Climate change: Winter migration of birds from Europe to Africa may end, researchers warnÂ
The winter southwards from Europe to Africa may become a thing of the past thanks to the impacts of , a study has warned. Many species are already spending up to an extra two months in their summer breeding grounds already, a team of researchers led from Durham University found. They came to this conclusion after studying more than 50 years of trans-Saharan migratory bird sightings from both Gibraltar and The Gambia. Among the affected species are some of Europe's most common migratory birds including Nightingales and Willow Warblers. The team's data suggest that these birds are able to survive longer in their European breeding grounds than before and may one day not need to migrate at all. The findings show that birds are not just timing their migrations based on day length, but make nuanced decisions factoring in climate and vegetation availability. It is estimated that some 4,000 bird species around 40 per cent of the world's total undertake regular migrations. 'If the trends we have seen in this study continue we may see that, in time, some birds will spend no time at all in sub-Saharan Africa, and instead spend the full year within Europe,' said paper author and Durham University ecologist Kieran Lawrence. 'The changes in migratory habits we are already seeing could lead to longer breeding seasons for these species, as well as knock-on effects on other species both here in the UK and in the traditional winter migration destinations. 'In Europe, the longer presence of traditionally migratory birds could lead to increased competition for autumn/winter food and resources for resident bird species that do not migrate. 'Meanwhile, in the traditional migration destinations of sub-Saharan Africa a reduction in the time migratory birds spend there could have implications for ecosystem services such as insect consumption, seed dispersal and pollination.' In their study, Mr Lawrence and colleagues analysed data on local bird sightings collected by ornithologists in The Gambia from 19642019 and members of the Gibraltar Ornithological & Natural History Society from 19912018. From this, the team assessed changes in migratory bird arrival and departure dates over time, comparing this with observed climate and vegetation changes. The researchers found that birds are arriving at their winter migration destinations later into the Autumn than they were in the past and also heading back north earlier in the spring. 'Next, we aim to apply a new model, which we are developing at Durham, to simulate these complex migrations,' added lead author and Durham University bioscientist Stephen Willis. This model, he explained, could be applied 'to future scenarios to understand how the patterns we have identified in trans-Saharan birds over recent decades may continue or change.' 'It is very satisfying to see the constructive way the Gambian migrant bird records are now being used to highlight the changing migratory patterns of these species,' said paper author Clive Barlow of the Birds of The Gambia 'Until the current research, no-one had realised the extent to which migrant birds are spending less of the year in sub-Saharan Africa,' he added. The full findings of the study were published in the journal .