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First systematic sampling approach to estimating the global population size of the Critically Endangered Blue-throated Macaw Ara glaucogularis

Published online by Cambridge University Press:  16 June 2020

SEBASTIAN K. HERZOG*
Affiliation:
Asociación Armonía, Av. Lomas de Arena 400, Casilla 3566, Santa Cruz de la Sierra, Bolivia
OSWALDO MAILLARD Z.
Affiliation:
Asociación Armonía, Av. Lomas de Arena 400, Casilla 3566, Santa Cruz de la Sierra, Bolivia
TJALLE BOORSMA
Affiliation:
Asociación Armonía, Av. Lomas de Arena 400, Casilla 3566, Santa Cruz de la Sierra, Bolivia
GUSTAVO SÁNCHEZ-ÁVILA
Affiliation:
Asociación Armonía, Av. Lomas de Arena 400, Casilla 3566, Santa Cruz de la Sierra, Bolivia
VÍCTOR HUGO GARCÍA-SOLÍZ
Affiliation:
Asociación Armonía, Av. Lomas de Arena 400, Casilla 3566, Santa Cruz de la Sierra, Bolivia
ANAHÍ C. PACA-CONDORI
Affiliation:
Asociación Armonía, Av. Lomas de Arena 400, Casilla 3566, Santa Cruz de la Sierra, Bolivia
MARTA VAÍLEZ DE ABAJO
Affiliation:
Asociación Armonía, Av. Lomas de Arena 400, Casilla 3566, Santa Cruz de la Sierra, Bolivia
RODRIGO W. SORIA-AUZA
Affiliation:
Asociación Armonía, Av. Lomas de Arena 400, Casilla 3566, Santa Cruz de la Sierra, Bolivia
*
*Author for correspondence; e-mail: skherzog@armonia-bo.org

Summary

Reliable population size estimates are imperative for effective conservation and management of globally threatened birds like the ‘Critically Endangered’ Blue-throated Macaw Ara glaucogularis. Endemic to one of South America’s largest grassland floodplains, the Llanos de Moxos in northern Bolivia, the species’ global population size is uncertain. The region’s inaccessibility renders the application of traditional methods for obtaining bird population estimates impracticable or cost prohibitive. We developed a simultaneous, multilocality, double-sampling approach combined with quantitative habitat availability analyses to obtain the first rigorous population size estimate for the Blue-throated Macaw. We established 11 survey areas across its three subpopulations that were visited twice by one team in each subpopulation over a 23-day period in the 2015 dry season and obtained additional count data from two roost sites. We classified suitable habitat (palm forest islands) using Landsat 8 images and CLASlite forest monitoring software. We extrapolated the number of macaws detected (conservative estimate of the total number of macaws [CETN], highest single count [HSC]) per 100 ha of suitable habitat in each survey area to the entire area of suitable habitat in all subpopulations combined, corrected for the species’ range occupancy of 34.3%. The total number of Blue-throated Macaws detected by survey (CETN) and roost site counts was 137. Across all survey areas, the number of macaws per 100 ha of suitable habitat was 4.7 for the first and 4.4 for the second period for CETN and 3.2 and 3.4, respectively, for HSC data. Corresponding global population estimates were 426–455 (CETN) and 312–329 (HSC) individuals. Other recent research and anecdotal data support these estimates. Although it would be premature to propose downlisting the species to ‘Endangered’, our findings indicate that it has a larger population and slightly larger range than previously thought, and that the positive effects of conservation actions are now becoming apparent.

