Dear all I’m a fish ecologist and regularly rummage through fish guts to get a feel for what they are eating and to describe their niche width etc. Generally we estimate contents by relative volume and then calculate the standardised Levins’ index (B’).
I’ve expanded my horizons and have started reading some papers on estimating mammal diets from scats and generally they are not so different from what we do in the fishy world. I read a paper on African carnivorous mammals where they reported diet information as frequency of occurrence (i.e. the percentage of individuals where that resource was found in their scats) and they then calculated Levins’ B from it. For the life of me I can’t work out how you could do this as the sum of the frequency of occurrences for all the different diet types can sum to more than 100%. The paper in question is Klare et al (2011) Mammal Review, 41, 294-312. I’ve emailed the corresponding author, but it’s Easter and I imagine they have better things to do then check email. So – if there is anyone out there who has a thought on whether it is possible to calculate Levins’ niche breadth index from frequency of occurrence data, I’d appreciate any pointers. All the best Chris ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> Professor Chris Harrod (Fish & Aquatic Ecology) Email: [email protected] Twitter: @chris_harrod www.harrodlab.net HarrodLab: Fish and Stable Isotope Ecology Laboratory Instituto de Ciencias Naturales Alexander von Humboldt, Universidad de Antofagasta, Avenida Angamos 601, Antofagasta, Chile Chile Mobile: +56 9 7399 7792 Chile Office: +56 55 2637400 <>< <>< <>< <>< <>< <>< <>< <>< <>< <>< <>< <>< <>< <>< <>< <>< <><
