Conservation Practices Benefit Golden-winged Warblers in Appalachia

12 Pages·2016·3.91 MB·English

United States Department of Agriculture
Natural Resources Conservation Service Conservation Practices
Conservation Effects Assessment Project (CEAP)
Benefit Golden-winged
CEAP-Wildlife Conservation Insight
December 2016 Warblers in Appalachia
cowbirds (Buehler et al. 2007 ). Of
Summary of Findings • The post-fledging period, par- these factors, loss of quality breeding
ticularly the first 4 days out of the habitat—young forests and shrublands
The golden-winged warbler has nest, results in significant fledgling embedded in extensively forested
experienced significant population mortality and could be a focal landscapes—is thought to be the most
declines throughout its Appala- point for habitat management to significant (Roth et al. 2012).
chian breeding range. Loss of increase reproductive output.
breeding habitat is thought to be a The Golden-winged Wabler Working
significant driver of these declines. • Quantifying differences in Group (gwwa.org) identified imple-
mentation of management prescrip-
post-fledgling survival among
An assessment was conducted to tions that create or maintain gold-
management systems is critical
evaluate golden-winged warbler en-winged warbler breeding habitat
for comparing and evaluating each
response to habitat management as a conservation priority (Roth et
system’s potential for successfully
using conservation practices sug- al. 2012). Recently, science-based
contributing to golden-winged
gested by the Natural Resources guidelines for creating golden-winged
warbler population recovery.
Conservation Service’s (NRCS) warbler breeding habitat were devel-
Working Lands For Wildlife oped (Bakermans et al. 2011, Roth et
• Ultimately, it is necessary that
(WLFW) in the southern and al. 2012). Conservationists are now
both the nesting and post-fledging
central Appalachian states. Key faced with the challenge of large-scale
habitat needs of the golden-winged
findings include: implementation of these habitat man-
warbler are considered when
agement guidelines to stabilize and
developing conservation plans for
• Most golden-winged warbler de- reverse golden-winged warbler popu-
private landowners.
lation declines. Habitat management
mographics (e.g., territory density,
targeting golden-winged warblers will
adult survival, and nest surviv-
also likely benefit other at-risk birds
al) did not differ among the five
that rely on young forest and shrub-
management systems evaluated,
Background land including eastern whip-poor-will,
thus indicating similar capabilities
prairie warbler, eastern towhee, field
to support breeding populations of
The golden-winged warbler (Vermi- sparrow, and American woodcock
this species.
vora chrysoptera) is a neotropical (North American Bird Conservation
migrant songbird that winters in Initiative 2009, Roth et al. 2012).
• Although some of the manage-
portions of Central and South Amer- Additionally, many mature forest
ment systems failed to achieve
ica and breeds in the northern Great nesting songbirds and their offspring
nest-site vegetation characteristics
Lakes regions of the United States and use young forest and shrubland habitat
in the ranges recommended by the
Canada, and at higher elevations of during post-fledging and migration
Golden-winged Warbler Conserva-
the central and southern Appalachian (King et al. 2006, Vitz and Rodewald
tion Plan (Roth et al. 2012), they
Mountains (Confer et al. 2011). The 2006, Labbe and King 2014).
still supported high nesting success.
