All About Wood Ducks At Union Bay

 Here is a recent post from the Union Bay Watch Blog published by Larry Hubbell, long-time local photographer and birder.

Ducks on Ice

Wood Ducks are one of my favorites.

Superficially, they can be somewhat similar to Mallards. For most of the year the males of both species have green heads, chestnut-breasts, canvas-colored sides, mostly-dark tails, and a band of white on their lower necks. 

Contrasting and observing these two species is a great place to start if you are just getting interested in birds. They are easy to find in the shallow waters around Union Bay. For the more experienced birders, these two species also have some more subtle differences.

For example, earlier this month when much of their preferred habitat was iced-over, I became entranced by a pair of Wood Ducks paddling through Duck Bay in the Arboretum.

When the male began climbing onto the edge of the ice, I thought this is interesting. 

The ice broke and I wondered if he would try again.

Instead, as the "berg" partially submerged, he pecked at the surface. Apparently, some small source of food floated off of the ice and became easier to retrieve.

Looking to the right, I noticed the female was having better luck getting onto the ice.

However, almost immediately she was also searching for food.

The male continued feeding. Even though I could not see anything on the ice, they must have been finding something really minuscule to eat. 

As they continued searching, a female of another species paddled past. Females are generally less colorful than males and therefore a bit more challenging to identify. 

I will leave this one unidentified as a challenge for the more experienced birders. However, she will be identified in the Going Native section at the end of the post.

Three Mallards paddled over. They were apparently curious what the Wood Ducks were eating.

The male Wood Duck sidled away but continued looking for food. Clearly, the relatively larger Mallards intimidated the smaller Wood Duck.

On average, Wood Ducks weigh around a pound and a half while Mallards weigh around two and a half pounds. There can be considerable variation in their weights. Examples that explain the variation may include the seasonal availability of food, whether a female has just laid eggs, whether the birds have just migrated hundreds of miles, or whether the shallow water where they normally feed is frozen over. 

Both species are considered dabbling ducks.

Neither species normally dives to chase fish or pull up the vegetation that grows below deeper water.

Although, this does not imply that they cannot dive. It is just not part of their preferred method of feeding.

The dive above was apparently part of a bathing display.

Which was followed by this flashing of wings.

Wood Ducks will often do a bathing display after mating and sometimes before as well. The males also do a variety of other displays including head jerks where they throw their heads backward.

Mallards often do head-pumping displays as part of courtship.

This can be easily overlooked since the bird is simply lowering its head. However, if the female responds the same way, this interaction often culminates in mating.

Another curious behavior is the way a Mallard will fully-commit to a head-down search for food. You would think this behavior would result in Bald Eagles plucking the unwary out of the water. Apparently this does not happen often enough to offset the value of the food they find.

On the other hand, Wood Ducks are generally more skittish than Mallards. As a matter of fact, while researching this post, I was not too surprised to learn that I had no photos of a Wood Duck feeding in this manner.

Speaking of Wood Ducks feeding, the male which we were following earlier, continued to search the edge of the ice.

The Mallards carefully observed his behavior, however they did not attempt to intervene or mimic the process. They simply sat as if they were waiting for the ice to melt.

Even though these birds live in the same habitat, and often eat similar food, they still have different habits and styles of feeding and mating.

Here are some other ways in which the two species differ. 

1) Wood Ducks nest in cavities. They will reuse pre-owned Pileated Woodpecker nest sites or artificial nest boxes. Nesting Mallards generally hide in tall grass and simply nest on the ground. Since Wood Ducks spend more time in trees they also have claws for climbing. Click Here to see photos of Wood Ducks in trees.

2) Mallards migrate more extensively. In North America, Mallards breed in much of Canada and virtually all of Alaska. Wood Ducks breed only as far north as southern Canada. Both birds breed in most of the lower 48 states. However, Mallards are scarce in Southeast Florida, and breeding Wood Ducks can be are hard to find in Utah, Arizona, and New Mexico. 

Because of the Wood Duck's nesting constraints, i.e. natural nests are normally only found in holes in large, dead, standing timber, they tend to nest in fewer locations than Mallards, especially in the Great Plain's states. By the way, unlike Wood Ducks, Mallards also breed in Europe and much of Asia.

After the breeding season, for three of four weeks both species replace their flight feathers, during which time they lose the ability to fly. This occurrence is most obvious among males because they also lose their breeding plumage. This makes them look a lot like females. During mid to late summer, people occasionally ask, Where did all the males go? This non-breeding plumage is generally referred to as eclipse plumage.

At this time, the male Mallards can be most easily identified by their yellow bills, which contrast quite clearly with the orange and black of a female's bill.

With male Wood Ducks, their most striking feature(s), during eclipse plumage, are their red eyes.

First-year males look similar to adult females and adult males in eclipse plumage. Although in late summer they often develop white "finger-like" markings on the face. These markings normally indicate a male. In combination with dark eyes, the markings suggests a young male who is not yet fully mature.

When you visit Union Bay, in 2022, I hope you are inspired to take a closer look at the ducks!