Konrad Lorenz Institute

Klosterneuburg, Austria

Konrad Lorenz Institute

Klosterneuburg, Austria
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Costa S.S.,ISPA University | Andrade R.,ISPA University | Carneiro L.A.,ISPA University | Goncalves E.J.,ISPA University | And 3 more authors.
Brain, Behavior and Evolution | Year: 2011

Blenniid fish exhibit a polygynandric mating system with parental care restricted to males. Nest-holder males defend a breeding territory centered on their nest, usually a crevice or hole in a rocky substrate, to which they attract females to spawn. Females, on the other hand, must search for nests in order to spawn and usually are the choosy sex, producing several sequential egg batches and broods during the breeding season. Therefore, male blennies are more site-attached than females. This situation offers an opportunity to investigate potential neural correlates of intraspecific differences in selective pressures for different spatial abilities in these species. Since the dorsolateral telencephalon has been considered a teleost homologue of the mammalian hippocampus, we predicted that the spatial abilities required for females to locate and return accurately to nests of males may have produced a sex difference in the size of the telencephalic nuclei involved in spatial abilities, biased towards females. To test this hypothesis, we assessed the home ranges and measured the size of the dorsolateral telencephalon of both sexes during the breeding season in two blenniid species, the shanny (Lipophrys pholis) and the Azorean rock-pool blenny (Parablennius parvicornis). We chose these two species because they differ in the degree of chemical communication they use, and this could also lead to differences in telencephalic areas. As predicted, in both species females present considerably larger home ranges paralleled by larger dorsolateral ventral telencephalic nuclei (DLv) than males. Other telencephalic nuclei that were measured did not show any sex difference in size. These results suggest that the DLv is involved in spatial abilities in blenniid fish and that sexual selection may be promoting this divergence as already described for mammals and birds. Copyright © 2011 S. Karger AG, Basel.


News Article | December 7, 2016
Site: www.eurekalert.org

The urine of house mice, unlike humans, contains large amounts of proteins, which are mainly major urinary proteins or MUPs. These proteins function to stabilize the release of volatile pheromones from urinary scent marks. MUP genes occur in a large cluster in mice, and there are 21 different MUP genes, whereas humans have only one MUP gene, which is no longer functional. Until now, researchers have assumed that MUP genes in wild populations of mice were highly variable, and that MUP proteins provide a unique individual signature or 'barcode' that mediates individual and kin recognition. Studies to confirm this critical assumption have nevertheless been lacking. Researchers from Vetmeduni Vienna now analysed the MUP genes in the respective cluster as well as the proteins. Their findings directly challenge the MUP barcode hypothesis. "We are interested in the genetic bases of chemical communication and kin recognition. We have been focusing on MUPs because they have are often claimed to provide the genetic basis of kin recognition and inbreeding avoidance, explains Dustin Penn from Konrad Lorenz Institute of Ethology at Vetmeduni Vienna. The barcode hypothesis presumes that MUP genes and proteins are highly variable in wild populations, and that individuals produce their own unique and stable combination of MUP proteins. Penn's team and proteomic specialists at Vetmeduni Vienna now provide evidence that directly challenge this hypothesis for the first time. The team started by analysing the MUP gene cluster of wild house mice by direct DNA sequencing. Rather than finding highly variable sequences, they discovered that individuals show no variation at MUP genes whatsoever. Moreover, they found unusually low genetic variation through the entire MUP cluster. "We initially wondered how natural selection could maintain high levels of variation of MUP genes, but now we have to explain the remarkable lack of variation. Because of the high sequence similarity or homology of different MUP genes, we were sceptical that they could simultaneously show high variability among individuals", says Penn. The team additionally discovered that conventional gel-based techniques do not separate different MUP proteins, which posed a difficult technical challenge for measuring the regulation of different proteins. Proteins had to be analysed with new, state-of-the-art mass spectroscopy instead. Using this gel-free method they found that individuals show almost no variation in the number of MUP proteins expressed. The assumption that MUPs provide a stable individual barcode was also refuted by Penn and his collaborators. The new proteomic methods made it possible to identify the different MUPs expressed in individual urine samples over time. "Our results show that mice change the MUPs they produce depending upon a social context. The number of MUPs in the urine of male house mice is surprisingly dynamic. Future experiments are now needed to determine genetic basis for kin recognition and why males differentially regulate MUPs depending upon the social and reproductive contexts", says Penn. The article "Diversity of major urinary proteins (MUPs) in wild house mice" by Michaela Thoß, Viktoria Enk, Hans Yu, Ingrid Miller, Kenneth C. Luzynski, Boglarka Balint, Steve Smith, Ebrahim Razzazi-Fazeli and Dustin J. Penn was published in Scientific Reports. http://www. The article "Regulation of highly homologous major urinary proteins in house mice quantified with label-free methods" by Michaela Thoß, Christian Baumann, Kenneth C. Luzynski, Ebrahim Razzazi-Fazeli and Dustin J. Penn was published in Molecular Biosystems. http://pubs. The University of Veterinary Medicine, Vienna in Austria is one of the leading academic and research institutions in the field of Veterinary Sciences in Europe. About 1,300 employees and 2,300 students work on the campus in the north of Vienna which also houses five university clinics and various research sites. Outside of Vienna the university operates Teaching and Research Farms. http://www.