species is experiencing steep popu-
lation declines throughout its Appa- While efforts to create and enhance
• Juvenile and adult gold- lachian Mountains breeding range golden-winged warbler breeding hab-
en-winged warblers used multiple (8.5% per year, Sauer et al. 2014) and itat on public lands in the Appalachian
stages of forest succession (i.e., has thus become rare and patchily Mountains are underway, the fate of
early, mid, and late successional distributed throughout this region. this species will likely depend on the
forest) during the breeding and Several factors are thought to be driv- consistent availability of high quality
post-breeding periods, thus stress- ing population declines of this song- habitat on private forestlands. In 2012,
ing the need for managing local bird, including habitat loss in both the the USDA Natural Resources Conser-
landscapes to create a mosaic of breeding and wintering range, hybrid- vation Service (NRCS) launched the
forest age classes. ization with the blue-winged warbler, Working Lands for Wildlife (WLFW)
and nest parasitism by brown-headed effort to create habitat on private lands
for seven imperiled wildlife species warbler habitat uses domestic live- restrict the growth of woody vegetation
including the golden-winged warbler. stock to limit natural succession. In and revert late successional shrublands
Through cost-share assistance associat- areas where golden-winged warblers to earlier stages of succession having
ed with WLFW, landowners are using are known to breed, low-intensity 30–60% shrub and sapling cover within
conservation practices such as Early grazing (1 animal unit/2–4 ha) may the targeted area. A shrub and sapling
Successional Habitat Development & be used during May-October or even cover closer to 60% allows immediate
Management (NRCS Practice Code year-round if overgrazing is not nesting by golden-winged warblers,
647) to create early successional or occurring. High-intensity grazing (up while a cover closer to 30% may
young forest patches within the forested to 1 animal unit/0.4 ha) may be used result in delayed nesting until woody
landscapes of Appalachia that provide during non-nesting periods to limit vegetation recovers.
critical nesting habitat for this imperiled natural succession in overgrown areas
songbird. (i.e., those with >60% shrub cover). E. Prescribed Fire - Old Field: This
management system maintains
Due to significant landscape heteroge- C. Prescribed Fire - Young Forest: existing shrubland habitat as old fields,
neity across the Appalachian Mountains This management system creates new including abandoned agricultural areas
portion of the golden-winged warbler’s and maintains existing golden-winged and reclaimed surface mines, primarily
range, there are numerous ways in warbler nesting habitat using pre- through the use of prescribed burning.
which young forest nesting habitat scribed fire as preparatory treatment The result of this management system
can be created or maintained for the for a timber harvest or as a method of is an early successional shrubland
species. These treatments can be cate- maintaining early successional habitat with herbaceous cover and slowed
gorized into five primary management after a harvest. Maintaining the area in growth of woody plants such as
systems (Fig. 1). early succession with prescribed fire shrubs and saplings. Prescribed fire on
may mimic natural disturbance events Appalachian surface mines can be used
A. Timber Harvest: This management that historically created breeding habi- to set back vegetative growth, but it
system creates new golden-winged war- tat for golden-winged warblers. must be used regularly to maintain the
bler nesting habitat via stands of young, area in an early successional state.
regenerating forest with adequate D. Old Field Management: This
residual trees. Timber Harvest involves management system can be used Assessment Partnership
removing overstory and results in a to maintain golden-winged warbler
regenerating forest with abundant sap- habitat through the use of the Monitoring the response of golden-
lings, shrubs, and forbs. Live residual NRCS conservation practice Brush winged warblers to habitat established
trees are usually the largest and health- Management and associated practices. via NRCS conservation practices is
iest of the deciduous hardwoods in the This management practice sets back necessary in order to 1) evaluate the
stand, and snags are also retained. the succession of shrubs and other effectiveness of primary management
woody plants primarily by using systems, 2) quantify WLFW’s relative
B. Grazing Management: This method mechanical methods to remove some contribution to the species’ recovery,
of maintaining existing golden-winged woody vegetation. The goal is to and 3) provide data necessary to
Figure 1. Five primary management systems used to provide early successional breeding habitat for golden-winged warblers:
(A) timber harvest, (B) grazing management, (C) prescribed fire - young forest, (D) old field management, (E) prescribed fire - old field.
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modify existing practice guidelines
via adaptive management to improve
WLFW program effectiveness.
