The bird appears to have an alate termite in its bill. Obviously there must have been a termite hatch nearby where winged male and female reproductives were released. For a short period these alate termites flutter around in a dense cloud to seek their mates, soon landing on the ground where they shed their wings.
Birds are always attracted to such termite hatches, as they provide ready food. The termites are easily picked off from the air or from the ground. After the feasting is over, the only evidence left is the pile of wings on the ground.