Tipping points are all around!

Posted by Ellen Hume

I feel it in my fingers

I feel it in my toes

Tipping points are all around me

And so the feeling grows!

It’s not quite as catchy as the original (Love is all around), and probably just as awkward as the Love Actually Billy Mack version (Christmas is all around), but it does make my point that tipping points are all around us, often without us realising.

The world around us is made up of lots and lots of systems and many of these are classed as ‘complex’. Complex systems can have tipping points, where unexpected behaviour and sudden large changes can result from seemingly small actions due to interactions between parts of the system. This is often difficult to anticipate as studying parts of the system separately doesn’t tell us how the system is going to behave as a whole (concept of emergence).

In my previous blog (The point of collapse), I gave the example of an environmental tipping point involving our freshwater ecosystems in New Zealand tipping suddenly into a degraded unhealthy state from gradual changes to the surrounding land. However, as complex systems can include anything from ecosystems, politics, economy and cities, to the human body and the individual cells that compose it, tipping points (both positive and negative) can also be found in these systems.

Here are some real-world examples:

If you are interested in social tipping points I’d recommend reading Malcolm Gladwell’s book The Tipping Point or checking out one of the many summaries out there like this.

So what examples of tipping points have you seen around you? What could you do to encourage positive tipping points or halt negative ones? Do you feel like singing out about them? I feel it in my fingers, I feel it in my toes, tipping points are all around me, and so the feeling grows… Maybe, just maybe, it’ll catch on!

Ellen Hume

Ellen Hume is a University of Auckland PhD student funded by Te Pūnaha Matatini Centre of Research Excellence. Her project is looking at tipping points in complex systems to enable better risk-based decision making, with supervision from Cate Macinnis-Ng and Shaun Hendy.


Bioacoustics tools- listening to the inner lives of animals

Posted by Ines Geraldine Moran

Birds’ melodious songs, bats’ echolocations, insects’ crackling lisps and shuffles are sounds heard in nature that have fascinated humans for many centuries. Bioacoustics, the science of natural sounds produced by living organisms, is a relatively new field of science that has become central to the study of linguistics, animal behaviour, animal ecology and animal conservation. 

Prior to any technological tools in the field of bioacoustics, scientists described animal sounds using various medium such as music notes, intricate words, or onomatopoeia with letter combinations that attempted to reproduce particular sounds. In order to accurately identify sounds in nature, scientists needed detailed behavioural notes associated to phonetic references. One may imagine how difficult it would have been to walk in a forest and try to detect an animal sound described as Grea-deal for example. For the curious minds, Greadeal was a phonetic sound that referred to Alder Flycatchers from Massachusetts.

Beethoven’s pastoral Symphony No. 6 in F major ends with instrumental European birdsongs from the nightingale (flute), the quail (oboe), and the cuckoo (clarinets) (here respectively denoted with the German translation Nachtigall, Wachtel and Kukuk). Image from muswrite.blogspot.com

Like with many advances in science, new technologies often play an essential role in making new discoveries. In the mid 20s century, a technological revolution changed how scientists studied animal sounds. In 1950s with the invention of recorders and sound visualization tools, a new era in the field of bioacoustics began. Thanks to these devices, scientists could record and visualize sounds of wild species. A new window in the inner lives of animals opened up to scientists. For the first time, scientists could record and measure complex vocalizations and repertoires, vocal differences between individuals, sound variation throughout seasons or even vocalizations produced during specific breeding stages in wild animals. With these technologies, new horizons opened up in linguistics, animal behaviour, animal ecology and conservation. For example, new sound libraries, like the Macaulay Library, have built up impressive collections of animal sounds from the wild. Playback experiments, in which animal sounds are played back to live animals, became a common technique for wildlife biologists and allowed researchers to answer new questions about animal behaviour. Later, automated recorders, devices left in nature for long periods of time, allowed researchers to record the sounds of habitats known as soundscapes, which in return provided important information about the health of ecosystems. 

Spectrograms help scientists visualize sounds, while recording devices help scientists record wildlife, and sound recordings ultimately become part of libraries of animal sounds on Earth, like the Macaulay Library. (Left) spectrogram with multiframe output made with SeeWave R package (image from http://www.rug.mnhn.fr/seewave/). (Right) map of the world with the number of wild species showing missing recorded sounds in the Macaulay Library, as of November 2018 (image from http://www.macaulaylibrary.org).

Recently, the Cain lab – at the University of Auckland where I am conducting a PhD in bioacoustics- started to use some of the latest technologies available in the field of bioacoustics, to advance our knowledge on the evolution of vocal learning in birds. Research in the Cain Lab investigates the vocal learning abilities of rifleman (a small passerine) in a remote reserve, Boundary Stream Mainland Island, New Zealand. Researchers at the Cain Lab use relatively novel bioacoustics technologies, such as automated recording devices, computer programming and machine learning, to record and analyse bird vocalizations.

Recording equipment deployed by researchers at the Cain Lab at the University of Auckland, are used to record the rifleman birds of a North Island forest, in Boundary Stream Mainland Island, New Zealand.(Left) a female rifleman; (middle) passive bioacoustic audio recorder (BAR) from The Frontier Labs; (right) a researcher, Ines G. Moran, from the Cain Lab, recording a rifleman in the tree canopy, with a handheld microphone, a recorder and a tripod. (Photo credit for left and middle photo: I.G. Moran; right photo: Y.Y. Loo)

The development of new technology in the field of wildlife bioacoustics has changed the way we study the vocal world of wild animals. New technologies in bioacoustics are rapidly advancing, and with them new questions are emerging. Animal vocalizations has fascinated humans for many centuries and will keep doing so for many more centuries. As frogs would say: ribbit ribbit!

R packages:

Recommended resources for the detection and analysis of animal sounds.

Several R packages, in particular warbleR, SeeWave, bioacoustics, and monitor, and software are available to analyse, detect and classify sound. Here are few examples of great R packages and software:

warbleR : warbleR is R package that combines analytic tools used to measure and detect acoustic signals. Authors: Marcelo Araya-Salas & Grace Smith-Vidaurre (araya-salas@cornell.ed)

Seewave Seewave offers a wide array of tools to analyze animal sounds with R signals. Acoustic template detection and monitoring database interface. Authors: Jerome Sueur et al. (sueur@mnhn.fr)

monitoR monitoR uses acoustic template to detect sounds. Authors: Sasha D. Hafner (sdh11@cornell.edu)

bioacousticsbioacoustics contains tools to transform, detect and classify animal sounds. Authors: Jean Marchal et al. (jean.marchal@wavx.ca) 

Sound autodetection software

Kaleidoscope Kaleidoscope uses sound recognizers to detect animal sounds. This software saves a lot of time when processing numerous and long audio files.

Interactive sound analysis software

Raven– Cornell Lab of Ornithology Raven is a user-friendly platform that allows visualizing of sounds and annotation of animal vocalizations. 

Ines G. Moran is a Ph.D. candidate in the Cain Lab at the University of Auckland, New Zealand. Her research investigates the evolution of vocal learning in birds, as well as dialects and vocal behaviours of kinship groups in the titpounamu/ rifleman (Acanthisitta chloris), New Zealand.