The Fairy Martin (Petrochelidon ariel) is mainly a summer visiting bird in my part of Australia. Like many Martins, they make nests from mud. In the case of Fairy Martins the nests are a characteristic bottle shape.
These birds were follwing the description in the guide books to perfection by building their nests under a bridge in the Dandenong Wetlands which I visited last week. These birds were obliging as sneaked up on them to get the photographs. You can see that a number of the birds have a beak full of mud, ready for nest building.
I went back to this area the following day, but after a night of heavy rain I think that the nest site may have been flooded out, as the birds were still there, but there was no sign of nest building. Also, the water was almost filling the arches of the bridge - so, I'll find time to go back soon and see what is happening.
As ever, to join in with WBW click on the link below. SM