Intercohort density dependence drives brown trout habitat selection

► We assess the effects of fluctuating densities of competing cohorts on brown trout habitat selection. ► All age classes studied were selective in habitat choice but changed their selection patterns across years. ► Younger trout were dominated by older ones but selected a wider range of habitats when competitor density decreased. ► Older trout did not seem to consider the density of younger individuals when distributing themselves. ► Biased estimates of habitat selection models could have profound effects on the success of management actions.