Golden-cheecked Warbler in Central America Pine-oak Forest Ecoregion
Ana José Cóbar-Carranza1, Efraín Castillejos-Castellanos2, Manolo
García Vettorazzi1, and Claudia Macias Caballero2. 1Universidad San Carlos de Guatemala . 2Pronatura Sur A.C.
2016 Golden-cheeked Warbler and Black-capped
Vireo Symposium Austin Texas January 2016
GCWA migrates through the mountains of eastern Mexico along the Sierra Madre Oriental in the states of Tamaulipas, Nuevo Leon, Coahuila, Queretaro, Veracruz and Chiapas.
• When arrive to winter grounds, It spends winter in temperate forests of Chiapas (Mexico), Guatemala, Salvador Honduras & Nicaragua.
Timeline GCWA Studies in winter grounds….
1990-1993
Pronatura Sur studies winter ecology of GCWA in Highlands of Chiapas
1999
SalvaNatura starts birds monitoring in pine-oak forest (Montecristo, El Salvador)
Defensores de la Naturaleza establishes conservation project for GCWA in Sierra de las Minas Biosphere Reserve (Guatemala)
2000-2003
Pronatura Sur (México) and defensores de la Naturaleza (Guatemala) studies distribution and ecology of GCWA in winter grounds
Defensores de la Naturaleza facilitate a regional workshop for GCWA Conservation in winter grounds. First protocol.
2001 2003
The Alliance was established during mesoamerican society for biological conservation meeting in Chiapas
2004
The Alliance develop a standar protocol for a regional monitoring of GCWA
2006-2010
First regional proyect. The Alliance apply standard protocol to monitoring GCWA in winter grounds (TPWD)
Standard Methodologies & Regionals Monitoring Projects
Increase knowledge about GCWA in winter grounds
What we know…..
• Habitat use
• Populations tendencies of GCWA
• Potential distribution of GCWA in the Central America Pine-oak Forest Ecoregion
• Mixed species flocks dynamic
ECOLOGY AND MONITORING OF GOLDEN-‐CHEEKED WARBLERS THROUGHOUT THEIR WINTER RANGE
Institutional collaboration among • Pronatura Sur (Mexico). • Defensores de la Naturaleza (Guatemala). • SalvaNATURA (El Salvador). • Fundacion-Gaia, ALAS, The Nature Conservancy &
MARENA (Nicaragua). • Fundación EDUCA, The Nature Conservancy, Centro
Zamorano de Biodiversidad & SERNA (Honduras). • The Nature Conservancy-Texas & Zoo Conservation
Outreach Group (USA).
• With the support of Section 6 Endangered Species Act funds (U.S.F.W.S.), administered by Texas Parks & Wildlife Department.
Methodology
• Four-‐year project (2006-2007, 2007-2008, 2008-2009 and 2009-2010).
• Each winter from November to February • 5 teams in 5 countries (Chiapas-‐Mexico, Guatemala, El Salvador, Honduras
and Nicaragua). • 5 localiHes per country. • Each locality studied 5 mixed foraging flocks of insecHvorous birds. • Protocol included 2 observers following each flock for 4 h in the morning
and describing vegetaHon in area occupied by flock. • AOer four seasons, we have data from over 600 flocks
(440 Golden-‐cheeked Warblers records).
Why do we study mixed foraging flocks
• GCWA has a special behavior when arrives to winter grounds.
• GCWA join mixed
foraging flocks during the morning to search food into the forests.