In 2012, NRCS formed a Conservation
Effects Assessment Project (CEAP)
partnership with the Indiana Universi-
ty of Pennsylvania Research Institute
to lead a team of scientists represent-
ing several universities, state and fed-
eral agencies, and non-governmental
conservation organizations to assess
golden-winged warbler response to
NRCS WLFW activities. The assess-
ment used multiple sites in four Appa-
lachian states to represent the scope of
habitats and WLFW practices across
the species’ Appalachian Mountains
breeding range. The study approach
and findings of the first three years of
this assessment are presented in detail
by Aldinger et al. (2015). Highlights
of the assessment are presented in
this Conservation Insight. Additional
work is underway to fine-tune initial
findings and to assess benefits to other
birds associated with early succession-
al habitats.
Assessment Approach
The assessment focused on evaluating
the demographic response of gold-
en-winged warblers to habitat manage-
ment guided by NRCS conservation
practices at 70 sites located across
portions of the species’ Appalachian
Mountains breeding range (Fig. 2). For
each of the five management systems,
assessments were made for (1) gold-
en-winged warbler minimum annual Figure 2. Assessment study sites were located throughout the Appalachian Mountains
and within the golden-winged warbler breeding range.
survival, territory size, and density
derived from territory mapping; (2)
territory density derived from point ping. The number of sites studied for
counts; (3) nest survival and fledgling each management system were: timber
productivity; (4) attainment of recom- harvest (n=26), grazing management
mended nesting vegetation; (5) space (n=12), old field management (n=17),
use by radio-tagged adult males; (6) prescribed fire - old field (n=2), and
fledgling survival, movements, and prescribed fire - young forest (n=13).
habitat use; and (7) implications drawn Captured males were fitted with a stan-
from these analyses on golden-winged dard USGS aluminum leg band and a
warbler demographic response to unique combination of 1–3 additional
USDA conservation practices. color leg bands (Fig. 3). Minimum
annual survival was estimated us-
Annual survival, territory size, and ing re-sighting data and the program
territory density MARK (version 7.1, Colorado State
Male golden-winged warblers were University, Ft. Collins, Colorado,
captured with mist nets and banded USA). Field technicians visited each Figure 3. A male golden-winged warbler
annually to estimate minimum survival study site every 1–3 days to visually fitted with an aluminum USGS leg band
rates and to aid in the identification of locate marked territorial males and and a unique combination of plastic color
bands for identification purposes.
individual males during territory map- record associated geographic coor-
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dinates. Approximately 30 locations of each plot’s center, the species and “attainment” was associated with the
per individual male were recorded on dbh of all trees (>10 cm dbh), number proportion of stand-level plots having
at least eight separate days during the of snags (>10 cm dbh), average shrub vegetation characteristics that fell
breeding season. Locations for each height, and average sapling height within ranges recommended by Roth
male (within a single breeding season) were also recorded. et al. (2012). Recommended values for
were used to delineate territory bound- vegetation within 1-m of nest sites in-
aries. Territory size was estimated for Nest survival: All golden-winged clude 0-10% bare ground, 5-25% grass
each male during each breeding season warbler nests that reached at least the cover, 4-45% forb cover in herba-
from 2012–2014. Estimates of territory egg-laying stage (i.e., active nests) ceous-dominated sites (grazing man-
density (males/ha) for each study site were included in nest-survival anal- agement, old field management, and
and for each management system as a yses. Two groups of models were prescribed fire - old field), 45-100%
whole were also made to enable com- developed for golden-winged warbler forb cover in silviculturally-derived
parisons among management systems. nest daily survival rate (DSR). Model sites (prescribed fire - young forest
suite I featured management system, and timber harvest), 5-40% Rubus
Golden-winged warbler territory study area, time within season, veg- cover, and 5-50% woody cover.
density was also estimated using data etation community type, and year
collected during 10-minute point covariates. Model suite 2 included Space use by adult male golden-
count surveys (n=95 sites). Each point models with vegetation covariates winged warblers
count survey location was visited 1–3 within each management system. Nest Between May and June 2012 and
times annually during the peak of the survival for each management system 2013, adult male golden-winged
breeding season (May 10–June 25). was analyzed separately. Prescribed warblers were captured at 16 sites
Over a 10-minute period, a laser range fire - young forest was excluded due to in Pennsylvania and West Virginia.
