House Martin collecting mud

House Martin collecting mudYesterday I watched a little group of House Martins collecting mud by a drain. They were wary of landing on their own and they seemed to dance in the air together until a brave one landed and the others follow, then rapidly picking up bits of mud on their beaks, wings  kept high, giving the impression of fluttering butterflies. Then one after the other they would leave back to their nests. I tried to portray the distinctive feathered legs and toes of this species, and their awkward stance on the ground.