Do Ducks Have Periods? (9 Facts About Ducks Reproductive Cycle)

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Even though it can be an uncomfortable subject sometimes, you may be wondering if, like humans, ducks have periods. This is a legitimate question when trying to understand the reproductive cycle and life of your ducks.

Do ducks have periods? Unlike some animals, ducks do not have periods. They ovulate, but they do not have menstrual cycles, and without a menstrual cycle, ducks cannot have periods. Interestingly, while most mammals share a similar reproductive system, only a few menstruate.

Menstruation involves shedding the uterine lining in the absence of insemination and in response to certain hormones.

But ducks do not have the typical mammalian uterus, so ducks do not have the necessity for a period. While they have a shell gland, which is sometimes referred to as the avian uterus, it is nothing like the mammalian uterus.

The function of the shell gland in ducks is to form a shell around fertilized eggs. Conversely, the role of the mammalian uterus is to nurture fertilized eggs and birth live offspring.

There is more to know about ducks having or not having periods. This article will shed more light on the ducks reproductive cycle.

9 Facts About Ducks Reproductive Cycle

Most Ducks Have 3 Phases of Reproductive System Development– Most ducks are seasonal layers, and seasonal laying birds have 3 phases of reproductive system development. These phases are the prenuptial acceleration phase, the culmination phase, and the refractory period.

In a duck’s ovary, there are thousands of tiny follicles. When the prenuptial acceleration phase starts, the follicles begin to mature hierarchically. This way, they will not all reach maturity at the same time. In the culmination phase, egg-laying starts, and the ovary looks more like a bunch of grapes as the follicles develop. The refractory phase is the period during which the duck takes a break from laying. In this phase, the follicles shrink, and the ovary shrinks accordingly and becomes inactive.
Ovulation in Ducks Is Hormonal-Ovulation in ducks is triggered by an increase in two hormones. These hormones are follicle-stimulating hormone and luteinizing hormone. They stimulate the development of follicles and the subsequent release of an ovum from the ovary.

Ovulation in ducks occurs at a fixed time after oviposition (after an egg is laid).
Ovum-Releasing Follicles Regress and Are Absorbed After Ovulation – After ovulation, the follicle that released the ovum regresses. While regressing, its cells are replaced with lipid-laden cells. This lipid is later converted into sex hormones, including progesterone.

The hormones prepare the oviduct for egg development, and they may make the duck go broody.
Ducks Become Sexually Mature Within 4 to 7 Months – Ducks usually become sexually mature within 17-30 weeks. Lightweight ducks typically mature earlier than heavier ducks. On average, a lightweight duck becomes sexually mature within 17-24 weeks, while a heavyweight duck matures in 20 to 30 weeks.
Ducks Have Only One Functional Ovary and Oviduct – When in embryonic form, female ducks have two ovaries and oviducts. However, when mature, only the left ovary and the left oviduct remain functional. Both of these organs are found in the body cavity around the spine.

The growth of the right ovary and oviduct regresses, and when the duck fully matures, it loses function totally.
Ducks Can Produce Eggs Without Drakes – Female ducks produce eggs with or without drakes. Eggs laid by ducks following insemination by drakes are called fertile eggs. While those formed without drakes are infertile eggs. There appears to be no difference in taste between fertile and infertile eggs.
There Is a Short Window for Sperm to Fertilize an Egg – When an ovum is released from a duck’s ovary, it enters the first section of the oviduct – the infundibulum.

The ovum spends around 30 minutes in the infundibulum before it is transferred to the magnum. For an egg to be fertilized, sperm must get to it within the 30 minutes the ovum spends in the infundibulum.

Interestingly, sperm is sometimes stored in the infundibulum. So, a drake does have to inseminate the duck immediately. Nonetheless, it is said that a duck’s egg may only be fertilized if it has mated with a drake 7 days before ovulation.
Shell Formation Takes Place in the Isthmus and Shell Gland – For ducks, shell formation starts in the Isthmus, the section of the oviduct after the magnum. In the Isthmus, the 2 membranes of the eggshell are formed. Also, calcification of the shell is initiated, and some protein is added to the albumen.

In the shell gland, a lot of calcium is extracted from the bloodstream. The extracted calcium is used in forming the testa and cuticle of the shell.
An Egg Spends About 20 Hours in the Distal Part of the Shell Gland Before It Is Laid.