When organisms' environmental conditions vary unpredictably in time, it can be advantageous for individuals to hedge their phenotypic bets. It has been shown that a bet-hedging strategy underlies the high inter-individual diversity of phototactic choice in Drosophila melanogaster. This study shows that fruit flies from a population living in a boreal and relatively unpredictable climate had more variable phototactic choices than fruit flies from a more stable tropical climate, consistent with bet-hedging theory. We experimentally...