Banner Photo Credit: Isabella Loberiza

Welcome to the wonderous world of Wood Ducks! Through this blog, I hope to help share some of the unique facts, features and research that make this bird so amazing. I hope you enjoy and learn something new along the way!

Description and ID

Now I know what you’re thinking, “how am I EVER going to be able to recognize or pick out such a bland looking duck while out for a walk!?” Ok maybe not. If you were to ask most birders, they’d probably tell you Wood Ducks are one of the easier species to pick out of a flock, particularly if you see a male in breeding plumage. But still, here are some useful characteristics to look out for when looking for this stunning species.

          Male Wood Ducks (Aix sponsa) in breeding plumage are often dressed to impress and easy to pick out in a crowd. They exhibit an iridescent green head streaked with white, a slicked back crest and piercing red eyes (All About Birds). Their body is easily recognizable by their prominent chestnut-coloured breast and contrasting beige sides.

Female Wood Ducks are a little more modest in colouration than their male counterparts, but stunning birds as well! To find a female Wood Duck, look for a grey to brown coloured head with a grey crest and characteristic white teardrop shaped patch of feathers surrounding their eyes (Ducks Unlimited). They have white throats and grey-brown breasts flecked with white that fades into a white belly.

Figure 2. A) Adult female in breeding plumage. Photo Credit: Samuel Detillieux. B) Female (left) and male (right) in breeding plumage. Photo credit: Samuel Detillieux

You can also identify Wood Ducks by their unique vocalizations, click on the audio clips below to hear a few Wood Duck vocalizations!

Migration and Habitat

Alright, so now you know how to recognize a wood duck in the wild, but don’t grab your binoculars and favourite bird ID field guide just yet! First, let’s take a look at where you might want to focus your search to see one of these wonderous waterfowl for yourself.

Wood Ducks can occupy a wide range of habitats, including creeks, rivers, swamps and marshes (Birds of the World). They feed on mostly vegetation and insects from within their environment, with an increase of insect and protein consumption observed during mating season, especially in females (Landers et al., 1977).

If you live in North America, you probably won’t have to look too far. Ranging as far north as Nova Scotia and as far south as Florida and the gulf of Mexico, Wood Ducks can be found across most of North America (Animal Diversity Web).

About one third of Wood Ducks in the United States are non-migratory, but the remaining two thirds typically migrate in flocks of 6-12 individuals. Populations further north will normally begin migration earlier than their southern counterparts, beginning their flight to their overwintering grounds sometime from mid-September to mid-November. Migrating Wood Ducks who live farther south on the other hand will begin their flight to their overwintering grounds sometime from early-November to mid-December. On the West Coast, Wood Ducks will migrate from southern BC to the central valley of California, those migrating from the East Coast of Canada often make the journey to North Carolina and Wood Ducks from the interior seem to converge south of Kentucky along the Mississippi River floodplain. Migration back to breeding grounds are not very well understood, however early season migrators will begin arriving around late February (Birds of the World).

Mating Behaviour

Now that we know where to look for a Wood Duck and how to pick on out from a crowd, let’s talk about the types of things you might see Wood Ducks doing in the wild!

Courtship in Wood Ducks occurs primarily in the fall, with most pairings of mates having been determined by the end of January. Due to the limited number of nesting cavities suitable for Wood Duck to inhabit within their environments, having a mate earlier in the breeding season, or even prior to migrating to their breeding site can be hugely beneficial as it allows these breeding pairs to waste no time in selecting an advantageous nest ( Armburster, 1981).

Male Wood Ducks use a range of vocalizations and behaviours to show off their colourful coats and convey their fitness to a prospective mate, with multiple males often trying impress the same female at one time (Armburster, 1981).

Fun Fact!

One of these mating behaviours, called the wing-and-tail flash, is unique to the Wood Duck and their close relative, the Mandarin Duck (Aix galericulata). This behaviour is characterized by the male quickly raising their closed wings and tail, while showing their side and tipping their beak down to fully display their iridescent green crest to the prospective female (Birds of the World). This behaviour allows male Wood Ducks to take full advantage of the impressive display of colours that makes this species so recognizable!

Parenting Behaviour

Once a mating pair has been established, Wood Ducks usually exhibit a monogamous mating system but will change mating partners between seasons. Females will lay 6 to 15 eggs on average and after a 30 day incubation period, will have a fresh litter of chicks to care for. Once emerging from their egg, life moves quickly for the newborn chicks, only 24 hours after hatching their mother will call them out of their nest and after 56 to 70 days the chicks will be entirely independent. Only female Wood Ducks exhibit parental care (Animal Diversity Web). Amazingly, Wood Ducks will often have two broods in a single season (Birds of the World)!

Conservation Status

As of 2020, the Wood Duck is considered of least concern by the international union for conservation of nature (IUCN). In fact, Wood Duck are even one of the few species of birds who’s populations are rising!

However, this wasn’t always the case.

In the early 20^th century, the chances of Wood Ducks surviving the century were looking bleak. Due to the destruction of vital habitat and extensive hunting, Wood Duck populations began to drop dangerously low (Ducks Unlimited). During this time, it was apparent to experts that if action were not taken fast to protect this species, then total extinction was inevitable (Bellrose, 1976). Luckily for this incredible species, the concerns of conservation experts at the time were heard and Wood Ducks became a completely protected species under the Federal Migratory Bird Act and Migratory Bird Treaty Act of 1916. By 1941, Wood Duck populations had made such a strong resurgence that they were once again permitted to be hunted.