Type
Research Article
Copyright
© The Author(s), 2020. Published by Cambridge University Press on behalf of BirdLife International

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References

Amato, G., Ryder, O., Rosenbaum, H. and DeSalle, R. (2009) Conservation genetics in the age of genomics. New York, USA: Columbia University Press.CrossRefGoogle Scholar
Asner, G. P., Knapp, D. E., Balaji, A. and Paez-Acosta, G. (2009) Automated mapping of tropical deforestation and forest degradation: CLASlite. J. Appl. Remote Sens. 3: 033543.CrossRefGoogle Scholar
Baños-Villalba, A., Blanco, G., Díaz-Luque, J. A., Denés, F. V., Hiraldo, F. and Tella, J. L. (2017) Seed dispersal by macaws shapes the landscape of an Amazonian ecosystem. Sci. Rep. 7: 7373. DOI:10.1038/s41598-017-07697-5.CrossRefGoogle ScholarPubMed
Berkunsky, I., Cepeda, R. E., Marinelli, C., Simoy, M. V., Daniele, G., Kacoliris, F. P., Díaz Luque, J. A., Gandoy, F., Aramburú, R. M. and Gilardi, J. D. (2016) Occupancy and abundance of large macaws in the Beni savannahs, Bolivia. Oryx 50: 113120.CrossRefGoogle Scholar
Berkunsky, I., Daniele, G., Kacoliris, F. P., Díaz-Luque, J. A., Silva Frias, C. P., Aramburu, R. M. and Gilardi, J. D. (2014) Reproductive parameters in the critically endangered Blue-throated Macaw: limits to the recovery of a parrot under intensive management . PLoS ONE 9: e99941.CrossRefGoogle ScholarPubMed
Berkunsky, I., Díaz Luque, J. A. and Daniele, G. (2011) Black market Blue-throats. PsittaScene 23(2): 67.Google Scholar
Berkunsky, I., Kacoliris, F. P., Daniele, G., Milpacher, S., Gilardi, J. D. and Martin, S. (2012) Blue-throated Macaw – 10 years. PsittaScene 24(3): 35.Google Scholar
Berkunsky, I., Simoy, M. V., Cepeda, R. E., Marinelli, C., Kacoliris, F. P., Daniele, G., Cortelezzi, A., Díaz-Luque, J. A., Friedman, J. M. and Aramburú, R. M. (2015) Assessing the use of forest islands by parrot species in a Neotropical savanna. Avian Conserv. Ecol . 10: http://dx.doi.org/10.5751/ACE-00753-100111.Google Scholar
Bibby, C. J., Hill, D. A., Burgess, N. D. and Mustoe, S. (2000) Bird census techniques. London, UK: Academic Press.Google Scholar
BirdLife International (2020a) Species factsheet: Ara glaucogularis. <http://www.birdlife.org> (Downloaded on 14 January 2020).+(Downloaded+on+14+January+2020).>Google Scholar
BirdLife International (2020b) Species factsheet: Ara macao. <http://www.birdlife.org> (Downloaded on 14 January 2020).+(Downloaded+on+14+January+2020).>Google Scholar
Bueno, M. (2000) International studbook for the Blue-throated Macaw Ara glaucogularis. 1st ed. Tenerife, Spain: Loro Parque Fundación.Google Scholar
Cardador, L., Díaz-Luque, J. A., Hiraldo, F., Gilardi, J. D. and Tella, J. L. (2018) The effects of spatial survey bias and habitat suitability on predicting the distribution of threatened species living in remote areas. Bird Conserv. Internatn. 28: 581592.CrossRefGoogle Scholar
Congalton, R. G. and Green, K. (2009) Assessing the accuracy of remotely sensed data. Principles and practices. Boca Raton, FL: CRC Press.Google Scholar
Courchamp, F., Clutton-Brock, T. and Grenfell, B. (1999) Inverse density dependence and the Allee effect. Trends Ecol. Evol. 14: 405410.CrossRefGoogle ScholarPubMed
Davies, N. B. and Welbergen, J. A. (2009) Social transmission of a host defense against cuckoo parasitism. Science 324: 13181320.CrossRefGoogle ScholarPubMed
de Waal, F. B. M. and Tyack, P. L., eds. (2003) Animal social complexity: Intelligence, culture, and individualized societies. Cambridge, USA: Harvard University Press.CrossRefGoogle Scholar
