Konrad Lorenz Institute for Ethology

Vienna, Austria

Konrad Lorenz Institute for Ethology

Vienna, Austria
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Olbermann P.,Institute for Medical Microbiology and Hospital Epidemiology | Olbermann P.,University of Würzburg | Josenhans C.,Institute for Medical Microbiology and Hospital Epidemiology | Moodley Y.,Max Planck Institute for Infection Biology | And 9 more authors.
PLoS Genetics | Year: 2010

The Helicobacter pylori cag pathogenicity island (cagPAI) encodes a type IV secretion system. Humans infected with cagPAI-carrying H. pylori are at increased risk for sequelae such as gastric cancer. Housekeeping genes in H. pylori show considerable genetic diversity; but the diversity of virulence factors such as the cagPAI, which transports the bacterial oncogene CagA into host cells, has not been systematically investigated. Here we compared the complete cagPAI sequences for 38 representative isolates from all known H. pylori biogeographic populations. Their gene content and gene order were highly conserved. The phylogeny of most cagPAI genes was similar to that of housekeeping genes, indicating that the cagPAI was probably acquired only once by H. pylori, and its genetic diversity reflects the isolation by distance that has shaped this bacterial species since modern humans migrated out of Africa. Most isolates induced IL-8 release in gastric epithelial cells, indicating that the function of the Cag secretion system has been conserved despite some genetic rearrangements. More than one third of cagPAI genes, in particular those encoding cell-surface exposed proteins, showed signatures of diversifying (Darwinian) selection at more than 5% of codons. Several unknown gene products predicted to be under Darwinian selection are also likely to be secreted proteins (e.g. HP0522, HP0535). One of these, HP0535, is predicted to code for either a new secreted candidate effector protein or a protein which interacts with CagA because it contains two genetic lineages, similar to cagA. Our study provides a resource that can guide future research on the biological roles and host interactions of cagPAI proteins, including several whose function is still unknown.© 2010 Olbermann et al.

Griggio M.,Konrad Lorenz Institute for Ethology | Serra L.,European Commission - Joint Research Center Ispra | Pilastro A.,University of Padua
Italian Journal of Zoology | Year: 2011

Colourful feathers are important traits in female mate choice in birds because the colour properties of the feathers are often correlated with individual condition during moult. Feather colour can change after moult, and dirt accumulation has been suggested to contribute to this variation. However, we still know little about the influence of dirt on feather colour change, possibly because it is difficult to experimentally manipulate the level of feather dirtiness. We investigated whether reflectance properties of feathers exposed to naturally deposited soil (atmospheric particle deposition such as dust, pollution and smoke) differ from feathers for which this contact was prevented. To achieve this, we compared the spectral colour of throat-breast feathers of European starling, Sturnus vulgaris, kept in the open air (dirty group) with those preserved within a plastic envelope (clean group). Before treatment and three and six weeks after the beginning of the treatment we measured the plumage reflectance of the two groups of feathers. While clean feathers did not change their reflectance spectra, the dirty group showed a reduced reflectance along the entire spectrum (300-700 nm). The reduction in reflectance was particularly pronounced in the UV range (300-400 nm). These preliminary results are consistent with the idea that feather colours are not static signals but are plastic traits. However, much work remains to determine the role of soil and air pollution in altering plumage colouration. © 2011 Unione Zoologica Italiana.

Griggio M.,Konrad Lorenz Institute for Ethology | Hoi H.,Konrad Lorenz Institute for Ethology | Pilastro A.,University of Padua
Behavioural Processes | Year: 2010

Elaborate or colourful feathers are important traits in female-mate choice in birds but little attention has been given to the potential costs of maintaining these traits in good condition via preening behaviour. While preening is known to be an important component of plumage maintenance, it has received little attention with respect to colouration. We investigated whether preening can influence plumage reflectance and whether females show a preference for plumage cleanliness in captive-bred, wild-type budgerigars, Melopsittacus undulatus. To do this, we compared the spectral colour of birds that were allowed to preen their plumage and individuals that were prevented from preening. The plumage of birds that were prevented from preening showed a significant lower reflectance in the UV range (300-400. nm). Subsequently, we measured females' preferences for preened and unpreened males using a two-choice test. In a second experiment we allowed females to choose between an unpreened male and a male smeared with UV-absorbing chemicals (UV-blocked male). The proportion of time that females stayed near preened males was statistically higher than for unpreened males, but females spent similar amounts of time with unpreened males and UV-blocked males. These results are consistent with the idea that female budgerigars are able to discriminate between preened and unpreened males, and that UV colours, mediated by preening, can convey information about a bird's current condition. © 2010 Elsevier B.V.

