The timing of spring migration in trans-Saharan migrants: a comparison between Ottenby, Sweden and Capri, Italy

Niclas Jonzén,Dario Piacentini,Martin Stervander,Arne Andersson,Alessandro Montemaggiori,Jonas Waldenström,Fernando Spina,Diego Rubolini

doi:10.34080/os.v16.22412

Niclas Jonzén, Dario Piacentini + Show 6 more

Open Access

https://doi.org/10.34080/os.v16.22412

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Abstract

Some migratory birds have advanced their spring arrival to Northern Europe, possibly by increasing the speed of migration through Europe in response to increased temperature en route. In this paper we compare the phenology of spring arrival of seven trans-Saharan migrants along their migration route and test for patterns indicating that migration speed varied over the season using long-term data collected on the Italian island of Capri and at Ottenby Bird Observatory, Sweden. There was a linear relationship between median arrival dates on Capri and at Ottenby. The slope was not significantly different from one. On average, the seven species arrived 15 days later at Ottenby compared to Capri. There was a (non-signiﬁcant) negative relationship between the species-speciﬁc arrival dates at Capri and the differences in median arrival dates between Capri and Ottenby, possibly indicating a tendency towards faster migration through Europe later in the season. To what extent different species are able to speed up their migration to beneﬁt from the advancement of spring events is unknown.

Highlights

Over the past decades many organisms have advanced the timing of spring events, most likely in response to recent climate change (e.g. Stenseth et al 2002, Walther et al 2002, Parmesan &Yohe 2003)
At present our understanding of these patterns in migrant birds is somewhat biased towards the situation close to the breeding areas, which makes it difficult to identify to what extent arrival patterns in Northern Europe are caused by processes in Africa or along the migration route through Europe
In order to see if migration speed varied over the season we tested if there was a relationship between species-specific arrival dates on Capri and the differences in median arrival dates between Capri and Ottenby

Summary

Introduction

Over the past decades many organisms have advanced the timing of spring events, most likely in response to recent climate change (e.g. Stenseth et al 2002, Walther et al 2002, Parmesan &Yohe 2003). Most ornithological studies demonstrating temporal trends towards earlier spring arrival or egg-laying dates have been carried out in the temperate region of Europe and North. At present our understanding of these patterns in migrant birds is somewhat biased towards the situation close to the breeding areas, which makes it difficult to identify to what extent arrival patterns in Northern Europe are caused by processes in Africa or along the migration route through Europe. One hypothesis to explain how tropical migrants can advance their spring arrival to Northern Europe is that the migration speed through Europe has increased, as suggested by e.g. Hüppop &. A more rapid spring migration in response to increased temperature en route has recently been demonstrated in the Pied Flycatcher

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