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Great interest in article about the "Handicap principle" in Biological Reviews

Research by Dustin Penn that was published in Biological Reviews has become one of the journal´s top 10 most downloaded papers.  The article "The Handicap Principle: How an Erroneous Hypothesis Became a Scientific Principle" by Dustin Penn from the Konrad Lorenz Institute of Ethology, University of Veterinary Medicine Vienna and Szabolcs Számadó from the Department of Sociology and Communication, Budapest University of Technology and Economics, addresses the so-called "Handicap Principle". This idea, proposed by Amotz Zahavi in 1975, is the most widely cited explanation for the evolution of reliable signals. It proposes that signals are honest because they are costly to produce and therefore cannot be faked. Zahavi´s hypothesis assumes that signals are wasteful as well as costly, and that they evolve because wastefulness enforces honesty. Penn and Számadó explain why this idea is erroneous and how it has nevertheless become a widely accepted explanation for honest signalling.

In 1990, Alan Grafen published models that he claimed vindicated Zahavi's Handicap Principle. His conclusions were widely accepted and the Handicap Principle subsequently became the dominant paradigm for explaining the evolution of honest signalling in the biological and social sciences. Penn and Számadó now show that Grafen's models do not support the handicap hypothesis, although they do support another hypothesis that Zahavi proposed, which argues that males adjust their investment into the expression of their sexual signals according to their condition and ability to bear the costs and risks to their survival. This idea is actually very different from the handicap hypothesis, but it has been widely misinterpreted and equated to the Handicap Principle. Theoretical studies have since shown that signalling costs per se are irrelevant to selective maintance of signal honesty, and that honesty can evolve through differential benefits, as well as differential costs. There have been some previous criticisms of the Handicap Principle, but they merely focused on the limitations of Grafen's model and overlooked the fact that it is not a handicap model. According to Penn and Számadó this model is better understood within a Darwinian framework of adaptive signalling trade-offs, without the added burden and confusing logic of the Handicap Principle. There is no theoretical or empirical support for the Handicap Principle and the time is long overdue to usher this idea into an ‘honorable retirement’.

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BootSnap – New machine learning tool for classifying vocalizations of mice

House mice and many other animal species use ultrasonic vocalisations to communicate in various contexts including social and sexual interactions. These vocalisations are increasingly investigated in research on animal communication and for studying the genetic basis of autism and speech disorders. Researchers at the University of Veterinary Medicine Vienna have now developed a new and improved method for classifying ultrasonic vocalisations.

As ultrasonic vocalizations (USVs) are above the range of human hearing (>20 kHz) and manual methods for analysing these vocalizations are extremely time consuming, several automated methods have been developed for USV detection and classification. In a study led by the Konrad Lorenz Institute of Ethology at the University of Veterinary Medicine Vienna, in collaboration with the Acoustics Research Institute, Austrian Academy of Science, researchers have now evaluated the advantages and disadvantages of the available analysis tools.

In addtion to evaluating detection tools, the researchers developed a new method for classifying USVs, which they call "BootSnap". The lead author, Reyhaneh Abbasi from the Konrad Lorenz Institute of Ethology at the University of Veterinary Medicine Vienna explains, “To improve USV classification, we developed an ensemble machine learning algorithm, which provides better performance than a single learning algorithm alone, and it allows us to successfully classify vocalisations into twelve types.” The researchers also tested the performance of their new method, and show that it provides greater generalisability than the current state-of-the-art tool. BootSnap is available free of charge for scientific use.

The article “Capturing the songs of mice with an improved detection and classification method for ultrasonic vocalizations (BootSnap)” by Reyhaneh Abbasi, Peter Balazs, Maria Adelaide Marconi, Doris Nicolakis, Sarah M. Zala and Dustin J. Penn was published in PLoS Computational Biology.

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Vetmeduni press release


A lot going on at the Vetmeduni Open House day

On Saturday, May 21st after a Corona-related break, the open house of the University of Veterinary Medicine Vienna finally took place again. Researchers and veterinarians presented the topics of their work to a broad public with a variety of demonstration and hands-on stations. Our department was also represented again and aroused great interest among the visitors.

A total of 2,700 people visited the Vetmeduni campus and found out about the diverse tasks and opportunities at our university.

The open day was therefore again an important contribution to our mission to carry the knowledge gained through our research beyond teaching into society.

