Pathways to paradise or highways of hell

If you travel overseas (especially to Australia) you are likely to hear a lot of sheep jokes about New Zealanders. This makes sense when you realise that nearly 40% of the total land area in New Zealand is sheep and beef farms (our conservation estate is 31% of the total land area) (see Jennifer Pannell’s super cool infographic below). These farms also contain 25% of the native vegetation in New Zealand. This means that farms provide an excellent opportunity for improving our native biodiversity.

I’m part of a National Science Challenge project that has been looking at just that; considering how the connectivity of bush patches on farms can help facilitate the movement of native species across the landscape. Connectivity can be thought of in two ways. Structural connectivity refers to how the vegetation is arranged, such as spacing between habitat patches or corridors of vegetation between them, while functional connectivity refers to species-specific needs and how species interact with landscape structures, such as how far birds can fly between bush patches and how large the patches need to be. So, if you are considering connectivity from the perspective of a robin, then patches of vegetation may need to be as close as 100m from each other, compared to a kereru which can fly 10s of kilometres between habitat patches.

It’s all well and good to enhance connectivity to help the robin, tūī or kōkako disperse and move throughout the landscape, but is this enhanced connectivity also facilitating the movement and populations of invasive mammalian predators? That would be a perverse outcome for bird species whose habitat we are aiming to improve. This is what I’m aiming to find out during my PhD. In particular I’ll be looking at feral cat movement on farms and how the distribution and arrangement of native vegetation influences their movement. Understanding cat movement on farms in relation to vegetation connectivity will help with both managing biodiversity and farmers hoping to minimise diseases, such as toxoplasmosis, on their farms.

Cathy is a PhD student in the Centre for Biodiversity & Biosecurity, School of Biological Sciences, University of Auckland. She is studing feral cat movement and landscape connectity in agroecosystems. She is supervised by Margaret Stanley, Hannah Buckley, Brad Case and Al Glen.

Just like time, intelligence is relative

By Juliane Gaviraghi Mussoi

Animal cognition can be defined as the mechanisms in which animals acquire, process, store and act on information of their environment (Shettleworth, 1998).

Figure 1. Simplified representation of the cognitive mechanism (1.Acquire, 2.Proccess, 3.Store, 4.Act)

As a research area, animal cognition is relatively new and full of unanswered questions. Testing for cognitive ability in animals can be challenging. Many experiments are human-centric and based on what humans are good at, e.g. tool use, language, numerical counting… It is also complex to measure something we don’t fully understand. For instance, how can we test the cognitive ability of a mosquito when we can barely grasp how they perceive the world? But it is still in our nature to try to differentiate “us” (humans) from “them” (other animals).

The more we learn about what animals can do, the less humans seem unique. For example, tool use, which was thought to be an ability exclusive to humans, is also present in monkeys, birds, elephants, dolphins and even invertebrates such as octopuses and ants. Some animals are also able to manufacture their own tools by shaping leaves and sticks.

Figure 2.  New Caledonian crow probing tree bark with a stick for insects. Image credit: James St Clair.

Further, there are some types of cognitive abilities that humans are very poor at and some animals excel. Spatial memory is one of them. Some species of birds and rodents , store food for times when resources are scarce and remember the exact location of their caches after weeks or months. Black-capped chickadees depend on stored food to survive during harsh winters and it is estimated that they can store up to 100 000 individual food items per year. Personally, I can’t relate to that. Every morning I forget where I put my keys and cell phone.

One of the biggest challenges in animal cognition research is to design tests that are relevant to the animal being studied, while still being comparable to other species. An animal that relies on smell to recognize peers, would be unlikely to pass a mirror self-recognition test. Not because it is not self-aware, but because the mirror does not provide the information needed for a species that relies on olfactory (smell) cues instead of visual cues.

Figure 3. This cartoon illustrates one of the issues when testing for cognitive ability. Artist unknown.

Another example are bees, which are faster than most animals when it comes to associating a colour with a food reward. However, that does not mean bees are “smarter”, it reflects their well-developed (and necessary) ability to find colourful flowers to get food in their natural environment.

Therefore, whenever you get the urge to compare a chimpanzee with a 3-year-old child or to say that a dog is smarter than a fish, try to remember that there are different types of “intelligence” and they are all relative.


Juliane Gaviraghi Mussoi is a Ph.D. student from the University of Auckland. Her research focuses on vocalization, ornamentation and cognition of New Zealand fantails and Australian magpies. She is supervised by Dr. Kristal Cain and Dr. Margaret Stanley.

