2a: Animal Movement Ecology

2a:     Animal Movement Ecology

Conveners:     Morrison Pot (Netherlands Institute of Ecology)

                        Jan Geisler (Netherlands Institute for Ecology)

                        Evy Gobbens (Royal Netherlands Institute for Sea Reserach)

1. Effects of fireworks disturbance on birds – results from GPS tracking

Andrea Kölzsch, (co-authors are missing), Radboud University, Max Planck Institute of Animal Behavior

During winter, most geese live in highly anthropogenic regions and are disturbed frequently, leading to more or less intensive and long- or short-term stress and flight responses. By analysis of a large set of GPS tracks of four Arctic migrating goose species that winter in Europe, we have quantified how New Year’s Eve fireworks in W-Europe affect flight patterns during the disturbance until many days after. Most birds reacted strongly with high and extremely long flights as well as increased foraging intensity for at least 12 days after the event. Indicating strong levels of energy loss during nightly flights, this might not impact migration or reproductive success, but can be fatal in harsh winters. Another effect can be that goose families are split and young lose the possibility of improved foraging and learning in winter with the family group, leading to potential long-term fitness consequences.

2. Scope for Arctic migrants to speed up migration in the face of climate warming
Hans Linssen, Emiel van Loon, Thomas Lameris, Rascha Nuijten, Michiel Boom, Nelleke Buitendijk, Götz Eichhorn, Jan Geisler, Andrea Kölzsch, Helmut Krückenberg, Jutta Leyrer, Carl Mitchell, Sander Moonen, Kees Schreven, Lisa Vergin, Tom Versluijs, Judy Shamoun-Baranes & Bart Nolet, University of Amsterdam, Netherlands Institute of Ecology

Spring phenology is advancing under the influence of climate change. Many migratory animals have been speeding up their spring migration in order to advance their arrival on the breeding grounds accordingly, and avoid suffering negative consequences of being late. We examined how much further scope there is for migrants to keep shortening the duration of their spring journey. Combining a wealth of multi-year GPS tracking and body mass data from a range of Arctic-breeding waterfowl, we quantified individual fuelling, both en route and pre-departure. We show that relatively large cutbacks in the total fuelling duration (or increase in fuelling rate) are required to substantially advance spring arrival. Individuals are flexible in their annual fuelling duration, but only enough to warrant migration shortening worth a couple decades of spring advance. Our findings suggest that birds have variable but limited scope to advance their spring arrival trough migrating faster.

3. Attraction to offshore wind farms of Lesser Black-backed Gulls in the context of fisheries

Rosemarie Kentie, Ruben Fijn, Judy Shamoun-Baranes, Kees Camphuysen, Eric Stienen, Rob van Bemmelen, Royal Netherlands Institute for Sea Research, University of Amsterdam

Offshore wind farms are increasing rapidly in number and scale, posing potential risks for seabirds. Discard-feeding seabirds could appear to avoid offshore wind farms, while in fact they are attracted to fishery activities outside the parks. Here we studied the attraction of Lesser Black-backed Gulls (Larus fuscus) to fishery activity and wind farms. We used a Step Selection Analysis to analyse movement of GPS-tracked individuals, and included individual variability, as gulls differ substantially in behaviour. We included day of the week in our analysis, as during weekends fisheries were nearly absent, and examined if these effects different for different periods within the year. Overall, we found that gulls were twice as likely to select areas with fishery activity compared to areas without, while, at the population level, the wind farm in reach was avoided, also during the weekends. Some individuals, however, were attracted to the wind farm and used the basis of a turbine to rest.

4. Simulating and analysing seabird flyways: an approach combining least-cost path modelling and machine learning

Nomikos Skyllas, Mo A. Verhoeven, Maarten J. J. E. Loonen, Richard Bintanja, University of Groningen, Royal Netherlands Meteorological Institute, University of Amsterdam

Seabird migration is shaped by wind circulation and ocean productivity, leading to distinct migration corridors known as “flyways,” which align with Earth’s atmospheric patterns. These flyways link climate and bird migration, and simulating them can provide insight into current pathways and potential future climate impacts. Our study combines climate data with a least-cost-path model to simulate and describe seabird flyways. Integrating bird tracking data and machine learning, we assess whether birds optimize their routes for time or energy. Focusing on five Arctic tern flyways, we model both spring and autumn migrations over the Atlantic. Our analysis examines how tailwinds, crosswinds, and food availability impact migration effort, allowing us to calculate how closely birds follow a theoretically optimal (time- or energy-minimizing) path. Our findings show that observed flyways can be recreated with environmental data, and that our model can aid in studying future climate change effects on migration.

5. Linking early-life behavior to behavioral syndromes in Eurasian Spoonbills

Arne van Eerden, Wouter van Steelant, Theunis Piersma, University of Groningen

Juvenile birds face a limited time window to develop essential life skills before their first migration. Tracking data of post-fledging Eurasian spoonbills reveals striking individual differences in mobility, exploration, and habitat use. Some extensively explore large areas, while others remain close to their natal colony for weeks. This inter-individual variation in early-life behavior may have long-term consequences, potentially funneling down into distinct behavioral syndromes and migratory routines.
We test whether these early-life experiences predict subsequent behavior such as migration timing, dispersion, exploration, and habitat use along the flyway. By linking fine-scale movement ecology to personality traits, we try to explore the ontogeny of behavioral syndromes in migratory birds.