finder was used to record the exact small sample size. Study sites were categorized as old
distance from the point count location field management (n=7), prescribed
to all golden-winged warblers detect- Fledgling productivity: Golden- fire - young forest (n=3), and grazing
ed. To characterize habitat conditions, winged warbler fledgling productivity management (n=6). Nineteen (n=19)
a detailed vegetation survey was also (number of fledglings produced/ha) males that weighed ≥9 g were each
collected at each point count location. was estimated for each management equipped with radio transmitters and
Two model suites exploring warbler system. Fledgling productivity was fitted with a metal U.S. Geological
density were evaluated: model suite 1 the product of four components: 1) Survey leg band and a unique combi-
(elevation, latitude, and management probability of nest success given nation of color bands for visual iden-
system effects) and model suite 2 three nesting attempts, 2) number of tification purposes. Visually mapped
(vegetation effects). fledglings produced per successful territories and telemetry-based home
nest, 3) territory density, and 4) male ranges for each male were delineat-
Nest survival and fledgling pairing rate. Territory density for ed using 100% and 50% minimum
productivity each management system was the convex polygons (MCPs) in ArcMap.
During 2012–2014, nests of golden- mean of the across-year territory The amount of overlap between each
winged warblers were located and mapped densities for sites within radio-tagged male’s visually mapped
monitored on 46 sites. Sites were each management system. A constant territory and telemetry-based home
searched multiple times weekly to locate pairing rate (0.8) was used among range was measured using the intersect
nests using behavioral cues of adults. management systems based on a tool in ArcMap. Vegetation data were
Once a nest was found, it was monitored compilation of pairing rates from collected within each visually mapped
to determine nest fate. A nest was golden-winged warbler populations territory and at all telemetry locations
classified as “successful” if at least one across the Appalachian Mountains that were ≥12 m outside the visually
golden-winged warbler nestling fledged. region (Confer et al., unpubl. data). mapped territory (to prevent potential
overlap of sampling areas).
Vegetation characteristics were mea- Attainment of recommended nesting
sured at nests after nest fate was deter- vegetation Fledgling survival, movements, and
mined. A nested plot design (1-m, 5-m, The same vegetation protocol used habitat use
and 11.3-m radius) was used to survey to survey nest sites was also used at Study sites in Pennsylvania (timber
vegetation centered at nest sites. Per- plots distributed randomly (1 plot/ harvest sites, n=8) and Tennessee (pre-
cent cover for leaf litter, bare ground, ha) throughout each study site (here- scribed fire - old field sites, n=2) were
grasses, forbs, vines, blackberry/rasp- after, “stand-level plots”). Stand-level searched multiple times weekly to
berry (Rubus spp.), and woody plant plots quantified the vegetation char- locate nests during 2013–2014. When
species within a 1-m radius of plot acteristics available across each site. nestlings were 7–8 days old (1–2 days
centers were recorded. Within 5 m of One primary management target for prior to the anticipated fledge date),
plot centers, 1–2 m tall shrubs (“short golden-winged warbler nesting habitat 1–3 birds were briefly removed from
shrubs”), >2 m tall shrubs (“tall was the nesting vegetation recom- their nest and weighed, and then a leg
shrubs”), and saplings (1–10 cm diam- mended in the Golden-winged Warbler band was attached. A radio transmitter
eter at breast height—dbh, >0.5 m tall) Conservation Plan (Roth et al. 2012). was also attached to each bird using
were tallied by species. Within 11.3 m Recommended nesting vegetation a figure-eight harness. The combined
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mass of radio transmitter, harness, and management system effects) included achieve average sapling densities that
leg band was < 5% of each nestling’s linear elevation and latitude effects range between 3,000–8,400 stems/ha
weight. Radio-tagged individuals that and an interaction between these two (1,300–3,300 stems/acre).
