Kevin Darras

Kevin Darras
Westlake University · SAT Lab

PhD Agroecology
Developing automated biodiversity monitoring methods and synthesizing global soundscapes

About

43
Publications
27,749
Reads
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1,674
Citations
Additional affiliations
January 2016 - present
Georg-August-Universität Göttingen
Position
  • PostDoc Position
April 2012 - May 2016
Georg-August-Universität Göttingen
Position
  • PhD Student
Description
  • Agroecology

Publications

Publications (43)
Article
Full-text available
Agri-environment schemes (AES) have become important tools for farmland biodiversity conservation, providing suitable habitats, resources, and connectivity within the agricultural landscapes. Bats are rarely studied in relation to AES effectiveness in contrast to birds, even though their presence and activity as biological control agents on insects...
Article
Full-text available
Emerging technologies based on the detection of electro-magnetic energy offer promising opportunities for sampling biodiversity. We exploit their potential by showing here how they can be used in bat point counts—a novel method to sample flying bats—to overcome shortcomings of traditional sampling methods, and to maximize sampling coverage and taxo...
Article
Full-text available
Bat communities can usually only be comprehensively monitored by combining ultrasound recording and trapping techniques. Here, we propose bat point counts, a novel, single method to sample all flying bats. We designed a sampling rig that combines a thermal scope to detect flying bats and their flight patterns, an ultrasound recorder to identify ech...
Article
Full-text available
Passive acoustic monitoring of wildlife requires sound recording systems. Several cheap, high-performance, or open-source solutions currently exist for recording soundscapes, but all rely on commercial microphones. Commercial microphones are relatively expensive, specialized for particular taxa, and often have incomplete technical specifications. W...
Article
Full-text available
Background Automated sound recorders are a popular sampling tool in ecology. However, the microphones themselves received little attention so far, and specifications that determine the recordings’ sound quality are seldom mentioned. Here, we demonstrate the importance of microphone signal-to-noise ratio for sampling sonant animals. Methods We test...
Article
Full-text available
Background Automated sound recorders are a popular sampling tool in ecology. However, the microphones themselves received little attention so far, and specifications that determine the recordings’ sound quality are seldom mentioned. Here, we demonstrate the importance of microphone signal-to-noise ratio for sampling sonant animals. Methods: We tes...
Article
Full-text available
Passive acoustic monitoring of soundscapes and biodiversity produces vast amounts of audio recordings. However, the management of these raw data presents technical challenges and their analysis suffers from bottlenecks. A multitude of software solutions exist, but none can perform all the data processing needed by ecologists for analysing large aco...
Article
Full-text available
Land-use transitions can enhance the livelihoods of smallholder farmers but potential economic-ecological trade-offs remain poorly understood. Here, we present an interdisciplinary study of the environmental, social and economic consequences of land-use transitions in a tropical smallholder landscape on Sumatra, Indonesia. We find widespread biodiv...
Article
Full-text available
Oil palm plantations are intensively managed agricultural systems that increasingly dominate certain tropical regions. Oil palm monocultures have been criticized because of their reduced biodiversity compared to the forests they historically replaced, and because of their negative impact on soils, water, and climate. We experimentally test whether...
Article
Full-text available
Passive acoustic monitoring of wildlife requires sound recording systems. Several cheap, high-performance open-source solutions currently exist for recording soundscapes, but all of them are still reliant on commercial microphones. Commercial microphones are relatively expensive, specialized for particular taxa, and often have incomplete technical...
Article
Autonomous sound recording techniques have gained considerable traction in the last decade, but the question remains whether they can replace human observation surveys to sample sonant animals. For birds in particular, survey methods have been tested extensively using point counts and sound recording surveys. Here, we review the latest evidence for...
Article