All the Small Things: Microbial Symbioses with Plants

By Megan Tan @meganlapin

When I talk about plants and what may influence their growth and occurrence in an environment, it’s easy to mention the presence of sunlight or how much rainfall it gets. These factors we would class as abiotic – physical influences.  When biotic factors are brought up, we would probably think of animals such as browsers, herbivores who graze on their favourite plants.  But what is often not thought about are the interactions that microbial organisms have in a terrestrial forestry system.

I find that microbial concepts in ecology are so easily looked over. This is probably due to a) we can’t observe their behaviour with our naked eye and b) we often don’t know that they’re present in the environment. With the development of advanced genetic technology in the last 20-30 years, we have a better idea of the microbial organisms present in the environment and their potential role. In terrestrial systems, many of these microbes interact with plants directly or indirectly.  For the simplicity of this blog entry I will be focusing on direct interactions. When a direct interaction occurs, this is known as symbiosis.

Symbiosis is the term used to describe any biological interaction between two different organisms. The interaction may be positive, negative or neutral. The main types of symbiotic relationships are parasitism, commensalism and mutualism. Figure 1 sums up the different types of symbioses that are possible.

Figure 1: The types of symbiotic relationships that occur between two organisms (Species A and B). Interactions may be positive (beneficial to the species (+)), negative (undesirable to the species (-)) or neutral (no positive or negative influence (0))

When it comes to plants in a forest you would probably have come across one of the aforementioned interactions. A parasitic interaction between a microbial organism and a plant causes disease. Resources from a host allows the parasite to live and grow, increasing their fitness. However, the fitness of the host is decreased because this interaction is detrimental. Disease has caused mass population loss to forestry systems. You may have heard of the impact kauri dieback has had on the Waitakere Ranges in the New Zealand media. This effect has also been observed internationally, such as Rapid Ohia disease in Hawaii (Figure 2)

Figure 2: Rapid decline of Metrosideros polymorpha (Ohia) forest caused by the fungus Ceratocystis fimbriata. Puha District, Hawaii, USA

However, not all interactions with microbes are negative for plants. One of the most vital functions in a terrestrial ecosystem involves the mutualistic interaction between plants and mycorrhizal fungi. The fungal party are involved with enhanced nutrient cycling, stress tolerance and even communication between plant individuals in a forest system. Mutualistic interactions such as this allows improvement of fitness between the plant and the fungi. This is a very beneficial interaction, so much so that mycorrhizal fungi and terrestrial plants have co-evolved together multiple times over millions of years. Nowadays mycorrhizal fungi occur with approximately 90% of the world’s plants.

Figure 3: Light microscopic image of a root squash. This root squash shows a vesicle and hyphae from an arbuscular mycorrhizal fungi penetrating the root cortical cells of kauri (Agathis australis). This specimen was stained using Trypan Blue, highlighting fungal structures . 600x magnification

So the next time you go for a trip outdoors, have a look at the surrounding environment. Look at what plants are present and have a think about how they may be thriving. Are they in an ideal environment? Could something else be influencing their survival?

Find out more about microbial symbioses and genetic technology here:
Roh, S., Abell, G., Kim, K., Nam, Y., & Bae, J. (2010). Comparing microarrays and next-generation sequencing technologies for microbial ecology research. Trends In Biotechnology28(6), 291-299.

Martin, F., Selosse, M., & Sanders, I. (2015). Mycorrhizal ecology and evolution: the past, the present, and the future. New Phytologist205(4), 1406-1423

van der Heijden, M., Bardgett, R., & van Straalen, N. (2008). The unseen majority: soil microbes as drivers of plant diversity and productivity in terrestrial ecosystems. Ecology Letters11(3), 296-310. van der Heijden, M.,

Megan Tan is a MSc student at the Joint School of Biodiversity and Biosecurity, University of Auckland. She is a recipient of the Sustainability Research Award for Students 2019 and has also received funding from the Centre for Biodiversity and Biosecurity. Her research is focusing on the effects of mycorrhizal fungi symbiosis on kauri growth. This study is supervised by Bruce Burns of the University of Auckland and Maj Padamsee of Manaaki Whenua Landcare Research. Megan is also a big fan of sweets

Mob-scene

Posted by Daria Erastova @Kuukso

This month I visited Australia for the first time in my life and was very impressed by the number of wildlife encounters I experienced in only 10 days! As an ornithologist, I always pay attention to birds and what they are up to. The avian diversity as well as all the noises the creatures were producing was simply overwhelming. But there was one thing which added significantly to the Aussie bird chorus and disturbed not just me, but other birds as well. I am talking about mobbing, which I have observed many times both in Europe and now in Australia, but never in New Zealand.