successfully fledged were tracked variables. At southern latitudes den-
daily to record each fledgling’s exact sity increased with elevation, and at Nest survival: Across 46 sites, the
location and survival status. Two northern latitudes density decreased survival of 288 golden-winged
groups (TN and PA) were used to with elevation. Models with manage- warbler nests was monitored during
model fledgling survival, and days 1–4 ment system had essentially no support 2012–2014. Of these nests, 79, 86, 61,
and days 5–25 were analyzed sepa- (ΔAIC > 10, Burnham and Anderson 48, and 14 nests were found in timber
rately because survival was noticeably 2002), suggesting that golden-winged harvest, old field management, grazing
lower in the first 4 days. warbler density overall was consistent management, prescribed fire - old
among management systems. The
field, and prescribed fire - young forest
Assessment Findings best-supported density model in model sites, respectively. Overall DSR for all
suite II (vegetation covariates) in-
golden-winged warbler nests was 0.963
Minimum annual survival: Over 3 cluded a sapling count effect whereby
± 0.003, which equates to a probability
field seasons, 290 male golden-winged density increased with sapling count.
of 0.767 ± 0.035 of producing a
warblers were captured and banded This finding is consistent with previ-
successful nest, given three attempts.
across all five management systems: ous management recommendations to
Successful golden-winged warbler
timber harvest, n=88; old field man-
agement, n=107; prescribed fire
- young forest, n=13; prescribed fire -
old field n=22; and prescribed grazing,
n=60. Adult male annual survival by
management system ranged wide-
ly from 0.40 to 0.81 (Fig. 4). When
combining birds from all management
systems, the average survival rate was
0.58, which falls near the rate (0.62)
found in Bulluck et al. (2013) in Ten-
nessee and Ontario.
Territory size: Over 3 field seasons,
526 golden-winged warbler territories
were mapped within 70 study sites.
Of these, 474 territories met the
criteria for inclusion in territory size
comparisons among the 5 management
systems. Average territory size Figure 4. Minimum annual survival rate estimates (± SE) for adult male golden-winged
was largest for those in grazing warblers.
management sites (1.77 ha, n = 98)
and smallest for timber harvest (0.82
ha, n = 172) (Fig. 5).
Territory density derived from territory
mapping: Golden-winged warbler
territory densities across the 70 sites
that were territory mapped ranged from
0.0–4.61 males/10 ha. Mean golden-
winged warbler density estimates
by management system ranged from
1.05–3.37 males/10 ha with a mean
density of 1.5 males/10 ha across all
five management systems (Table 1).
Territory density derived from point
counts: A total of 864 point count
surveys were completed at 191 unique
locations across 70 sites during Figure 5. Territory sizes of golden-winged warblers mapped in 2012-2014. Error bars
2012–2014. The best-supported gold- represent 95% confidence intervals. Sample sizes were: grazing magagement (GRAZ)
en-winged warbler density model in = 86, old field mangagement (OLFD) = 159, prescribed fire - old field (PF-OF) = 45,
model suite I (elevation, latitude, and prescribed fire - young forest (PF-YF) = 22, and timber harvest (TIMB) = 162.
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nests (n = 143) produced on average at 2,719 random plots across 45 nest vegetation variables occurred
4.0 ± 0.1 fledglings. For model suite I managed sites over the course of our in 39 of 2,719 (1.4%) random plots.

(management system, study area, time study (746 in grazing management, The average number of variables
within season, vegetation community 627 in old field management, 146 that attained recommended levels
type, and year covariates), DSR in prescribed fire - old field, 335 in simultaneously within a single
decreased as the season progressed prescribed fire - young forest, and 865 random plot ranged from 1.9 (SE:
(Fig. 6). For models that included in timber harvest). The attainment 0.12) in timber harvests to 2.5 (SE:
management system, DSR was of recommended levels for all five 0.08) in grazing management sites.
similar among management systems.
