Advertisement

International Journal of Primatology

, Volume 39, Issue 2, pp 222–236 | Cite as

Improving the Estimation of Calling Probability and Correction Factors in Gibbon Monitoring Using the Auditory Point Count Method

  • Thinh Tien Vu
  • Long Manh Tran
  • Manh Dac Nguyen
  • Dung Van Tran
  • Nga Tuyet Ta
Article

Abstract

Estimating the population size of primate species is very important in identifying appropriate conservation actions and measuring their effectiveness. All 17 species of gibbons recognized by the IUCN are considered threatened with extinction. Thus, there is a great need to determine and monitor their status, to conduct effective conservation interventions. Gibbons can be detected by their loud and long song bouts, and surveys usually rely on auditory point count methods. However, gibbon groups do not call daily, so we need a correction factor based on the daily calling probability to estimate gibbon population size accurately. Several studies have estimated such correction factors, but these estimates might be negatively biased if gibbon groups move beyond the maximum hearing distance or are far from the listening post and their calls are faint. We aimed to address this issue and estimate the calling probability and correction factor accurately. We collected data on southern yellow-cheeked crested gibbon (Nomascus gabriellae) in Cat Tien National Park, Vietnam, from July to October 2016, using an auditory point count method. We explored the influence of the maximum distance between the listening post and the gibbons on estimates of the calling probability, correction factor, and population size. We detected 44 gibbon groups during the survey. The calling probability and correction factor decreased with the maximum distance from the listening post to the gibbon groups. If we used all the gibbon groups to estimate the correction factor, population estimates were 15% and 18% higher than those estimated using only gibbon groups detected within 700 m and 500 m, respectively. Based on these findings, we recommend that researchers calculate the calling probability and correction factor for several maximum distances and determine the percentage overestimation of the gibbon population. They should then choose the correction factor so as to balance sample size and the risk of overestimation of gibbon population size.

Keywords

Hylobatidae Correction factor Gibbon Mark-recapture Nomascus 

Notes

Acknowledgments

We thank the Vietnam National Foundation for Science and Technology (NAFOSTED) for support given to this project (Contract number 06-NN.06-2015.37). Our gratitude also extends to the forest rangers in Cat Tien National Park for permitting us to conduct the survey. We also thank all the field assistants for helping us with the field survey. Finally, we thank the reviewers and editors for their insightful comments, suggestions, and corrections.

