Egg Laying

By Dave Hanks

Egg clutch size is defined as the number laid by one individual in one continuous, uninterrupted period. All reproduction, including egg laying, is under the influence of the endocrine system. The activity of this system is influenced by environmental factors such as: weather, length of daylight, amount of fat on the body, or the amount of food available. I have learned, through practical livestock experiences, that females that are too fat or too thin do not come into estrus very readily. Thin females that suddenly begin to increase in weight are the best candidates for pregnancy.

The time required for the oviduct to secrete the material to surround the ovum and form a shell is anywhere between 24 hours, in small birds, to 48 in larger ones. Therefore, each egg is laid at the same time of day, usually in the cool of the morning. The clutch size is determined by these limiting factors: (1) the physiological capacity of the individual, (2) the size of the birdís brood patch, (3) the mortality rate of the species, and (4) the largest number of young the parent can feed. Also, the closer one is to the pole, the greater is oneís reproductive capacity. Removing an egg daily from a nest will also stimulate the continual production in an innate effort to reach the normal clutch size dictated by the birdís DNA. Domestic chickens are stimulated in this manner, when eggs are gathered every day.

The WOOD DUCK is a tree cavity nester (one of only a few tree nesting ducks) and fewer eggs are laid (average of 12) than for a ground nester (like a Mallard). This is because the eggs are incubated in a safer environment. This most glorious duck, needs streamside or wetland trees as habitat items. Newly hatched young will jump from the tree to the water and can survive a 40 foot fall without harm. Courtship begins in the fall and continues through winter and spring. The pairs are monogamous during the year and the male is very territorial during the mating season.

Wood Ducks are identified by their many colors: their iridescent green and purple crests, cinnamon chests, white bellies, red eyes, and white stripes.

(A Wood Duck clothed in his many colors)