However, the probability of producing Table 1. Mean territory density (males/10 ha) across each of five management systems.
a successful nest given three attempts
(a common number of attempts among Number of Golden-winged warbler
study areas according to Aldinger et Management system sites territory mean (±SE) density
al. 2015) showed more differentiation mapped
among management systems and was
Grazing management 12 1.26 (0.30)
lowest for prescribed fire - young
Old field management 17 1.39 (0.31)
forest (Fig. 7).
Prescribed fire - old field 2 3.37 (0.82)
The effects of vegetation (model
Prescribed fire - young forest 13 1.05 (0.41)
suite II) on nest success was evaluat-
Timber harvest 26 1.69 (0.30)
ed within each management system.
Prescribed fire - young forest was not
analyzed due to small sample size
(n=13 nests). Modelling revealed
that, for timber harvest and prescribed
fire - old field, nest survival was not
well explained by vegetation vari-
ables. It is inferred from these results
that timber harvest and prescribed
fire - old field consistently produced
vegetation characteristics associated
with average nesting success. There
were significant effects of vegeta-
tion variables on nesting survival for
grazing management and old field
management. Intermediate levels of
Rubus were best for nest survival on
grazing management sites, whereas
tall shrub (>2m) count was negatively
associated with nest survival on Old
Figure 6. Daily survival rate (DSR) of golden-winged warbler nests decreased as the 69-
Field Management sites (Fig. 8).
day nesting season progressed.
Fledgling Productivity: Mean gold-
en-winged warbler fledgling pro-
ductivity across all five management
systems was 0.56 (± 0.10) fledglings/
ha. Fledgling productivity among the
management systems ranged from
0.21 ± 0.16 fledglings/ha for pre-
scribed fire - young forest sites to 0.87
± 0.23 fledglings/ha for prescribed
fire - old field sites (Fig. 9). However,
these two management systems also
had the widest variation in two of the
productivity components: 1) probabili-
ty of nest success given three attempts
and 2) number of young fledged per
successful nest.
Figure 7. Probability of golden-winged warbler nest success (± SE) given three attempts
among management systems: grazing management (GRAZ), old field mangagement
Attainment of recommended nesting (OLFD), prescribed fire - old field (PF-OF), prescribed fire - young forest (PF-YF), and
vegetation: Vegetation was quantified timber harvest (TIMB).
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Golden-winged warbler territories Pennsylvania and 488 telemetry and dance was greater in home ranges (7.3
are structurally diverse and must 616 visually mapped locations among trees/11.3-m radius plot ± 0.8) than in
support activities other than nesting 7 males in West Virginia were record- visually mapped territories (1.9 ± 0.6)
(e.g., singing, foraging, and fledgling- ed. Telemetry-delineated home ranges and telemetry locations were closer
rearing). Thus, while it is important were 2–4 times larger than visually (14.3 m ± 8.0) to intact forested edges
that managed sites provide multiple mapped territories (Table 2, Fig. 10) than were visually mapped locations
options for nest placement, the (Frantz et al. 2016). (44.8 m ± 6.7). More telemetry loca-
attainment of recommended levels tions than visually mapped locations
of nest site vegetation should not be Forty percent of radio telemetry loca- occurred in forest in both states. On
expected to approach 100% across an tions were outside of visually mapped several occasions, radio-marked
entire site. territories. Sapling abundance was individuals were observed >200 m
greater in home ranges (mean 20.7 (maximum of 1.5 km) from their
Space use of radio-tagged adult saplings/5-m radius plot ± 2.9 SE) than visually mapped territory boundaries.
males: A total of 524 telemetry and in visually mapped territories (11.5 Why golden-winged warblers left their
439 visually mapped locations among ± 2.9) in Pennsylvania. In managed visually mapped territories is unknown,
12 male golden-winged warblers in pastures of West Virginia, tree abun- but observations suggest foraging, ex-
tra-pair copulation, and reconnaissance
for post-breeding movement as possi-
ble motives (Frantz et al. 2016).
