Other exponents of the united front in domestic matters are the brush turkeys of Australia, exotic birds that work together to accumulate heaps of decaying vegetation. Large communal mounds are thus built; and eggs deposited in the heat-generating mass hatch without benefit of brooding. Finally we turn to those winged citizens who gain a measure of nest-security by the nature of the situation they select. The voluble cactus wren of south-western desert lands makes use of a time-honoured method of household "insurance." The spiny, protective maze of the treacherous cholla cactus is its favoured home-site. But in a region so blessed with barbs and thorns it can afford to be versatile. This giant among American wrens often places the large, cylindrical grass house among the spears of Spanish bayonet, in the thorny tangles of cat's-claw or mesquite, and amidst the keen bristles of Joshua trees. The owner readily pops in or out at the tunnel doorway, but a hand thrust into the feather-lined interior suffers cruelly from the host-plant's spiny armament.

The osprey, a feathered fisherman of worldwide distribution, owes its extensive range in part to the inaccessible nesting sites that insure increase of its kind. Islands have similarly isolated the gulls, pelicans, petrels, shear waters, penguins, puffins and allied hosts through the ages. Marshes and swamps have long provided haven for hunted home makers, while that fraternity of carpenters, the woodpeckers and nuthatches, makes use of the forest's stout walls in its own singular way. The floating platforms built by grebes are a superb utilisation of the protective conditions of their aquatic habitat.

Dead reeds, grasses, water weeds, mud, and other decaying vegetable matter, piled skilfully upon green stalks to give the structure minimum buoyancy, form low, offshore nests of deceptive appearance. Attached loosely to the surrounding stems, they rise or fall with changing water levels. Being only soggy collections of old marsh growth, they are as little likely to attract attention as the "water witches" themselves. The pied-billed grebe may not even anchor its floating egg basket, but lets it drift at random about the cattail pond.

Situation of nest site is a prime factor in the locations sought by breeding bank swallows. And once they have found a bluff or bank to their liking they will confirm their troglodyte ownership by annual occupation. Kingfishers have taken a cue from them, and the vertical stream-cuts along its chosen creek are this feathered Waltonian's idea of a happy homestead. At the end of a narrow nest-tunnel, a tufted puffin's great, uncouth beak becomes a truly formidable weapon in defence of her subterranean, sea-island home.