Two pairs of House Martins have started nest building on the house. After several days of singing and chattering loudly from dawn every morning they have made their decision and are adding mud pellets. First they build a substantial shelf about five inches from the soffit board. This will support the side walls as they progress. Once they have built a substantial foundation they will start roosting on it. I love the sound of martins and their graceful flight as they approach the eaves. They are collecting mud from a puddle about 100metres from the house but have been delayed over the last two days by the strength of the wind. At least the rain will have topped up their mud supply.