Causes and consequences of spatial variation in Willow Warbler sex ratios
New BTO research shows a recent imbalance in Willow Warbler sex ratios, with 60% of adult birds being male. Such a skewed ratio has implications for the conservation of this migrant species.
Northern Wrens weather the winter better than southerners
New BTO research reveals that one of our most widespread songbirds – the Wren – varies in its resilience to winter weather, depending on where in Britain it lives. Scottish Wrens are larger than those living in southern Britain, and are more resilient to hard winter frosts.
Monitoring Little Owls with playback
Little Owls are in decline in the UK, but are hard to monitor, making it difficult to establish this species' conservation and management needs. Newly-published research by the BTO demonstrates how playback could be an effective tool for helping to detect and monitor this species.
Climate change drives bird populations on both sides of the Atlantic
New research involving the BTO shows how the populations of hundreds of species of common birds are consistently responding to the effects of climate change on two continents - Europe and North America.
Summer migrants stay for longer as the UK climate warms
New BTO research has used volunteer data from long-running citizen science schemes to show how the timing of bird migration to and from the UK has changed since the 1960s.