Female ducks, or hens, typically lay a clutch of several eggs before starting the incubation process. This period of egg-laying can span multiple days, with the duck not beginning to sit continuously until her full clutch is laid. This ensures that the ducklings will hatch around the same time.
The Necessity of Incubation
Successful development of a duck embryo within its egg requires a consistent, maintained environment. The female duck provides the precise warmth and humidity needed, maintaining a temperature around 99.5°F (37.5°C) and relative humidity between 55% and 80%. This stable temperature is vital for embryonic growth. Without proper incubation, the embryo’s development falters, leading to its failure.
A duck’s body is adapted for this role; she develops a “brood patch” on her belly, an area of bare skin with an increased blood supply that directly transfers heat to the eggs. The duck also periodically turns the eggs, ensuring even heat distribution and preventing the embryo from sticking to the shell membrane. Interruptions to this continuous warmth, or fluctuations in humidity, can severely impact the embryo’s viability, making sustained incubation necessary for healthy ducklings.
Factors Influencing Incubation
While continuous incubation is important, a mother duck occasionally leaves her nest to feed, drink, or preen. During these brief absences, she instinctively covers her eggs with nesting material, often including down feathers plucked from her own breast. This covering helps to insulate the eggs, maintaining their warmth and concealing them from potential predators. The eggs can withstand these short breaks, but prolonged periods without the hen’s warmth can jeopardize the embryos.
The involvement of male ducks, or drakes, in incubation is minimal; they do not sit on the eggs. In many species, the drake’s role in the reproductive cycle is primarily mating, with the female assuming sole responsibility for nesting and incubation. Wild ducks build concealed nests, but some domestic breeds may be less inclined to exhibit natural brooding behaviors.
From Egg to Duckling
Hatching, the culmination of incubation, takes about 28 days for most domestic duck breeds, though Muscovy ducks require approximately 35 days. Hatching begins with an “internal pip,” where the duckling breaks through the inner membrane and into the air cell within the egg, taking its first breath. This is followed by an “external pip,” creating a small crack in the shell.
The duckling then uses a specialized “egg tooth” and a “pipping muscle” to crack the shell in a circular motion, a process known as “zipping.” This hatching sequence can take 12 to 48 hours. Once hatched, ducklings are precocial, meaning they are mature and mobile, able to walk and follow their mother shortly after drying. They rely on the mother duck for continued warmth, protection from predators, and guidance in finding food and water, often imprinting on her within hours of hatching.