Fledgling survival: A total of 76
fledglings were radio-tracked during
the 2-year post-fledging study (TN
2013, n = 10; TN 2014, n = 31; and
PA 2014, n = 35). Depredation was
greatest during the first four days
after fledging, with 81% (34/42)
of the mortalities occurring within
this period. Daily survival increased
considerably thereafter (5+ days
post-fledging). Daily survival for the
Figure 8. Vegetation features associated with nest survival as described by best-support-
5–25 day interval was 98.7 ± 0.8% in
ed models of golden-winged warbler nest survival. Grazing management showed nest
Tennessee and 98.2 ± 0.8% in Penn-
survival related to percent Rubus cover within 1 m in a manner where intermediate levels
sylvania. Fledgling survival for the
were best. The model for Old field Management revealed that tall shrub (>2m) count
within 5 m of the nest was negatively associated with nest survival. entire 25-day post-fledging period was
25.3 ± 8.2% in Tennessee and 45.5
± 13.3% in Pennsylvania. Average
shrub height at each fledgling loca-
tion was the most important habitat
feature associated with daily survival,
as fledgling survival was negatively
related to average shrub height during
the first four days after fledging.
Fledgling habitat use and
movement: Habitat use changed
considerably as the fledglings
aged over their first 30 days post-
fledging. Very young fledglings
(<5 days out of the nest) used
primarily early-successional habitat
on the first day post-fledging but
gradually used other cover types
as they aged (Figs. 11 and 12).
By Day-12 post-fledging, early-
successional habitat made up less
than half of total cover types used
Figure 9. Fledgling productivity among management systems. Fledgling productivity
was the product of four components: (1) probability of nest success given three nesting by fledglings in Pennsylvania and
attempts, (2) number of fledglings produced per successful nest, (3) territory density, and Tennessee. Fledglings studied in
(4) pairing rates. Low and high estimates were calculated using lower and upper 95% Tennessee used proportionally more
confidence intervals. pole-staged stands than fledglings in
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Table 2. Size comparisons of radio-marked golden-winged warbler visually mapped territories and telemetry-delineated home ranges
using 50% and 100% minimum convex polygons (MCPs).
Visually mapped territory (ha) Telemetry-delineated home range (ha)
Metric State n Mean ± SE Range Mean ± SE Range
Territory Size (ha):
100% MCP PA 12 1.7 0.2 0.65–3.69 6.3 1.7 1.40–19.76
WV 7 2.4 0.5 0.79–4.77 11.8 6.2 2.27–47.99
50% MCP PA 12 0.3 0.1 0.12–0.69 0.5 0.1 0.13–1.03
WV 7 0.3 0.1 0.13–0.63 0.6 0.1 0.20–1.28
Figure 10. A visually mapped territory (gray)
and telemetry-delineated home range
(dashed polygon) for an individual male
golden-winged warbler in West Virginia. This
individual’s visually mapped territory over-
lapped with one other individual’s visually
mapped territory (hollow polygons), but his
telemetry-delineated home range over-
lapped with portions of visually mapped ter-
ritories of nine other males. Visually mapped
territory point locations are represented as
circles and telemetry locations as stars.
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Figure 11. The use of five different cover types by golden-winged warbler fledglings during four time intervals across the first 30 days
post-fledging. (Note: Wetlands and shelterwoods were not present in the Tennessee study area.)
Figure 12. An example of mid-succession-
al habitat used by older golden-winged
warbler fledglings in Pennsylvania—often
a patch of moderately dense regeneration
within canopy gaps created by individual Figure 13. Daily movement patterns of fledgling golden-winged warblers in Tennessee
tree falls or gypsy moth mortality. and Pennsylvania over the first 20 days post-fledging. Movement is measured as day-to-
day movements and distance to nest.
