We examined Hawaiian hoary bat (Lasiurus semotus) presence and foraging activity at Hakalau Forest National Wildlife Refuge and Lāupahoehoe Forest Reserve on Hawai‘i Island during the 2013 koa moth (Geometridea: Scotorythra paludicola) outbreak. Hawaiian hoary bat echolocation vocalizations were recorded at seven acoustic stations between 1069 and 1200 m above sea level, that operated nightly from May 2013 through September 2013. We compared these data to data collected at similar locations in 2011 to determine the response of bats to increased moth abundance during 2013. This data set includes data derived from these acoustic recording stations. Each acoustic recording station was comprised of an acoustic recording unit (Anabat SD1, Titely Scientific, Ballina, Australia) programmed to record from 1700 to 0500 each recording night. Each recording unit was deployed in a waterproof housing and powered by a 12 V external battery. An ultrasonic Hi-Mic microphone was mounted inside PVC pipe oriented toward the ground to prevent rain damage. A 15 x 15 cm plexiglass plate was attached below the microphone at a 45-degree angle to reflect and enhance calls from bats flying above the microphone. The PVC and microphone were affixed to the top of a 7- meter steel pole. Anabat Hi-Mics in this configuration have an omnidirectional maximum effective range of 30 meters. Upon detection of a vocalizing bat a call file was stored with the corresponding date and time on a compact flash (CF) memory card. Memory cards and batteries were replaced every 1-2 weeks during which quality checks on equipment were made. In this abstract we refer to the Hawaiian hoary bat as a full species, Lasiurus semotus, following updated taxonomy for Hawaiian hoary bats (Pinzari et al. 2020; see full citation below in the cross-references section).