Event page



Technology meets nature: 2nd Mallnitz Days

Innovations in wildlife monitoring were the focus of the 2nd Mallnitz Days on May 13th, which emerged in 2019 from the cooperation between the University of Veterinary Medicine Vienna, the state of Carinthia and the Hohe Tauern National Park.*

New technologies open up numerous possibilities for observing changes in ecosystems and have become indispensable in the field of nature conservation. The options in wildlife monitoring go far beyond the well-known GPS collar. Experts from Vienna and Carinthia informed the participants of the 2nd Mallnitz Days current high-tech methods for wildlife monitoring and about the practical use and effects of the technologies used.

LH Peter Kaiser: "I am pleased that high-tech innovations can add value to nature conservation in the Hohe Tauern National Park. In this way it is possible to observe animals and nature in relation to the occurring climate change in the best possible way and to react to it with the necessary measures."

Many interesting topics were presented, including a new research project on the Heiligenblut chamois, an update on the population development of owls and birds of prey in Austria, exciting information on the development of the native bird world, the topic of drones, climate change and health: future topics in the field of wildlife monitoring, as well as the role of genetics in the monitoring of wildlife populations. Equally important was information on the health monitoring of wild animals with demonstration at the show table, and the use of radio transmitters through to satellite technology: modern methods of wildlife telemetry.

Otto Doblhoff-Dier, Vice Rector for Research and International Relations at the University of Veterinary Medicine, Vienna: "I am very pleased that the Mallnitz Days could take place again this year after a break due to corona: They are an important building block in our VetmedRegio initiative, in which we make the expertise of our university available to all interested parties throughout Austria.”

*Press release Hohe Tauern National Park, May 13, 2022

Vetmeduni press release


Valuable habitats: birds are real railway fans

Even abandoned and unused, railways clearly beat roadways in environmental terms, as demonstrated by a Polish team, under the lead of Marcin Tobolka, who is now visiting scientist at Vetmeduni. The study, funded by National Science Centre (Poland) has been recently published in Agriculture, Ecosystems and Environment. The study examined abandoned railway lines with regard to their quality as a habitat for birds. Unused railway tracks make an attractive habitat for birds, offering a variety of opportunities and considerable biodiversity. The abandoned infrastructure is of great relevance especially where birds are displaced from their traditional habitats due to agricultural intensification.

Over a study period of a year the two researchers compared three different habitat types – unused railway lines, dirt road verges and fields – in terms of bird abundance and species diversity. The scientists recorded a total of 9,678 individual birds from 99 bird species, counting 4,614 individuals from 80 species along unused railway lines, 3,124 individuals from 73 species along dirt roads in farming areas, and 1,940 individuals from 60 species in agricultural fields.

As these types of structures have a high potential as alternative habitats and are beneficial for nature conservation, they should be considered in landscape planning programmes. Unused railway lines may be used among several tools to mitigate biodiversity loss in farmland, which is also one of the goals of the European Union’s Common Agricultural Policy, as the study authors point out.

The article "Unused railway lines as a contributor to bird abundance, species richness and diversity in intensively managed farmland“ by Łukasz Dylewski and Marcin Tobolka was published in „Agriculture, Ecosystems and Environment".

Die study was supported by the National Science Center (Poland); Project 2016/21/N/NZ8/01289

Scientific article

Vetmeduni press release


Weather conditions determine the life of hoopoe chicks

There is surprisingly little scientific information on the behaviour of birds with their young in the nest. A current international study led by Herbert Hoi from the Konrad Lorenz Institute of Ethology at the University of Veterinary Medicine, Vienna, now shows that the influence of the weather is a determining factor that affects aspects such as breeding performance, food supply, but also nest use.

The study used hoopoe chicks (Upupa epops) to investigate the influence of different weather conditions on breeding performance, food supply and use of nest space. Study author Herbert Hoi says: "In particular, the place where the parents hand over the food and the size of the prey can lead to different use of the nest space by the nestlings. Parental feeding strategy and prey size are, in turn, influenced by weather conditions, which are the most important determinants of nest interior use by chicks.” The study also provides important new insights into communication between parents and their offspring.

Chicks supplied with large prey were more likely to remain hidden in a more distant nest area, whatever the weather. The prey is the most important factor directly influencing the use of nest space, which indicates a crucial role of large insects for the hoopoe. In addition, it was shown that long-term effects of the weather influence the entire food supply of the chicks and thus their behaviour. It is therefore to be expected that climate changes will have consequences for the population of the hoopoe.

According to the research team, the findings are also of great relevance for nature conservation and provide new insights into the theoretical basis of habitat selection.

The article „Influence of different weather aspects on breeding performance, food supply and nest‑space use in hoopoe offspring“ by Soňa Nuhlíčková, Ján Svetlík, Manfred Eckenfellner, Felix Knauer, and Herbert Hoi was published in „Behavioral Ecology and Sociobiology“.


Scientific paper

Vetmeduni Press release