Behavioural Ecology

A new research collaboration between Hydrophis Gas and researchers in our School of Life Sciences began in September 2019.

The project, worth £350,000 to ARU over three years, is funded by Hydrophis Gas – a UK based R&D start-up company carrying out biomimicry research in order to design and commercialise innovative technologies for carbon sequestration.

The research team, consisting of Dr Bas Boots, Dr Dannielle Green, Dr Jacob Dunn and Prof Chris Parris, will be working with the Hydrophis Gas team to develop new technologies inspired by sea snake respiration. The aim of the project is to design carbon-negative technologies, including radically new gas filters to sequester CO2 from marine environments. This will provide significant advances in the design of technologies for reducing ocean acidification and improving carbon sequestration.

Scientists have discovered that the larynx, or voice box, of primates is significantly larger relative to body size, has greater variation, and is under faster rates of evolution than in other mammals.

Published in the journal PLOS Biology and led by academics from ARU, Stanford University, and the University of Vienna, the research is the first large-scale study into the evolution of the larynx.

The larynx has three main functions: protecting the airway during feeding, regulating the supply of air to the lungs, and vocal communication. Because of its important role in facilitating social behaviour, through vocalisation, the larynx was thought to be a key area of evolution, particularly in species with highly developed vocal communication systems.

The researchers made CT-scans of specimens from 55 different species, and produced 3D computer models of their larynges. These were studied alongside detailed measurements, including body length and body mass.

The primates ranged in size from a pygmy marmoset (Cebuella pygmaea) weighing just 110g, to a Western gorilla (Gorilla gorilla) weighing approximately 120kg. The carnivorans spanned from a 280g common dwarf mongoose (Helogale parvula) to a 180kg tiger (Panthera tigris).

The study found that, for a given body length, primate larynges are on average 38% larger than those of carnivorans, and that the rate of larynx evolution is faster in these species.

There is also more variation in larynx size relative to body size among primates, indicating that primates have greater flexibility to evolve in different ways. Carnivorans follow more of a fixed larynx-size to body-size ratio.

Larynx size was also found to be a good predictor of the call frequency of a species, which demonstrates the relevance of the observed size variations for vocal communication.

Co-lead author Dr Jacob Dunn, Reader in Evolutionary Biology at ARU, said: "This study has demonstrated clear differences in the evolution of the larynx between groups of mammals."

"Specifically, we have shown for the first time that the primate larynx is larger, less closely linked to body size, and under faster rates of evolution than the carnivoran larynx – a well-matched comparison group – indicating fundamental differences in the evolution of the vocal organ across species."

Co-lead author Dr Daniel Bowling, Instructor in Psychiatry and Behavioral Sciences at Stanford University added: "Our study also shows that differences in larynx size predict changes in voice pitch, highlighting the larynx’s crucial role in vocal communication. This is demonstrated by the rich and varied calls produced by many primate species."

"The results imply fundamental differences between primates and carnivorans in the forces constraining larynx size, as well as highlighting an evolutionary flexibility in primates that may help explain why they have developed complex and diverse uses of the vocal organ for communication. This provides an exciting avenue for future studies examining variation among other mammalian groups."

PhD student Fiene Steinbrecher raised $4500 for her research project 'How does noise affect captive pied tamarins?'

The pied tamarin is a very sensitive and critically endangered primate species. With only a small population left in the wild, maintaining a healthy captive population is a vital conservation strategy. However, in captivity pied tamarins tend to struggle more than other species of tamarin, and this can lead to health problems.

Why is this? Fiene's study will focus on the different noises they experience in captive environments and investigate if and how sounds affect them. Find out more about Fiene's project.

Camilla Hinde recently won £8000 from the Association for the Study of Animal Behaviour. The research project will investigate the influence of environmental conditions on negotiation over parental care.

Dr Jacob Dunn, alongside collaborators from the University of Cambridge, recently won a grant from the Cambridge Language Sciences Network & Issac Newton Trust. The project is titled 'The evolution of speech: insight from variation in primate laryngeal anatomy’'.

Dr Tom O'Mahoney recently went on a staff Erasmus exchange to Amsterdam Medical University, where he will be setting up long-term collaborative projects with the anatomy section, looking at developmental anatomy.

Dr Jacob Dunn, Director of the Behavioural Ecology Research Group and a Senior Lecturer in the School of Life Sciences, recently won a £10K research grant.

