[5] Members of a guild within a given ecosystem could be competing for resources, such as space or light, while cooperating in resisting wind stresses, attracting pollinators, or detecting predators, such as happens among savannah-dwelling antelope and zebra.
Nor is a guild the same as a trophic species, which is a functional group of taxa sharing the same set of predators and prey within a food web.
[8] Some authors have proposed a formal definition for guilds that avoids this inherent ambiguity of niche exploitation, and a quantification method considering the problems arising from degeneracy in protein functions.
[9] According to the authors, any organism that performs a function, regardless of its phylogenetic lineage, its environmental preferences or how it carries it out, would be regarded as a representative member of the guild.
This contrasts with the definitions used for the study of macro organisms, where membership demanded that the different forms of exploitation of the resource were related or similar.