidence for declining insect abundance. This apparent mismatch suggests that changes in prey quantity alone cannot fully explain recent developmental trends. Instead, climate-driven changes in prey composition and nutritional quality may contribute to the observed increase in nestling growth. Aquatic and terrestrial insects respond differently to environmental change and differ markedly in their nutritional value, with aquatic insects being particularly rich in long-chain polyunsaturated fatty acids (LC-PUFAs), essential nutrients involved in growth and physiological development. Because LC-PUFAs have been shown to enhance growth and performance in insectivorous birds, changes in access to PUFA-rich prey could represent a key mechanism linking climate-driven changes in insect communities to Alpine swift development. This project will address this question by experimentally increasing dietary PUFA availability in Alpine swift nestlings and assessing its effects on growth and physiological responses.

To investigate how experimentally altered diet quality influences Alpine swift nestling growth and physiological development.

You will contribute to the field implementation of a PUFA supplementation experiment in Alpine swift nestlings, including nestling handling, feeding treatments, and growth monitoring. You will analyse how experimentally induced differences in dietary PUFA composition translate into variation in nestling growth and physiological responses. The MSc thesis can be tailored to different aspects of nestling performance—such as energetics, oxidative stress, or immune function—to match your interests.

We are looking for a student interested in nutritional ecology and avian physiology; available from May to July 2027 to carry out fieldwork in Switzerland (area Biel-Solothurn-Luzern). We can provide accommodation in the field, and traveling between field colonies is done by train. Previous experience with fieldwork, especially bird handling, and R for statistics is desirable but not required.

This project is part of the SNSF-funded PhD project of Lara Hinninger on Linking climate change to changes in nutrition, physiology and life history in a long-lived insectivorous bird. Supervision will be provided by Lara, Pierre Bize (Swiss Ornithological Institute/UNIL) and Cornelia Twining (Eawag/ETH).