Category: Methods papers

Methods papers, Online extras, Practical Tools

The Arborist Throw-line Launcher

Collecting leaves or seeds from tall trees is a difficult task that many plant physiologists, ecologists, geneticists and forest managers encounter repeatedly. In a series of videos on the Methods in Ecology and Evolution YouTube channel, Kara N. Youngentob, Christina Zdenek and Eva van Gorsel demonstrate how to use the arborist throw-line launcher, which significantly simplifies this task. This new way of collecting seeds and leaves from tall trees is explained in their Applications article ‘A simple and effective method to collect leaves and seeds from tall trees‘. As this is an Applications paper, it is freely available to everyone.

Basic Techniques for the Arborist Throw-line Launcher

The first of the three videos is a basic overview of the method. In this tutorial, the authors teach you how to find the ideal branch, how to use the throw-line launcher and go through some important safety information. Continue reading “The Arborist Throw-line Launcher”

Unknown's avatarIndia Stephenson2 Comments
Conservation and management, Methods papers

Spatially-explicit Power Analysis: A First Step for Occupancy-Based Monitoring

Post provided by Martha Ellis and Jody Tucker

Where’s Waldo? Trying to find this fisher somewhere in a giant landscape is going to be tricky! ©Mike Schwartz
Where’s Waldo? Trying to find this little guy somewhere in a giant landscape is going to be tricky! © Mike Schwartz

The seemingly basic question of whether a population is increasing, decreasing, or stable can be one of the most difficult to answer. Collecting data on rare and elusive species is hard. Imagine trying to detect a handful of fisher or wolverine across hundreds of thousands of acres – it is physically demanding, time consuming and logistically complicated. And that’s just to do it once! To monitor a population for changes, you have to repeat these surveys regularly over many years. The long-term monitoring that is necessary for conservation requires careful planning and a substantial commitment of resources and funding. So before we spend these valuable resources, it’s critical to know whether the data we are collecting can help us to answer our questions. Continue reading “Spatially-explicit Power Analysis: A First Step for Occupancy-Based Monitoring”

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Methods papers

Biggest Library of Bat Sounds Compiled

Below is a press release about the Methods paper ‘Acoustic identification of Mexican bats based on taxonomic and ecological constraints on call design‘ taken from the University College London.

The Funnel-eared bat (Natalus stramineus)
The Funnel-eared bat (Natalus stramineus)

The biggest library of bat sounds has been compiled to detect bats in Mexico – a country which harbours many of the Earth’s species and has one of the highest rates of species extinction and habitat loss.

An international team led by scientists from UCL, University of Cambridge and the Zoological Society of London, developed the reference call library and a new way of classifying calls to accurately and quickly identify and differentiate between bat species.

It is the first time automatic classification for bat calls has been attempted for a large variety of species, most of them previously noted as hard to identify acoustically. Continue reading “Biggest Library of Bat Sounds Compiled”

Unknown's avatarIndia Stephenson3 Comments
Conservation and management, Methods papers, Virtual Issues

Space-time continuum and conservation planning: Helping Species Adapt to Climate Change

Post provided by Diogo André Alagador

The world’s most threatened felid (Iberian lynx) is endemic in a region predicted to be severely impacted by climate change: the Iberian Peninsula. ©lynxexsitu.es
The world’s most threatened felid (Iberian lynx) is from a region predicted to be severely impacted by climate change: the Iberian Peninsula. ©lynxexsitu.es

Climate change is driving many species to alter their geographic distributions. The ranges of some species contract, expand or shift as individuals track favorable climate conditions. In some cases, threatened species are moving out of protected areas. These trends are expected to intensify in the coming years.

To increase conservation effectiveness within protected areas in the future, researchers at the Research Center on Biodiversity and Genetic Resources at the University of Évora and the Department of Mathematics of the Faculty of Sciences and Technology from the NOVA University in Lisbon, Portugal, have come up with a set of modelling tools to optimize the scheduling of conservation area allocation as the climate changes. These take into account restrictions of conservation area expansion derived from the prevailing socio-economic activities. “The objective is to select the best dispersal corridors for each species considering a budget restriction or competition with other socioeconomic activities” said Diogo Alagador. “These selections are complex and non-trivial as they incorporate decisions on the spatial and temporal trends of large sets of species.”

