Our October Issue is out now! It’s a bumper issue, with 26 articles presenting the latest methods in ecology and evolution. We have methods for measuring temporal change in alpha diversity, aerial imaging of field plots, analysing 3D morphology images and more, plus four Applications and five Practical Tools articles for your reading. Find out more below!
The potential and practice of arboreal camera trapping Arboreal camera trapping provides a novel and effective technique to answer research questions across a variety of ecosystems. However, there is little guidance for dealing with the unique challenges of working in the arboreal realm. This review by Moore et al. draws on the expertise of researchers from six continents and the broader literature to investigate the advantages and disadvantages of arboreal camera trapping, and challenges to consider when using this technology.
Replication in field ecology The concepts of replication, reproducibility and replicability are not always clearly distinguished, and complicate the identification of best practices. Furthermore, conducting experiments under the high variability of natural field conditions reduces the capacity for replication relative to other biological disciplines working under controlled conditions. Field ecologists are therefore facing a significant challenge in assessing the replicability of their research with implications for overall confidence in study outcomes. In this review, Filazzola & Cahill Jr discuss several aspects of experimental design that can enhance confidence in scientific outcomes, suggesting several tangible steps that could be taken to improve confidence in ecological research.
The Australian Acoustic Observatory Low-cost hardware and storage mean that acoustic recording now has the potential to efficiently build scale in terrestrial fauna surveys, both spatially and temporally. With this aim, Roe et al. have constructed the Australian Acoustic Observatory, which provides a direct and permanent record of terrestrial soundscapes through continuous recording across Australian ecoregions, including those periodically subject to fire and flood, when manual surveys are dangerous or impossible. The observatory comprises 360 permanent listening stations deployed across Australia. Each station continuously records sound, resulting in year-round data collection and all data are made freely available under an open access licence.
Measuring temporal change in alpha diversity Biodiversity is a multifaceted concept covering different levels of organisation from genes to ecosystems. Here, Chao et al. integrate the three dimensions of diversity (taxonomic diversity, phylogenetic diversity and functional diversity) under a unified framework of Hill numbers and their generalisations. They apply the integrative framework and the proposed iNEXT (interpolation and extrapolation) 3D standardisation to measure temporal alpha-diversity changes for estuarine fish assemblage data spanning four decades.
This month we have a forum article ‘On the need for rigorous welfare and methodological reporting for the live capture of large carnivores‘ by Caravaggi et al., in response to an article by Ribeiro de Araujo et al. on the use of foot snares to capture felids from our February issue. You can read Ribeiro de Araujo et al.’s forum response here, as well as the journal’s response from Executive Editor Aaron Ellison here.
BEE-STEWARD *open access* The demand for agent-based models to explore the effects of environmental change on pollinator population dynamics is growing. However, models need a simple yet flexible interface to enable adoption by a wide range of stakeholders. Here, Twiston-Davies et al. introduce BEE-STEWARD, a research and decision-support software tool, enabling researchers, policymakers, land management advisors and practitioners to predict and compare the effects of bee-friendly management interventions on bumblebee populations over several years.
SlicerMorph *open access* Large-scale digitisation projects such as #ScanAllFishes and oVert are generating high-resolution microCT scans of vertebrates by the thousands. Data from these projects are shared with the community using aggregate 3D specimen repositories, but the road from a series of images to analysis is fraught with challenges for most biologists. In answer to this, Rolfe et. al developed SlicerMorph as an extension of 3D Slicer. In addition to the core functionalities of Slicer, SlicerMorph provides users with modules to conveniently retrieve open-access 3D models or import users own 3D volumes, to annotate 3D curve and patch-based landmarks, generate landmark templates, conduct geometric morphometric analyses of 3D organismal form using both landmark-driven and landmark-free approaches, and create 3D animations from their results.
ipmr *open access* Integral projection models (IPMs) are an important tool for studying the dynamics of populations structured by one or more continuous traits. Researchers use IPMs to investigate questions ranging from linking drivers to population dynamics, planning conservation and management strategies, and quantifying selective pressures in natural populations. The popularity of stage-structured population models has been supported by R scripts and packages, but pressing ecological, evolutionary and conservation biology topics require developing more complex IPMs, and considerably more expertise to implement them. In answer to this, Levin et al. introduce ipmr, a flexible R package for building, analysing and interpreting IPMs.
