Variation in climate warming along the migration route uncouples arrival and breeding dates

Abstract

Migratory species are of special concern in the face of global climate change, since they may be affected by changes in the wintering area, along the migration route and at the breeding grounds. Here we show that migration and breeding times of a trans-Saharan migrant, the pied flycatcher Ficedula hypoleuca, closely follow local temperatures along the migration route and at the breeding grounds. Because of differences in long-term temperature trends of short within-spring periods, the migration period and the time interval between migration and breeding dates of this species have extended in SW Finland. Temperatures in northern parts of Central Europe have risen at the time when the first migrants arrive there, facilitating their migration northward. Temperatures later in the spring have not changed, and the last individuals arrive at the same time as before. The timing of breeding has not advanced because temperatures at the breeding site after arrival have not changed. These results show that the pied flycatchers can speed up their migration in response to rising temperatures along the migration route. Our results strongly indicate that the effects of climate change have to be studied at the appropriate time and geographical scales for each species and population concerned.

Trends and Temperature Effects in the Arrival of Spring Migrants in Portland (United Kingdom) 1959–2005

“…Reasons for this may include the (unexamined) influence of environmental conditions over the (usually greater) African portion of their migration journey, the rather crude nature of monthly temperature data for birds that can cover several hundred kilometres each day, an inexact knowledge on the exact migration route of the species and the possibility that the route may vary from year to year (Huin & Sparks 1998). Explanatory power in our results is generally lower than those reported by Ahola et al (2004). However they analysed median arrival dates, which have been shown ) to be less variable than FADs, and from a time series of shorter duration.…”

The Relevance of Environmental Conditions for Departure Decision Changes en Route in Migrating Geese

“…Consequently, species or populations wintering closer to their breeding areas and/or staging for longer or more often during migration should be better able to adjust to climate change. Although long-distance migrants wintering south of the Sahara are thought to rely mainly on internal rhythms and photoperiod to schedule their migration (Berthold 1996, Gwinner 1996b, it has recently also been found that environmental conditions in the wintering areas and temperatures en route are important (Ahola et al 2004, Saino et al 2004, Hu¨ppop and Winkel 2006. However, whether and how well short-and long-distance migrants can adjust to climate change by phenotypic plasticity will depend on the nature of the relevant factors.…”

Populations of migratory bird species that did not show a phenological response to climate change are declining

“…Most of these observatories are located in central Europe and southern Fennoscandia, and intercept populations of migratory birds on the way to their breeding grounds (9). This fact prevented us from quantifying change in migration phenology in relation to local climate, because climate during any part of the migratory path could potentially affect change in phenology (44,45). Therefore, we analyzed change in phenology over time, assuming that such change was due to change in climate, as has been done in other studies (8,9,21,35,46,47).…”