AMERICAN WOOD DUCK
By Paul Dye

A duck of forested shallow water bodies and swamp, the wood duck is commonly known as woodie in the US, and as Carolina duck in Europe. It is considered by many to be North America’s most colorful waterfowl species. It scientific name Aix Sponsa, loosely translates into "water bird in bridal dress". Those living in remote habitats are observed to be extremely shy of humans, while on occasion woodies get reasonably tame and trusting, especially while wintering in a public park or zoo. They are considered to be the American duck most fond of fruit, although acorns and nuts are relished even more.

Wood Duck Drake -  Photo by James T. Jones

Currently the wood duck is one of the most common waterfowl species breeding in the United States. In the early years of the 20th century that was not the case, wood ducks had virtually disappeared from much of their former range, which included the eastern half of the US and the far west coast. Much of the blame has been attributed to wetland drainage, and the elimination of their nesting sites in hollow old trees due to excessive cutting of great areas of hardwood forest. Also contributing to the decline may have been the introduction of automatic shotguns, market gunning for meat and feathers and unregulated sport hunting. Possibly in response to the establishment of the Migratory Bird Treaty in 1916 and the enactment of the Federal Migratory Bird Treaty Act in 1918, wood duck populations began to rebound, probably from remnant populations left in isolated habitats. The development of the artificial nest box in the 1930’s brought about an almost immediate increase in wood duck numbers, as they readily accepted these structures. Their spectacular population recovery brought them to a high of 3.5 million by the 1960’s, when they began their continuing slow decline due to impacts of an increasing human population coupled with habitat loss. Although they were totally protected from 1918 to 1940, a limited hunting season resumed in 1941 and continues to the present. They currently rank third after mallards and green-winged teal, in terms of numbers taken by hunters.

The normal range of the wood duck is largely limited to the United States and the southern edge of Canada. Although wood ducks in the most northern part of their range are mostly migratory, those that breed in areas where the freeze-up is not extensive often do not migrate, but simply gather at secluded local freshwater swamps and marshes. In the area of my farm, north of Seattle, winter is the season, when up to a hundred woodies often rest on my trout ponds and marshes, occasionally gathering in large numbers on top of my aviaries. It’s hard to be sure whether they’re attracted by my captive woodies, or by the food- producing nut and fruit trees, grain fields and water plants I’ve planted. Those far west, birds that do migrate winter mostly in California, while those that nest near the east coast follow the coastal plain south to the Carolinas, Georgia and northern Florida. The more inland segment of the eastern population is known to generally follow the Mississippi valley south to Arkansas, Louisiana, Texas and Mississippi.

Wood ducks are usually first year breeders, making them quite prolific if breeding conditions are ideal. Indications are that wild pair bonds are not permanent, as females usually do the incubation of eggs and brood rearing without the company of their mates. Some males do, however, stay near the nest and join the female when she leaves the nest to feed for the first week or so of incubation.

The preferred nest sites for woodies are cavities in trees, usually after they’ve been abandoned by Pileated woodpeckers or Flickers. In parts of their range they have to compete for use of these cavities with squirrels, bees, hornets, sparrow hawks, screech owls, hooded mergansers and starlings. They also run the risk of predation of these nest sites by raccoons and snakes, among others. Although they prefer nest sites close to water it’s not unusual for them to nest up to a mile from its safety, requiring a long and risky trip for their newly hatched ducklings. The lack of natural cavities can usually be made up for by the installation of nest boxes in proximity to good brood rearing habitat. Good designs for woodie nest boxes are available from many sources, such as university extension offices, wildlife departments, and at http://www.npwrc.usgs.gov/resource/1999/woodduck/wdnbox.htm

on the internet. When planning the location of nest boxes it is important to keep proximity to productive wetlands and the discouragement of predators as primary considerations. The proximity to wetlands that can support brood rearing assures that a majority of the newly hatched ducklings will make it at least that far past an assortment of predators that consider duckling a favored meal. A nest box installation that incorporates deterrents to predator ingress increases the odds that the eggs will survive the approximately 30 days of incubation to the point of hatching. An example of a successful deterrent is a metal collar around the mounting pole that prevents raccoons and snakes from reaching the nest. An example of a way reported to discourage starlings from competing for nest boxes is to allow the ingress of some light, as starlings seem to be less light tolerant than wood ducks.

Once they safely reach the safety of a water area with adequate vegetative cover the brood begins the dangerous process of survival. Insects, aquatic invertebrates, and vegetative material, such as duckweed and small seeds provide the nutrition needed for rapid growth. Although broods sometimes number as high as 13 at hatch, it’s quite an accomplishment for even half to survive the onslaught of fish, frogs, turtles, crows, birds of prey, minks, otters and raccoons. There have been reports of second nests and broods in the southern portions of their range, however predation usually takes a higher percentage of these late broods, often resulting in less than 25% survival.

Molting of male wood ducks takes place shortly after they abandon their mates on the nest. The females molt later, after their broods are fledged. I both cases they seek out heavily vegetated wetlands and watercourses where they stay hidden until flight is regained. Here at Northwest Wildfowl Farm and the adjacent Corson Wildlife Area, they use the man-made 8 acre swamp, and the slow-moving stretches of Catherine Creek.

