Technological advancements in the past 20 years or so have spurred rapid growth in the study of migratory connectivity (the linkage of individuals and populations between seasons of the annual cycle). A new article in Methods in Ecology and Evolution provides methods to help make quantitative comparisons of migratory connectivity across studies, data types, and taxa to better understand the causes and consequences of the seasonal distributions of populations.
In a new Methods in Ecology and Evolution video, Javier Puy outlines a new method of experimental plant DNA demethylation for ecological epigenetic experiments. While the traditionally-used approach causes underdeveloped root systems and high mortality of treated plants, this new one overcomes the unwanted effects while maintaining the demethylation efficiency. The authors demonstrate its application for ecological epigenetic experiments: testing transgenerational effects of plant–plant competition.
This novel method could be better suited for experimental studies seeking valuable insights into ecological epigenetics. As it’s based on periodical spraying of azacytidine on established plants, it’s suitable for clonal species reproducing asexually, and it opens the possibility of community-level experimental demethylation of plants.
Motion vision is an important source of information for many animals. It facilitates an animal’s movement through an environment, as well as being essential for locating prey and detecting predators. However, information on the conditions for motion vision in natural environments is limited.
To address this, Bian et al. have developed an innovative approach that combines novel field techniques with tools from 3D animation to determine how habitat structure, weather and motion vision influence animal behaviour. Their project focuses on Australia’s charismatic dragon lizards, and will place the animals’ motion displays in a visual-ecological context. The application of this approach goes well beyond this topic and the authors suggest the motion graphic technologies is a valuable tool for investigating the visual ecology of animals in a range of environments and at different spatial and temporal scales.
Measurements of morphological features are important for ecological studies, especially on free-ranging wild animal species. Conventionally, specimens either dead or in captivity are used for morphometric studies, which is difficult in the case of wild species for several reasons.‘In situ measurements of animal morphological features: a non-invasive method’ presents a new way to estimate an individual’s morphometric measurements using metadata from digital photographs.
Dr. Mylswamy Mahendiran and Mr. Mylswamy Parthiban, two of the authors of the article, discuss their paper in the video below. The authors cover the main messages of the article – including who will benefit from reading it; how their method is relevant to animal welfare and wildlife studies; the scope and utility of digital photographic advancements; and how other disciplines could use this method.
Understanding how animals perceive, learn and remember stimuli is critical for understanding both how cognition is shaped by natural selection, and how ecological factors impact behaviour.Unfortunately, the limited number of protocols currently available for studying insect cognition has restricted research to a few commercially available bee species, in almost exclusively laboratory settings.
In a new video Felicity Muth describes a simple method she developed with Trenton Cooper, Rene Bonilla and Anne Leonard for testing both lab- and wild-caught bees for their preferences, learning and memory. They hope this method will be useful for students and researchers who have not worked on cognition in bees before. The video includes a tutorial for carrying out the method and describes the data presented in their Methods in Ecology and Evolutionarticle, also titled ‘A novel protocol for studying bee cognition in the wild‘.
Occupancy surveys are widely used in ecology to study wildlife and plant habitat use. To account for imperfect detection probability many researchers use occupancy models. But occupancy probability estimates for rare species tend to be biased because we’re unlikely to observe the animals at all and as a result, the data aren’t very informative.
In the review paper we also show under what conditions soft sweeps are likely (e.g., high population-wide mutation rate, multi-locus selection target). Finally, we describe relevant examples in fruitflies, humans and microbes and we discuss future research directions.
The video focuses on one aspect of the paper, which is illustrated in figure 3: “Why soft sweeps from standing genetic variation are more likely than you may think.”
Ordination and clustering methods are widely applied to ecological data that are non-negative (like species abundances or biomasses). These methods rely on a measure of multivariate proximity that quantifies differences between the sampling units (e.g. individuals, stations, time points), leading to results such as:
Ordinations of the units, where interpoint distances optimally display the measured differences
Clustering the units into homogeneous clusters
Assessing differences between pre-specified groups of units (e.g. regions, periods, treatment–control groups)
In this video, Michael Greenacre introduces his new article, ‘‘Size’ and ‘Shape’ in the Measurement of Multivariate Proximity’, published in Methods in Ecology and Evolution, May 2017. In the context of species abundances, for example, he explains how much a chosen proximity measure captures the difference in “size” between two samples, i.e. difference in overall abundances, and differences in “shape”, i.e. differences in compositions or relative abundances. He shows that the popular Bray-Curtis dissimilarity inevitably includes a part of the “size” difference in its measurement of multivariate proximity.
In this video, the authors explore the potential of DNA metabarcoding to access stream health using macroinvertebrates. They compared DNA and morphology-based identification of bulk monitoring samples from 18 Finnish stream ecosystems. DNA-based methods show higher taxonomic resolution and similar assessment results as currently used morphology-based methods. Their study shows that the tested DNA-based methods integrate well with current approaches, but further optimisation and validation of DNA metabarcoding methods is encouraged.
Habitat destruction and degradation represent serious threats to biodiversity, and quantification of land-use change over time is important for understanding the consequences of these changes to organisms and ecosystem service provision.
Historical land-use maps are important for documenting how habitat cover has changed over time, but digitizing these maps is a time consuming process. HistMapR is an R package designed to speed up the digitization process, and in this video we take an example map to show you how the method works.
Digitization is fast, and agreement with manually digitized maps of around 80–90% meets common targets for image classification. We hope that the ability to quickly classify large areas of historical land use will promote the inclusion of land-use change into analyses of biodiversity, species distributions and ecosystem services.