Widespread declines in house martin numbers have been reported from central and northern Europe since 1970.
House martins and the weather
From 1970-2014 there was a 47 per cent reduction in numbers of house martins with a 10 per cent reduction between 1995-2014. They currently have Amber status.
House martin populations are affected greatly by weather.
They require rain so that there will be plenty of wet mud to build their nests as well as warm weather to ensure there are plenty of insects for them to eat. When weather is either cool or dry this causes problems with insect presence and mud availability impacting on their ability to breed. In dry weather, making an area of wet mud can be beneficial to them to make their nests.
Their numbers have also been impacted by reduction in suitable nesting habitat due in part to barn conversions.
Their habitat in their overwintering grounds in Africa is also being degraded.
Large-scale mortality is regularly recorded during and after periods of bad weather, during both breeding and migration. On the other hand, hot and dry weather can result in mortality through dehydration and heat stress.