House martins are aerial insectivores that nest in colonies under house eaves. Their populations have declined significantly as modern buildings offer fewer nest attachment points.
House martin welfare in breeding colonies depends on access to appropriate nest sites and abundant aerial insects for chick provisioning. Modern buildings with smooth UPVC soffits provide no natural attachment points for mud nests. Artificial nest cups overcome this barrier and are demonstrably effective at establishing and expanding colonies. Insect availability determines chick survival rates and adult condition before migration. Gardens and neighbourhoods that reduce pesticide use and support insect populations directly improve house martin breeding welfare.