Golden Cheeked Warbler Townsend´s Warbler
Black-throated Green Warbler Hermit Warbler
Black-and-white Warbler Slate-throated Redstart
• Applied Multiple regression - 19 variables
Efect of habitat characteristics
– midlevel encino cover (2-10 m) (P=0.000, R2= 11.9%)
– Tree Maximum height (P=0.005, R2= 2.0%)
– Canopy encino cover (alto, > 10 m) (P=0.007, R2= 1.0%)
RESULTS
Tree where GCWA were first sighted
0
50
100
150
200
250
300
pine roble encino Quercus sp. sweetgum broadleaf
tree taxon
ind
ivid
ual
s
male typefemale typeall
Population Tendencies Table. GLM analysis of absolute abundance of GCWA per migration season
Es8mator Standard Error Z Value Pr(>|z|) Intercept 1.0335 0.0981 10.54 0.0000 Season 07-‐08 0.1880 0.1241 1.52 0.1297 Season 08-‐09 0.2160 0.1276 1.69 0.0906 Season 09-‐10 0.0175 0.1332 0.13 0.8954
- No significant differences between migration season
- The abundance of GCWA is stable
Figure. Absolute abundance of GCWA per migraHon season
Table. GLM analysis of absolute abundance of GCWA by country and migration season Country Es8mator Standard Error z Value Pr(>|z|) GUATEMALA Intercept 0.4055 0.3333 1.22 0.2238 Season 07-‐08 0.3677 0.4336 0.85 0.3964 Season 08-‐09 0.4055 0.3849 1.05 0.2921 Season 09-‐10 0.3567 0.4216 0.85 0.3976 HONDURAS Intercept 1.1451 0.2132 5.37 0.0000 Season 07-‐08 0.6466 0.2575 2.51 0.0120* Season 08-‐09 1.3563 0.2487 5.45 0.0000* Season 09-‐10 0.7156 0.2601 2.75 0.0059* MÉXICO Intercept 1.3499 0.1361 9.92 0.0000 Season 07-‐08 0.0249 0.1732 0.14 0.0376* Season 08-‐09 -‐0.4336 0.2086 -‐2.08 0.8855 Season 09-‐10 -‐0.1067 0.1943 -‐0.55 0.5828 NICARAGUA Intercept 0.1823 0.4082 0.45 0.6552 Season 07-‐08 0.0800 0.4935 0.16 0.8712 Season 08-‐09 0.6650 0.4880 1.36 0.1729 Season 09-‐10 -‐0.1067 0.1943 -‐0.55 0.5828 EL SALVADOR Intercept 0.9555 0.2773 3.45 0.0006 Season 07-‐08 -‐0.0800 0.4003 -‐0.20 0.8415 Season 08-‐09 -‐0.2624 0.4494 -‐0.58 0.5593 Season 09-‐10 -‐0.3677 0.4336 -‐0.85 0.3964
• In Mexico the season 2007-2008 a higher number of GCWA was recorded (season 2007-2008 No. GCWA= 41, χ=26.2 ± 5) and more monitoring sites were surveyed.
• In Honduras the season 2006-2007 showed the lowest number of GCWA in comparison to other seasons (season 2006-2007 No. GCWA= 19, χ=26.3 ± 2.6).
Country Monitoring site No. GCWA/ flock Status
México
Reforma 3
Very common
Sierra Morena 1.5 Laguna Cochi 1.1 Arcotetes 1 Moxviquil 1 Tres Picos 1 Buenos Aires 1
Guatemala Cubulco 1.4 Very common San Jerónimo 0.95 Common San Lorenzo Mármol 0.8
Honduras Uyuca 2.43
Very common La Tigra 1.61 La Muralla 1
El Salvador Parque Nacional Montecristo 1.05 Very common El Manzano 0.75 Common
Nicaragua Miramar 0.5 Common
Potential Distribution
Less probability More probability
Record of presence
Variables: - Altitud - 19 bioclimatic var.
Central America Pine Oak Ecoregion GCWA potential habitat
Countries Potential habitat (km2) %
Guatemala 21,552.8 40 Honduras 15,553.12 29 México 12,768.91 24 Nicaragua 3,684.56 7 El Salvador 402.14 1 TOTAL 53,961.53
Challenges for the future
• Determine population density of GCWA – Are there changes in population of GCWA
in the monitoring sites?
• Characterize the habitat of the GCWA – Which are the key species of the habitat?
– Which are determining factors in the habitat (plant species richness, structure, others) to ensure the presence and abundance of GCWA?
Acknowledges:
• U.S. Fish and Wildlife Service, Section 6 grant program (Endangered Species Act fund) and Texas Parks and Wildlife Department for the grants for fieldwork
• Neotropical Migratory Conservation Act grant for the analysis
• Pronatura‐Sur in México, Fundación Defensores de la Naturaleza in Guatemala,SalvaNATURA in El Salvador and FUNDECI/GAIA in Nicaragua
• Members of the Alliance for the Conservation of Pine‐Oak Forests in Mesoamerica.