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 →
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 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 →
Researchers from EPFL and the University of Zurich have developed a model that uses data from sensors worn by meerkats to gain a more detailed picture of how animals behave in the wild.
Advancement in sensor technologies has meant that field biologists are now collecting a growing mass of ever more precise data on animal behaviour. Yet there is currently no standardised method for determining exactly how to interpret these signals. Take meerkats, for instance. A signal that the animal is active could mean that it is moving; alternatively, it could indicate that it is digging in search of its favourite prey, scorpions. Likewise, an immobile meerkat could be resting – or keeping watch.
In an effort to answer these questions, researchers from EPFL’s School of Engineering Laboratory of Movement Analysis and Measurement (LMAM) teamed up with colleagues from the University of Zurich’s Population Ecology Research Group to develop a behavior recognition model. The research was conducted in affiliation with the Kalahari Research Centre. Continue reading →
Post provided by Damien Farine, Sebastian Sosa, David Jacoby, Mathieu Lihoreau and Cédric Sueur
Social network visualization. Photo by Martin Grandjean CC-SA.
Here at Methods in Ecology & Evolution and the Journal of Animal Ecology we are excited by the new directions that the next decade of research into animal social networks will bring. We hope to encourage new advances in the study of animal social networks by calling for high-quality papers for a cross-journal Special Feature on animal social networks. Below, Damien Farine and the Special Feature Guest Editors have reviewed some areas of animal social network research that deserve particular attention.
There are a wide variety of network metrics (node-based, dyadic, and global) and the application and development of new metrics continue to evolve. It is crucial to consider how the values generated by a network metrics (new and old) are interpreted biologically and recognize their limitations. It would be useful to have manuscripts that address questions about:
How mathematical definitions of different network metrics translate to biological processes;
Which metrics provide similar, redundant, or unique information relative to other metrics.
Mathematicians and conservationists from the UK, Africa and the United States have used machine-learning and citizen science techniques to accurately count wildebeest in the Serengeti National Park in Tanzania more rapidly than is possible using traditional methods.
Evaluating wildebeest abundance is currently extremely costly and time-intensive, requiring manual counts of animals in thousands of aerial photographs of their habitats. From those counts, which can take months to complete, wildlife researchers use statistical estimates to determine the size of the population. Detecting changes in the population helps wildlife managers make more informed decisions about how best to keep herds healthy and sustainable. Continue reading →
There’s a frustrating yin and yang to biological research: motivated by curiosity and imagination, we often find ourselves instead defined by limitations. Some of these are fundamental human conditions. The spectrum of light detectable by human eyes, for example, means we can never see a flower the way a bee sees it. Others limitations, like funding and time, are realities of modern-day social and economic systems.
Early career researchers (ECRs) starting new projects and delving into new research systems must be especially creative to overcome the odds. Large grants can be transformative, giving a research group the equipment and resources to complete a study, but they’re tough to get. Inexperienced ECRs are at a disadvantage when competing against battle-hardened investigators with years of grant writing experience. Small grants of up to about $5000 USD, on the other hand, are comparatively easy to find. So, how can ECRs make the most of small, intermittent sources of funding?
I found myself faced with this question in the second year of my PhD field work. Continue reading →
Hay un frustrante toma-y-dame en el campo de la investigación biológica: motivados por la curiosidad y la imaginación, a menudo nos encontramos definidos por limitaciones. Algunas de estas, como nuestros sentidos, son condiciones humanas fundamentales. El espectro de luz detectable por los ojos humanos, por ejemplo, significa que nunca podremos ver a una flor de la misma forma en que la ve una abeja. Otras limitaciones, como financiamiento y tiempo, representan las realidades de los sistemas sociales y económicos de hoy día.
Los investigadores al comienzo de sus carreras (Early Career Researchers, o ECRs en sus siglas en inglés) que se embarcan en nuevos proyectos y se involucran con sistemas nuevos de investigación deben ser especialmente creativos para poder superar las probabilidades. Una generosa beca puede ser transformativa, pero un ECR con poca experiencia está en desventaja cuando compite con investigadores ya endurecidos por la batalla, quienes tienen años de experiencia escribiendo propuestas de financiamiento. Por otra parte, las pequeñas becas en el rango de $2.000 a $5.000 son comparativamente fáciles de encontrar. ¿Cómo puede un ECR aprovechar al máximo estas pequeñas e intermitentes fuentes de financiamiento?
En el segundo año del trabajo de campo de mi doctorado me enfrenté con este enigma. Continue reading →
For the first time ZSL scientists were able to use the calls of a species as a proxy for their movement. A happy hihi call sounds like two marbles clanging together in what is known as the ‘stitch’ call. Scientists saw the calls change from an initial random distribution to a more settled home range – marking the hihi reintroduction and the new method a success. Continue reading →
Scientists at the University of Southampton have developed maps of chemicals found in jellyfish which could offer a new tool for conservation in British waters and fisheries. The maps will also be able to detect fraudulently labelled food in retail outlets by helping to trace the origins of seafood.
The Southampton based research team including Dr Clive Trueman, Dr Katie St. John Glew and Dr Laura Graham, built maps of the chemical variations in jellyfish caught in an area of approximately 1 million km2 of the UK shelf seas. These chemical signals vary according to where the fish has been feeding due to differences in the marine environment’s chemistry, biology and physical processes. Continue reading →