Habitat use, diet, prey availability and foraging ecology of the endangered Hawaiian hoary bat (Lasiurus cinereus semotus, Vespertilionidae), was examined in the east Maui region inclusive of the Waihou Mitigation Area, Pu‘u Makua Restoration Area and the wind power facility operated by Auwahi Wind Energy, LLC. The study was conducted to inform the mitigation and management requirements of Auwahi Wind Energy, research funding was provided by Auwahi Wind Energy, LLC (Auwahi Wind) to fulfill requirements for mitigating bat fatalities under its approved incidental take permit. This study included the first genetic analysis of Hawaiian hoary bat diet items, and broadly confirms the major arthropod orders (Coleoptera, Lepidoptera, Diptera, Hemiptera, and Blattodea) found in previous microscopy-based studies of guano samples. Hawaiian hoary bats consumed both native and non-native insect species, and moths were the primary diet component, both in terms of its prevalence among individual bats and proportion of gene sequence counts. A total of 18 Lepidoptera families and 24 genus- or species-level taxa were identified in the analysis.