News Article | November 22, 2016
Site: www.eurekalert.org

Birds share their nests with a rich community of other inhabitants like parasites and mainly invertebrates, such as insects, that are attracted to the nest because of the stable climatic conditions for their larvae as well as the rich supply of food. With the exception of parasites, no study to date has examined the role of insects in this community. As they use faeces and food remains as a source of food, their presence could have a positive effect on the development of nestlings among birds like the European bee-eater (Merops apiaster), which completely lack any nest sanitation behaviour. The richly coloured bee-eaters practice absolutely no nest sanitation. The birds dig small nesting tunnels in steep banks or cliffs with a nest chamber at the end. From egg-laying to fledging of the offspring, a considerable amount of food remains, faeces and skin particles accumulate on the chamber floor. The birds do not remove these residues themselves, which could threaten the health of the offspring, the so-called nestlings. "Faces and food remains may stimulate the production of gases that change the composition of the air in the nesting cave. This could result in an increased risk of illness and weaker young," explains study director Herbert Hoi from the Vetmeduni Vienna's Konrad Lorenz Institute of Ethology. Using Fannia spp. fly larvae, he examined whether the waste-foraging co-inhabitants of bee-eater nests contribute to nest sanitation with a positive effect on nestling development. Fannia spp. fly larvae are present in great numbers, undetected by the birds, on the floor of the bee-eater's nest chamber. For their experiment, Hoi and his team added additional larvae to the nesting cave of one group of European bee-eaters and reduced the number of larvae in another. Two further groups served as control groups for how nestlings develop without any change in larvae numbers. Soil samples were taken from the floor of the nests and the nestlings were examined at regular intervals and at the end of the experiment. The team documented important developmental indicators such as weight and size, searched for signs of inflammation and compared the oxygen saturation of the blood. The analysis of these parameters confirmed a positive effect from the presence of the "waste removers". The presence of more fly larvae correlated to heavier and larger nestlings in comparison to the control groups. A lower number of larvae in the nest had a negative effect on nestling development. These were comparatively smaller and weighed less than all other nestlings. The oxygen saturation and inflammation values were nearly the same for all groups. The experiment with the fly larvae clearly showed that at least some nest inhabitants represent a benefit for the birds. Birds like the bee-eater, which lack any sanitation behaviour, benefit from the presence of insect larvae that clean the nest well enough to allow the offspring to develop normally. Hoi sees the positive role of the fly larvae as an example of a functioning community among the inhabitants of bird nests. "Many birds do not practice nest sanitation behaviour. This may also have to do with the fact that they do not want to call the attention of predators to the nest through the presence of waste," the researcher explains. "But if the insect larvae didn't take care of the waste, this would be a great disadvantage for the health of the nestlings." More than 100 animal species have been found living in the nests of bee-eaters. Hoi wants to use such nest communities for future research. "They present a perfect model for small ecosystems." The article „Housekeeping by lodgers: the importance of bird nest fauna on offspring condition" by Jan Kristof?k, Alzbeta Darolova, Christine Hoi and Herbert Hoi was published in Journal of Ornithology. http://link. The University of Veterinary Medicine, Vienna in Austria is one of the leading academic and research institutions in the field of Veterinary Sciences in Europe. About 1,300 employees and 2,300 students work on the campus in the north of Vienna which also houses five university clinics and various research sites. Outside of Vienna the university operates Teaching and Research Farms. http://www.