Fig. 1 Mobbing a hawk.

Mobbing is a popular term and is used to describe bullying of an individual by a person or a group in any context. However, not many people know that this sociological term was first described by the remarkable and outstanding ‘father of ethology’, Konrad Lorenz in 1966. Lorenz observed this behaviour among birds and other animals and suggested it has something to do with the deepest animal instincts aimed at surviving and protecting a group. Later it was found that some non-predator birds use mobbing against diurnal and night predators, such as owls, hawks, etc. Mobbing birds fly in very noisy and angry groups around a roosting place or a tree hole where they found a predator to attract as much attention as possible and to finally make their enemy retreat from the area. It makes perfect sense for them to get rid of potential threats before darkness falls when they all become helpless while roosting. It also explains why night hunters have camouflage plumage and sit still in the day with their eyes closed. Nothing could be more frustrating than to be awakened by a bunch of clamorous moppets!

Fig. 2 Crows mobbing long-eared owl.

The way evolution works, one advantage can often be used in a different context. As I’ve mentioned, bird diversity in Australia is exceptionally high, which leads to high competition for resources. The scene I witnessed in Sydney, was a mobbing of a kookaburra family by species with a very self-explanatory name, the noisy miner. I was sad to see it, not only because the population of kookaburras is declining while the population of noisy miners grows exponentially, but also because I am very fond of kookaburras. These birds feed mostly on small animals and rarely on smaller birds, imposing no threat to things like noisy miners. However, when we think of evolutionary pathways, we could conclude, that mobbing in this situation is directed to resource and space access, which is indirectly connected to survival, rather than direct mortality.

Fig.3 A pair of kookaburras recovering from the stress of being mobbed by noisy miners.

In New Zealand mobbing is not that widespread probably due to the low number of natural avian or mammalian predators. Brent Stephenson showed that morepork is mobbed by at least 9 passerine species, including natives like fantail, silvereye, saddleback, stitchbird and tui. Alison Stanes revealed that the native diurnal predator, the swamp harrier, gets mobbed by colonial birds, such as stilts. But how about mobbing invasive pests? A very interesting work by Richard Maloney and Ian McLean showed that native New Zealand robins were capable of recognising and mobbing stoats after a one-event learning experience. The good news for us is that this study suggests predator training may be a valuable addition to many reintroduction programmes for endangered species. Let’s mob the pest away!

Daria Erastova is a PhD student at the School of Biological Sciences, University of Auckland, who studies the effect of sugar-water feeding on behaviour and health of native New Zealand birds in urban context. This research is supervised by Margaret Stanley, Kristal Cain (The University of Auckland) and Josie Galbraith (War Memorial Museum). The study is funded by Birds New Zealand, Forest and Bird, and Centre for Biodiversity and Biosecurity.

twitter: @Kuukso

web-page: https://sugarfeederproject.wixsite.com/sugarfeeder

email: dera076@aucklanduni.ac.nz

Globally mindful. Locally active.

Posted by Kaavya Benjamin

Recently, I had the opportunity to hear Dame Dr. Jane Goodall speak about her Roots & Shoots program at Kristin School. Her intense passion for science began when, as a little girl, she saved money and bought as many second-hand books as she could. One book, ‘Tarzan of the Apes’, which she still treasures, caught her attention. She fell in love with Tarzan, but what did Tarzan do? He fell in love with the wrong Jane. Heartbreak aside, Tarzan inspired her to grow up, live in Africa among wild animals, and write books about them. Seventy-five years later, Jane has realized her dreams and more. For 50 years, she has revolutionized the field of primatology and redefined species conservation to include the needs of local societies and environments.

Dr. Goodall, clutching her ever-popular handful of soft toys, began her talk by declaring that every person can make a difference, especially the youth. Announcing that young people are some of the most compassionate and creative solutionaries our world has seen. She founded Roots & Shoots, in 1991, to empower and encourage young people to pursue their passion, rally their peers and become the compassionate leaders our world needs to ensure a better future for animals, people, and environment (A.P.E.). Roots & Shoots started with 12 students in Tanzania and has grown to 150,000 groups helping develop skills for young people worldwide. The organizations’ mission is to promote respect and compassion for all organisms, further understanding of all cultures and beliefs, and to inspire everyone to act to make the world a better place.

