DOI: 10.5061/dryad.866t1g1rh
title: Acoustic recordings and corresponding mammal, bird, human activity, vegetation, and climate data from a tropical forest landscape

description: Obtaining and analysing sound data can be a tedious and lengthy process.
 We present sound data consisting of 38,065 1-minute sound recordings
 obtained in three sites within a rainforest landscape in southeast
 Cameroon. The sites differ in anthropogenic disturbance. We also present
 meta data corresponding to 20,485 of these recordings with the
 identification of all animal vocalisations in each 1-minute sound
 recording. Additionally, we provide a raw database with data on habitat,
 human activities, remoteness, accessibility, temperature, humidity,
 rainfall, moon phase, and mammal and bird observations in the area during
 the recording period. The data were used by Diepstraten & Willie
 (2021) to investigate the structure and drivers of biological sounds along
 a disturbance gradient. The data contribute to call libraries of tropical
 species and can also be used to build classifiers for automatic detection
 and classification of animal vocalisations.
description: Data were obtained in three study sites
 that differ in land-use type and conservation management in the northern
 part of the Dja Faunal Reserve’s buffer zone in Cameroon.
 Data were
 collected between February and May 2020. In every study
 site, 6 transects of 1-km each were opened. Audio data were
 obtained using the following procedure: An AudioMoth
 bioacoustics sensor was deployed in the middle of every
 transect. The sensors were deployed at a 2-m
 height at a 90° orientation. The sensors were kept in zip lock bags
 within a protective case, with a small hole at the location of the
 sensors’ microphone, to protect them from rain and animals.
 All
 sensors were set to record the first minute of every hour at 48kHz and
 30.6dB. Recordings made during the night were
 screened beforehand. Only night recordings with vocalisations from other
 species than easily recognisable insects, amphibians or western tree
 hyraxes were played to the local experts. Recordings were
 played to two local experts, who identified all audible
 species. Names of the vocalising species were
 noted down in Badjué (local language). Vocalisations of
 birds and mammals were identified by species. Vocalisations of insects and
 amphibians were identified by class. Unidentifiable vocalisations were
 recorded as “Animal unknown” or “Bird unknown”. 
 Field surveys were conducted to collect
 data on anthropogenic and ecological factors: Vegetation types
 were described at every 50-m interval in each transect. Human activity
 was described by identifying all human signs within a 2-m range
 perpendicular to each transect. For each sign, the location along the
 transect and the vegetation type was recorded. Mammal activity
 was described indirectly by identifying animal signs within 2-m on either
 side of the transect and corresponding location along the transect,
 vegetation type, canopy openness, understory openness, and horizontal
 visibility. The local guide identified the type of animal sign and local
 name of the species. All transects were walked twice. Rainfall between the
 two surveys prevented overlap. Presence of great apes, central
 chimpanzees (<em>Pan troglodytes troglodytes</em>), and
 western lowland gorillas (<em>Gorilla gorilla gorilla</em>)
 was described by the observation of their nests along the transects. For
 every nest, age, location along the transect (m), perpendicular distance
 from the transect (m), and circumference (cm) were recorded. Furthermore,
 vegetation type, canopy openness, understory openness, and horizontal
 visibility (m) were noted. Additionally, for gorillas, the type of nest
 was described by the composition of plants used for construction. For
 chimpanzee nests, the type of nest was described by its position in the
 tree. These surveys were conducted twice for each transect, with one month
 in between surveys. No nest was counted twice. Mammal activity
 was described directly by slowly walking along each transect (1km/h). For
 all observed mammals, number, location along the transect (m), distance
 between the observer and the mammal (m), angle of observation, vegetation
 type, canopy openness, understory openness, and horizontal visibility (m)
 were recorded. Bird activity was surveyed using point
 counts in fixed stations and direct observations. For the point counts,
 birds were recorded for 8 minutes at the start, middle, and end of each
 transect. An initial observation direction was randomly chosen and, after
 two minutes of observation, the observers rotated 90° in a clockwise
 direction. During direct observations, birds were recorded while walking
 the transect in the same manner as during the direct mammal surveys. For
 every observation, vegetation type, canopy openness, understory openness,
 and horizontal visibility (m) were recorded. Data on rainfall,
 humidity, and temperature were obtained in one site. Rainfall (mm) was
 measured daily. Temperature (°C) and humidity (RH) were measured
 hourly. To assess additional anthropogenic
 factors, the shortest straight-line distance (m) between each sound
 recorder and the closest village and trail was measured using ArcGIS to
 give a proxy of remoteness and accessibility, respectively.