Thanks for this, I will investigate. Database attached - To explain, all info required is in this one table, and objective is:
For AnimalGroup=1 on any given SightDate, were any 2 (or 3 or 4 etc) Species (so could be 1 and 2, or 1 and 3 or 4 and 5 etc) Sighted>1 (1 = 0 sighted) for a given lake (sl)