Review and download Chapter 3 - Golden-winged Warbler Working ...

Habitat Interspersion —
A high degree of within-patch habitat
interspersion and heterogeneity is important for
Golden-winged Warblers. To get a sense of this,
as a rule of thumb, one should be able to stand
anywhere within an appropriately managed
patch and be within 20 ft (6 m) of a microedge
(see sidebar, page 3–15 and Figure 3–12). A
microedge is any readily perceived change in
vegetation type or height, such as where grasses
change to sedge at the border of a wet area or
where an herbaceous opening is bordered by
dogwood or Rubus shrubs. Shrubs should be
scattered and clumped, with herbaceous
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openings and ground cover separating the
clumps.
Bulluck and Harding 2010 developed a
“clumpiness index” for sites in Virginia to
describe the spatial configuration of woody
vegetation (shrubs and saplings) and the
relationship to Golden-winged Warbler habitat
use. Shrubs that were spaced < 7 ft (2 m) apart
were classified as clumped and shrubs spaced > 7
ft (2 m) apart were classified as scattered (Figure
3–12). The majority of sites occupied by Goldenwinged
Warblers had 50% or more of their shrubs
and saplings in a contiguous clump.
Figure 3–12. The left photo shows a site with a high clumpiness index value (i.e., contiguous patches of
shrubs),and presence of adequate microedge indicating high quality habitat for Golden-winged Warblers, and
the right shows a site with a low clumpiness index value (i.e., scattered shrubs) and limited microedge that
indicates low quality habitat for Golden-winged Warblers (from Bulluck and Harding (2010)).