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How long does it take for mallards to go through the molting process and what are the differences between the first and second molt?

Q: How long does it take for mallards to go through the molting process and what are the differences between the first and second molt? –Bobby Wooldridge

A: Great question! I’d like to start off by answering a question that I think a lot of folks out there have and that is, why do ducks molt? As we all know, ducks go through a lot in a typical year. There are two migrations (one in the fall and one in the spring), they’re in the water a large percentage of the time, and they live out in the elements including inclement weather. Because of all this, their feathers wear out and need to be replaced. Molting their feathers requires a lot of protein and is a very energetically expensive process meaning that it uses up a lot of reserves that they carry.

As you stated, mallards molt twice a year, but there are distinct differences in the timing, duration, and characteristics of each molt. We’ll start off by talking about drakes and the molt from their colorful breeding plumage (also known as their “alternate” plumage) into their drab, non-breeding plumage (also known as their “basic or eclipse” plumage). This molt takes place after the breeding season when mating has been completed, typically late-June or early-July. During this molt, ducks molt their flight feathers. What is interesting and what sets ducks apart from a lot of other bird species is that ducks molt all of their flight feathers at the same time and are actually “flightless” for a period of about 3 weeks. As you can imagine, a flightless duck is truly a “sitting duck” when it comes to safety from predators. This is why drakes molt into a basic plumage that resembles a hen prior to molting his flight feathers. It doesn’t take too long for drakes to molt into this basic plumage, usually a couple of weeks. Once the molting of their flight feathers is complete and they have the ability to fly again, drake mallards begin the slow process of molting back into their breeding plumage. This molt takes considerably longer to complete simply because they have exhausted all of their stored reserves on the previous molt and don’t have the protein available to molt quickly. Coupled with fall migration (also energetically expensive) and you can see why it takes a while. Also, during the migration, mallards take advantage of easy food in the form of small grains in agricultural fields which are a great source of carbohydrates but not a great source of protein. Therefore, length of the second molt into the breeding plumage can vary quite a bit depending on what the individual duck is eating and how much energy they are putting into migration.

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