Various Roots & Shoots projects are currently undertaken by Kiwi students, from kindergarteners planting gardens to attract bees and butterflies; to educating local communities near Mount Pirongia about endangered bats; and even the famous the ‘BAN THE BAG’ campaign. Students from the De La Salle College gave a presentation about implementing their ‘Our Stream, Our Taonga’ restoration project on a small stream that runs through their campus and flows into Otaki Creek. The land around the stream was open fields, saturated with weeds. Rain runoffs from the area, leaf litter and rubbish used to flow into the stream resulting in an unpleasant smell and an unhealthy waterway. The students understood that people had destroyed this ecosystem and they had to do something or else it would never change. A small group of students in 2015 took charge of the clean-up and started small. They pulled out debris from the stream, including tires, branches, and even a bicycle. Next, they cleared weeds from the creek banks and planted native trees to stop soil runoff, increasing oxygen levels, restoring carbon into the ecosystem and attracting birds and insects. Since 2015, 100 students and staff have maintained this project and planted approximately 3,500 native trees. The students continue to monitor, pH, and water clarity along with birds, fish, and invertebrate, who have all returned in numbers to the stream.

Dr. Goodall stated there has been a disconnect between our brains and the human heart and “only when head and heart work in harmony can we attain our true human potential.” The Roots & Shoots program is hugely beneficial and an excellent way of involving students to think about imparting positive impacts in their world, and encouraging them to work within their local communities to achieve a global goal.

You can join the Roots & Shoots Facebook group to see what other projects young Kiwis are undertaking https://www.facebook.com/pg/rootsandshoots/groups/

Find out more about the Jane Goodall Institute New Zealand at http://www.janegoodall.org.nz/our-team/our-perspectives/

You can follow the Jane Goodall Institute New Zealand @jane_goodall_nz on Instagram and @JGI_NZ on Twitter

Kaavya is a MSc student studying the spread of exotic insects into natural ecosystems in New Zealand, and is supervised by Darren Ward at the University of Auckland and Landcare Research.

Hidden Diversity

Posted by Darren Ward @nzhymenoptera

New Zealand is a weird place for biodiversity. An estimated 20,000 invertebrate species live in New Zealand and at least 50% are undescribed. When discussed, perhaps most often mentioned is the ‘high degree of endemism’. This is the proportion of species found only in NZ and nowhere else in the world. Overall, about 90% of insect species in NZ are endemic.

What is far less appreciated is the number of new species still to be discovered and described. I am often asked ‘Are there still new species to be found in NZ?’ Yes, there are, and many hundreds of them.

Recently, twenty-four new species of Mecodema, a genus of large-bodied ground beetles, have been described (Seldon & Buckley 2019), with one species even from Clevedon in the northern Wairoa! This genus is highly diverse with species spread throughout mainland New Zealand, and on many offshore islands. Many species are found in relatively restricted geographic areas and their presence indicates past geological events which have shaped New Zealand; including, isolation from the mainland, diversification and adaption in alpine zones; and volcanic activity.

Just this week, a new species of parasitoid wasp, Sierola houdiniae, was described (see Magnacca 2019) from a single specimen, reared from the larvae of a caterpillar, Houdinia flexilissima, better known as “Fred the Thread”. The caterpillar is found in Waikato bogs and peatlands in the living stems of Sporadanthus ferrugineus, a large endemic New Zealand rush, and is considered a species of high conservation status.

Discovering such hidden diversity is an important part of understanding how the world works, but also gives a sense of wonder about the diversity of the weird and wonderful little critters around us.

Darren Ward is an entomologist in the New Zealand Arthropod Collection at Landcare Research, and a senior lecturer at the School of Biological Sciences, University of Auckland.

Seldon & Buckley. 2019. The genus Mecodema Blanchard 1853 (Coleoptera: Carabidae: Broscini) from the North Island, New Zealand. Zootaxa. doi.org/10.11646/zootaxa.4598.1.1

Magnacca. 2019. Two new species of Sierola Cameron (Hymenoptera: Bethylidae) from New Zealand and Australia. New Zealand Entomologist. doi.org/10.1080/00779962.2019.1602899

Sustainability or the drawback of perfectionism

Posted by Julia Schmack

This word cloud gives you an impression of the topics that went through my head during a University seminar on “Sustainability, science, society, water, food production and consumption”. The speakers covered a wide range of interesting topics and ideas. But there was one thing missing: a pragmatic approach on a scale that is larger than the local guerrilla gardening initiative, but still practical enough to not be forgotten as some idealist’s dream. After the fourth talk, I was still waiting for this one term “organic agriculture”.

