We analysed years separately because abundances of nuts differed significantly between 2008/ 2009 and 2009/ 2010 (U-test: P = 0.005) and differences in invertebrate abundances between years approached significance ( P = 0.093).
As there was a highly significant difference in body condition index between sexes we a) ran the same analysis for both sexes separately and b) further tested whether this difference was possibly caused by different morphometrics between sexes [ 39 ] or indeed due to differences in body condition.