Item
Universitat de Girona. Departament d’Informàtica i Matemàtica Aplicada  
Martín Fernández, Josep Antoni
Pierotti, Michele E. R. Barceló i Vidal, Carles 

2011 May 13  
The variety of resources that a population exploits is known as the “niche width”. A particular population has a narrow niche if only few kinds of the available resources are exploited by its members. When the individuals of a population exploit many different resources, then the population has a wide niche. From this point of view it seems that the niche is a property of the population as a whole. However, it is well known that many apparently generalist populations are in fact composed of individual specialists, that is, members that use only small subsets of the population’s niche. This approach justifies the definition of indices to measure the individuallevel resource specialization. Although this kind of analysis could be applied to any niche variation: oviposition sites, habitat, etc., we focus the discussion in terms of analysis of diet data. So as to measure species niche breadth a comparison between the frequency distribution of the species’ resource use with that of all available resources is carried out. When a measure of individual specialization is considered, then one should compare the population’s total diet with the individual use. In particular, the total niche width of a population should be compared with its two components: within and betweenindividual variation. In this sense, in the literature several indices of intrapopulation niche variation are proposed. Our goal is to describe, compare and evaluate four of the most relevant indices applied in ecology. In this work we point out how these techniques could be developed in a compositional framework, particularly when these indices are applied to discrete diet data [e.g. frequency of different prey specimen in the diet].  
application/pdf  
http://hdl.handle.net/10256/13654  
eng  
Universitat de Girona. Departament d’Informàtica i Matemàtica Aplicada  
CoDaWork 2011. The 4th International Workshop on Compositional Data Analysis  
Tots els drets reservats  
Estadística matemàtica  Congressos
Mathematical statistics  Congresses Anàlisi multivariable  Congressos Mathematical statistics  Congresses Ecologia  Mètodes estadístics  Congressos Ecology  Statistical methods  Congresses Biologia  Mètodes estadístics  Congressos Biology  Statistical methods  Congresses Biologia de poblacions  Mètodes estadístics  Congressos Population biology  Mètodes estadístics  Congressos 

Examining Indices of Individuallevel Resource Specialization  
info:eurepo/semantics/conferenceObject  
DUGiDocs 