Denés, F. V., Tella, J. L. and Beissinger, S. R. (2018) Revisiting methods for estimating parrot abundance and population size. Emu 118: 6779.CrossRefGoogle Scholar
Dresser, C. M., Ogle, R. M. and Fitzpatrick, B. M. (2017) Genome scale assessment of a species translocation program. Conserv. Genet. 18: 11911199.CrossRefGoogle Scholar
Erickson, C. L. (2006) The domesticated landscapes of the Bolivian Amazon. Pp. 236-278 in Balée, W. and Erickson, C. L., eds. Time and complexity in historical ecology. New York, USA: Columbia University Press.Google Scholar
Erickson, C. L. and Balée, W. (2006) The historical ecology of a complex landscape in Bolivia. Pp. 187-233 in Balée, W. and Erickson, C. L., eds. Time and complexity in historical ecology. New York, USA: Columbia University Press.Google Scholar
Ganter, B. and Madsen, J. (2001) An examination of methods to estimate population size in wintering geese. Bird Study 48: 90101.CrossRefGoogle Scholar
Hamilton, S. K., Sippel, S. J. and Melack, J. M. (2004) Seasonal inundation patterns in two large savanna floodplains of South America: the Llanos de Moxos (Bolivia) and the Llanos del Orinoco (Venezuela and Colombia). Hydrol. Process. 18: 21032116.CrossRefGoogle Scholar
Herrera, M. and Hennessey, A. B. (2007) Quantifying the illegal parrot trade in Santa Cruz de la Sierra, Bolivia, with emphasis on threatened species. Bird Conserv. Internatn. 17: 295300.CrossRefGoogle Scholar
Herrera, M., Vargas, H., Sandoval, V., Perkins, T. and Rendón, O. (2007) Nuevo dato en la distribución de la Paraba barba azul (Ara glaucogularis). Kempffiana 3: 1824.Google Scholar
Herzog, S. K., Bürger, J., Troncoso, A. J., Vargas, R. R., Boorsma, T. and Soria-Auza, R. W. (2018) Deterministic population growth models and conservation translocation as a management strategy for the critically endangered Blue-throated Macaw (Ara glaucogularis): A critique of Maestri et al. Ecol. Modell. 388: 145148.CrossRefGoogle Scholar
Herzog, S. K., Maillard, Z.O., Embert, D., Caballero, P. and Quiroga, D. (2012) Range size estimates of Bolivian endemic bird species revisited: the importance of environmental data and national expert knowledge. J. Ornithol. 153: 11891202.CrossRefGoogle Scholar
Herzog, S. K., Terrill, R. S., Jahn, A. E., Remsen, J. V. Jr., Maillard, Z. O., García-Solíz, V. H., MacLeod, R., Maccormick, A. and Vidoz, J. Q. (2016) Birds of Bolivia. Field guide. Santa Cruz de la Sierra, Bolivia: Asociación Armonía.Google Scholar
Hesse, A. J. and Duffield, G. E. (2000) The status and conservation of the Blue-throated Macaw Ara glaucogularis. Bird Conserv. Internatn. 10: 255275.CrossRefGoogle Scholar
Hordijk, I., Meijer, F., Nissen, E., Boorsma, T. and Poorter, L. (2019) Cattle affect regeneration of the palm species Attalea princeps in a Bolivian forest-savannah mosaic. Biotropica 51: 2838.CrossRefGoogle Scholar
Ibisch, P. L., Beck, S. G., Gerkmann, B. and Carretero, A. (2003) Ecoregiones y ecosistemas. Pp. 47-88 in Ibisch, P. L. and Mérida, G., eds. Biodiversidad: la riqueza de Bolivia. Santa Cruz de la Sierra, Bolivia: Editorial FAN.Google Scholar
Jordán, O. C. and Munn, C. A. (1993) First observations of the Blue-throated Macaw in Bolivia. Wilson Bull. 105: 694695.Google Scholar
Langstroth Plotkin, R. (2011) Biogeography of the Llanos de Moxos: natural and anthropogenic determinants. Geographica Helvetica 66: 183192.CrossRefGoogle Scholar
