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Populations of ground breeding birds, including partridges (Perdix perdix), are declining. Measures to monitor breeding success are therefore necessary. How can we record as efficiently as possible where nesting sites are exposed to increased risks, such as predation? A study by the University of Veterinary Medicine, Vienna, published in the “European Journal of Wildlife Research” investigated this question. The probability of nest robbery was investigated. The researchers found evidence that birds in Central European agricultural landscapes could themselves be the most dangerous nest predators.

Satellite-based measurements of habitat structure are just as good as data collected locally by scientists for predicting predation on artificial nests - this is the key finding of the study that has now been published. The background to the analysis is a worrying trend: the number of ground-nesting birds has fallen drastically across Europe. The deterioration of the habitat structure in agricultural areas is one of the main reasons for this. This is because habitat structure is not only crucial for the provision of food and suitable microclimates, but also limits nest predation.

Cost-effective, time-saving and reliable alternative

In the past, the assessment of habitat structure by an on-site scientist was the most common method for identifying areas with low nest predation. However, for time, financial and logistical reasons, it is only applicable to a limited extent. Remote sensing data recorded by a satellite, for example, can solve these problems. One measure of the “greenness” of an area is the normalized difference vegetation index (NDVI), which correlates with the habitat structure. The NDVI data is available free of charge to interested users worldwide.

Satellite measurements deliver equally good results as locally recorded data

To validate the satellite measurements, the researchers conducted an experiment with artificial nests. The experiment ran for three years (2019, 2020, 2023) in Baden near Vienna to test the relationship between NDVI and nest predators in an agricultural landscape. “We compared whether the NDVI can predict nest predation just as well as locally recorded ground cover or vegetation height. Our results show that a specific combination of monthly NDVI values produces equally good results in predicting nest predation,” says study first author Shane D. Morris from the Research Institute of Wildlife Ecology (FIWI) at Vetmeduni.

Birds as nest predators

The probability of nest predation decreased with higher NDVI values, indicating better habitat structures. This is supported by the finding that predation probability decreased with increasing ground cover - a locally recorded variable. In addition, the scientists gained another exciting insight, as study last author Claudia Bieber, head of FIWI, reports: “The reason for further studies is that we found high predation on the clutches in open areas such as open fields. As martens and foxes very specifically prefer marginal structures to search for prey, this could be an important indication that birds are significant predators here.” Overall, according to Bieber, the study shows that satellite-based measurements of habitat structure have great potential.

The article „Satellite-derived measures of habitat structure perform as well as locally recorded measures in predicting predation on artificial nests in central European agricultural landscapes“ by Shane D. Morris, Larissa Bosseler, Aldin Selimovic and Claudia Bieber was published in „European Journal of Wildlife Research“.


Scientific article

Bird migrations are one of the most extreme and energy-consuming strategies that have evolved in the animal kingdom. Against this background, seasonal migrations in birds are characterized by a rapid physiological and metabolic transformation. This includes the considerable accumulation of fat stores and an increase in nocturnal activity. However, the role played by the molecular basis and adaptations of the brain in this process was hardly known until now. An international study led by Vetmeduni now sheds light on this. The paper was published in Scientific Reports.

In their study, the researchers exposed quails (Coturnix coturnix) to controlled changes in day length in order to simulate autumn migration to the south. They then blocked the photoperiod until the birds entered the non-migratory hibernation phase.

Up-regulation of gene expression networks during bird migration

Now, the research team performed RNA sequencing of selected brain samples (hypothalamus) taken from birds at a standardized time during the night when agitation was highest and body mass was at its peak. “We found that the migratory state was associated with an upregulation of a few but functionally well-defined gene expression networks involved in fat transport, protein and carbohydrate metabolism,” says Valeria Marasco, first author of the study and Assistant Professor of Wildlife Physiology at the Research Institute of Wildlife Ecology at Vetmeduni.

Gene expression follows the time of day with a maximum during the night

Further analyses focusing on candidate genes (apolipoprotein H [APOH], lysosomal-associated membrane protein-2 [LAMP2]) from samples collected during the day or night from the entire study population revealed differences in the expression of these genes depending on the time of day, with the highest expression levels found in samples collected at night from migratory birds. “We also found clear evidence that the expression of APOH was positively associated with nocturnal activity in the migratory birds. However, no such association was seen in the control group of non-migratory birds or in the migratory birds sampled during the day,” explain study authors Steve Smith and Leonida Fusani from the Konrad Lorenz Institute of Ethology at Vetmeduni (KLIVV). 

