Martins are master builders of mudbrick

RETURNING from an unsuccessful search for gliders — possums not aircraft — I stopped to check a hollow fencepost near Lara.

Over the last few years it has been used as the nest site for various birds, first parrots then starlings.

This year it held two little pink nestlings, just hatched, and two blue eggs — a family of mynas.

Common mynas had taken possession, but rather than cramming it full of litter, there was just a bed of gum leaves on the floor.

Mynas, and starlings, often use a large amount of nesting material in the hollows where they raise their families. This makes it unusable by other birds in the following years.

But not here, not this time.

I’m always amazed at the skill and energy many birds use in building their nests. A few weeks ago I was shown a colony of fairy martins that had built their nests in a huge, disused concrete pipe.

There were dozens of nests, each built against its neighbour, much like a high-rise apartment block.

The martins use mud, beakful by beakful, with hundreds of pellets set as a master bricklayer would do. The nests are shaped like bottles lying on their sides in a haphazard stack, the entrance at the bottle neck.

But there is nothing random in the nest placements. Each has a clear flyway to and from the entrance, such that even with scores of birds coming and going, there are no collisions.

It is just mud that they use, with a few strands of grass, nothing to harm the place where the nests are built.

Other birds use equal skills when building their nurseries. Cuckoos don’t make their own nests, laying an egg in the nest of an unwitting host.