Friday, April 25, 2014 - No Work… Here’s Why!
That’s right, the boat refit project has been delayed for a few days, and not by choice. A Mallard has taken up residence in a flower pot on the back deck. The boat is only a few feet from her nest and every time I get on board, she flies away.
We checked on line to see if we could find out how long she'll be nesting.
Here’s the story:
Mallard Nesting Behavior
I'm assuming your duck is a mallard. Few wild ducks of other species seem to nest around homes, but even if they do, their behavior is similar enough to the mallard that the following should cover them as well. If you are dealing with a Muscovy or other domestic breed, all bets are off...go see your local farmer or pet dealer for information.
Wild mallards typically nest on the ground, in tall grass and shrubs. Occasionally we find nests built on piles of decaying vegetation in the middle of a wetland. Even less frequently, they will nest in trees, most commonly in old crow or hawk nests. Man, of course, has provided all sorts of nesting structures that are placed in wetlands and designed to protect nests from predators. These are heavily used by mallards in some locations. Perhaps with brood after brood of ducklings hatching in artificial nest structures, it is only to be expected that some will also take up residence on a flower pot on your front porch or on your second story balcony. One other point on nest location: mallards are philopatric, which means that the hen frequently will return to the site of last year's successful nest; this may have implications for next year if you had to relinquish your barbecue to a mallard this spring.
Be that as it may, Ma Mallard typically lays one egg per day until she has accumulated a full clutch. Early in the nesting season, a full clutch averages 12 eggs. Hens that lose the first nest will commonly nest a second (and even third or fourth) time later in the summer; these "renesting" hens generally lay fewer eggs, commonly 8-10. The first few eggs are laid in a shallow "scrape" in the ground. As laying progresses, Ma will add grass, twigs, and copious amounts of her own down to the nest, resulting in a well insulated and surprisingly well camouflaged nest bowl.
During the laying period, Ma visits the nest for only about one hour per day. While there she lays an egg and works on nest construction. Don't be concerned if she skips a day. She does not incubate the eggs during the laying stage. Because no embryo development has occurred, weather conditions in her absence generally have very little effect on the clutch. An exception is a hard freeze, which may kill the embryos if it occurs before the hen has insulated the nest. Once she has constructed a nest bowl, she will cover the eggs with nest material whenever she voluntarily leaves the nest. This behavior makes the nest less obvious to predators, and protects the eggs from temperature extremes.
Incubation begins after the clutch is complete, and typically lasts for about 25-29 days. During this period she will usually cover the nest and go off to feed for about an hour each morning and afternoon. As hatch date approaches, she will begin to feign injury if she is disturbed. This behavior evolved to lead predators away from the nest...once she is a safe distance from the nest, her "broken wing" will miraculously mend, and she will return to the nest as soon as the danger has passed. This behavior is fun to watch, but be aware that she is risking real injury in the process.
Because no incubation occurred during the laying stage, all viable eggs will hatch within 12-24 hours of one another. After a short period of brooding the ducklings at the nest, Ma will lead the gang off to her chosen wetland. This may be up to 3 miles away, so don't be surprised if you don't see "your" brood on the pond right behind your house...she will take them to where she has found the best source of aquatic invertebrates to feed them. Not uncommonly, one or more unhatched eggs will remain in the nest bowl. Some of these are infertile; others are "addled" (eggs in which a partially developed embryo died during incubation). Discard the leftover eggs, but do it carefully; gas buildup in an addled egg can cause it to explode when handled, and the results are not appetizing.
By the way…if you are wondering about Pa Mallard, he's off looking for an unattended female during most of this. He and Ma stayed together during selection of the nest site and the laying process, but as Ma began to leave him for long periods during incubation, he gradually lost interest and flew the coop. Not politically correct, but that's nature for you.
Prior to today, she was apparently laying eggs; as mentioned in the article, one egg per day. She'd be on the nest for two or three hours and then leave until the next day, when she repeated the behavior. In eight days, she laid eight eggs. She started laying on the nest today, so we think she’ll be less skittish. Hopefully, I won't scare her when I get on the boat to work.