News Article | December 7, 2016
Site: phys.org

Until now, researchers have assumed that MUP genes in wild populations of mice were highly variable, and that MUP proteins provide a unique individual signature or 'barcode' that mediates individual and kin recognition. Studies to confirm this critical assumption have nevertheless been lacking. Researchers from Vetmeduni Vienna now analysed the MUP genes in the respective cluster as well as the proteins. Their findings directly challenge the MUP barcode hypothesis. "We are interested in the genetic bases of chemical communication and kin recognition. We have been focusing on MUPs because they have are often claimed to provide the genetic basis of kin recognition and inbreeding avoidance, explains Dustin Penn from Konrad Lorenz Institute of Ethology at Vetmeduni Vienna. The barcode hypothesis presumes that MUP genes and proteins are highly variable in wild populations, and that individuals produce their own unique and stable combination of MUP proteins. Penn's team and proteomic specialists at Vetmeduni Vienna now provide evidence that directly challenge this hypothesis for the first time. Kin recognition must be controlled by other mechanisms The team started by analysing the MUP gene cluster of wild house mice by direct DNA sequencing. Rather than finding highly variable sequences, they discovered that individuals show no variation at MUP genes whatsoever. Moreover, they found unusually low genetic variation through the entire MUP cluster. "We initially wondered how natural selection could maintain high levels of variation of MUP genes, but now we have to explain the remarkable lack of variation. Because of the high sequence similarity or homology of different MUP genes, we were sceptical that they could simultaneously show high variability among individuals," says Penn. The team additionally discovered that conventional gel-based techniques do not separate different MUP proteins, which posed a difficult technical challenge for measuring the regulation of different proteins. Proteins had to be analysed with new, state-of-the-art mass spectroscopy instead. Using this gel-free method they found that individuals show almost no variation in the number of MUP proteins expressed. The assumption that MUPs provide a stable individual barcode was also refuted by Penn and his collaborators. The new proteomic methods made it possible to identify the different MUPs expressed in individual urine samples over time. "Our results show that mice change the MUPs they produce depending upon a social context. The number of MUPs in the urine of male house mice is surprisingly dynamic. Future experiments are now needed to determine genetic basis for kin recognition and why males differentially regulate MUPs depending upon the social and reproductive contexts," says Penn. Explore further: Female mice can identify inbred males by their scent More information: Michaela Thoß et al. Diversity of major urinary proteins (MUPs) in wild house mice, Scientific Reports (2016). DOI: 10.1038/srep38378 Viktoria M. Enk et al. Regulation of highly homologous major urinary proteins in house mice quantified with label-free proteomic methods, Mol. BioSyst. (2016). DOI: 10.1039/C6MB00278A


