Ducks

Ducks are kept for two returns at once. They lay well - commercial strains give 300 to 350 eggs a year against about 250 for a hen - and they hunt slugs and snails out of living ground cover better than any other bird. Where a flock is grazed hard through the growing season, slug numbers fall by roughly three quarters. The same appetite does a second job: slugs and snails carry the middle stage of a worm that infects sheep and goats, so running ducks through a paddock before the small ruminants come in breaks that cycle.

The most useful thing to know before building for ducks is that swimming water is not required. A duck is a dabbler, feeding by tipping tail-up in the shallows rather than diving, and suits water under about 45 cm (18 in) deep, so a pond is a convenience and not a condition. What they must have is drinking water beside the feed at all times, because a duck can choke on dry feed without it, refilled and cleaned daily. Shelter is at least 0.37 to 0.46 square metres (4 to 5 sq ft) of dry, draft-free floor per bird, and it has to be built against predators rather than merely roofed, since owls, foxes and raccoons take birds overnight. Ducklings need a brooder, a heated pen started at 32 to 35 degrees C (90 to 95 F) and stepped down about 3 degrees C (5 F) a week until they feather.

A duck does not scratch the way a chicken does, so it belongs among standing perennials, mushroom logs and an orchard understorey rather than on a seedbed. It will still eat the crop it is protecting where that crop is soft and within reach of its bill, so logs and low fruit may need fencing of their own. Its manure runs far wetter than a hen's, so the house is cleaned daily rather than weekly. Meat is the weakest return: carcass weight depends heavily on breed and the economics only work at a scale far past a household, so eggs and pest control are the yields to count on.