Evaluaci車n de estimadores no param谷tricos de la riqueza de especies. Un ejemplo con aves en 芍reas verdes de la ciudad de Puebla, M谷xico

作者：J A Gonzalez– Oreja; A A De la Fuente– Diaz– Ordaz; L Hernandez– Santin; D Buzo– Franco

来源：Animal Biodiversity and Conservation, 2010.

• Accuracy
• Bias
• Biodiversity
• Birds
• Inventories
• Jackknife
• Precision
• Urbanization

Assessing non每parametric estimators of species richness. A case study with birds in green areas of the city of Puebla, MexicoOur objective was to evaluate the performance of non每parametric estimators of spe cies richness with real data. During the 2003 breeding season, bird communities were sampled in two green areas in the city of Puebla (Mexico), and the corresponding sample每based rarefaction curves were obtained. Mean data were adjusted to two non每asymptotic and seven asymptotic accumulation functions, and the best model was selected by means of reliability criteria in information theory. The cumulative Weibull and the beta每P functions were the best每fit models. Bias, precision and accuracy of five non每parametric estimators of species richness (ICE, Chao2, Jackknife 1, Jackknife 2, and Bootstrap) were then assessed for increasing sampling efforts (1每53 sampling units) against the asymptote of the selected accumulation functions. All the non每parametric estimators here evaluated underestimated true richness most of the time, specially in one of the sites. However, after combining data from the two assemblages, only ICE, and Jackknife 1 and 2 exhibited bias below 10% with different sampling efforts, and only Jackknife 1 was globally accurate (scaled mean squared errorx100%26lt; 5%, even with low sampling efforts, ca. 20% of the total). Therefore, we propose using the Jackknife 1 non每parametric estimator as a lower limit to measure bird species richness in urban sites similar to those in the present study.