Auersperg A.M.I.,University of Vienna | Auersperg A.M.I.,Konrad Lorenz Institute for Ethology | Huber L.,University of Vienna | Gajdon G.K.,Konrad Lorenz Institute for Ethology
Biology Letters | Year: 2011

This study depicts how captive kea, New Zealand parrots, which are not known to use tools in the wild, employ a stick-tool to retrieve a food reward after receiving demonstration trials. Four out of six animals succeeded in doing so despite physical (beak curvature) and ecological (no stick-like materials used during nest construction) constraints when handling elongated objects. We further demonstrate that the same animals can thereafter direct the functional end of a stick-tool into a desired direction, aiming at a positive option while avoiding a negative one. © 2011 The Royal Society.

Auersperg A.M.I.,University of Vienna | Auersperg A.M.I.,Konrad Lorenz Institute for Ethology | von Bayern A.M.P.,University of Oxford | Gajdon G.K.,University of Vienna | And 3 more authors.
PLoS ONE | Year: 2011

Parrots and corvids show outstanding innovative and flexible behaviour. In particular, kea and New Caledonian crows are often singled out as being exceptionally sophisticated in physical cognition, so that comparing them in this respect is particularly interesting. However, comparing cognitive mechanisms among species requires consideration of non-cognitive behavioural propensities and morphological characteristics evolved from different ancestry and adapted to fit different ecological niches. We used a novel experimental approach based on a Multi-Access-Box (MAB). Food could be extracted by four different techniques, two of them involving tools. Initially all four options were available to the subjects. Once they reached criterion for mastering one option, this task was blocked, until the subjects became proficient in another solution. The exploratory behaviour differed considerably. Only one (of six) kea and one (of five) NCC mastered all four options, including a first report of innovative stick tool use in kea. The crows were more efficient in using the stick tool, the kea the ball tool. The kea were haptically more explorative than the NCC, discovered two or three solutions within the first ten trials (against a mean of 0.75 discoveries by the crows) and switched more quickly to new solutions when the previous one was blocked. Differences in exploration technique, neophobia and object manipulation are likely to explain differential performance across the set of tasks. Our study further underlines the need to use a diversity of tasks when comparing cognitive traits between members of different species. Extension of a similar method to other taxa could help developing a comparative cognition research program. © 2011 Auersperg et al.

Girardello M.,Northumbria University | Griggio M.,Konrad Lorenz Institute for Ethology | Whittingham M.J.,Northumbria University | Rushton S.P.,Northumbria University
Ecological Research | Year: 2010

Analyzing the relationships between the distribution of animal species and climatic variables is not only important for understanding which factors govern species distribution but also for improving our ability to predict future ecological responses to climate change. In the context of global climate change, amphibians are of particular interest because of their extreme sensitivity to the variation of temperature and precipitation regimes. We analyzed species-climate relationships for 17 amphibian species occurring in Italy using species distribution data at the 10 × 10 km resolution. A machine learning method, Random Forests, was used to model the distribution of amphibians in relation to a set of 18 climatic variables. The results showed that the variables which had the highest importance were those related to precipitation, indicating that precipitation is an important factor in determining amphibian distribution. Future projections showed a complex response of species distributions, emphasizing the potential severity of climate change on the distributions of amphibians in Italy. The species that will decrease the most are those occurring in mountainous and Mediterranean areas. Our results provide some preliminary information that could be useful for amphibian conservation, indicating if future conservation priorities for some species should be enhanced. © The Ecological Society of Japan 2009.

News Article | January 13, 2016
Site: phys.org

(Phys.org)—A trio of biologists has conducted a study of one kind of song bird and their results suggest that the females of the species may have lost the desire to sing out of fear it would lead predators to their nest. In their paper published in the journal Biology Letters, Sonia Kleindorfer and Christine Evans, with Flinders University in Australia, and Katharina Mahr with the Konrad Lorenz Institute for Ethology in Austria, describe their study of superb fairy wrens in their native habitat and what they observed. Much study has been conducted regarding male songbirds, the researchers note, but little research has been done to better understand singing in female birds. Traditionally, the thinking has been that males sing to attract the females, thus females have little to no reason to sing. But, as the group also note, a prior study by an international team of researchers back in 2013 showed that approximately 71 percent of female songbirds sing—they just don't do it in the same ways or for the same reasons. In this new effort, the researchers sought to learn more about why female superb fairy wrens sing and when, and if it causes problems for them, such as attracting predators. They set up monitoring stations near 72 nesting sites in the wilds of Australia, home to the birds, and recorded their activities over a two year period. In studying the behavior of both the males and females, the researchers found that the females generally only sang in response to singing from their mate—the birds are monogamous. Males announced their presence when returning to the nest from foraging, the females replied with the same song, though it was muted. The back and forth sing-song between mated pairs was more prominent, the researchers noted, during nest building. To find out if the female returning the call put her eggs or chicks at risk, the team set up some artificial nests with quail eggs in them and played female songs from them, varying the number of calls per hour. Predators ate the eggs 40 percent of the time when the song rate was set at 20 songs per hour, but only did so 20 percent of the time when it was set at 6 calls per hour, showing that such calling did indeed put the offspring at risk. These findings, the researchers propose, suggest that it might be possible that evolution, rather than selecting for male songbird singing, has actually been selecting against female singing. Explore further: Warbling wrens don't just tweet, they sing duets Abstract Female song is an ancestral trait in songbirds, yet extant females generally sing less than males. Here, we examine sex differences in the predation cost of singing behaviour. The superb fairy-wren (Malurus cyaneus) is a Southern Hemisphere songbird; males and females provision the brood and produce solo song year-round. Both sexes had higher song rate during the fertile period and lower song rate during incubation and chick feeding. Females were more likely than males to sing close to or inside the nest. For this reason, female but not male song rate predicted egg and nestling predation. This study identifies a high fitness cost of song when a parent bird attends offspring inside a nest and explains gender differences in singing when there are gender differences in parental care.

