Ecology of Red Maple Swamps in the Glaciated Northeast: A ...

Fig. 7.6. Wood duck (Aix sponsa). This
species uses seasonally flooded and
temporarily flooded red maple
swamps extensively, both in breeding
and in spring and fall migration. Photo
by W Byme.
(McLaughlin and Grice 1952; McGilvrey 1968; Bell- was less attractive for wood duck nestii. A8 a
rose 1976).
result, breeding densities declined, but nest success
Green-timber impoundments at the Montezuma increased.
National Wildlife Refuge provided high quality Black ducks, which breed in a great variety of
nesting habitat for wood ducks (Reed 1968; habitah, are most co-only found in fieshwabr
'I'hompson et al. 1968; Haramis 1975). Water depth or estuarine rnarshes; however, swamps and beaver
was maintained at about 25 cm throughout the flowages important breeding habitats in
nesting season, and the density of II~tllral cavities many areas of the Northeast (coder and Mendall
was relatively high Wed 1968; Haramis 1968; Reed 1968; Thompon et 1968; Rhgeh
The introduction of nest boxes dramatically inet
1982; Kirby 1988). In central Maine, breeding
popuJatiOn Wood ducks for years black ducks showed preference9 in descending order
after the boxes were installed; however, competiof
importance, for emergent marsh, deciduous fortion
for nesting boxes, dump-nesting by hens unested
wetland, and deciduous shrub swamp
able to eecure nesting cavities, and increased predation
on eggs by woodpeckers (primarily northern
(Ringelman et al. 1982). Diefenbach and Owen
flicker, Colaptes aumtus) lowered wood duck hatch- (1989) developed a model of breeding season habiing
Bumess and increased +.he frequency of nest tat use in the same area of central Maine and found
desertion ( ~ and Thompson ~ 1985). ~ This ~ four habitat i variables ~ to be most Fmprtant in p ~ -
trend was reversed in 1978, when flooding of the dicting wetland US^ by black ducks: (I) perimeter
impoundment was discontinued to reduce stress on of surface water area, (2) area of timber flooded by
the forest community. Without abundant surface at least 10 cm of water, (3) presence of beaver, and
water, the forested interior of the impoundment (4) visibility of occupied human dwellings (negative