WOODIES IN THE AVIARY

After nearly a life time keeping and breeding woodies I still find them fascinating, if not particularly challenging. That fascination partly stems from the fact that even after a dozen or more generations of captive breeding they still usually retain their shy and distrusting nature. In the odd cases where one is kept alone, or they are kept in constant association with humans, they have been known to become tame. This tameness often ends, and their shy nature usually returns, when they are moved to a new aviary or are tended to by someone new.

The reason I don’t particularly find them challenging is that compared to many other species, such as the seaducks, their dietary and nesting requirements are fairly simple to provide. Basic grain & poultry pellet feeds satisfy their nutritional needs, and the same basic cavity type nest boxes used for Mandarins and Ring Teal are adequate for their nesting needs. While on the subject of nest boxes I want to emphasize that a common mistake made by beginners is not providing enough boxes for the number of cavity nesting pairs housed in an aviary. I always recommend at least 3 nest boxes for each 2 pair of cavity nesting species of age to breed in the enclosure. The reason for this is that, for most of us, it is practically impossible to locate all boxes in places desirable to our ducks, and frequently they will spend valuable time fighting for a particular box instead of getting down to serious nesting. Many new aviculturists have had a disappointing first season because of this common mistake.

While most experienced waterfowl aviculturists find woodies fairly easy to raise, many people attempting it for the first time, are disappointed by excessive losses of the ducklings at 4 - 6 days of age. This is not unusual, and usually results from the fact that they did not settle down enough to begin eating, or did not like the food offered or the way it was presented. Let me describe the way I do it, so that those who desire to do so can adapt the ideas to their own conditions.

I always start newly hatched Wood Ducks off in dry brooders for the first 1 to 2 weeks. I recently have been using 33 gallon plastic totes, available in most stores with a hardware department for this purpose. The bottom of these totes is lined with newspaper, which is then covered with paper toweling for the first 5 - 7 days. The paper toweling provides good traction for the hatchlings, as well as a "spongy" base that depresses slightly from the weight of the duckling, causing any food nearby to move, making it look alive. This is especially true for our fairly new starter ration, Mazuri Waterfowl Starter, as it is a tiny round extruded pellet, that rolls and bounces quite easily. The food is presented in a very shallow food dish, but at first is also sprinkled directly onto the paper toweling around the food dish to give the duckling every chance to find and investigate it.

Providing the newly hatched woodies are comfortable in their brooder this investigation will begin shortly after they recover strength from the ordeal of hatching. During this period of investigation it is imperative that they find both food and water, as their little bodies will need this nourishment upon exhausting that supplied by their yolk sac. The first indication you will have that this introductory phase is not going well is if you see a majority of the ducklings crying incessantly and jumping against the side of their brooder, trying to escape. At this point it’s important to cover the brooder with a screen to keep them in while you solve their problem.

For me, the best way to assure that adequate water is found early, before the ducklings discover their fount, is to place a shallow pie pan near the fount, but far enough from the heat lamp to stay cool. This shallow pan contains small, clean rocks, ½" to 1’ in size to keep them from immersing in the water, becoming soaked and chilled. As soon as a majority of them are observed using the water fount the rock filled pie pan is removed, reducing the opportunity for them to make a wet mess of their brooder by tracking moisture about.

To expand a little on the use of the heat lamp mentioned earlier, I install it above the tote near the back end, the end furthest from you when you are doing any feeding or cleaning. I usually use 250 watt red infrared bulbs, but have found 125 watt bulbs to be adequate in some cases, depending on the ambient temperature in the room. There are two ways I’ve used to control the temperature under the bulb, rheostats, or by raising or lowering the bulb. The rheostat is by far the least expensive method, as it saves on electricity, but temperature at duckling level has to be monitored carefully to make sure they don’t chill as the room cools late is the day or when the weather changes. In my case, since as many as four different people may on occasion tend to the babies, and there may be 10 or more totes in use at once, I use the raising and lowering method, as it’s readily apparent from the height of the lamp and the temperature of the room whether the temperature of a tote needs to be double-checked. As with most other species, I strive to keep the temperature at 95 degrees f the first week, and then lower it by approximately 5 degrees each week.

Depending on their growth rate and overall condition, I try to introduce the young woodies to wet brooding at 7 to 10 days of age. The objective is to let them swim at least part of each day to develop their waterproofing. I use the same type of tote for a wet brooder that I do for dry brooding. I simply install a small drain and overflow and tilt the tote slightly to form a wet area in the low end. With the overflow installed properly you can use a basic ¼" drip irrigation system to have constant flow of water through each tote 24 hours a day. Both the wet and dry areas of the wet brooder will need to be thoroughly cleaned at least twice each day to maintain your ducklings in a healthy condition.

For those of you contemplating the rearing of wood ducks or who have been discouraged by problems, I hope I have provided some assistance.

References for some of the wild wood duck information:

Johnsgard, Paul A., Waterfowl Of North America, Indiana University Press,
ISBN 0-253-36360-8
Todd, Frank S., Natural History of The Waterfowl, Ibis Publishing Co.,
ISBN 0-934797-11-0
USGS, Wood Duck General Information, http://www.npwrc.usgs.gov/resource/1999/woodduck/woodduck.htm