(Phys.org)—A trio of researchers, two with Stockholm University, the other with the Konrad Lorenz Institute of Ethology in Austria, has found via experiments they conducted with guppies, that larger brain size in an organism may lead to a weaker immune system. In their paper published in Proceedings of the Royal Society B, Alexander Kotrschal, Niclas Kolm and Dustin Penn describe their experiments and results and why they believe other similar studies may one day prove that larger brained animals tend to have weaker immune systems than do those with smaller brains. Scientists have suspected for some time that larger brained animals pay for their larger brains by having to survive with reductions in other organs—animals are capable of supporting only so many energy consuming organs based on how much they eat, their metabolism, etc.—thus, tradeoffs must be made. Prior research has shown, for example, that big brained primates, including humans, tend to have relatively small guts. In this new effort, the researchers wanted to know if a larger brain might also mean a less robust immune system compared to smaller brained animals. To learn more, they conducted experiments with Trindadian guppies that had been artificially selected for large or small brain size. Each fish had scales from another guppy grafted onto its body—the degree of rejection response by the individual fish over a period of eight days would be a measure of an innate immune response. As expected, the researchers found that those fish that had larger brains tended to exert a less ardent rejection response than did those with smaller brains. Interestingly, the same fish were given a second set of scale grafts two weeks later, but this time around the response was identical for both groups, which suggested that the larger brain did not impact an adaptive immune response. The researchers note that while the study indicates that larger brains do tend to mean weaker immune systems, nature has found a way to make up the difference—with humans for example, our large brain has meant more intelligence which has allowed us to modify our environment to make us less susceptible to infections and to use natural and artificial remedies to treat illnesses. Explore further: Big-brained birds survive better in nature More information: Alexander Kotrschal et al. Selection for brain size impairs innate, but not adaptive immune responses, Proceedings of the Royal Society B: Biological Sciences (2016). DOI: 10.1098/rspb.2015.2857 Abstract Both the brain and the immune system are energetically demanding organs, and when natural selection favours increased investment into one, then the size or performance of the other should be reduced. While comparative analyses have attempted to test this potential evolutionary trade-off, the results remain inconclusive. To test this hypothesis, we compared the tissue graft rejection (an assay for measuring innate and acquired immune responses) in guppies (Poecilia reticulata) artificially selected for large and small relative brain size. Individual scales were transplanted between pairs of fish, creating reciprocal allografts, and the rejection reaction was scored over 8 days (before acquired immunity develops). Acquired immune responses were tested two weeks later, when the same pairs of fish received a second set of allografts and were scored again. Compared with large-brained animals, small-brained animals of both sexes mounted a significantly stronger rejection response to the first allograft. The rejection response to the second set of allografts did not differ between large- and small-brained fish. Our results show that selection for large brain size reduced innate immune responses to an allograft, which supports the hypothesis that there is a selective trade-off between investing into brain size and innate immunity.


Archetti M.,Harvard University | Scheuring I.,A.P.S. University | Scheuring I.,Konrad Lorenz Institute
Evolution | Year: 2011

The production of public goods by the contribution of individual volunteers is a social dilemma because an individual that does not volunteer can benefit from the public good produced by the contributions of others. Therefore it is generally believed that public goods can be produced only in the presence of repeated interactions (which allow reciprocation, reputation effects and punishment) or relatedness (kin selection). Cooperation, however, often occurs in the absence of iterations and relatedness. We show that when the production of a public good is a Volunteer's Dilemma, in which a fixed number of cooperators is necessary to produce the public good, cooperators and defectors persist in a mixed equilibrium, without iterations and without relatedness. This mixed equilibrium is absent in the N-person Prisoner's Dilemma, in which the public good is a linear function of the individual contributions. We also show that the Prisoner's Dilemma and the Volunteer's Dilemma are the two opposite extremes of a general public goods game, and that all intermediate cases can have a mixed equilibrium like the Volunteer's Dilemma. The coexistence of cooperators and defectors, therefore, is a typical outcome of most social dilemmas, which requires neither relatedness nor iterations. © 2010 The Author(s). Evolution© 2010 The Society for the Study of Evolution.


