Scientific Name:
Sphyrapicus varius
Nest Type: Cavity
Nest Location: Deciduous
trees, 8-40', avg. 25'
Clutch Size: 3-7;
avg. 5-6
Food: Insects, tree
sap
Foraging Guild:
Bark gleaner, hawks
The Yellow-bellied Sapsucker
is a common breeding species across most of Canada, and in the Rocky
Mountains of the western United States. In the eastern United States,
its range includes the New England states, New York, and Pennsylvania,
and extends south in the Appalachians to eastern Tennessee. In the Midwest,
it breeds in northern Michigan, northern Wisconsin (Peterson 1980),
and throughout the more heavily forested regions of Minnesota (Janssen
1987). It is most common in the northern regions of the state and rare
south of the Minnesota River (Janssen 1987). This species is a short
to long distance migrant, wintering in the southern United States, Mexico,
and south to Central America and the West Indies (Short 1982). It generally
returns to Minnesota from late March through early May, with peak numbers
arriving in mid-April. In the fall, it leaves the northern regions of
the state by late September, but many stragglers remain in the south
into early winter. There are a number of December and early January
records from the Twin Cities and southern portions of the state (Janssen
1987).
The diet of this species
consists primarily of sap and insects, especially ants. Sapsuckers drill
parallel rows of small holes in live trees, and later return to feed
on the sap and the insects attracted to it (Short 1982). The primary
nesting habitat of the species is upland deciduous forest, but it can
be found in a wide variety of woodland and forest types.
The Yellow-bellied Sapsucker
is a cavity nester, and the availability of suitable nest trees is among
the primary limiting factors for the species. Several studies have shown
that aspen is frequently chosen as nest sites in northern hardwood forests
(Runde and Capen 1987, Lawrence 1966, Rushmore 1969). In a study conducted
in southeastern Vermont, 26 of 38 Sapsucker nests were located in quaking
aspen, and 30 of the nests were in live, deciduous trees with fruiting
bodies of heartwood decay fungi (Phellinus tremulae and
Fomes fomentarius) (Runde and Capen 1987). The presence
of fruiting bodies of fungi indicates advanced heartrot which softens
the heartwood and makes excavation easier for the Sapsucker. The sapwood
is unaffected by the fungi and remains intact, providing a sturdy, protective
exterior for the nest cavity (Kilham 1971).
Diameters of the nest trees
used by Yellow-bellied Sapsuckers in Vermont were larger than adjacent
non-nest trees, indicating that the birds were selecting large trees
in proportion to their body size (Runde and Capen 1987). This suggests
that if only minimum diameter trees are available, populations could
suffer as a result of poor nesting success (Conner 1979, Evans and Conner
1979). These data support the classification of this species as a bird
of mature, deciduous forests.
Availability of nest sites
are often scarce in young forests and in intensively managed forests
of all ages (i.e., if dead trees or live trees with heartwood decay
are removed). Clearcutting, timber stand improvement, short harvest
rotations, and the removal of snags to reduce fire and safety hazards
tend to reduce the number of potential nest sites available for Yellow-bellied
Sapsuckers and other cavity-nesting species (Runde and Capen 1987).
