In altricial avian species, nutrition can significantly impact nestling fitness by increasing chances of survival and recruitment after fledging. Therefore, the effort invested by parents towards provisioning nestlings is crucial and represents a critical link between habitat resources and reproductive success. Recent studies suggest that provisioning rate has little or no effect on nestling growth rate. However, these studies do not consider prey quality, which could force breeding pairs to adjust provisioning rates to account for variation in prey nutritional value. In this eight-year study using black-capped (Poecile atricapillus) and boreal chickadees (Poecile hudsonicus) as model species, we hypothesized that provisioning rates would negatively correlate with prey energy content across years as parents adjust their effort to maximise nestling growth rate. Mean daily growth rate was consistent across years in both species. However, prey energy content differed among years, and our results showed that parents brought more food to the nest and fed at a higher rate in years of low prey quality. This compensatory effect likely explains the lack of a relationship between provisioning rate and growth rate often reported in this and other studies. Therefore, our data support the hypothesis that parents increase provisioning effort to compensate for poor prey quality, thereby maintaining optimal nestling growth rate.