There is a lot of scientific evidence for and against organic farming. I won’t give you a literature review here, as I think it’s up to everyone to inform themselves. Although some controversy about organic farming, I was surprised to not hear it mentioned in the discussion of “sustainable food production and consumption”. Do Kiwis still doubt the credibility of organic certification? Are most thinking “In New Zealand, everything used to be organic and that’s why we don’t need this organics fuss”? Or are organics still considered elite products for health freaks and people with pockets deeper than PhD students?

Here’s the definition of organic agriculture by the International Federation of Organic Agriculture Movements, a long-established umbrella organization for organic food production:

Organic Agriculture is a production system that sustains the health of soils, ecosystems and people. It relies on ecological processes, biodiversity and cycles adapted to local conditions, rather than the use of inputs with adverse effects. Organic Agriculture combines tradition, innovation and science to benefit the shared environment and promote fair relationships and a good quality of life for all involved.”

(c) Julia Schmack

Sounds rather far-fetched, doesn’t it?

Well, it’s not. It’s important to have goals and to work hard to reach them. Although you may not reach organic utopia, it’s certainly better than not having tried at all. Perfectionism often keeps us from trying to make change. We are bound to make mistakes when we try to improve conventional systems, and will likely be disproportionately criticised for not being perfect. This is too often the case when it comes to organic farming. There are logical benefits for biodiversity and animal welfare on organic farms compared to conventional farms. However, scattered cases of fraud cause people to mistrust the entire movement and, unfortunately, revert to the comfort of the status-quo.

I worked at the Research Institute for Organic Farming in Frankfurt for three years. There are things in organic agriculture I disagree with, such as the transport of organics over thousands of kilometres. It would be a lot more sustainable to eat local and seasonal, that much is obvious. I also disagree with the working conditions on some organic farms that rely on the hard work of volunteers. But I also understand that surviving as an alternative system in an economy that is ruled by stock markets is not easy. I don’t like that, in any kind of agriculture, baby cows get taken away from their mothers so that we can pump their milk into plastic bottles only to be let ferment in the communal fridge.

Despite these critiques, after visiting some 60 organic and conventional farms and meeting the farmers, there is one thing that I can say for certain: if I were a cow, pig, or chicken, and I could choose between the two farming systems, I know which farm I would choose. 100% the organic farm! The same goes if I were an earthworm, bird or plant. If I were a weed, the organic farmer wouldn’t be allowed to spray me with nasty chemicals. They would have to use less invasive and often more time intensive methods. But this is what you get when you pay that extra dollar.

(c) Julia Schmack

There is a lot of confusion around certification systems, which leaves many thinking “I don’t trust all these certifications. The ‘free range chicken’ that gets an hour of daylight and is still called ‘free range’”. It’s all too easy to throw your hands in the air and claim “well, who really knows” than to inform yourself. But on the website of the Ministry of Primary Industries you can read up on organics in NZ.

It’s up to you what you want to support with your money, but I think these small decisions make a big difference. In New Zealand, organics are still a somewhat elite and often expensive product, but it doesn’t have to stay like that. Remember that supply and demand means that a higher demand from the organic sector results in its growth. In Europe, the high demand for organics resulted in more affordable organics along the entire value chain. New Zealand is already very successful in exporting high-end organic products, but we need more sustainable foods in our schools, kindergartens, universities, hospitals, and defence forces.

What about a little experiment at University of Auckland. On the UoA Sustainability Website it states that “The University of Auckland is committed to pursuing sustainability via research, teaching and learning, operating practices, partnerships and capacity building”. UoA also recently came out first in the international sustainability rankings for universities showing commitment to sustainability. Sweet, here’s my idea for an operating practice to increase sustainability at UoA:

Let’s swap the conventional milk (a brand that so many people complain about) for an organic alternative, and provide plant-based options.

(c) pexels.com

Taking a bunch of money from big corporations and investing it into farmers with a sustainable vision of agriculture, is a simple and practical step. It not only makes a big difference for the farmer themselves, who now has an entire institution backing him, but it also makes a statement: we want our food to be produced sustainably and we invest in those with the best outcomes for all levels of sustainability, economy, ecology and society!

