Estimating population trends using population viability analyses for the conservation of Capra pyrenaica

• Autorzy: Escos J. M. , Alados C.L. , Pulido A. , Romera J. , Gonzalez-Sanchez N. , Martinez F.
• Języki publikacji: EN

Abstrakty

EN

Large herbivore populations can suffer important oscillations with considerable effects on ecosystem functions and services, yet our capacity to predict population fate is limited and conditional upon the availability of data. This study investigated the interannual variation in the growth rate of populations ofCapra pyrenaica Schinz, 1838, and its extinction risk by comparing the dynamics of populations that were stable for more than two decades (Gredos and Tortosa-Beceite), populations that had increased recently (Tejeda-Almijara), and populations that were in decline (Cazorla-Segura) or extinct (the Pyrenees population; hereafter, bucardo). To estimate quasi-extinction threshold assessments (50% of population extinct in this study), which have implications for the conservation of the species, we used empirical data and the predictions derived from several theoretical models. The results indicate that when variance of log population growth rate reaches a specific threshold, the probability of quasi-extinction increased drastically. ForC. pyrenaica, we recommend keeping population variance < 0.05, which will reduce the likelihood that the irruptive oscillations caused by environmental and demographic stochasticity will put the population at risk. Models to predict the dynamics ofC. pyrenaica populations should incorporate temporal stochasticity because, in this study, it strongly increased the likelihood that a population declined.

Słowa kluczowe

EN

population trend; conservation; temporal variability; Capra pyrenaica; population viability analysis; Iberian wild goat; density-dependent model; extinction risk

• Wydawca: -
• Czasopismo: Acta Theriologica
• Rocznik: 2008
• Tom: 53
• Numer: 3
• Opis fizyczny: p.275-286,fig.,ref.

Twórcy

autor

Escos J. M.

• Universidad de Zaragoza, Carretera de Cuarte s/n 22071 Huesca, Spain

autor

Alados C.L.

autor

Pulido A.

autor

Romera J.

autor

Gonzalez-Sanchez N.

autor

Martinez F.