Pennsylvania over all time intervals. Putting Findings into Practice drastically. To reverse these population
Pennsylvania birds used wetlands declines, many government natural
and shelterwoods (which were The purpose of this assessment was resource agencies and their partners are
not available in Tennessee) more to evaluate golden-winged warbler using active management (e.g., timber
frequently as they aged. Day-to- response to active habitat management harvest, brush mowing, and prescribed
day movements and total distance using conservation practices suggested fire) to increase the availability of early
from the nest increased during by NRCS’s Working Lands for Wildlife successional communities in forested
each of five time steps examined in the southern and central Appalachian landscapes. The financial and human
for all radio-marked individuals states. Golden-winged warbler popula- resource costs associated with these
(Fig. 13). Figure 14 shows the daily tions, and those of many other wildlife efforts are often considerably high. As
movements of a fledgling golden- species that require forested landscapes such, evaluating which conservation
winged warbler in Pennsylvania. with a mix of young and old succes- systems are effective and identifying
sional communities, have declined potential ways to improve management
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• Golden-winged warbler density
increased linearly with sapling count.
Management should result in average
sapling densities that range between
3,000–8,400 stems/ha (1,200–3,300
stems/acre).
• Although the simultaneous
attainment of recommended levels
of the five nest site vegetation
characteristics presented in
the Golden-winged Warbler
Conservation Plan (Roth et al. 2012)
was rare for all five management
systems, they still maintained the
capacity to produce high-quality
nesting habitat.
• While WLFW sites were used
by golden-winged warblers, there
are a few aspects of vegetation that
managers need to pay close attention
to in order to improve attainment
of recommended levels outlined
in the Golden-winged Warbler
Conservation Plan. Specifically,
woody-dominated sites (timber
harvest and prescribed fire - young
forest) generally needed more
grass cover (observed 2–6% vs.
the recommended 5–25%) and
herbaceous-dominated sites (old
field management, grazing, and
prescribed fire) needed to reduce
grass cover (observed 30–35% vs.
the recommended 5–25%). The
recommended values for these
particular vegetation components
can be achieved by incorporating the
appropriate facilitating practices into
Figure 14. An example of a 27-day movement pathway of a fledgling golden-winged NRCS conservation plans.
warbler within a timber harvest management system site in Pennsylvania.
• This assessment represents one
of the single largest efforts to relate
effectiveness is important. Assessment • Golden-winged warbler territories golden-winged warbler nesting
findings can be used to maximize the were relatively small with most success to a suite of specific land
contribution of NRCS’s Working Lands (>90%, n = 463) defended territories management systems. Two hundred
for Wildlife to reversing the decline of being <3 ha (7.5 acres) in size. eighty-eight golden-winged warbler
this imperiled songbird. Average territory size was greatest nests across all study areas were found
for grazing sites (1.77 ha) and least and monitored. Management system
• Many of the golden-winged warbler
for timber harvests (0.82 ha). Across itself was not associated with survival
demographic metrics assessed (e.g.,
all sites, regardless of management of golden-winged warbler nests.
annual adult survival, territory density,
system, territory size averaged 1.36 ha
and nest survival) did not differ among (3.5 acres). • Individual management systems
the five management systems (timber supported different vegetation
harvest, prescribed fire - young forest, • On average, managed sites supported relationships with respect to nest
prescribed fire - old field, grazing 1.5 males/10 ha (0.6 males/10 acres). survival. Timber harvest and
management, and old field man- prescribed fire - old field had no
agement), thus indicating that each • Across all management systems, apparent relationships with micro-
was effective at supporting breeding adult males had a minimum annual habitat characteristics while old
populations of this species in the land- survival probability of 0.58 (± 0.04, n field management and grazing
scapes where it was applied. = 290 males). management nests survived as a
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