This presentation will summarize what biologists have discovered about the behavior and life history of the endangered Golden-cheeked Warbler. In particular, we will examine some preliminary insights gleaned from the first three years of intensive study involving the color-banding of Golden-cheeks on the Balcones Canyonlands Preserve.

1. Learning More About Our Native Texan:
The Golden-cheeked Warbler

2. Central Texas is home
to a wide variety of
fascinating wildlife.

3. Among them are many
species of birds.
Photos: Jim & Lynne Weber, and City of Austin staff files
But of all the birds that can
be found here, only one
nests nowhere else in the
world but Texas.

4. Photo: Bill Reiner
Because every Golden-cheeked
Warbler was born in Texas, every
one is a native Texan.

5. Golden-cheeked Warbler
(Setophaga chrysoparia)
Photos by John Ingram
about 5 inches longBoth sexes have a black line through each eye,
across an otherwise immaculate yellow face.
Older males have a
black back and crown…
…and a black “bib”
Females and some young males have variable
amounts of green on the back and crown…
Warbler bills are slender, like forceps
… and
black on
the throat

6. A Look-Alike Migrant
Black-throated Green Warblers migrate
through central Texas in spring and fall. They
can look much like female Golden-cheeks.
Adult Golden-cheeked Warblers always have
bold black eye lines, and an immaculate white
vent area.
A yellowish wash at the vent is a distinctive
mark for Black-throated Green Warblers.
The back is green and the cheeks are yellow,
but the eye line is less prominent, and there are
dusky marks on the face.

7. A Gold-and-Black Bird at Your Birdfeeder
Lesser Goldfinch
loves birdseed, especially thistle seed;
comes to birdfeeders
Golden-cheeked Warbler
eats insects and spiders – not birdseed;
does not come to birdfeeders
Photo by John Ingram
is not a Golden-cheeked Warbler

8. The Golden-cheeked Warbler is a “forest-interior” species. The healthiest
populations are in large patches of mature, closed-canopy juniper-oak woodlands.
Photo by John Ingram
Golden-cheeked Warbler Habitat Requirements:

9. Tall trees with a high percentage of canopy cover are typical of their habitat.
Golden-cheeked Warbler Habitat Requirements:

10. Golden-cheeked Warblers need mature
Ashe juniper for nesting and food
(insects and spiders).
Photo by John Ingram
Golden-cheeked Warbler Habitat Requirements:
Champion Ashe juniper tree
New Braunfels
41 feet tall, 3.7 feet diameter

11. GCWAs are often seen on or near the ground,
so understory vegetation provides important
protective cover.
Golden-cheeked Warbler Habitat Requirements:
Photo by Jim O’Donnell

12. GCWAs often drink and bath in springs and shallow pools,
even crossing through neighboring territories to do so.
Photo by John Ingram
Golden-cheeked Warbler Habitat Requirements:

13. Hatch-year (“teenage”) Golden-cheeked Warblers
bathing and drinking from a puddle on a Preserve road
Film clip: Bill Reiner

14. They winter in pine-oak
woodlands in the highlands
of southern Mexico and
Central America.
Where do Golden-cheeked Warblers Live?
These birds breed only in the
juniper (also known as
“cedar”) and oak woodlands
of central Texas.
They migrate along the Sierra
Madre Oriental in coniferous
forest.
Photo by John Ingram

15. The Golden-
cheeked Warbler’s
range lies in the
Texas Hill Country,
west and north of
the Balcones Fault
Zone (Balcones
Escarpment)

16. Travis County supports some of the best and largest tracts of habitat in
the heart of the Golden-cheeked Warblers’ breeding range
Photo by John Ingram

17. Sketch of Friesenhahn Cave from the Bulletin of
the Texas Memorial Museum (1961)
Fossilized juniper and oak pollen from Friesenhahn Cave in northern Bexar County
date to the last ice age, about 14,000-20,000 years ago. – S. Hall and S. Valastro (1995)
Historical records provide evidence that the Hill Country has
supported juniper-oak woodlands for a very long time.

