Aix sponsa (Linnaeus 1758)

More info for the term: hardwood

Wood ducks inhabit mostly forested wetland communities, such as southern
and central floodplain forests, red maple (Acer rubrum) swamps,
temporarily flooded oak (Quercus spp.)-hickory (Carya spp.) forests,
and northern bottomland hardwood sites [13].


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wood duck

More info for the terms: basal area, cover, herbaceous, shrubs

Wood ducks prefer sites with nest cavities within 0.3 miles (0.5 km) of
water, but will nest more than 0.6 miles (1 km) from cover if necessary.
Nest cavity trees must have a d.b.h. of greater than 12 inches (30 cm).
The nest entrance hole should be at least 6 feet (2 m) above ground, and
greater than 3.5 inches (8.9 cm) in diameter. The interior basal area
should be greater than 40 inches squared (258 cm sq) [5].

Water depths are important in brooding and breeding habitat from
mid-April to late September in the North and mid-January to late
September in the South. In breeding habitat, depth should be 3 to 18
inches (7.5-45 cm), and banks should be sheltered with shrubs. In
brooding habitat, chicks need a water depth of less than 12 inches (30
cm) so they can forage for invertebrates [13].

Ideal cover for wood ducks is provided by shrubs that hang in a dense
canopy about 2 feet (6 m) above the water surface. Downed timber can
provide year-round cover. Habitat consisting of downed timber, woody
and herbaceous plants, and interspersed water channels provides good
brood cover [13]. Optimum cover for brooding consists of 30 to 50
percent shrubs, 40 to 70 percent emergent plants, up to 10 percent
trees, and 25 percent open water [13].

The wood duck's breeding range includes most of the states and the
southern portions of the provinces of North America. Populations are
scarce in the western interior states, especially Utah, Arizona, and New
Mexico [5]. Breeding densities are highest in the Mississippi River
valleys [2,5]. In winter, wood ducks are found on the West Coast from
southern British Columbia to southern California, and on the eastern
coasts from southern New Jersey to southern Florida and west to
central Texas. Winter densities are high in California's Central Valley
and the southern states of the Mississippi and Atlantic flyways [5].

The Atlantic population is distributed throughout the Atlantic Flyway
states and in southeastern Canada. The Interior population is found on
the Mississippi Flyway, parts of Ontario, and the eastern tier of states
in the Central Flyway. The Pacific population is distributed from
British Columbia south to California and east to western Montana [5].

The majority of wood duck food consists of plant material, with a
supplement of invertebrates. During winter almost 100 percent of the
diet is plants, with an increase in animal protein (35 percent) in early
spring [5]. These percentages remain constant for males during the
summer and fall molts, but increase for females to about 80 percent
animal protein during egg laying. This percentage drops for females
during incubation, when their diet includes high-energy seeds. Wood
ducks usually will not forage in agricultural fields as long as their
native food sources are plentiful [13].

Some plant foods of wood ducks include fruits of maples (Acer spp.),
oaks, ash (Franius spp.), sassafras (Sassafras albidum), sweetgum
(Liquidambar styraciflua), baldcypress, water hickory (Carya aquatica),
buttonbush (Cephalanthus occidentalis), Asiatic dayflower (Aneilema
keisak), watershield (Brassenia schreberi), barnyard grass (Echinochloa
spp.), rice cutgrass (Leersia oryzoides), primrose willow (Ludwigia
leptocarpa), white waterlily (Nymphaea odorata), panicum (Panicum spp.),
smartweeds (Polygonum spp.), pondweeds (Potamogeton spp.), water bulrush
(Scirpus subterminalis), and slough grass (Sclera reticularis).
Invertebrate foods include spiders, crayfish, midges, scuds, water
boatmen, sowbugs, damselflies, dragonflies, caddis flies, and orb snails
[5,13].

More info for the terms: cover, mast, root crown, tree

Specific information regarding the effects of fire on wood duck habitat
has not been found. The author concludes that because wood ducks need
forested wetlands for cover and food, fires that substantially remove
overstory, especially that providing nesting cavities and mast, could
harm wood duck populations.

Hydric hammock communities in the South, which support wintering wood
ducks, are not as fire-dependent or adapted as neighboring pine flatwood
communities [15]. Some tree species in these hydric hammock communities
can be damaged by fire, thus becoming susceptible to fungal attack and
decay.