Manipulating temperature in aquatic environments One valuable approach to identify mechanisms and pathways of thermally driven change at the community level is through the manipulation of temperature in the field. However, where methods exist, they are often costly or unable to produce ecologically relevant changes in temperature. Here, Konecny et al. present a low-cost, easily assembled and readily customisable thermal manipulation system for tide pools or other small bodies of water—the Seaside Array for Understanding Thermal Effects (SAUTE)—and demonstrate its ability to effectively alter the temperature in tide pools.
Measuring respiration of individual nematodes *open access* Meiofauna represent the most abundant and diverse animal group on Earth, but empirical evidence of their role in benthic respiration, production and carbon cycling across ecosystems is not well documented. Here, Macuite et al. further developed an incubation system, in which oxygen and temperature conditions are easily controlled and single meiofaunal nematode respiration is resolved in glass capillary tubes, using Clark-type oxygen microsensor. The presented method can be adapted to a wide range of experimental conditions and can therefore be used to assess meiofauna contribution to ecosystem processes and investigate species-specific responses to changing environmental conditions, for example, oxygen stress, increasing water temperature.
An Acoustic Mosquito Monitoring Tool *open access* Mosquito surveys are time-consuming, expensive and can provide a biased spatial sample of occurrence data—the data often representing the location of the surveys, not the occurrence of the mosquitoes. Here, Sinka et al. present the HumBug project, an acoustic system that can turn any Android smartphone into a mosquito sensor. The sensor has the potential to significantly increase the quantity of mosquito occurrence data as well as access locations that are more difficult to survey by traditional means.
Automated aerial imaging of field plots Equipment currently available for precise aerial imaging of plants is most applicable only to large-scale settings (e.g. entire fields) or controlled environments (e.g. greenhouses or growth chambers). There is a lack of technology suited to 1 × 1 m quadrat surveys of natural communities. To satisfy this need, Potter et al. developed a portable, low-cost platform ‘Robotany’ that automatically takes a set of data samples to precisely cover a 1 m2 field plot. The device was reliable and precise in its initial two summers of field testing, and images were of sufficient resolution to identify common plant taxa, and to collect information on plant size, flowering status, and damage by foliar pathogens and herbivores.
An open-source multi-sensor device for wildlife research *open access* Knowledge about the behaviour, ecology and conservation status of bats is limited. Direct observation of marked individuals (commonly applied to birds) is not possible due to their small size, rapid movement and nocturnal lifestyle, while neither popular observation methods such as camera traps nor conventional tracking technologies sufficiently capture the behaviour of individuals. Here, Gottwald et al. present BatRack, a multi-sensor device that combines ultrasonic audio recordings, automatic radio telemetry and video camera recordings in a single modular unit. It consists of off-the-shelf hardware and both its hardware blueprints and the required software have been published under an open license to allow scientists and practitioners to replicate the system.
The Katydid on the Cover
This issue’s cover shows a katydid feeding on a leaf in the Tirimbina Rainforest National Wildlife Refuge of Costa Rica. As the katydid assimilates nutrients in the leaf, it incorporates nitrogen in the form of amino acids. Study of variation in the nitrogen isotope composition of amino acids in consumer tissues has emerged as a transformative approach to study ecosystem change and estimate trophic positions that are internally indexed to the nitrogen isotope composition of primary producers at the base of food webs. In their article, Ramirez et al. present a meta-analysis to comprehensively evaluate relevant sources of variation in individual amino acid nitrogen isotope patterns across diverse primary producers in terrestrial and aquatic ecosystems. Results indicate that key primary producer nitrogen isotope parameters needed to accurately characterize consumer trophic position are two times more variable than previously recognized, with degree of tissue vascularization providing the greatest source of variability. This work outlines four key recommendations for identifying, constraining, and accounting for primary producer amino acid nitrogen isotope variability to further improve trophic position estimation accuracy and precision. Photo credit: ©Taegan McMahon.