18. Historical photo of Bull Creek, below Cat Mountain and RM 2222, looking NW
(early 1900s)

19. Historical photo of a ravine near Wild Basin/Vireo Preserve, prior to clearing
-- William Bray (1904)

20. Historical photo of a ravine near Wild Basin/Vireo Preserve, following clearing
-- William Bray 1904

21. “[Golden-cheeked Warblers] are nowhere abundant, and only to be met
with in the thickest cedar brakes, and as these are fast being cut and
burnt out, the bird will no doubt become still more rare.” – H.P. Attwater, 1892
© John Ingram
Historical photo of land near Wild Basin/Vireo Preserve
being cut a second time (first cut ~1875). – Wm Bray (1904)

22. Unfortunately, a very limited
range makes these birds
vulnerable to habitat loss.

23. Unfortunately, a very limited
range makes these birds
vulnerable to habitat loss.

24. In 1990, the U.S. Fish &
Wildlife Service agreed,
and listed the species as
endangered.
Regulations slowed the
rapid loss of the birds’
habitat, but also caused
headaches for developers,
especially in fast-growing
urban areas such as Travis
County.
To ease the conflict, the
City of Austin and Travis
County applied for a U.S.
Fish & Wildlife Service
permit for a Habitat
Conservation Plan (HCP).
The basic plan allows
individual land-owners to
pay a mitigation fee to
develop their land. The
fees collected would be
used by the City and
County to purchase land as
a sanctuary for this and
other endangered species.
The approved plan is the
Balcones Canyonlands
Conservation Plan (BCCP),
the first multi-species HCP
in the country. The land
protected under this plan is
the Balcones Canyonlands
Preserve (BCP).
With the sprawl of cities
along the Interstate 35
corridor, biologists feared
for the species’ survival.

25. A Biological Advisory Team recommended
protecting 125,000 acres in Travis County to be
certain that this important population would survive.
A preserve that large was considered not feasible,
politically or economically, so a compromise of
75,000 acres was proposed.
The BCP partners determined that this second
proposal would also not be attainable, but 30,000
acres would be.
To reach a minimum viable size for the
population, the U.S. Fish & Wildlife Service
committed to creating a national wildlife refuge of
40,000 to 44,000 acres to protect the species.
(That refuge is the Balcones Canyonlands
National Wildlife Refuge.)
In addition to the warbler, the BCP
also protects habitat for the
endangered Black-capped Vireo, and
6 endangered karst invertebrates.
Establishing the Preserve

27. The Balcones Canyonlands Preserve (BCP) is not
a single preserve but a system of preserves
owned and managed by these partners.
City of Austin
Travis County
Private Landowners
Strengthened by Partnership
Lower Colorado River Authority
The Nature Conservancy
Travis Audubon Society
But preserving the land is only the first step…

28. Measures: How
Are They Doing?
• Dispersal – do individual warblers shift locations?
• Abundance and density
• Pairing success – whether males
attract mates
• Reproductive success – whether pairs
successfully raise young, and how many
(fecundity)
• Survival – what proportion of the birds return
to breed from the wintering range

29. • Territory mapping
• March 15-May 25
• Prime habitat: 10 visits
• Transitional habitat: 5 visits
• Productivity
• March 15-June 15, based on
behavioral observations
• 1 person per plot
• Average 6 hours/visit
• 60 hours prime habitat plots
• 30 hours transitional habitat
plots
Survey Methods
1998-2008

30. GCWA Population Viability &
Habitat Suitability Modeling Project
• Study conducted on the BCP under a 5-year contract with the
U.S. Forest Service
Photo by Gil Eckrich, Fort Hood
• Addressing 3 Key Questions:
– How many GCWAs are there on the
BCP?
– How are they doing?
– What management strategies can
best promote recovery of the
GCWAs and their habitat over the
long-term?
• Collaborative project with BCP partners
(and a great corps of volunteers!!!)

31. USFS Project Methods
• Intensive study plots across the
BCP
– Color banding
– Nest monitoring
– Territory mapping
• Point counts across the BCP
• Vegetation data for point counts & nests

32. Study Plots
• Color-banding
– Average >70% adult males banded
per plot
• Intensive territory mapping
– March 15-May 25, 10-20+ visits
• Typically 2 people per plot
• Average >130 hours/100 acres
• Nest monitoring, productivity
– March 15-June 15

33. Removing a Golden-cheeked Warbler
from a mist net

34. GCWA Color Banding
Altogether, we have banded 766
Golden-cheeked Warblers (2009-2014)

35. GCWA banding/re-sighting
Preliminary Results
• 162 adult males banded in 2011
94 adult males banded in 2012
103 adult males banded in 2013
115 adult males banded in 2014
667 adult males banded since 2009
• Male return rates:
– BCP = 44% in 2010
41% in 2011
56% in 2012
48% in 2013
46% in 2014
– Fort Hood 37-56% (8 yrs)
• 49 ad. females banded since 2009

36. GCWA banding/re-sighting
Preliminary Results
• In 2014, USFWS issued a permit
to band nestling Golden-cheeked
Warblers.
• Successfully banded 50
nestlings from 16 nests.