Red oak swamps are important for wintering wood ducks. Red oak is more
susceptible to fire than many other oak species (see FEIS DATABASE:
Quercus rubra). Severe fire may kill seedlings and sawtimber-sized red
oak; however, larger red oak sprout from the root crown and/or trunk
following such fire.

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This species is known to occur in association with the following cover types (as classified by the Society of American Foresters):

More info for the term: swamp

1 Jack pine
14 Northern pin oak
15 Red pine
16 Aspen
21 Eastern white pine
25 Sugar maple - beech - yellow birch
26 Sugar maple - basswood
27 Sugar maple
28 Black cherry - maple
39 Black ash - American elm - red maple
40 Post oak - blackjack oak
42 Bur oak
52 White oak - black oak - northern red oak
53 White oak
55 Northern red oak
59 Yellow-poplar - white oak - northern red oak
60 Beech - sugar maple
61 River birch - sycamore
62 Silver maple - American elm
63 Cottonwood
64 Sassafras - persimmon
65 Pin oak - sweetgum
70 Longleaf pine
75 Shortleaf pine
80 Loblolly pine - shortleaf pine
81 Loblolly pine
84 Slash pine
88 Willow oak - water oak - diamondleaf oak
91 Swamp chestnut oak - cherrybark oak
92 Sweetgum - willow oak
93 Sugarberry - American elm - green ash
94 Sycamore - sweetgum - American elm
95 Black willow
96 Overcup oak - water hickory
101 Baldcypress
108 Red maple
110 Black oak
111 South Florida slash pine
210 Interior Douglas-fir
212 Western larch
213 Grand fir
215 Western white pine
217 Aspen
218 Lodgepole pine

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This species is known to occur in the following ecosystem types (as named by the U.S. Forest Service in their Forest and Range Ecosystem [FRES] Type classification):

FRES10 White-red-jack pine
FRES11 Spruce-fir
FRES12 Longleaf-slash pine
FRES13 Loblolly-shortleaf pine
FRES14 Oak-pine
FRES15 Oak-hickory
FRES16 Oak-gum-cypress
FRES17 Elm-ash-cottonwood
FRES18 Maple-beech-birch
FRES19 Aspen-birch
FRES20 Douglas-fir
FRES21 Ponderosa pine
FRES22 Western white pine
FRES25 Larch
FRES26 Lodgepole pine
FRES27 Redwood
FRES28 Western hardwoods

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This species is known to occur in association with the following plant community types (as classified by Küchler 1964):

More info for the term: forest

K005 Mixed conifer forest
K006 Redwood forest
K008 Lodgepole pine - subalpine forest
K011 Western ponderosa forest
K012 Douglas-fir forest
K013 Cedar - hemlock - pine forest
K014 Grand fir - Douglas-fir forest
K015 Western spruce - fir forest
K018 Pine - Douglas-fir forest
K020 Spruce - fir - Douglas-fir forest
K091 Cypress savanna
K092 Everglades
K093 Great Lakes spruce - fir forest
K095 Great Lakes pine forest
K097 Southeastern spruce - fir forest
K098 Northern floodplain forest
K099 Maple - basswood forest
K100 Oak - hickory forest
K101 Elm - ash forest
K102 Beech - maple forest
K103 Mixed mesophytic forest
K104 Appalachian oak forest
K106 Northern hardwoods
K107 Northern hardwoods - fir forest
K108 Northern hardwoods - spruce forest
K110 Northeastern oak - pine forest
K111 Oak - hickory - pine forest
K112 Southern mixed forest
K113 Southern floodplain forest

More info for the terms: hardwood, mast

Overmature trees and snags should be left on logging sites for wood duck
nesting cavities. Mixed stands of trees, including those producing mast
and/or providing nesting cavities, should be left on these sites. Elm
(Ulmus spp.) and maple are an important component of wood dick habitat
because they provide both [5]. Nest boxes constructed of wood, metal,
or plastic can be used in areas where cavities are limited. If placed
in direct sunlight, however, plastic or metal may reach internal
temperatures high enough to kill embryos. For detailed information on
constructing nest boxes, refer to the U.S. Fish and Wildlife Service
[14].

In bottomland hardwood sites where flooding is controlled, it is
important to maintain a flooding regime that promotes oaks that bear
small acorns. Overcup oak (Quercus lyrata) produces large acorns which
are usually unsuitable as wood duck food [5]. Water depths in foraging
areas should be maintained at levels less than 8 inches (20 cm), but can
be deeper in resting and roosting sites. Detailed information for
managing flood-controlled wetlands for wildlife habitat across the
United States is available [4].

