RFCX ARBIMON PUBLICATIONS

For Inquiries Contact: contact@rfcx.org

Have bird distributions shifted along an
elevational gradient on a tropical mountain?

September 28, 2017

An upward shift in elevation is one of the most conspicuous species responses to climate change. Nevertheless, downward shifts and, apparently, the absences of response have also been recently reported. Given the growing evidence of multiple responses of species distributions due to climate change and the paucity of studies in the tropics, we evaluated the response of a montane bird community to climate change, without the confounding effects of land-use change.

Click here to download article

Species-specific audio detection: a
comparison of three template based detection
algorithms using random forests

April 24, 2017

We developed a web-based cloud-hosted system that allow users to archive, listen, visualize, and annotate recordings. The system also provides tools to convert these annotations into datasets that can be used to train a computer to detect the presence or absence of a species. The algorithm used by the system was selected after comparing the accuracy and efficiency of three variants of a template-based detection.

Click here to download article

Soundscape analysis and acoustic monitoring document impacts of
natural gas exploration on biodiversity in a tropical forest

November 18, 2016

Natural resource extraction is increasing rapidly in tropical forests, but we lag behind in understanding the impacts of these disturbances on biodiversity. In high diversity tropical habitats, acoustic monitoring is an efficient tool for sampling a large proportion of the fauna across varied spatial and temporal scales.

Click here to download article

Audio segmentation using Flattened Local
Trimmed Range for ecological acoustic
space analysis

June 27, 2016

The acoustic space in a given environment is filled with footprints arising from three processes: biophony, geophony and anthrophony. Bioacoustic research using passive acoustic sensors can result in thousands of recordings. An important component of processing these recordings is to automate signal detection. In this paper, we describe a new spectrogram-based approach for extracting individual audio events.

Click here to download article

Impacts of small-scale gold mining on birds
and anurans near the Tambopata Natural Reserve, Peru,
assessed using passive acoustic monitoring

June 27, 2016

Artisanal and small-scale gold mining (ASM) is becoming a significant cause of environmental degradation in tropical ecosystems. In this study, we conducted a rapid assessment on the impact of an ASM gold mine on the vocalizing avian and anuran communities in the buffer zone of the Tambopata National Reserve in Peru.

Click here to download article

Improving distribution data of threatened species by
combining acoustic monitoring and occupancy
modelling

May 25, 2016

Conservation of threatened species relies on predictions about their spatial distribution; however, it is often difficult to detect species in the wild. The combination of acoustic monitoring to improve species detectability and statistical methods to account for false-negative detections can improve species distribution estimates. Here, we combine a novel automated species-specific identification approach with occupancy models that account for imperfect detectability to provide a more accurate species distribution map of the Elfin Woods Warbler Setophaga angelae, a rare, elusive and threatened bird species.

Click here to download article

Real-time bioacoustics monitoring and
automated species identification

July 16, 2013

Traditionally, animal species diversity and abundance is assessed using a variety of methods that are generally costly, limited in space and time, and most importantly, they rarely include a permanent record. Given the urgency of climate change and the loss of habitat, it is vital that we use new technologies to improve and expand global biodiversity monitoring to thousands of sites around the world.

Click here to download article

Variable response of anuran calling activity
to daily precipitation and temperature:
implications for climate change

April 4, 2013

Long-term monitoring of frog populations is needed to understand the effects of global change. To better understand the relationships between climate variation and calling activity, we monitored an anuran assemblage in a Puerto Rican wetland by sampling the acoustic environment for one minute every 10 minutes, for 41 months.

Click here to download article

Calling activity of the common tink frog
in secondary forests of the Caribbean of Costa Rica

March 19, 2012

Calling activity in terrestrial frogs can be used as a measure of habitat suitability for reproduction. We evaluated the calling activity of the common tink frog Diasporus diastema (Eleutherodactylidae) in 12 secondary forest sites that vary in age of recovery, and three old growth sites in the Caribbean of Costa Rica. We used visual and acoustic surveys along transects, and we identified only 26 individuals in a total of 12 hours of censuses for each site.

Click here to download article

Recovery of amphibian species richness and composition in a
chronosequence of secondary forests, northeastern Costa Rica

December 27, 2011

In some tropical regions, following the abandonment of agriculture and pastures, secondary forests can recover plant species richness and forest structure (e.g. canopy cover, biomass); however, the importance of these secondary forests for fauna is not clear. Secondary forests can benefit fauna by providing suitable habitats, connecting forests fragments, and increasing gene flow.

Click here to download article