The common blue butterfly has declined significantly with loss of flower-rich grassland. Its welfare depends on bird's-foot trefoil availability and traditionally managed short grassland.
Common blue welfare depends on the abundance of bird's-foot trefoil in warm, traditionally managed grassland. Agricultural improvement eliminating flower-rich swards removes larval food plants. Road verge management cutting before seed set removes breeding sites at grassland margins. Conservation grazing that maintains short warm turf with abundant legumes supports both larval food and adult nectar sources. Road verge management timing protocols that delay cutting until after August allow late broods to complete development.