Jacob’s research is focused on animal vocal communication and its relevance for our understanding of the evolution of human language. His work is multi-disciplinary, and ranges from detailed anatomical and physiological investigation of vocal production to understanding the evolutionary processes that shape communication across species.

Jacob has recently taken on the curation of a large historical collection of mammalian larynges, called the Harrison Collection. This unique collection, dating from the 1970s, includes over 500 larynges from an incredibly wide range of mammalian species, and offers the opportunity to investigate the origin, development and mechanism of this unique and fascinating organ.

Jacob recently won a £10K research grant from the Rhinology and Laryngology Research Fund so that the collection can be modernised and maintained for research. The grant will also provide funds to start digitising the larynges to create 3D virtual models, allowing the collection to be shared openly, and modern morphometric analyses to be carried out. These analyses will allow us to better understand the evolutionary pressures that lead to variation in vocal communication among species, and, ultimately, provide insight into the reasons why humans evolved the incredible ability to articulate speech.

This article originally appeared in the June 2019 issue of 'First', our Faculty Research Newsletter.

Dr Jacob Dunn, Senior Lecturer in our Department of Biology and Director of the Behavioural Ecology Research Group, won a £20K research grant from the Royal Society for a project on the evolution of speech.

The project, entitled ‘The evolution of speech: insight from variation in primate laryngeal anatomy’, forms part of Jacob’s research that’s focused on primate vocal communication and its relevance for our understanding of the evolution of human language. His work is multi-disciplinary, and ranges from detailed anatomical and physiological investigation of vocal production, to understanding the evolutionary processes that shape communication across species.

He conducts and supervises theoretical, observational and experimental studies on a wide range of species, which take place in the lab, in museum collections, in captivity and in the field. His research is highly collaborative and includes close links with researchers in the USA, Austria, Japan, and the UK.

The award will allow Jacob to travel to Japan and Austria in order to carry out anatomical investigation of primate museum collections. He will use CT and MRI scanning, as well as traditional dissection techniques to learn more about the structure and function of the larynx. These analyses will allow us to better understand the evolutionary pressures that lead to variation in vocal communication among species and, ultimately, gain insight into the reasons why humans evolved the incredible ability to articulate speech.

This article originally appeared in the April 2018 issue of 'First', our Faculty Research Newsletter.

Together with Dr Claudia Wascher from the Department of Biology, Dr Didone Frigerio and her team from the Konrad Lorenz Research Station (KLF) presented a session ‘Citizens as Behavioural Biologists?’ at the Cambridge Science Festival in March.

At the KLF in Austria, long-term behavioural research is conducted on different avian model organisms, such as greylag geese, Northern bald ibis and common ravens. In an on-going project ‘GRASS - Greylag geese as a model for animal social systems’, pupils from local schools visit the research station and collect data on spatial and temporal distribution patterns of the greylag geese.

A number of pupils from the Körner Gymansium in Linz joined the researchers from the KLF and presented their work at the Cambridge Science festival. In five interactive workstations, visitors could learn about the history of KLF, how to individually identify greylag geese with the help of coloured leg bands, differentiate between different behaviours and how to record behaviour of greylag geese with the help of an online app.

Finally, the pupils presented the scientific results of their project. The event was visited by more than 100 people from all age groups.

This article originally appeared in the April 2018 issue of 'First', our Faculty Research Newsletter.

Dr Claudia Wascher is leading a new study into the relationships of greylag geese with results suggesting potential health effects following mate loss or social isolation.

Greylag geese are highly social animals and within their flock form strong relationships with their pair-partner and family members. These bonds are important and help individuals to cope with social stress. Agonistic encounters with other flock members are amongst the strongest stressors in greylag geese, as confirmed by heart rate measurements. Greylag geese at resting have a heart rate of about 100 beats per minute, but during aggressive encounters this can increase to nearer 500 beats per minute, illustrating how stressful these events are for those involved.

A strong social embedding helps individuals cope with social stress. The unpaired males exhibit a higher increase in heart rate during agonistic encounters compared to paired males. However, a short term increase in heart rate may be beneficial for unpaired males, as it activates the energy to cope with an aggressive interaction and potentially win, and may not have any long-term costs.

In a recent experiment Claudia aimed to investigate potential health benefits of having a social partner.

Claudia explains:

Claudia’s results suggest relatively swift potential health effects of mate loss and social isolation in free-living geese.

This article originally appeared in the August 2017 issue of 'First', our Faculty Research Newsletter.