Curdioderma hangs from habitual perches to wait for mainly terrestrial prey. Their broad wings provide the lift at low speeds necessary to capture such prey from the ground. Male-female pairs were found in the long dry season, a period when reduced insect availability led to lower body weights and males used song to delineate their feeding territories. Males moved between perches more frequently during the first half-hour of nightly singing. An enlargement of foraging area was associated with earlier singing, as well as an increase in song rate, movement between perches and pair contact-vocalizations. Females are larger than males and the sex ratio favoured the latter. There was evidence of long-term territories and breeding throughout the year. These results are discussed in relation to pair-bonding and environmental seasonality.