Autonomous sound recording techniques have gained considerable traction in the last decade, but the question remains whether they can replace human observation surveys to sample sonant animals. For birds in particular, survey methods have been tested extensively using point counts and sound recording surveys. Here, we review the latest evidence for...
Article
Full-text available
This study examines conservation effects of wildlife trade using demand and supply data from caged-bird markets in Sumatra, Indonesia. When consumers have a strong preference for species rarity, trade could result in wildlife overexploitation and species extinction. Results from a choice experiment show that buyers of caged birds indeed value speci...
Article
Full-text available
Passive acoustic monitoring of wildlife requires microphones. Several cheap, high-performance open-source solutions currently exist for recording sounds, but all of them are still reliant on commercial microphones. Commercial microphones are relatively expensive, specialized on particular taxa, and often have opaque technical specifications. We des...
Article
Indonesia is the largest producer of oil palm and the second largest exporter of rubber worldwide; a significant part of the country's rainforests have been converted to agriculture. Conservation measures are needed to assess and reduce the impact of agricultural intensification on the vertebrate fauna, but limited effort has been put so far in und...
Article
We report knemidokoptiasis in a wild male Little Spiderhunter ( Arachnothera longirostra cinireicollis; family Nectariniidae; order Passeriformes) from Jambi, Sumatra, Indonesia, in September 2017. Microscopic examination of a scraping from its leg lesion revealed the presence of Knemidocoptes jamaicensis as the cause of the condition.
Article
Autonomous sound recording is a promising sampling method for birds and other vocalizing terrestrial wildlife. However, while there are clear advantages of passive acoustic monitoring methods over classical point counts conducted by humans, it has been difficult to quantitatively assess how they compare in their sampling performance. Quantitative c...
Article
1.Autonomous sound recorders are increasingly used to survey birds, and other wildlife taxa. Species richness estimates from sound recordings are usually compared with estimates obtained from established methods like point counts, but so far the comparisons were biased: Detection ranges usually differ between the survey methods, and bird detection...
Article
Full-text available
Background: Tropical lowland rainforests are threatened by deforestation and degradation worldwide. Relatively little research has investigated the degradation of the forests of South-east Asia and its impact on biodiversity, and even less research has focused on the important peat swamp forests of Indonesia, which experienced major losses through...
Article
Full-text available
Background: Tropical lowland rainforests are threatened by deforestation and degradation worldwide. Relatively little research has investigated the degradation of the forests of South-east Asia and its impact on biodiversity, and even less research has focused on the important peat swamp forests of Indonesia, which experienced major losses through...
Article
Full-text available
The conversion of tropical rainforest to agricultural systems such as oil palm alters biodiversity across a large range of inter- acting taxa and trophic levels. Yet, it remains unclear how direct and cascading effects of land-use change simultaneously drive ecological shifts. Combining data from a multi-taxon research initiative in Sumatra, Indone...
Article
One of the world’s most important and rapidly expanding crops, oil palm, is associated with low levels of biodiversity. Changes in predator communities might alter ecosystem services and subsequently sustainable management but these links have received little attention to date. Here, for the first time, we manipulated ant and flying vertebrate (bir...
Presentation
Full-text available
This study addresses the conservation effects of wildlife trade.
Article
Full-text available
Smallholder-dominated agricultural mosaic landscapes are highlighted as model production systems that deliver both economic and ecological goods in tropical agricultural landscapes, but trade-offs underlying current land-use dynamics are poorly known. Here, using the most comprehensive quan-tification of land-use change and associated bundles of ec...
Data
Primer pair sequences for plants, bacteria, and archaea
Data
Supplementary Figures 1 - 9, Supplementary Tables 1 - 5, Supplementary Note 1 and Supplementary References
Article
Sound recordings obtained from passive acoustic monitoring systems are increasingly used to sample animal biodiversity. However, sound recorders sample variable detection spaces, so that data may not be comparable between sampling sites and recording setups. Focusing on terrestrial systems, we measured understory vegetation, tree structure, sound...
