IAP-24-054

Explaining and predicting the migratory behaviour and population dynamics of a long-distance migratory bird.

The populations of many migratory songbirds are declining rapidly, but why? Climate and land-use change, and overexploitation are well-recognised threats to migratory animals (Kubelka, Sandercock, Székely, & Freckleton, 2022). The complex annual cycles of migratory songbirds, during which they rely on multiple locations throughout the year, however, makes the identification of key threats challenging (Howard et al., 2020). To understand the drivers of these population declines, we require detailed knowledge of threatening processes that migratory songbirds are exposed to on their breeding and wintering grounds, as well as at stopover locations, and how these threats impact population trends.

Tracking devices offer an insight into the movements of migratory animals, with recent technical advances providing more detailed data on the migratory journeys of songbirds. These data can be paired with remotely sensed weather and land-use data and recently developed individual based models of migratory behaviour, giving us the tool to model the movements of individual migratory songbirds between Europe and Africa (Howard et al., 2024). However, we are yet to establish how these migratory movements and threats encountered on migration impact the population trends of migratory birds.

In this exciting project – which combines fieldwork with cutting edge individual-based models of migratory behaviour – the student will track the migratory journeys and breeding ecology of pied flycatchers (Ficedula hypoleuca) to develop a modelling framework that simulates the relationship between the migratory behaviour and population dynamics of a long-distance migratory songbird. Vulnerable to the impacts of climate change (Nater et al., 2023), pied flycatchers provide an ideal system to develop and test our models of migratory behaviour, whilst the development of this modelling framework will allow us to explore how conditions encountered during the annual cycle impact individuals and drive population declines. Considering the scale of recent climate and land-use changes across the ranges of migratory songbirds, such models are urgently required.

This project will have two key objectives:

Objective 1: To use multisensor loggers and nest box monitoring to collect data on the breeding ecology and migratory movements of pied flycatchers. The student will then use this data to develop an existing modelling framework to provide a better understanding of the link between the annual migratory movements and population dynamics.

Objective 2: To use this model developed in objective one to answer ecological and evolutionary questions about migratory journeys and population dynamics. Specifically, the student will explore impacts of weather on the migratory journeys and annual survival rates of pied flycatchers. This modelling framework will also allow the student to investigate the evolution of the migratory routes of pied flycatchers across their European range and predict the likely impacts of future climate and land cover change on this species.

To achieve objective one, the student will monitor pied flycatcher breeding attempts at an established site in west Durham, providing data on individual and population-level breeding ecology parameters, such as egg laying dates, clutch size, and fledgling success. The student will then deploy multisensor tags to track the routes, altitudes and timings of the migratory journeys of individual birds between their breeding site and wintering grounds in west Africa. The tags and the data they collect during the migrations will be retrieved when the birds return to their Durham breeding grounds the following spring. The student will then monitor subsequent breeding attempts to detect any carry over effects of conditions encountered on the migratory journey on breeding productivity.

The data linking the breeding ecology of individual birds with their migratory journeys in year 1 will then be used to parameterise and modify an existing migration modelling framework, to link migratory movements with the population dynamics of pied flycatchers. Additional tracking and breeding data collected in years 2 and 3 of the project can be used to further inform and test the model.

To achieve objective two, the student will apply the developed model to various environmental scenarios including variations in local weather conditions, as well as large scale changes in climate and land cover, to establish the likely impacts of these changes on the migratory journeys and population trends. Similarly, by applying the model to historic climate data, the student can test how the optimal migration route, and survival for this species has changed over time. The weather, climate and land cover data required to parameterise this model will be sourced from freely accessible online databases, including ERA5, Worldclim and ISIMIP.

In addition to the supervisory team based in IAPETUS2, this project will also be under the supervision of Dr Malcolm Burgess, a Research Fellow at the University of Exeter. Dr Burgess has a strong track-record in the research of long-distance migratory species, including the deployment of tracking devices. He offers technical expertise for collecting, analysing, and interpreting tracking data on migration ecology and conservation application.

Year 1

– Conduct a comprehensive literature review.
– Software training including R.
– Complete first field season- deploy additional nest boxes at the study site early spring, monitor any breeding attempts, deploy first batch of multisensor loggers

Year 2

– Process geolocator data from the first field season
– Using processed data from the first field season adapt existing migration models to incorporate the impacts of migratory behaviour on breeding productivity.
– Complete second field season – collect geolocators from returned birds and monitor subsequent breeding attempts, deploy second batch of geolocator devices.
– Attend national conference to present initial findings and network.
– Write first manuscript on methodological developments (to be submitted to Methods in Ecology and Evolution, objective 1).

Year 3

– Using data from second field season test the transferability of the developed migration model across time.
– Complete third field season – collect loggers from returned birds and monitor subsequent breeding attempts.
– Write a second manuscript that investigates the impacts of weather conditions on the migratory journeys and annual survival rates of pied flycatchers (objective 2).
– Write a third manuscript that uses the migration model to investigate the evolution of the migratory routes of pied flycatchers across their European range (objective 2).

Year 3.5

– Submit manuscripts to peer-reviewed, high impact journals.
– Attend international conference to present findings.
– Complete thesis

The prospective student should have a background in ecology. Experience of handling birds and/or bird ringing is also desirable but not essential. An interest in computational modelling is essential, and any experience therein is desirable. Due to the remote nature of the field site a UK valid driving licence is also desirable. The student will benefit from being part of the DU DTP cohort, where they will receive excellent interdisciplinary training (including field work, mechanistic modelling techniques, and analysis) and career development. Additional training will be identified to meet the needs throughout the studentship.