Expression of apolipoproteins as the basis of nocturnal migratory movements

According to the scientists, the results provide new experimental evidence that hypothalamic changes in the expression of apolipoproteins, which regulate the circulating transport of lipids, are likely to be important regulatory activators of nocturnal migratory movements. “We anticipate that our study will pave the way for deeper functional investigations of the seasonal physiological reorganization underlying the development of the migratory phenotype,” says Valeria Marasco. “Understanding the neurological and molecular substrates by which highly seasonal species such as migratory and hibernating vertebrates can adapt their energy metabolism on a seasonal and daily basis is key if we want to understand the impact of ongoing climatic challenges on the life history and fitness of organisms as we enter the disruptive phases of the Anthropocene,” concludes Marasco.

The article „Brain gene expression reveals pathways underlying nocturnal migratory restlessness“ by Valeria Marasco, Leonida Fusani, Patricia Haubensak, Gianni Pola and Steve Smith was published in „Scientific Reports“.


Scientific Article

The book "Ecology of Wild Bird Diseases", edited by Sasan Fereidouni, focuses on the ecology of the most important infectious diseases of wild avian hosts, especially those with high morbidity and mortality rates. Disease ecology is an important scientific approach to study the relationships and interactions between living organisms, their environment, and potential pathogens. Birds have high diversity, and the very special ability to fly and migrate. They migrate over long distances, and share ecosystems with other animals, even humans. They serve as the most important natural source of several pathogens with zoonotic potential. Bird-pathogen interactions are increasingly changing due to the continuous anthropogenic disturbances in habitats and ecosystems. With intensified climate change and improved environmental conditions for vectors, as well as higher susceptibility of avian hosts due to simultaneous exposure to environmental stressors (e.g., contamination, food limitation, etc.), the probability of emerging new infections and their expansion into new territories increase tremendously. The Covid-19 pandemic has shown that neglected ecological and epidemiological interactions between wildlife, domestic animals and humans are paramount to global health.

The book has a different approach to understanding complex and multiscale interactions among various ecological factors for the most important infectious diseases of wild birds. It provides valuable data to students and everyone who deals with avian species including biologists, researchers, conservationists, and policymakers.

Starting in Zurich (Switzerland), the StadtWildTiere project has since been expanded to a total of 13 cities in Austria, Germany and Switzerland, including Vienna and Berlin. Observations of random encounters with wild animals in urban neighbourhoods are collected on a joint online platform. In Austria, reports can be submitted via the website www.stadtwildtiere.at.  A recently published international study involving the University of Veterinary Medicine Vienna has now analysed the benefits of this transnational initiative.

StadtWildTiere collects sightings of wildlife in cities to raise awareness of biodiversity in urban areas throughout Central Europe. The collection of data also serves as a basis for scientific analyses. Furthermore, the knowledge collected by the citizens is used to promote nature and biodiversity in urban areas.

Climate change, interactions:
Community project uncovers the unknown for the first time

Urban ecology is still a young field and urban wildlife populations have not yet been the focus of many studies. "StadtWildTiere enables us to recognise previously hidden patterns and temporal trends, e.g. in the context of urban densification and the heat island effect, particularly with regard to climate change. The initiative can therefore also serve as a sensor for future interactions between humans and wildlife," explains study co-author Theresa Walter from the Research Institute of Wildlife Ecology at Vetmeduni.

Important basis for decisions at political level

In the long term, the scientists suggest that projects such as StadtWildTiere should create a basis for comparative, international monitoring in order to close the existing gaps in knowledge about urban wildlife populations. According to study co-author Richard Zink from the Konrad Lorenz Institute for Comparative Behavioural Research (KLIVV) at Vetmeduni, the data obtained from the study goes far beyond science: "This knowledge is also of crucial importance for political decision-makers and wildlife managers in order to establish the right strategies and measures. In particular, this also concerns the question of how to effectively improve biodiversity in cities."

The article „StadtWildTiere – added value and impact of transnational urban wildlife community science projects“ by Madeleine Geiger, Anouk Lisa Taucher, Sandra Gloor, Mirco Lauper, Sarah Kiefer, Sophia E. Kimmig, Janette Siebert, Theresa Walter, Richard Zink, Fabio Bontadina and Daniel Hegglin was published in „Frontiers in Ecology and Evolution“.

Scientific article

StadtWildTiere Österreich