Griggio M.,Konrad Lorenz Institute for Ethology | Zanollo V.,Konrad Lorenz Institute for Ethology | Hoi H.,Konrad Lorenz Institute for Ethology
Journal of Ethology | Year: 2010

The evolution of female ornaments is poorly understood. Recent evidence suggests not only that female ornaments may be genetic correlates of selection on males but may also have evolved through male mate choice and/or through female-female aggressive interactions. In the rock sparrow, Petronia petronia, both sexes have a carotenoid-based yellow patch that is sexually selected by both sexes. The benefits that male may gain from choosing an attractive female remain unidentified. Both parents participate in caring for the young, so there should be mutual mate choice because males and females should both benefit from choosing a good parent (good parent hypothesis; GPH). Moreover, it has already been demonstrated that the yellow patch in males is also a badge of status (armament). Therefore, the yellow patch could also serve as both ornament and armament in females (dual utility hypothesis; DUH). We investigated the hypothesis that male and female yellow patch size signals parental quality in the field. We tested by an experiment in captivity the signal function of the yellow patch in female-female aggressive interactions for access to food. Yellow patch size correlated with paternal, but not maternal, feeding rates. Thus, this study supports the hypothesis that yellow patch dimension signals male parental quality, but there is no evidence for the GPH to explain female ornamentation. In the experiment females with relatively large yellow patches had earlier access to food than those with small patches. These results seem to suggest that a sexually selected carotenoid-feather signal may be used in female-female competition, in agreement with the DUH. Males may benefit from choosing well ornamented females because these may be superior competitors. © 2010 Japan Ethological Society and Springer.

Hoi H.,Konrad Lorenz Institute for Ethology | Tost H.,Konrad Lorenz Institute for Ethology | Griggio M.,Konrad Lorenz Institute for Ethology
Journal of Ethology | Year: 2011

Several factors can influence the risk of cuckoldry through extra-pair paternity for male birds. The number of neighbouring males is thought to affect the chance of females engaging in extra-pair copulations, and species which breed both socially (colonially) and solitarily provide an ideal opportunity to test the effect of close proximity on extra-pair behaviour and paternity guards. In this study, the extent to which male house sparrows, Passer domesticus, used two alternative strategies, namely frequent copulation and mate-guarding, to ensure paternity was investigated. We also examined how males vary the two paternity guards according to their breeding sociality. Pairs at the dense colony started to copulate at a higher rate at the beginning of the fertile period than those of the medium-sized colony and solitary breeding pairs. Male house sparrows appear to fine-tune their strategies according to the breeding density. Both strategies are alternatively used in the weak fertile period but are simultaneously used in the peak fertile period. Our results suggest that males modify their strategy according to their individual abilities: mate-guarding intensity was positively correlated with the black breast badge size. © 2010 Japan Ethological Society and Springer.

Griggio M.,Konrad Lorenz Institute for Ethology | Hoi H.,Konrad Lorenz Institute for Ethology
BMC Evolutionary Biology | Year: 2010

Background. Female condition-dependent variation in mate preference may have important evolutionary implications, not only within the same population but also among populations. There are few experiments, however, on how condition and/or genotype influences female mate preferences. The black throat patch of the male house sparrow, Passer domesticus, is an intensively studied plumage trait. It is often referred to as a 'badge of status' and seems to be involved in female mate choice, but differences exist among populations. Between-population variation in mate preference may occur for condition-dependent mate preferences. We tested the hypothesis that female preference may vary with female quality (body condition). Therefore, we measured female preference for badge size using an aviary two-choice test in which females were presented with two males that had different sizes of badges (enlarged or averaged). Results. Overall we did not find a female preference for enlarged or average badges, but low-quality females spent more time near average badge males. Conversely, high-quality females did not show a clear preference. Conclusions. Collectively, these results indicate that female preference varies with female quality. Differences in female condition are causes of within-population variation in mating preferences. To our knowledge, our results provide one of the first experimental evidences that variation in preference for a male ornament is associated with female condition. In our study, however, only females of low condition displayed a clear mate preference. Differences observed among populations could be partly explained by differences in female condition. © 2010 Griggio and Hoi; licensee BioMed Central Ltd.

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