I think it would be worth a try to buy good, quality milk, and allocate a greater portion of our budget to plant-based alternatives. The greenhouse gases emitted by producing one glass of dairy milk are about three times as high as for plant-based alternatives.

Let’s do it! Let’s make a change by investing in good (but not perfect) ideas!

ny

Julia Schmack is a PhD student at the Centre for Biodiversity & Biosecurity, School of Biological Sciences, University of Auckland. She is researching the ecology and control of social wasps, supervised by Jacqueline Beggs and Darren Ward (Landcare Research). Her PhD is funded by the Biological Heritage National Science Challenge. twitter: @julia_schmack

email: j.schmack@auckland.ac.nz

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.


The Current Status of Predators on New Zealand Offshore Islands

Posted by Zach Carter

New Zealand is committed to preserving its uniquely rich biological heritage with Predator-Free New Zealand (PFNZ). This audacious programme is focused on ridding the country of the three most biologically and economically harmful mammalian taxa by the year 2050 (Innes, Kelly, Overton, & Gillies, 2010). Pests targeted for eradication include rodents (Rattus rattus, R. norvegicus, R. exulans), mustelids (Mustela furo, M. ermine, M. nivalis) and the common brushtail possum (Trichosurus vulpecula). These mammals predate upon native biota and threaten to undermine New Zealand’s most lucrative industries, including tourism and the primary industries. There is unilateral support for PFNZ, but how close are we to actually achieving this goal on New Zealand’s offshore islands?

If we exclude large islands that are source to substantial pest populations, including Stewart Island (Rakiura) and Great Barrier Island (Aotea), and islands that cannot support mammalian life for extended periods (islands < 5 hectares, ha), 85 offshore islands (islands ≤ 50 kilometres from the mainland) currently host PFNZ mammal pests. Insofar, 87 offshore islands have been eradicated of mammals since New Zealand began systematic removals in 1980 (Figure 1). This means that over half (50.5%) of the islands with a historical pest presence have been eradicated!

Figure 1: PFNZ mammal eradications that have occurred on New Zealand offshore islands from 1980 through present.

If we investigate the total amount of island area eradicated in this dataset, we paint a slightly different picture; 84,300 ha of island area currently host mammal pests, and 24,200 ha have been eradicated. This means that only 22.3% of island area historically hosting mammals have been eradicated. Note, this dataset includes only cases of confirmed pest presence (islands with an unknown status were excluded) and excludes incursions as being considered confirmation of pest presence. Moreover, these numbers do not coincide with other eradication estimates that use different geographical boundaries or different pest species (e.g.(Towns, West, & Broome, 2013).

Admittedly, there is much work left to accomplish. This does not mean that PFNZ is impossible, though, only that it will be an uphill battle. In order to keep with the designated timeline, multiple government agencies and private groups have come together seeking creation of new (or “future”) control technologies that can address issues of ethical and technical concern. Transformative genetic control tools (including virus-vectored immunocontraception, RNA interference, and transgenic ‘Trojan’ approaches), and novel takes on current-day technology (including automated self-resetting traps, remote monitoring, and highly attractive lures) are being designed to target specific species in a manner that is cost-effective, environmentally benign, and exceeds the public conception of humaneness (Campbell et al., 2015). Such tools will be essential to the success of PFNZ. If they can be implemented in a timely manner, New Zealand will be well on its way to being the first nationwide endemic sanctuary.

Zach Carter is a PhD student at the University of Auckland in the School of Biological Sciences. He works with Dr. James Russell prioritising eradications of mammal pest species throughout New Zealand.

References

Campbell, K. J., Beek, J., Eason, C. T., Glen, A. S., Godwin, J., Gould, F., . . . Ponder, J. B. (2015). The next generation of rodent eradications: innovative technologies and tools to improve species specificity and increase their feasibility on islands. Biological Conservation, 185, 47-58.

Campbell, K. J., Beek, J., Eason, C. T., Glen, A. S., Godwin, J., Gould, F., . . . Ponder, J. B. (2015). The next generation of rodent eradications: innovative technologies and tools to improve species specificity and increase their feasibility on islands. Biological Conservation, 185, 47-58.

Innes, J., Kelly, D., Overton, J. M., & Gillies, C. (2010). Predation and other factors currently limiting New Zealand forest birds. New Zealand Journal of Ecology, 34(1), 86.

Towns, D. R., West, C., & Broome, K. (2013). Purposes, outcomes and challenges of eradicating invasive mammals from New Zealand islands: an historical perspective. Wildlife Research, 40(2), 94. 10.1071/wr12064