All You (Possibly) Ever Wanted to Know about ‘Trap Nests’

Post provided by Michael Staab

What are ‘Trap Nests’ and What are They Good For?

Females are attracted to the hollow material in trap nests.

Females are attracted to the hollow material in trap nests.

When thinking of bees and wasps, most people have social insects living in colonies in mind. But most species are actually solitary. In these species, every female builds her own nest and does not care for the offspring once nest construction is completed. Most of those species nest in the ground. Several thousand species of bees and wasps use pre-existing above-ground cavities though (such as hollow twigs and stems, cracks under bark, or empty galleries of wood-boring insects).

To keep you in suspense, I’ll resolve the importance of studying cavity-nesting species later in this blog post. First, I’ll introduce you to one of the more elegant research methods in ecology: trap nests. To study and collect these cavity-nesting species, you can take advantage of their nesting preferences. By exposing artificial cavities and offering access to an otherwise restricted nesting resource, you can attract females searching for suitable nesting sites.

Building these trap nests is simple, but the design can vary greatly. Many designs and materials can be used to build the artificial nesting sites, such as drilling holes in wooden blocks or packing hollow plant material (e.g. reeds) in plastic tubes. Once females find the trap nest and finish their nest construction, the developing offspring are literally ‘trapped’ in their nests. They can then be collected, their trophic interactions (e.g. food and natural enemies) observed, and the specimens can be reared for identification. Continue reading

How Many Animals are Infected with Chronic Wasting Disease?

Post provided by Hildegunn Viljugrein

©Alexandre Buisse

©Alexandre Buisse

The discovery of Chronic Wasting Disease (CWD) in Norway in 2016 has led to extensive measures and testing of deer in Norway. Since 2018 there have been similar measures within the EU. But how many deer need to be tested before we can be (almost) certain that a population is not infected by CWD?

In our article – ‘A method that accounts for differential detectability in mixed samples of long‐term infections with applications to the case of Chronic Wasting Disease in cervids’ – we provide important tools for estimation of prevalence and likelihood of finding infected animals in a given population. The paper is a result of a collaborative work between a multidisciplinary group of scientists from the Norwegian Veterinary Institute, Norwegian Institute for Nature Research and Prof. Atle Mysterud from Centre for Ecological and Evolutionary Synthesis at the University of Oslo. Continue reading

Spatial Capture-Recapture: The Pros and Cons of Aggregating Detections

Post provided by Cyril Milleret

Spatial Capture-Recapture and Computation Time

SCR models simultaneously estimate the detection function and density of individual activity centres. A half-normal detection model is generally used.

SCR models simultaneously estimate the detection function and density of individual activity centres. A half-normal detection model is generally used.

The estimation of population size is one of the primary goals and challenges in wildlife ecology. Within the last decade and a half, a new class of tools has emerged, allowing us to estimate abundance and other key population parameters in specific areas. So-called spatial capture-recapture (SCR) models are growing in popularity not only because they can map abundance, but also because they can be fitted to data collected from a variety of monitoring methods. For example, the ever increasing use of non-invasive monitoring methods, such as camera trapping and non-invasive genetic-sampling, is one of the reason that makes SCR models so popular.

One other strengths of SCR models is the ability to make population level inferences. But the wider the region you’re monitoring, the greater the computational burden, challenging the use of such methods at really large scale. Continue reading

R2ucare: An Interview with Olivier Gimenez

At the International Statistical Ecology Conference in St Andrews this July (ISEC 2018) David Warton interviewed Olivier Gimenez about R2ucare. R2ucare is an R package for goodness-of-fit tests for capture-recapture models. The full Methods in Ecology and Evolution article on this package – R2ucare: An r package to perform goodness‐of‐fit tests for capture–recapture models – was published in the July 2018 issue of the journal.

David and Olivier also discuss some tips for creating R packages. They mention that if you’re new to writing R packages, there are some excellent resources online. Here’s one of them: A Quickstart Guide for Building Your First R Package

We’ll have more of David’s interviews from the ISEC coming out over the next few weeks. Keep an eye out for them here and on the Methods in Ecology and Evolution YouTube channel.

You can find David’s first ISEC interview (with Kate Jones) here.

Bats, Acoustic Methods and Conservation 4.0: An Interview with Kate Jones

At this year’s International Statistical Ecology Conference (ISEC 2018) David Warton interviewed Kate Jones, Chair in Ecology and Biodiversity at University College, London. Their conversation mainly focused on how to classify bats from acoustic data, with particular reference to ‘Acoustic identification of Mexican bats based on taxonomic and ecological constraints on call design‘ by Veronica Zamora‐Gutierrez et al. They also discuss Conservation 4.0!

We’ll have more of David’s interviews from the ISEC coming out over the next few weeks. Keep an eye out for them here and on the Methods in Ecology and Evolution YouTube channel.

Integrating Evolution and Ecology

©H. Zell

©H. Zell

The latest Methods in Ecology and Evolution Virtual Issue – ‘Integrating Evolution and Ecology‘ – is in honour of the late Isabelle Olivieri (1957-2016): an international, interdisciplinary and ground-breaking biologist. It was edited by Louise Johnson and James Bullock and features papers on topics she researched, and in many cases pioneered. But it might perhaps have been more difficult to find 15 Methods papers on areas outside of Isabelle’s research interests!