The concept of a spatio-temporal corridor for a species in an environmental heterogeneous region.
The concept of a spatio-temporal corridor for a species in an environmental heterogeneous region.

Continue reading “Space-time continuum and conservation planning: Helping Species Adapt to Climate Change”

Unknown's avatarIndia Stephenson1 Comment
Methods papers

Stage-dependent Demographic Modelling at Your Finger Tips

Post provided by EELKE JONGEJANS and ROB SALGUERO- GÓMEZ

Soay sheep: an organism that can be modelled with two-sex dynamics. ©Julian Paren
Soay sheep: an organism that can be modelled with two-sex dynamics. ©Julian Paren

Typically, ecology courses contain at least a day of matrix population models. So most ecologists are somewhat familiar with how simple life cycles (and complex ones) can be depicted and analysed using matrix models. Briefly, these models represent what happens to individuals over a certain time interval (do they die? do they reproduce? if so, how much?). What individuals do in the context of these models can then be used to study the dynamics of a population.

Often, individuals are classified by size in matrix models, as small individuals tend to have different survival, growth and reproduction rates than large ones. But how many classes do you need to model the dynamics of a size-structured population properly? Instead of choosing arbitrary size class boundaries, Easterling, Ellner and Dixon (2000) came up with the idea of using continuous size variables and integrals to define a population model… and that’s how the first Integral Projection Model (‘IPM’ for us friends) came to be.

Naturally, for the development of a new demographic tool to prove useful to the scientific community, it must be flexible enough to be ‘one-size-fits-all’… and the needs of ecologists, evolutionary biologists and conservation biologists – who have to date used extensively size-based matrix models – are rather variable in size, colour and shape. Continue reading “Stage-dependent Demographic Modelling at Your Finger Tips”

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General, Journal updates, Methods papers, Robert May Prize, Society, Virtual Issues

2015 Robert May Prize Winner: Kim Calders

The Robert May Prize is awarded annually for the best paper published in Methods in Ecology and Evolution by an Early Career Researcher. We’re delighted to announce that the 2015 winner is Kim Calders, for his article ‘Nondestructive estimates of above-ground biomass using terrestrial laser scanning‘.

Kim led the work on this article and had an international team of co-authors. They have developed a way to harness laser technology for use in measurements of vegetation structure of forests. The study is an important development in the monitoring of carbon stocks for worldwide climate policy-making. Continue reading “2015 Robert May Prize Winner: Kim Calders”

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Conservation and management, Methods papers

Being Certain about Uncertainty: Can We Trust Data from Citizen Science Programs?

Post provided by VIVIANA RUIZ GUTIERREZ

Citizen Science: A Growing Field

Thousands of volunteers around the world work on Citizen Science projects. ©GlacierNPS
Thousands of volunteers around the world work on Citizen Science projects. ©GlacierNPS

As you read this, thousands of volunteers of all ages and backgrounds are collecting information for over 1,100 citizen science projects worldwide. These projects cover a broad range of topics: from volunteers collecting samples of the microbes in their digestive tracts, to tourists providing images of endangered species (such as tigers) that are often costly to survey.

The popularity of citizen science initiatives has been increasing exponentially in the past decade, and the wealth of knowledge being contributed is overwhelming. For example, almost 300,000 participants have submitted around 300 million bird observations from 252 countries worldwide to the eBird program since 2002. Amazingly, rates of submissions have exceeded 9.5 million observations in a single month! Continue reading “Being Certain about Uncertainty: Can We Trust Data from Citizen Science Programs?”

