Fig. 5. Enhanced non-elemental visual learning and long-term memory in H. erato relative to Dryas iulia.

A Both species solve a visual positive patterning task, but H. erato is significantly more accurate. B H. erato can solve the more difficult and strictly non-elemental biconditional discrimination task, whereas Dryas iulia cannot. C H. erato has superior memory of a learned visual cue after 8 days compared with Dryas iulia. The box encompasses two middle quartiles, with central line showing median. Whiskers extend to the furthest data point within 1.5 times the interquartile range. Data were analysed with generalised linear models treating species and training as fixed effects along with an individual-level random effect. Posthoc comparisons were made by deriving the estimated marginal means and using a two-sided z-test, correcting for multiple comparisons using Tukey’s test. *p < 0.05; **p < 0.01; ***p < 0.001. Source data files: A: pospatdata.csv; B: bicondiscdata.csv; C: LTMdata.xslx.