Hello, I want to calculate niche width of a species in a community using Smith's selectivity measure (Smith 1982), as described in Ecological Methodology (Krebs 1999). Is there a package/function available that can do this? I have searched and found the niche.width function in SPAA (below). However, the indices used are "shannon" and "levins" , which don't take resource availability into account. Smith's would take resource availability into account. niche.width {spaa} Description Compute niche width of the species in a community. Usage niche.width(mat, method = c("shannon", "levins")) Thanks! Carmen [[alternative HTML version deleted]]