CEPAVE   05420
CENTRO DE ESTUDIOS PARASITOLOGICOS Y DE VECTORES
Unidad Ejecutora - UE
artículos
Título:
Bayesian inference on the effect of density dependence and weather on a guanaco population from Chile
Autor/es:
MARÍA ZUBILLAGA; SKEWES, OSCAR; NICOLAS SOTO; JORGE RABINOVICH; FERNANDO COLCHERO
Revista:
PLOS ONE
Editorial:
PUBLIC LIBRARY SCIENCE
Referencias:
Lugar: San Francisco; Año: 2014 vol. 9 p. 1 - 17
ISSN:
1932-6203
Resumen:
Understanding the mechanisms that drive population dynamics is fundamental formanagement of wild populations. The guanaco (Lama guanicoe) is one of two wildcamelid species in South America. We evaluated the effects of density dependenceand weather variables on population regulation based on a time series of 36 yearsof population sampling of guanacos in Tierra del Fuego, Chile. The populationdensity varied between 2.7 and 30.7 guanaco/km2, with an apparent monotonicgrowth during the first 25 years; however, in the last 10 years the population hasshown large fluctuations, suggesting that it might have reached its carryingcapacity. We used a Bayesian state-space framework and model selection todetermine the effect of density and environmental variables on guanaco populationdynamics. Our results show that the population is under density dependentregulation and that it is currently fluctuating around an average carrying capacity of45,000 guanacos. We also found a significant positive effect of previous wintertemperature while sheep density has a strong negative effect on the guanacopopulation growth. We conclude that there are significant density dependentprocesses and that climate as well as competition with domestic species haveimportant effects determining the population size of guanacos, with importantimplications for management and conservation.