Spatial and temporal variation in long-tailed bat echolocation activity in a New Zealand city

Abstract

Knowing when and where animals are active improves wildlife management. We monitored variation in long-tailed bat (Chalinolobus tuberculatus) echolocation activity at two sites (one urban, one rural) in Hamilton, New Zealand, across different nights, seasons, microhabitats and environmental conditions. Activity peaked between the first and third hours after sunset. Activity was higher during spring and summer compared with winter. At the rural site, more passes were recorded at 4–6 m than at 15–30 m. More bat passes were recorded in microhabitats with water. Temperature correlated positively with activity at the rural site only. To maximize detections we recommend that bats be monitored: (1) during warmer months (spring/summer), (2) on warm nights (≥ 7°C), 3) at lower heights (≤ 6 m from the ground), and (4) in open edge and forested microhabitats with water. Recommendations should enable practitioners to focus resources so that bats are effectively detected in urban and rural habitats.