Bottomland hardwood sites need openings to increase the growth of mast-
producing oaks. Their growth is stunted under closed canopies [11].
Openings can be created by thinning or select cutting.

Long-term studies indicate that growth of trees on greentree reservoir
sites (GTRs) is reduced by several years of flooding. However, there
is no indication that this poses any threat to wildlife, such as
wintering wood ducks, that use GTRs. Flooding GTRs is recommended from
mid-September in the North and continuing through mid- to late October in
the South. Drawdown should begin in mid-February [11].


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AL
AZ
AR
CA
CO
CT
DE
GA

ID
IL
IN
IA
KS
KY
LA
ME
MD
MA

MI
MN
MS
MO
MT
NE
NV
NJ
NM

NY
NC
ND
OH
OK
OR
PA
RI
SC
SD

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TX
UT
VT
VA
WA
WV
WI
WY





AB
BC
MB
NB
NS
ON
PE
PQ

SK
YT













MEXICO

Wood duck predators include humans, mink (Mustela vison), raccoon
(Procyon lotor), fox squirrel (Sciurus niger), bullfrog (Rana
catesbeiana), snapping turtle (Chelydra serpentina), largemouth bass
(Micropterus floridanus), crows (Corvidae spp.), and starling (Sturnus
vulgaris) [2,5].

More info for the terms: hardwood, shrub, tree

Wood ducks prefer wooded wetlands and forests with small lakes, ponds,
or riparian corridors, and flooded forested bottomlands. They nest in
tree cavities or man-made boxes, usually within 0.6 miles (1 km) from
water [5]. They prefer riparian areas with a large amount of shoreline
per unit area of water, and with the opposite shore at least 100 feet
(30 km) away [13]. In the Mississippi River valleys, chicks prefer water
sites where currents are less than 1 mile per hour (1.6 km/h). Chicks
less than 2 weeks old use flooded lowland forests, while older chicks
use shrub communities [13]. Breeding and brooding hens prefer sites
with ratios of 50 to 75 percent cover:25 to 50 percent open water.
Detailed habitat suitability index models have been developed for wood
ducks [13].

Wood duck preference for trees used for cavity nesting have been listed
in order of descending importance. In floodplain forests these are
baldcypress (Taxodium distichum), sycamore (Platanus spp.), silver maple
(Acer saccharinum), black ash (Fraxinus nigra), sourgum (Nyssa spp.),
and black willow (Salix nigra). On upland areas these are black oak
(Quercus velutina), red oak (Q. rubra), white oak (Q. alba), blackjack
oak (Q. marilandica), bur oak (Q. macrocarpa), and basswood (Tilia
americana) [2].

A study in northcentral Minnesota identified 31 wood duck nest cavities
and found that 21 of these were in mature (60-75 years) quaking aspen
(Populus tremuloides) stands, while the rest were in mature (100-120
years) mixed hardwood stands. Nest sites were within 1,150 feet (350 m)
of water, and entrance holes were not less than 12 feet (4 m) above
ground [8].

More info on this topic.

This species can be found in the following regions of the western United States (according to the Bureau of Land Management classification of Physiographic Regions of the western United States):

1 Northern Pacific Border
2 Cascade Mountains
3 Southern Pacific Border
4 Sierra Mountains
5 Columbia Plateau
8 Northern Rocky Mountains
9 Middle Rocky Mountains
14 Great Plains
16 Upper Missouri Basin and Broken Lands

The currently accepted scientific name for wood duck is Aix sponsa
Linnaeus [1]. There are no recognized subspecies [5].

Courting- before fall migration and again in spring
Age of Maturity- 1 year
Nesting- late January (South); early March (Midwest); March-April (North)
Clutch- 7 to 15 eggs; average 12; some females deposit eggs in
another female's nest (called "dumping")
Incubation- 26 to 37 days
Fledging- 56 to 70 days
Migration- some southern residents are year-round; northern populations
head south in late September and north in late February [5]

More info for the terms: fire regime, hardwood

Fire is NOT recommended to rejuvenate elm-ash-cottonwood stands in
bottomlands of the north-central United States. These genera, and
others in this type, are susceptible to fire damage. Fires could lead
to loss of the bottomland hardwood stand, which is important wood duck
habitat [12].

FIRE REGIMES :
Find fire regime information for the plant communities in which this
species may occur by entering the species name in the FEIS home page under
"Find FIRE REGIMES".