Shannon-Weaver question - please help me

Sorry if this is in the wrong place. Is the Shannon-Weaver Diversity Index even a statistical test? I don't know.........
I think I need to apply this test to my animal behaviour dissertation to compare grooming preferences among chimpanzees. I have found many references to it in the literature, but I cannot figure out how to translate the formula. My data consists of individual grooming frequencies for the animals, as both recipient/giver and in mutual grooming sessions. I can't make sense of how to compute this, but think it would be interesting as I expect it to show that mothers and daughters prefer to groom each other. I know that by looking....but I need to prove it!
Does anyone know of any (free) websites that will explain how to calculate this index with the sort of subject I have? I am going around in circles and getting upset by it all.
I have no experience with statistics, and have only barely survived Mann Whitney U Tests and calculating standard deviations! My supervisor should be listed on the Missing Persons Register!

Thanks anyone.