Isabelle was the first Professor of Population Genetics at Montpellier, a past President of the European Society for Evolutionary Biology (2007-2009), and a member of the European Molecular Biology Organization. She spanned subject boundaries as easily as she collaborated across geographical borders. Her publications range through metapopulation and dispersal ecology, host-parasite coevolution, life history, invasive species and conservation ecology. In keeping with this breadth of interests, she also combined theory easily with experiment, and worked with a wide range of study systems from mites to Medicago. Continue reading

The Manager’s Dilemma: Which Species to Monitor?

Post provided by Payal Bal and Jonathan Rhodes

The greater bilby (M.Lagotis). ©Save the Bilby Fund

The greater bilby (M.Lagotis). ©Save the Bilby Fund

Imagine you’re the manager of a national park. One that’s rich in endemic biodiversity found nowhere else on the planet. It’s under the influence of multiple human pressures causing irreversible declines in the biodiversity, possibly even leading to the extinction of some of the species. You’re working with a complex system of multiple species and threats, limited knowledge of which threats are causing the biggest declines and limited resources. How do you decide what course of action to take to conserve the biodiversity of the park? This is the dilemma faced by biodiversity managers across the globe.

In our recent paper, ‘Quantifying the value of monitoring species in multi‐species, multi‐threat systems’, we address this problem and propose a method using value of information (VOI) analysis. VOI estimates the benefit of monitoring for management decision-making. Specifically, it’s a valuation tool that can be used to disentangle the trade-offs in competing monitoring actions. It helps managers decide how to invest (or whether to invest) their money in monitoring actions when faced with imminent biodiversity declines and the urgency of efficient conservation action. Continue reading

Improving Biodiversity Monitoring using Satellite Remote Sensing

Increased access to satellite imagery and new developments in remote sensing data analyses can support biodiversity conservation targets by stepping up monitoring processes at various spatial and temporal scales. More satellite imagery is becoming available as open data. Remote sensing based techniques to capitalise on the information contained in spatially-explicit species data, such as Global Biodiversity Information Facility (GBIF), are developing constantly. Current free and open data policy will have a dramatic impact on our ability to understand how biodiversity is being affected by anthropogenic pressures, while improving our ability to predict the consequences of changes at different scales.

In our latest Special Feature, ‘Improving Biodiversity Monitoring using Satellite Remote Sensing‘, Sandra Luque, Nathalie Pettorelli, Petteri Vihervaara and Martin Wegmann explain why tackling this challenge is worth doing. The articles demonstrate how combining satellite remote sensing data with ground observations and adequate modelling can help to give us a better understanding of natural systems, leading to improved management practices. They focus on three key conservation challenges:

  1. Monitoring of biodiversity
  2. Developing an improved understanding of biodiversity patterns
  3. Assessing biodiversity’s vulnerability to climate change

Continue reading

TV Coverage of Cycling Races Can Help Document the Effects of Climate Change

Archive footage of the Tour of Flanders obtained by Flemish broadcaster VRT - Flanders Classics

Archive footage of the Tour of Flanders obtained by Flemish broadcaster VRT – Flanders Classics

Analysing nearly four decades of archive footage from the Tour of Flanders, researchers from Ghent University have been able to detect climate change impacts on trees. Their findings were published today in the journal Methods in Ecology and Evolution.

Focusing on trees and shrubs growing around recognisable climbs and other ‘landmarks’ along the route of this major annual road cycling race in Belgium, the team looked at video footage from 1981 to 2016 obtained by Flemish broadcaster VRT. They visually estimated how many leaves and flowers were present on the day of the course (usually in early April) and linked their scores to climate data. Continue reading

Overcoming the Challenges of Studying Soil Nematodes: A New Approach with Implications for All (Soil) Organisms

Post provided by Stefan Geisen

(Soil) Nematodes

“…if all the matter in the universe except the nematodes were swept away, our world would still be dimly recognizable, and if, as disembodied spirits, we could then investigate it, we should find its mountains, hills, vales, rivers, lakes, and oceans represented by a film of nematodes…” (Cobb 1914)

He may have said it more than a century ago but we now, more than ever, realise that Nathan Augustus Cobb was right. Nematodes are by far the most abundant animals soil, freshwater and marine ecosystems. These tiny worms are barely visible to the human eye (if they’re visible at all), hundreds can inhabit a single gram of soil . Their similar shape might lead you to think that they’re all alike, but that’s not the case. More than 25,000 species have been identified and estimates put their entire species diversity in the 100,000s.

Some common nematode species found in most soils. a) Plectus sp; b) Aphelenchus sp; c) Helicotylenchus sp; d) Thonus sp; e) Mononchus sp; © Wageningen University, Laboratory of Nematology, NL; Hanny van Megen

Some common nematode species found in most soils. a) Plectus sp, b) Aphelenchus sp, c) Helicotylenchus sp, d) Thonus sp, e) Mononchus sp. © Wageningen University, Laboratory of Nematology, NL; Hanny van Megen

This taxonomic and functional diversity has boosted nematodes to become useful bioindicators for soil quality. Nematodes perform many different functions in both terrestrial and aquatic ecosystems. These are mainly defined by what they eat:

  • Bacteria/Fungi: Many nematode groups eat bacteria and fungi. They control the population of these organisms and keep them active.
  • Plants: Plant feeders are the unwanted guests in agricultural systems as well as in our gardens. They can destroy entire harvests by piercing into or infiltrating roots.
  • Omnivores/Predators: Many nematode species prey on other smaller organisms including smaller nematodes and control their abundances.
  • Parasites: These species inhabit other larger organisms and can act as biocontrol agents.

Continue reading