Unknown's avatarIndia Stephenson9 Comments
Methods papers

Dealing with Variation in Hormone Metabolite Measurements: A Tale of Poop

Post provided by EVE DAVIDIAN and SARAH BENHAIEM (DEPARTMENT OF EVOLUTIONARY ECOLOGY, IZW, BERLIN)

On the Art of Collecting Faeces

Sarah Benhaiem waiting for a faecal sample from a spotted hyena in the Serengeti National Park.©Sarah Benhaiem
Sarah Benhaiem waiting for a faecal sample from a spotted hyena in the Serengeti National Park.©Sarah Benhaiem

Whether you are a laboratory or a field scientist, you have to be willing to get your hands dirty from time to time for the good of science. Sarah and I took that literally and spent a large part of our respective PhD projects handling faeces of free-ranging spotted hyenas from the Serengeti National Park and the Ngorongoro Crater, Tanzania.

Though faeces often are underrated, they are highly valuable material to work with because they conceal the most secret details about an animal’s social and sexual life. But having the privilege of holding a still-steaming poop is something you have to earn! Continue reading “Dealing with Variation in Hormone Metabolite Measurements: A Tale of Poop”

Unknown's avatarIndia Stephenson3 Comments
Conservation and management, Methods papers

Getting Every Last Bit Out of Dives: Data Abstraction On-board Telemetry Tags

Post provided by THEONI PHOTOPOULOU, MIKE FEDAK, LEN THOMAS and JASON MATTHIOPOULOS

Animal Telemetry for Air-breathing Divers

CTD-SRDL Tags
CTD-SRDL telemetry tags being primed for deployment. ©Theoni Photopoulou

Nowadays animal telemetry tags for air-breathing divers come in all shapes and sizes. In four short decades tags for diving animals have gone from prototypes like the one built by Jerry Kooyman for deployment on Weddell seals – which consisted of a kitchen timer and a roll of graph paper – to a multitude of sophisticated electronic devices, fit for just about any animal or purpose you can think of.

All this progress has meant we can collect more information than ever before and do so remotely. Nevertheless, the lives of most divers remain a well-kept secret. For tags that transmit what they collect (as opposed to those that store data until they’re retrieved), the transmission stage is usually the bottleneck. This has driven the development of energy and time efficient software and data processing.

For a tag like the conductivity-temperature-depth Satellite Relay Data Logger (CTD-SRDL) built by the Sea Mammal Research Unit Instrumentation Group at the University of St Andrews – which was designed to spend months at sea – the problem boils down to one thing. Data are collected at a high resolution on-board the tag amounting to 100kB daily, but only 1kB of this information (at best) can be transmitted to the ground station. Therefore in preparation for transmission, the data need to be chosen carefully, compacted and fitted into several satellite messages of fixed size to ensure that enough useful information is received. Each satellite message can hold up to 248bits of information. To give an idea of how limiting this is, consider that this sentence would (without compaction) take up 896bits! Continue reading “Getting Every Last Bit Out of Dives: Data Abstraction On-board Telemetry Tags”

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Conservation and management, Methods papers

Inferring Extinction: When is a Species as Dead as a Dodo?

Post provided by ELIZABETH BOAKES

The indisputably extinct Dodo (Raphus cucullatus). ©Ballista
The indisputably extinct Dodo (Raphus cucullatus). ©Ballista

A species is either extant or extinct – it exists or it does not exist. Black and white, a binary choice. Surely it should not be difficult to assign species to one of these two categories? Well, in practice it can be extremely challenging and a plethora of methods have been developed to deal with the problem.  This of course leads to a second challenge – which of the plethora should you use?! (More on this later…)

There are a few well-studied cases where we can assert extinction confidently. For example, the chances of the Dodo (Raphus cucullatus) having existed undetected for upwards of 300 years on an island now densely populated by humans are infinitesimally small. However, many extinctions are far harder to diagnose. Species typically become extremely rare before becoming extinct. If taxa are particularly cryptic or are found across a huge geographic range it is quite plausible that the few remaining individuals may exist undetected for decades. An extreme illustration of this is the 1938 discovery of Latimeria chalumnae, a deep-sea member of the Coelacanths, the entire order of which was believed to have become extinct 80 million years earlier! Continue reading “Inferring Extinction: When is a Species as Dead as a Dodo?”

Unknown's avatarIndia Stephenson2 Comments