English   español  
Por favor, use este identificador para citar o enlazar a este item: http://hdl.handle.net/10261/43194
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:

Mass/lenght residuals: measures of body condition or generators of spurious results?

AutorGreen, Andy J.
Palabras claveavian morphometry
body mass
body size indicator
reduced major axis
Fecha de publicaciónmay-2001
EditorEcological Society of America
CitaciónEcology, 82(5), 2001, pp. 1473–1483
Resumen. In studies of animal ecology, it is fashionable to use the residuals from an ordinar y least squares (OLS) linear regression of body mass against a linear measure of size (the body size indicator, BSI) as an index of body condition. These residual indices are used to study the relationship between condition and reproductive investment, sur vi- vorship, habitat use, and other parameters. I identify a series of key assumptions underlying the use of this method, each of which is likely to be violated in some or all studies. These assumptions are: (1) that the functional relationship between mass and BSI is linear; (2) that condition is independent of BSI length; (3) that BSI length accurately indicates struc- tural size; (4) that there is no correlation between the size of BSI relative to other structural components (i.e., shape) and the parameter against which the residuals are analyzed; (5) that BSI length is strictly independent of mass; and (6) that BSI length is not subjected to error. Violations of these assumptions place the results of some studies in question and explain the poor relationship obser ved between OLS residuals and more direct measures of condition. I use avian morphometric data to illustrate how OLS methods can easily lead to Type I and Type II errors through violations of assumptions (5) and (6). Significant relationships reported between OLS residual indices and parameters correlating with body size (e.g., size of sexual ornaments or egg size) are at particular risk of being spurious when the correlation coefficient between mass and BSI is low. Residual indices of condition are often likely to be more reliable when calculated with alternative methods such as nonparametric or model II regression. However, whatever the method used to produce them, residual indices are not suitable for studying the heritability of condition
Versión del editorhttp://www.esajournals.org/doi/pdf/10.1890/0012-9658%282001%29082%5B1473%3AMLRMOB%5D2.0.CO%3B2
Aparece en las colecciones: (EBD) Artículos
Ficheros en este ítem:
Fichero Descripción Tamaño Formato  
Ecology01.pdf106,07 kBAdobe PDFVista previa
Mostrar el registro completo

NOTA: Los ítems de Digital.CSIC están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.