Category Archives: Field Methods

The tripod frame: mooring acoustic receivers on the seabed

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Post provided by Jolien Goossens

Jolien Goossens tells us about the challenges of installing acoustic receivers on the seabed and the tripod they designed to overcome them.

sea

Installing scientific instruments in the marine environment comes with many challenges. Equipment has to withstand the physical forces of tides, currents and storms. Researchers have to take into account the effects of biofouling, corrosion and human activities. Even access to the study site can pose its difficulties, as diving is limited by depth and weather conditions. Practical deployment mechanisms are therefore needed to sustain consistent data flows.

Acoustic telemetry enables the observation of animal movements in aquatic environments. Individual animals are fitted with a transmitter, relaying a signal that can be picked up by acoustic receivers. To facilitate a convenient installation of these instruments, we developed and tested a new design, mounting a receiver with an acoustic release on a tripod frame. This frame enables the recovery of all equipment and better yet, improves the quality of the data.

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An interview with the editors of “Population Ecology in Practice”: Part II

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Post provided by Daniel Caetano

Today we bring the second part of an interview with Dennis Murray and Brett Sandercock about their brand new book in population ecology methods: “Population Ecology in Practice.” This time we talked about their experience as editors, including some useful advice for new editors.

If you missed the first part of the interview, check it out here.

Population Ecology in Practice introduces a synthesis of analytical and modelling approaches currently used in demographic, genetic, and spatial analyses. Chapters provide examples based on real datasets together with a companion website with study cases and exercises implemented in the R statistical programming language.

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An interview with the editors of “Population Ecology in Practice”: Part I

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Post provided by Daniel Caetano

Today we bring the first part of an interview with Dennis Murray and Brett Sandercock about their brand new book in population ecology methods: “Population Ecology in Practice.” The editors were kind enough to share some interesting backstage information with us.

Snowshoe hare in winter

Population Ecology in Practice introduces a synthesis of analytical and modelling approaches currently used in demographic, genetic, and spatial analyses. Chapters provide examples based on real datasets together with a companion website with study cases and exercises implemented in the R statistical programming language.

Stay tuned for the second part of this interview, where we talk about some of the challenges of editing a large book and the editors share essential advice for anyone looking into leading such a project!

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Earth Day 2020: Monitoring Biodiversity for Climate Action

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Post provided by Chloe Robinson

The demands of a growing human population are putting increasing pressure on the Earth’s natural systems and services. Dubbed the ‘Anthropocene’, we are currently living in a period where human actions are directly altering many earth processes, including atmospheric, geologic, hydrologic and biospheric processes. Climatic change and the resulting consequences, including rising temperatures, changing precipitation (i.e. rainfall, snow etc) and increase in frequency of storm events, represent the biggest challenge to our future and the life-support ecosystems that make our world habitable.

Artist’s interpretation of global climate change. Photo credit: Pete Linforth/Pixabay.

In 1970, Earth Day was launched as a modern environmental movement and a unified response to an environment in crisis. Earth Day has provided a platform for action, resulting in the creation of the Environmental Protection Agency (EPA), The Clean Air, Clean Water and Endangered Species Acts in the US and more globally. This year, 22 April marks the 50th anniversary of Earth Day, and the number one environmental crisis theme which needs immediate attention is ‘Climate Action’. Many of our ecosystems on earth are degrading at an alarming pace and we are currently experiencing a species loss at a rate of tens or hundreds of times faster than in the past. 

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Methods behind the Madness: Ecology at the Poles

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Post provided by Chloe Robinson, Crystal Sobel and Valerie Levesque-Beaudin

Aurora Borealis in the polar north. Photo: Noel Bauza, Pixabay

For those of us in the Northern Hemisphere, the coldest months of the year are upon us. A combination of post-holiday ‘blues’ and the cold, dark mornings make the daily trudge to work all that less inspiring. Recent snow storms in locations such as Newfoundland (Canada), have made it nearly impossible for many people to leave their homes, let alone commute to work. Now cast your mind to a little over 2,000 km north of Newfoundland and imagine the challenges faced with carrying out a job during the coldest, darkest months of the year.

As with every other biome on the planet, polar biomes contain a variety of different species, from bugs to baleen whales. To better understand the different species at our poles, scientists need to collect ecological data, but this is far from a walk in the park.

Iceberg in the Gerlache Strait, Antarctica. Photo: Liam Quinn, flikr.

With the year 2020 marking 200 years since the discovery of Antarctica and the Centenary of ‘vital’ Scott Polar Research Institute (Cambridge, UK), we wanted to highlight some of the polar research published in the journal, featuring challenges faced and current research being undertaken at the poles.

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Making a Self-Preserving eDNA Filter

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Below is a press release about the Methods in Ecology and Evolution article ‘A self‐preserving, partially biodegradable eDNA filter‘ taken from the Smith-Root.

A new self-preserving filter housing automatically preserves eDNA, while reducing the risk of contamination, and creating less plastic waste.

Researcher collecting an eDNA sample using the self-preserving filter housing.