Larrea-Alcázar, D. M., Embert, D., Aguirre, L. F., Ríos-Uzeda, B., Quintanilla, M. and Vargas, A. (2011) Spatial patterns of biological diversity in a Neotropical lowland savanna of northeastern Bolivia. Biodiv. Conserv. 20: 11671182.CrossRefGoogle Scholar
Maestri, M. L., Ferrati, R. and Berkunsky, I. (2017) Evaluating management strategies in the conservation of the critically endangered Blue-throated Macaw (Ara glaucogularis). Ecol. Model. 361: 7479.CrossRefGoogle Scholar
Marsden, S. J. (1999) Estimation of parrot and hornbill densities using a point count distance sampling method. Ibis 141:327390.CrossRefGoogle Scholar
Mayle, F. E., Langstroth, R. P., Fisher, R. A. and Meir, P. (2007) Long-term forest-savannah dynamics in the Bolivian Amazon: implications for conservation. Phil. Trans. Roy. Soc. Lond. B Biol. Sci. 362: 291307.CrossRefGoogle ScholarPubMed
Milpacher, S. (2013) A wild idea. PsittaScene 25(2): 5.Google Scholar
Negro, J. J. (2011) The ghost fraction of populations: a taxon-dependent problem. Anim. Conserv. 14: 338339.Google Scholar
Newson, S. E., Evans, K. L., Noble, D. G., Greenwood, J. J. D. and Gaston, K. J. (2008) Use of distance sampling to improve estimates of national population sizes for common and widespread breeding birds in the UK. J. Appl. Ecol. 45: 13301338.CrossRefGoogle Scholar
Olah, G., Smith, A. L., Asner, G. P., Brightsmith, D. J., Heinsohn, R. G. and Peakall, R. (2017) Exploring dispersal barriers using landscape genetic resistance modelling in scarlet macaws of the Peruvian Amazon. Landscape Ecol. 32: 445456.CrossRefGoogle Scholar
Pacífico, E. C, Barbosa, E. A., Filadelfo, T., Oliveira, K. G., Silveira, L. F. and Tella, J. L. (2014) Breeding to non-breeding population ratio and breeding performance of the globally Endangered Lear’s Macaw Anodorhynchus leari: conservation and monitoring implications. Bird Conserv. Internatn. 24: 466476.CrossRefGoogle Scholar
Sandercock, B. K., Beissinger, S. R., Stoleson, S. H., Melland, R. R. and Hughes, C. R. (2000) Survival rates of a Neotropical parrot: implications for latitudinal comparisons of avian demography. Ecology 81: 13511370.CrossRefGoogle Scholar
Simonetti, D., Marelli, A. and Eva, H. (2015) IMPACT Toolbox. JRC Technical Report . Brussels, Belgium: European Commission Joint Research Centre.Google Scholar
Strem, R. I. and Bouzat, J. L. (2012) Population viability analysis of the Blue-throated Macaw (Ara glaucogularis) using individual-based and cohort-based PVA programs. Open Conserv. Biol. J. 6: 1224.CrossRefGoogle Scholar
Sutherland, W. J., Newton, I. and Green, R., eds. (2004) Bird ecology and conservation: a handbook of techniques. Oxford, UK: Oxford University Press.CrossRefGoogle Scholar
Tella, J. L., Rojas, A., Carrete, M. and Hiraldo, F. (2013) Simple assessments of age and spatial population structure can aid conservation of poorly known species. Biol. Conserv. 167: 425434.CrossRefGoogle Scholar
Voss, I. (2005) Comportamiento de las parejas de guacamayos de barba azul (Ara glaucogularis). Cyanopsitta 7: 1617.Google Scholar
Walker, J. H. (2008) Pre-Columbian ring ditches along the Yacuma and Rapulo Rivers, Beni, Bolivia: a preliminary review. J. Field Archaeol. 33: 413427.Google Scholar
Waugh, D. (2007) Sensational new discovery of Blue-throated Macaws in Bolivia. AFA Watchbird 34(3): 53.Google Scholar
Yamashita, C. and Machado de Barros, Y. (1997) The Blue-throated Macaw Ara glaucogularis: characterization of its distinctive habitats in savannahs of the Beni, Bolivia. Ararajuba 5: 141150.Google Scholar