Stories such as this serve as an important reminder to never take for granted species that seem to be found in abundance, but also to realize that through swift action and effective conservation practices, even a species on the brink of extinction can be saved.

Current Conservation Work

Because Wood Ducks don’t construct their own nest cavities, the number of high-quality nesting sites are very limited and a source of intense competition within populations. One conservation strategy used to help support Wood Duck populations is using nest boxes. Nest boxes can be used to increase the amount of available high quality nesting habitat for wood ducks and other cavity nesting waterfowl. Extensive research has been done to improve nest box designs for wood duck (Semel and Sherman, 1995).

Current Research

The effect of social cues and indicators on the behaviour of individuals within a population is a topic of growing interest within the study of animal behaviour. The role of this social information in birds ability to select high quality nesting sites has been a topic of particular interest in past studies. Particularly in species who exhibit a type of social behaviour known as conspecific brood parasitism (CBP), a behaviour characterized by a female bird laying its eggs in a neighbours nest of the same species. This allows them to pass on the work of raising its young to its neighbour. As mentioned previously, the selection of suitable nesting sites can be a very competitive endeavor for breeding Wood Ducks and can have major impacts on the abilities for a mating pair to successfully hatch and raise offspring that year. As a result the ability of female Wood Ducks to identify high quality nesting sites can have a great impact on their individual fitness. When unable to find a suitable nesting site, CBP is one strategy that has been observed in Wood Ducks to try to maximize their offsprings chances of survival for the season (Berg and Eadie, 2020). A study conducted by Berg and Eadie published in 2020 aimed to test for the effects of both environmental and social cues in a female Wood Ducks ability to select a nesting site. They used 3 different types of nesting boxes to test for these effects. Boxes used to simulate an unused nest (acting as a control), which contained only wood shavings, boxes used to simulate an active nest during the laying stage, which contained eggs sitting on top of shavings and finally boxes used to simulate a previously successful nest, which contained eggshells and down.

Berg and Eadie (2020) found that the social information present had no effect on the Wood Duck’s selection of nesting sites. Over the course of the experiment, the control boxes, containing only wood shavings, were selected as nesting sites the most overall. Similarly, it was found that social information had no effect on how likely the site was to be parasitized due to the fact that of the 6 nesting sites that were parasitized, 2 belonged to each of the treatment groups. However, the test for effect of environmental factors on nesting site selection found that factors such as nest box visibility, presence of trees in front of the box and orientation did have an effect.

In contrast to the findings of Berg and Eadie (2020), past studies on other species of waterfowl, as well as a past study on one of the same populations of Wood Duck studied here, found that social information was used by individuals. The findings in this study could be due to a few different explanations. First, as the Wood Ducks have to find relatively rare nesting sites within their habitat, they could be less sensitive to these social cues within the nesting boxes. Second, it could be that female Wood Ducks do take social cues, but from the presence and activity of other female Wood Ducks and not from evidence left behind in previously used nesting sites. Third, female Wood Ducks could use a mixture of environmental and social cues, and due to the fact that the nesting boxes were brand new at the start of the study, the female Wood Ducks relied on environmental cues as they had no knowledge of the history of these nesting sites and after observing the success or failures of others to use these nesting sites would rely more heavily on social information in the future (Berg and Eadie, 2020).

That’s it for this Blog post! Thank you for reading and I hope you learnt something about the Wonderous World of Wood Ducks!

References

All About Birds Cornell Lab of Ornithology. (n.d.).  Wood duck overview. https://www.allaboutbirds.org/guide/Wood_Duck/overview

Animal Diversity Web. (n.d.) Aix sponsa (wood duck). . https://animaldiversity.org/accounts/Aix_sponsa/#a61c0d878d9d7960bddbfc2a44fc87a4

 Armbruster, J.S. . (1982). Wood Duck Displays and Pairing Chronology. The Auk, 99(1), 116–122. https://doi.org/10.2307/4086027

Berg, E. C., & Eadie, J. M. (2020). An experimental test of information use by wood ducks (Aix sponsa): external habitat cues, not social visual cues, influence initial nest site selection. Behavioral Ecology and Sociobiology, 74(10), 1–16. https://www.jstor.org/stable/48727818

Bellrose, F. C. (1976). The Comeback of the Wood Duck. Wildlife Society Bulletin (1973-2006), 4(3), 107–110. http://www.jstor.org/stable/3780986

BirdLife International. 2021. Aix sponsa. The IUCN Red List of Threatened Species 2021: e.T22680104A136999461. https://dx.doi.org/10.2305/IUCN.UK.2021-3.RLTS.T22680104A136999461.en. 

Ducks Unlimited. (n.d.) Status of the Wood Duck. https://www.ducks.org/conservation/waterfowl-research-science/status-of-the-wood-duck

Ducks Unlimited (n.d.) Wood Duck. https://www.ducks.org/hunting/waterfowl-id/wood-duck

Hepp, G. R. and F. C. Bellrose (2020). Wood Duck (Aix sponsa), version 1.0. In Birds of the World (A. F. Poole, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.wooduc.01

Landers, J. L., Fendley, T. T., & Johnson, A. S. (1977). Feeding Ecology of Wood Ducks in South Carolina. The Journal of Wildlife Management, 41(1), 118–127. https://doi.org/10.2307/3800100

Semel, B., & Sherman, P. W. (1995). Alternative Placement Strategies for Wood Duck Nest Boxes. Wildlife Society Bulletin (1973-2006), 23(3), 463–471. http://www.jstor.org/stable/3782956