In 2015 the inventor of the Keurig disposable coffee cartridge (K-Cups) told reporters that sometimes he regrets ever inventing the technology. The single-use design simply produces too much non-recyclable trash. Well, that very same problem is what ultimately led to the creation of a self-preserving filter for environmental DNA (eDNA); a recently reported Practical Tool in Methods in Ecology and Evolution.

eDNA scientists rely on single-use sampling equipment because eDNA surveys are highly sensitive to potential contamination. “We started out simply looking for biodegradable plastics that could be molded into a filter housing, with the objective of reducing plastic waste.” says Dr. Austen Thomas who led the team of researchers and engineers who invented the Smith-Root eDNA Sampler. “That’s when we realized that some of the biodegradable compounds function by being highly hydrophilic.” Continue reading →

Scant Amounts of DNA Reveal Conservation Clues

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Below is a press release about the Methods in Ecology and Evolution article ‘Empowering conservation practice with efficient and economical genotyping from poor quality samples‘ taken from the Stanford Woods Institute for the Environment.

Wild tiger in India. ©Prasenjeet Yadav

The challenges of collecting DNA samples directly from endangered species makes understanding and protecting them harder. A new approach promises cheap, rapid analysis of genetic clues in degraded and left-behind material, such as hair and commercial food products.

The key to solving a mystery is finding the right clues. Wildlife detectives aiming to protect endangered species have long been hobbled by the near impossibility of collecting DNA samples from rare and elusive animals. Continue reading →

Studying Wild Bats with Small On-Board Sound and Movement Recorders

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Post provided by LAURA STIDSHOLT

Releasing a female Greater mouse-eared bat with the tag in collaboration with Holger Goerlitz, Stefan Greif and Yossi Yovel. ©Stefan Greif

The way that bats acrobatically navigate and forage in complete darkness has grasped the interest of scientists since the 18th century. These seemingly exotic animals make up one in four mammalian species and play important roles in many ecosystems across the globe from rainforests to deserts. Yet, their elusive ways continue to fascinate and frighten people even today. Over the last 200 years, dedicated scientists have worked to uncover how bats hunt and navigate using only their voice and ears while flying at high speed in complete darkness. Still, the inaccessible lifestyle of these small, nocturnal fliers continues to challenge what we know about their activities in the wild.

Understanding the impact bats have on their ecosystems – for example how many insects a bat catches per night – has still not been directly measured. Most of our knowledge on the natural behaviour and foraging ecology is based on elaborate, but ground-based experiments carried out in the wild. These experiments generally track their behaviour using radio-telemetry, record snapshots of their emitted echolocation calls with microphones, or involve extensive observations. Continue reading →

What Biases Could Your Sampling Methods Add to Your Data?

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Post provided by ROGER HO LEE

這篇博客文章也有中文版

Have you ever gone fishing? If so, you may have had the experience of not catching any fish, while the person next to you got plenty. If you walked along the pier or bank, you may have seen that other fishermen and -women caught fish of various shapes and sizes. You’d soon realise that each person was using a different set of equipment and baits, and of course, that the anglers differed in their skills and experience. Beneath the water were many fish, but whether you could catch them, or which species could even be caught, all depended on your fishing method, as well as where and how the fish you were targeting lived.

Designing Sampling Protocols

Head view of different ant species found in Hong Kong and further in SE Asia.

Head view of different ant species found in Hong Kong and further in South East Asia.

This is a lot like the situation that ecologists often face when designing sampling protocols for field surveys. While a comprehensive survey will yield the most complete information, few of us have the resources to capture every member of the community we’re studying. So, we take representative samples instead. But the method(s) used for sampling will only allow us to collect a subset of the species which are present. This selection of the species is not random per se – it’s dependent on species’ life history. Continue reading →

採樣方法會帶來怎樣的數據偏差?

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作者：李灝

This blog post is also available in English

你有釣魚的經驗嗎？若有的話，以下的經歷對你應該不會陌生。自己釣了大半天，魚杆動也沒動過，但身旁的釣手卻滿載而歸。感到灰心時，你沿著碼頭或岸邊巡視，你看到其他人的魚獲大大小小的也有﹑形態不同的的也有。心裡被疑惑與不甘的思緒纏繞著的一刻，你突然意識到每個人都在使用不同的釣具和魚餌（當然每位垂釣者的技能和經驗也不同）。在水中有各種各樣的魚，但你能否釣到牠們，或者釣到那一些品種，都取決於你釣魚的方法，以及你目標魚種的活動範圍和生活方式。

採樣方案的設計

Head view of different ant species found in Hong Kong and further in SE Asia.

香港和東南亞地區的螞蟻品種。

上述的經歷與生態學家在設計野外調查時所遇到的情況非常相似。雖然全面的調查能取得最完整的資料，但我們很少會有充足的資源去完整地採集整個物種群落。取而代之的是我們只能採集一部份的物種來作寫照。值得我們留意的是每種採樣方法只允許我們收集到群落中的某些物種；這些物種不是隨機地被選中，而是取決於物種的生活史。 Continue reading →