A new study method of microhabitat structure of small mammals

• Autor(a) principal: CERQUEIRA,R.
• Data de Publicação: 1999
• Outros Autores: FREITAS,S. R.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Revista Brasileira de Biologia (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0034-71081999000200006
• topic: discriminant analysis; methods; niche; neotropics; small mammals

The variables in habitat studies are usually transformed in such a way that they become abstractions and intuition is lost. We tested a new method for the analysis of habitat using data collected in a grid laid at the "restinga de Maricá", in Rio de Janeiro State, Brazil. Thirty-seven microhabitat variables were measured at each trap station. We assume that these variables characterize the microhabitat structure at the moment when measurements were taken. The data are transformed in 3 ways: (1) the averages of the measured variables were calculated, as usual in habitat studies; (2) the data are transformed in densities per area in square meters without reduction in the number of variables; and (3) we calculated the natural logarithms of the data thus transformed. The 3 sets were analised through discriminant analysis. The logarithms of densities were the most efficient kind of transformation. This transformation resulted in a significance of p = 0.0001 with 39.72% of variance in the 1st discriminant function and of p = 0.0426 with 31.45% of variance in the 2nd function, and 84.62% of groups correctly classified. We obtained better classification results than previous similar works and we kept the intuition through the data analysis.