References

  1. BirdLife International & Forest inventory and planning institute (2001). Sourcebook of existing and proposed protected areas in Vietnam. Hanoi: BirdLife International Vietnam Programme and the Forest Inventory and Planning Institute.Google Scholar
  2. Brockelman, W. Y., & Ali, R. (1987). Methods of surveying and sampling forest primate populations. In C. W. Marsh & R. A. Mittermeier (Eds.), Primate conservation in the tropical rainforest (pp. 23–62). New York: Alan R. Liss.Google Scholar
  3. Brockelman, W. Y., & Srikosamatara, S. (1993). Estimation of density of gibbon groups by use of loud songs. American Journal of Primatology, 29(2), 93–108.CrossRefGoogle Scholar
  4. Buckland, S. T., Anderson, D. R., Burnham, K. P., Laake, J. L., Borchers, D. L., & Thomas, L. (2001). Introduction to distance sampling: Estimating abundance of biological populations. Oxford: Oxford University Press.Google Scholar
  5. Burnham, K. P., & Anderson, D. (2002). Model selection and multi-model inference: A practical information – Theoretic approach, 2nd ed. New York: Springer Science+Business Media.Google Scholar
  6. Cheyne, S. M., Gilhooly L. J., Hamard, M. C., Höing, A., Houlihan, P. J., et al. (2016) Population mapping of gibbons in Kalimantan, Indonesia: Correlates of gibbon density and vegetation across the species range. Endangered Species Research 2016, 30, 133–143.Google Scholar
  7. Geissmann, T. (1993). Evolution of communication in gibbons (Hylobatidae). PhD dissertation: Zürich University.Google Scholar
  8. Geissmann, T., & Orgeldinger, M. (2000). The relationship between duet songs and pair bonds in siamangs, Hylobates syndactylus. Animal Behavior, 60, 805–809.CrossRefGoogle Scholar
  9. Huggins, R. M. (1991). Some practical aspects of a conditional likelihood approach to capture experiments. Biometrics, 47, 725–732.CrossRefGoogle Scholar
  10. Jiang, X. L., Luo, Z. H., & Zhao, S. Y. (2006). Status and distribution patterns of black crested gibbon (Nomascus concolor jingdongensis) in Wulian Mountains, Yunnan, China: Implications for conservation. Primates, 47, 264–271.CrossRefPubMedGoogle Scholar
  11. Kidney, D., Rawson, B. M., Borchers, D. L., Stevenson, B. C., Marques, T. A., & Thomas, L. (2016). An efficient acoustic density estimation method with human detectors applied to gibbons in Cambodia. PLoS One, 11.  https://doi.org/10.1371/journal.pone.0155066.
  12. O’Brien, T. G., Kinnaird, M. F., Nurcahyo, A., Iqbal, M., & Rusmanto, M. (2004). Abundance and distribution of sympatric gibbons in a threatened Sumatran rain forest. International Journal of Primatology, 25, 267–284.CrossRefGoogle Scholar
  13. Otis, D. L., Burnham, K. P., White, G. C., & Anderson, D. R. (1978). Statistical inference from capture data on closed animal populations. Wildlife Monographs, 62, 1–135.Google Scholar
  14. Raemaekers, J. J., & Raemaekers, P. M. (1985). Field playback of loud calls to gibbons (Hylobates lar): Territorial, sex-specific and species-specific responses. Animal Behaviour, 33, 481–493.CrossRefGoogle Scholar
  15. Rawson, B. M. (2004). Vocalisation patterns in the yellow-cheeked crested gibbon (Nomascus gabriellae). In T. Nadler, U. Streicher, & T. L. Ha (Eds.), Conservation of primates in Vietnam (pp. 130–136). Hanoi: Haki Publishing.Google Scholar
  16. Reichard, U. (1998). Sleeping sites, sleeping places, and presleep behavior of gibbons (Hylobates lar). American Journal of Primatology, 62, 35–62.CrossRefGoogle Scholar
  17. The IUCN Red List of Threatened Species (2017). Version 2017–1. www.iucnredlist.org (accessed June 9, 2017).
  18. Vu, T. T., & Dong, T. H. (2015). Estimation of northern yellow-cheeked gibbon (Nomascus annamensis) population size in Kon cha rang nature reserve: A new method–using a weighted correction factor. Vietnamese Journal of Primatology, 2, 41–48.Google Scholar
  19. Vu, T. T., & Rawson, B. M. (2011). Package for calculating gibbon population density from auditory surveys. Hanoi: Conservation International and Fauna & Flora International.Google Scholar
  20. Vu, T. T., Tran, V. D., Giang, T. T., Nguyen, H. V., Nguyen, D. M., et al (2016). A mark-recapture population size estimation of southern yellow-cheeked crested gibbon Nomascus gabriellae (Thomas, 1909) in Chu Yang sin National Park, Vietnam. Asian Primate Journal, 6, 33–42.Google Scholar
  21. White, G. C., & Burnham, K. P. (1999). Program MARK: Survival estimation from populations of marked animals. Bird Study, 46, 120–139.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  • Thinh Tien Vu
    • 1
  • Long Manh Tran
    • 2
  • Manh Dac Nguyen
    • 1
  • Dung Van Tran
    • 1
  • Nga Tuyet Ta
    • 1
  1. 1.Department of Wildlife, Faculty of Forest Resource and Environment ManagementVietnam National University of ForestryHanoiVietnam
  2. 2.Forest Protection DepartmentMinistry of Agriculture and Rural DevelopmentBa DinhVietnam

Personalised recommendations