Dvorak M.,BirdLife Austria | Fessl B.,Charles Darwin Foundation | Nemeth E.,Konrad Lorenz Institute | Nemeth E.,Max Planck Institute for Ornithology (Seewiesen) | And 2 more authors.
ORYX | Year: 2012

Population monitoring is a vital tool for conservation management and for testing hypotheses about population trends in changing environments. Darwin's finches on Santa Cruz Island in the Galápagos archipelago have experienced habitat alteration because of human activity, introduced predators, parasites and disease. We used point counts to conduct systematic quantitative surveys of Darwin's finches and other land birds between 1997 and 2010. The temporal analysis revealed that six of the nine species investigated declined significantly and that this decline was most pronounced at higher elevations in humid native forest and agricultural areas; the highland areas have been most affected by introduced species or direct human impact. Five of the six declining species are insectivorous, which suggests that changes in insect abundance or insect availability are a critical factor in the declines. Further study is required to test this idea. Other factors including habitat alteration and introduced parasites or pathogens may be contributing to the observed declines. © 2012 Fauna & Flora Internationa.


Nemeth E.,Max Planck Institute for Ornithology (Seewiesen) | Nemeth E.,Konrad Lorenz Institute | Brumm H.,Max Planck Institute for Ornithology (Seewiesen)
American Naturalist | Year: 2010

In cities with intense low-frequency traffic noise, birds have been observed to sing louder and at a higher pitch. Several studies argue that higher song pitch is an adaptation to reduce masking from noise, and it has even been suggested that the song divergence between urban and nonurban songs might lead to reproductive isolation. Here we present models of signal transmission to compare the benefits of raised song amplitude and song pitch in terms of sound transmission. We chose two bird species that sing with higher pitch in urban areas, the great tit (Parus major) and the blackbird (Turdus merula). For both species, we calculated communication distances in response to different levels of urban noise and in their natural forest habitats. We found that an increase in vocal pitch increased communication distance only marginally. In contrast, vocal amplitude adjustments had a strong and significantly larger effect. Our results indicate that frequency changes of urban songs are not very effective in mitigating masking from traffic noise. Increased song pitch might not be an adaptation to reduce signal masking but a physiological side effect of singing at high amplitudes or an epiphenomenon of urbanization that is not related to signal transmission. © 2010 by The University of Chicago.


Scheuring I.,Hungarian Academy of Sciences | Scheuring I.,Konrad Lorenz Institute
BioSystems | Year: 2010

Evolution of cooperative norms is studied in a population where individual and group level selection are both in operation. Individuals play indirect reciprocity game within their group and follow second order norms. Individuals are norm-followers, and imitate their successful group mates. Aside from direct observation individuals can be informed about the previous actions and reputations by information transferred by others. A potential donor estimates the reputation of a potential receiver either by her own observation or by the opinion of the majority of others (indirect observation). Following a previous study (Scheuring, 2009) we assume that norms determine only the probabilities of actions, and mutants can differ in these probabilities. Similarly, we assume that individuals follow a stochastic information transfer strategy. The central question is whether cooperative norm and honest social information transfer can emerge in a population where initially only non-cooperative norms were present, and the transferred information was not sufficiently honest. It is shown that evolution can lead to a cooperative state where information transferred in a reliable manner, where generous cooperative strategies are dominant. This cooperative state emerges along a sharp transition of norms. We studied the characteristics of actions and strategies in this transition by classifying the stochastic norms, and found that a series of more and more judging strategies invade each other before the stabilization of the so-called generous judging strategy. Numerical experiments on the coevolution of social parameters (e.g. probability of direct observation and the number of indirect observers) reveal that it is advantageous to lean on indirect observation even if information transfer is much noisier than for direct observation, which is because to follow the majorities' opinion suppresses information noise meaningfully. © 2010 Elsevier Ireland Ltd.


Morin O.,Konrad Lorenz Institute
Behavioral and Brain Sciences | Year: 2016

I argue that demographic selection migration and cultural diffusion three mechanisms of institutional change have little in common. Two of these lack the key features associated with group selection: they do not present us with group-level selection pressures counteracting individual-level ones need not produce behavioral altruism and do not require competition between groups whose members cooperate preferentially with one another. Cultural norms vary change and influence cooperation; but that is not group selection. © Cambridge University Press 2016.

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