37. Photo by Amanda Aurora
Golden-cheeked Warbler
Nest Monitoring
To date, we have found and
monitored:
• 109 nests in 2011
• 151 nests in 2012
• 154 nests in 2013
• 194 nests in 2014
Photo by John Ingram
Most nests are found in Ashe
junipers, followed by live oak,
cedar elm, and other hardwoods

38. Results …so far
To model the viability of the population, we need at least
three years of data. But we do have preliminary findings:
• Higher density of territories in larger
blocs of closed-canopy woodlands
Territories on JJ&T
transitional plot in 2010
Territories on Kent Butler
prime plot in 2010

39. Results …so far
To model the viability of the population, we need at least
three years of data. But we do have preliminary findings:
Territories on JJ&T
transitional plot in 2010
Territories on Kent Butler
prime plot in 2010
• Higher density of territories in larger
blocs of closed-canopy woodlands
• Older males make up more of the
population in prime habitat sites
= second-year male
= after-second-year male

40. • About half of the males banded in 2009-
2013 returned in subsequent years (44-
56%) – return rates tend to be higher on
plots with prime habitat
Results …so far
To model the viability of the population, we need at least
three years of data. But we do have preliminary findings:
No banded males returned to JJ&T plot.
About half returned to Kent Butler plot.

41. • About half of the males banded in 2009-
2014 returned in subsequent years (44-
56%) – return rates tend to be higher on
plots with prime habitat
• Very little dispersal
Results …so far
To model the viability of the population, we need at least
three years of data. But we do have preliminary findings:
• Higher density of territories in larger
blocs of closed-canopy woodlands
• Older males make up more of the
population in prime habitat sites
2009
2010
2011

42. Resighting/Dispersal
2012 Results
7 dispersal events
• 1.2 - 16 km
• 6 SY males, 1 ASY
However, >90% of
the banded GCWAs
found in subsequent
years have returned
to the same area

43. • Very little dispersal
• Pairing success generally averages more
than 90%, especially on prime plots
Results …so far
To model the viability of the population, we need at least
three years of data. But we do have preliminary findings:
• Higher density of territories in larger
blocs of closed-canopy woodlands
• Older males make up more of the
population in prime habitat sites
Photos by John Ingram
• About 1/2 of males banded returned in
subsequent years (44-56%) – return rates
higher on plots with prime habitat

44. • Averaged 63-78% from 2009-2013
Results …so far
Breeding success (% territories fledging young)
• Tends to be higher on prime plots and for
older males
• Variable statistics, partly from difficulty of finding
all young when they leave the nest.
Reproduction (# of young/site)
• Largest patches of closed canopy woodlands have
the highest reproductive output (Bull Creek,
Cypress Creek, North Lake Austin macrosites)
• Study plots in smaller habitat patches (Barton
Creek, West Austin) and young/recovering
woodlands have the lowest reproductive output
• Lower success rate on small, isolated patches
and young/recovering woodlands
To model the viability of the population, we need at least
three years of data. But we do have preliminary findings:

45. So… How are the Golden-cheeked Warblers doing?
Range-wide:
• Many estimates of population
• Habitat loss continues, so likely a
downward trend
On the Preserve:
• Population appeared
stable through 2012, but…
• Before 2009, counting un-banded birds
• Truly stable? Or constantly
supplemented by displaced birds?
• Extreme heat & drought of 2011 killed
many trees in some areas
• In 2013, few birds where trees died
• Where trees survived, higher densities
of birds in 2013…
• …but lower reproductive success
• Endangered status based upon
loss of habitat
• Endangered Species Act has led to
protection of some habitat, but allowed
some destruction as compromise.
• Re-growing suitable old-growth
habitat will take several decades to
a century or more.
Photo: Nancy Norman
Photo: Nancy Norman
• Reproductive success appears to have
been good for 2014.

46. Photo: Paul Brick
The more data we collect, the more we learn
about:
• What are the characteristics – tree cover,
types of trees, understory, etc. – of habitat
where successful nests are built, and what
can we do to improve those features on
less-than-optimal sites
• How we can help these Native Texans
continue to thrive!
• Where and which birds are having the
most success raising young.
• Minimizing the threats from predators…
and people.

47. Barton Creek Wilderness Park/Greenbelt
So where can I see a Golden-cheeked Warbler?
Wild Basin Wilderness Preserve
Emma Long Park (City Park)
- Turkey Creek Trail
Travis Audubon’s Baker Sanctuary
Laguna Gloria
Bull Creek Greenbelt
St. Edwards Park
Cypress Creek Park, Lake Travis
Hamilton Pool
Balcones Canyonlands National Wildlife Refuge
- Warbler Vista

48. Golden-cheeked Warbler
fledglings taking a bath
Photo by: John Ingram
Thank you for
protecting our
habitat!
To get involved with protecting warblers and their habitat, contact:
COA Volunteer Coordinator Louise Liller
Louise.Liller@austintexas.gov