Bibliografia

• Alados C. L. 1985. Distribution and status of the Spanish ibex (Capra pyrenaica Schinz). [In: The biology and management of mountain ungulates. S. Lovari, ed]. Croom-Holm Ltd., Beckenham, London: 204–211.
• Alados C. L. 1997. Spain. [In: Wild sheep and goats and their relatives. Status Survey and Conservation Action Plan for Caprinae. D. M. Shackleton, ed]. IUCN/SSC, Information Press, Oxford: 125–130.
• Bagchi S., Mishra C. and Bhatnagar Y. V. 2004. Conflicts between traditional pastoralism and conservation of Himalaya ibex (Capra sibirica) in the Trans-Himalayan mountains. Animal Conservation 7: 121–128.
• Berducou C., Besson J. P. and GardesMoniteurs du P. N. P. O. 1982. Dynamique des populations d’isards du Parc National des Pyrénées Occidentales de 1968–1981. Acta Biologica Montana 1: 153–175.
• Brooks B. W. and Bradshaw C. J. A. 2006. Strength of evidence for density dependence in abundance time series of 1198 species. Ecology 87: 1445–1451.
• Burnham K. P. and Anderson D. R. (eds) 1998. Model selection and inference: A practical Information-Theoretic Approach. Springer, New York: 1–488.
• Cabrera A. 1911. The subspecies of the Spanish ibex. Proceedings of the Zoological Society of London 66: 963–967.
• Caughley G. 1976. Plant-herbivore systems. [In: Theoretical ecology. R. M. May, ed]. Blackwell, Oxford: 94–113.
• Clutton-Brock T., Major M., Albon S. D. and Guinness F. E. 1987. Early development and population dynamics in red deer. I. Density-dependent effects on juvenile survival. Journal of Animal Ecology 56: 53–64.
• Clutton-Brock T., Price O. F., Albon S. D. and Jewell P. A. 1991. Persistency instability and population regulation in Soay sheep. Journal of Animal Ecology 60: 593–608.
• Dennis B., Munholland P. L. and Scott J. M. 1991. Estimation of growth and extinction parameters for endangered species. Ecological Monographs 61: 115–143.
• Dennis B. and Taper M. L. 1994. Density dependence in time series observations of natural populations: estimation and testing. Ecological Monographs 64: 205–224.
• Eberhardt L. L. 1977. Optimal policies for conservation of large mammals with special reference to marine ecosystems. Environmental Conservation 4: 205–212.
• Escós J. and Alados C. L. 1991. Influence of weather and population characteristic of free-ranging Spanish ibex in the Sierras de Cazorla y Segura. Mammalia 55: 67–78.
• Escós J., Alados C. L. and Emlen J. M. 1994. Application of the stage-projection model with density-dependent fecundity to the population dynamics of Spanish ibex. Canadian Journal of Zoology 72: 731–737.
• Foley P. 1994. Predicting extinction times from environmental stochasticity and carrying-capacity. Conservation Biology 8: 124–137.
• Freckleton R. P., Watkinson A. R., Green R. E. and Sutherland W. J. 2006. Census error and the detection of density dependence. Journal of Animal Ecology 75: 837–851.PubMedView Article
• Gaillard J. M., Festa-Bianchet M., Yoccoz N. G., Loison A. and Toigo C. 2000. Temporal variation in fitness components and population dynamics of large herbivores. Annual Review of Ecology and Systematics 31: 367–393.
• García-González R. and Herreo J. 1999. El bucardo de los Pirineos: historia de una extinción. Galemys 11: 17–26.
• Gilpin M. E. and Ayala F. J. 1973. Global models of growth and competition. Proceedings of the National Academy of Sciences of the U.S.A. 70: 3590–3593.
• Gordon I. J., Hester A. J. and Festa-Bianchet M. 2004. The management of wild large herbivores to meet economic, conservation and environmental objectives. Journal of Applied Ecology 41: 1021–1031.
• Grøtan V., Sæther B.-E., Filli F. and Engen S. 2008. Effects of climate on population fluctuations of ibex. Global Change Biology 14: 218–228.
• Hilborn R. and Mangel M. (eds) 1997. The ecological detective. Confronting models with data. Princeton University Press, New Jersey: 1–315.
• Jacobson A. R., Provenzale A., Von Hardenberg A., Bassano B. and Festa-Bianchet M. 2004. Climate forcing and density dependence in a mountain ungulate population. Ecology 85: 1598–1610.
• Kie J. G., Bowyer R. T., Nicholson M. C., Boroski B. B. and Loft E. R. 2002. Landscape heterogeneity at different scales: effects of spatial distribution of mule deer. Ecology 83: 530–544.
• Lande R. 1993. Risks of population extinction from demographic and environmental stochasticity and random catastrophes. The American Naturalist 142: 911–927.
• Lande R. and Orzack S. H. 1988. Extinction dynamics of age-structures populations in a fluctuating environment. Proceedings of the National Academy of Sciences of the USA 85: 7418–7421.PubMedView Article
• Langvatn R. and Loison A. 1999. Consequences of harvesting on age structure, sex ratio and population dynamics of red deerCervus elaphus in central Norway. Wildlife Biology 5: 213–233.
• Latham J. 1999. Interspecific interactions of ungulates in European forests: an overview. Forest Ecology and Management 120: 13–21.
• Lewontin R. C. and Cohen D. 1969. On population growth in a randomly varying environment. Proceedings of the National Academy of Sciences of the USA 62: 1056–1060.PubMedView Article
• McCullough D. R. 1997. Irruptive behavior in ungulates. [In: The science of overabundance. W. J. McShea, H. B. Underwood and J. H. Rappole, eds]. Smithsonia Institute Press, Washington, DC: 69–98.
• Milner-Gulland E. J. 1994. A population model for the management of saiga antelope. Journal of Applied Ecology 31: 25–39.
• Morris W. F. and Doak D. F. (eds) 2002. Quantitative conservation biology. Sinauer Associates, Sunderland, Massachusetts: 1–418.
• Nogués-Bravo D., Araújo M. B., Errea M. P. and Martínez-Rica J. P. 2007. Exposure of global mountain systems to climate warming during the 21st Century. Global Environmental Change 17: 420–428.
• Owen-Smith N. 2004. Functional heterogeneity in resources within landscapes and herbivore population dynamics. Landscape Ecology 19: 761–771.
• Pérez J. M., Granados J. E., Soriguer R. C., Fandos P., Marquez F. J. and Crampe J. P. 2002. Distribution, status and conservation problems of the Spanish Ibex,Capra pyrenaica (Mammalia: Artiodactyla). Mammal Review 32: 26–39.
• Peterson R. O. 1999. Wolf-moose interactions on Isle Royal: the end of natural regulation? Ecological Applications 9: 10–16.
• Portier C., Festa-Bianchet M., Gaillard J.-M., Jorgenson J. T. and Yoccoz N. G. 1988. Effects of density and weather on survival of bighorn sheep lambs (Ovis canadensis). Journal of Animal Ecology 245: 271–278.
• Putman R. J. (ed) 1996. Competition and resource partitioning in temperate ungulate assemblies. Chapman and Hall, London: 1–152.
• Ricker W. E. 1954. Stock and recruitment. Journal of the Fisheries Research Board of Canada 11: 559–623.
• Sabo J. L., Holmes E. E. and Kareiva P. 2004. Efficacy of simple viability models in ecological risk assessment: does density dependence matter? Ecology 85: 328–341.
• Sæther B.-E. 1997. Environmental stochasticity and population dynamics of large herbivores: a search for mechanisms. Trends in Ecology and Evolution 12: 143–149.
• Walter G., Beissner S. and Burga C. A. 2005. Trends in the upward shift of alpine plants. Journal of Vegetation Science 16: 541–548.