Article
Full-text available
Oil palm plantations have expanded rapidly in recent decades. This large-scale land-use change has had great ecological, economic, and social impacts on both the areas converted to oil palm and their surroundings. However, research on the impacts of oil palm cultivation is scattered and patchy, and no clear overview exists. We address this gap thro...
Article
Full-text available
Rapid land-use change in the tropics causes dramatic losses in biodiversity and associated functions. In Sumatra, Indonesia, lowland rainforest has mainly been transformed by smallholders into oil palm (Elaeis guineensis) and rubber (Hevea brasiliensis) monocultures, interspersed with jungle rubber (rubber agroforests) and a few forest remnants. In...
Data
Estimated percent cloud cover during each core plot visit in each land-use type. Means are indicated in red, error bars represent the standard error of the mean. (TIF)
Data
Total bird species richness after three 20 minute visits in each feeding guild per land-use type. Feeding guild categories were based on Thiollay et al. (1995). (TIF)
Data
Bird abundance after three 20 minute visits in each habitat preference group per land-use type for two regions of the province of Jambi, Sumatra. Habitat preferences were mainly obtained from Thiollay et al. (1995). (TIF)
Data
An example of homegarden (BG1) sampled in our study. (JPG)
Data
Histograms of bird detections in each land-use type depending on the distance from the observer, divided in bins of equal area. (TIF)
Data
Bird abundance after three 20 minute visits in each stratum preference group per land-use type for two regions of the province of Jambi, Sumatra. Strata preferences were obtained from Wilman et al. (2014). (TIF)
Data
Homegarden household questionnaire. (DOCX)
Data
Rarefaction curves for each land-use type. Total species richness was rarefied to the lowest sample size occurring in jungle rubber, where 88 birds were observed. Total rarefied richness forest: 38; jungle rubber: 27; rubber: 25, oil palm: 16. (TIF)
Article
Understanding distribution patterns and multitrophic interactions is critical for managing bat- and bird-mediated ecosystem services such as the suppression of pest and non-pest arthropods. Despite the ecological and economic importance of bats and birds in tropical forests, agroforestry systems, and agricultural systems mixed with natural forest,...
Article
Sustainable rice production is critical to food security especially in Asia. Effective biocontrol of major rice pests such as the White-Backed Planthopper (Sogatella furcifera, Horváth; WBP) is, hence, of eminent importance. We use newly compiled data from Thailand on the Wrinkle-Lipped Bat (Tadarida plicata, Buchanan), WBP distributions and an ite...
Article
Full-text available
Local and landscape-scale agricultural intensification is a major driver of global biodiversity loss. Controversially discussed solutions include wildlife-friendly farming or combining high-intensity farming with land-sparing for nature. Here, we integrate biodiversity and crop productivity data for smallholder cacao in Indonesia to exemplify for t...
Chapter
Full-text available
The need to capture primary production in order to sustain and improve economic livelihoods has lead to increasing conversion of natural habitat and intensification of agricultural practices in many parts of the world including most tropical regions. Understanding how these processes affect ecosystems and their functioning, in particular in the hig...
Chapter
Full-text available
The need to capture primary production in order to sustain and improve economic livelihoods has lead to increasing conversion of natural habitat and intensification of agricultural practices in many parts of the world including most tropical regions. Understanding how these processes affect ecosystems and their functioning, in particular in the hig...

Questions

Question (1)
Question
We are about to buy that stereo microscope but the sales woman did not have an actual model with integrated camera. The demonstration with an axiocam mounted to a Stemi 508 was not so convincing either. So we do not know how good the performance of the camera is (especially compared to a trinocular model where we could connect our own camera). Anyone has experience?

Network

Cited By

Projects

Projects (5)
Project
Collate meta-data of soundscape recording datasets gathered in terrestrial and aquatic (freshwater and marine) realms across the globe. both natural and anthropogenic. https://ecosound-web.uni-goettingen.de/ecosound_web/project/gsp
Project
Understand the factors affecting the efficiency and effectiveness of autonomous sound recording approaches for terrestrial ecology. Develop standards and realize the technology's potential.