I stood enthralled and watched at least 36 House Martins swooping and descending together to collect mud (for nesting) from a small area of wet ground and a shallow puddle, created by some sort of leakage running down the side of the track that leads down from the housing estate.
Everywhere was so very dry and this seemed to be the only wet patch in the vicinity. The martins must have been desperate to get their nests made and start laying. Hence the large numbers seen at once. It was an equivalent of a feeding frenzy. Alwyn.