Experts from our Department of Biosciences think this is a possibility after new research found that some species of trans-Saharan migratory birds, like Nightingales and Willow Warblers, are spending as many as 50-60 fewer days a year in their non-breeding grounds in Africa.
Changing historical patterns
The research was the first to look at how long trans-Saharan migratory birds are spending in their traditional winter retreats in Africa.
Using over 50 years of bird records collated by ornithologists in The Gambia and Gibraltar, our experts explored the arrival and departure dates of migratory birds over time. They also related these observed changes to changes in climate and vegetation.
They found that many of Europe’s most common migratory birds are spending longer in their European breeding-grounds; departing later for sub-Saharan Africa and choosing to return to Europe earlier.
This change suggests that the birds are able to survive longer in their European breeding grounds than before, leading experts to question whether some birds may eventually stop their traditional long-distance migrations.
Nuanced decisions and knock-on effects
It was previously thought that birds timed migration based on day length, however the findings from this study suggest that birds are also making more nuanced decisions, responding to factors such as changes in climate and available vegetation.
Changes in migratory habits could lead to longer breeding seasons for these species, and have knock-on effects on other species, both in the UK and in traditional winter migration destinations.
In Europe, the longer presence of traditionally migratory birds could see more competition for autumn/winter food and resources for resident bird species that do not migrate.
Whilst in the traditional migration destinations of sub-Saharan Africa a reduction in the time migratory birds spend there could have implications for ecosystems such as insect consumption, seed dispersal and pollination.
More on:
Posted On: 25/10/2021