The biodiversity of tropical rainforests is under extreme pressure due to the expansion of agricultural land. Beyond the immediate risk of species extinction, the intensification of land use can alter species' behaviour with consequences for the entire ecosystem.
In this study we investigated the impact of land use on the acoustic behaviour of cicadas in the highly biodiverse Ecuadorian Chocó region. We used passive acoustic monitoring (PAM) for the collection of audio data, from which we identified and analysed the sound activity of cicadas and the structure of daily patterns along a chronosequence of forest recovery. At landscape scale we studied the impact of a surrounding either dominated by agricultural land use or forests on the acoustic behaviour of cicadas.
Cicada sound activity was significantly lower in active agriculture compared to undisturbed old‐growth forest and increased along the forest recovery gradient. The diurnal pattern changed from simple in active agriculture to more complex and highly synchronized along the recovery gradient towards old‐growth forests. A surrounding dominated by agricultural land use additionally reduced the sound activity of cicadas and simplified the diurnal pattern in old‐growth forests.
Taken together, agricultural land use at local and landscape scales affects overall activity, diurnal patterns and synchrony of vocalizing song cicadas. This is a concerning trend considering the direct link between chorusing and fitness for cicadas. However, mature restoration forests embedded in forest dominated landscape surroundings showed restored cicada song behaviours similar to those of old‐growth forests, which underlines the conservation value of advanced secondary forests and the importance to support forest regeneration in the tropics.
