Corticosterone in feathers is affected by tropical forest management

In a collaborative project with several labs, we found that glucocorticoid hormones are potential mediators of carry‐over effects on population abundance linked to forest management. The study was conducted on a series of species in the tropical forests of Borneo, and involved measurement of corticosterone in feathers which was conducted in our endocrinology laboratory. The article was published in Functional Ecology.

Simone Messina, the first author of the paper, worked in our endocrinology laboratory to measure corticosterone in the feathers collected in Borneo.

Stopover strategies of 12 passerines on Ponza

Small coastal islands are known to birdwatchers because they attract large numbers of migrants at the appropriate time of the year. Many of these islands are especially fruitful during bad weather conditions, because they act as safe havens for birds that have to interrupt their flight. In Italy, a handful of islands in the Tyrrhenian Sea are also attracting thousands of migrants during spring migration, but their peculiarity is that they do so even when there is no weather emergency. We analyzed ringing data from our station on Ponza to investigate what might be the reason to stop there for so many birds. On Ponza, we can reach tips of 1500-2000 individual birds caught in one single day! By looking at the body mass data at first capture and at recapture data we hoped to determine whether birds stopping on Ponza might do so to refuel their depleted energies after the crossing of the Mediterranean Sea. We analyzed 12 different species and we consistently found very low recapture rates (below 2% of the birds were ever recaptured), indicating that most birds stay on Ponza just for a very short time. Of the birds that were recaptured, we noticed that these were mostly carrying less fat than the average for their species. This means that a stop on Ponza was forced when birds had too low energy stores for continuing their flight. However, only in two species (Subalpine Warblers and Common Chiffchaffs) birds were actually able to increase their fat stores during the stay on Ponza. In all other species, birds staying on Ponza did not manage to add body mass. In conclusion, it appears that generally stopping on these islands for refuelling is not convenient, so the question remains open: why do so many birds stop on these islands at all, considering that the mainland is just an extra hour or two away? We believe that birds need a short stop, possibly just for a nap, after the long sea crossing, and islands are a safest place for that than the mainland, especially when they lack predators. Read our article here!

Using an immune response to measure stress in migrating birds

Measuring corticosterone levels is the standard method to assess stress levels in birds. However, this hormone is involved in multiple other physiological processes during migration making its interpretation in the context of stress difficult. Therefore, in our study published in the Journal of Ornithology, we investigated whether an immunological tool called leukocyte coping capacity (LCC) provides useful complementary information on the stress response in migratory Garden Warblers caught at their stopover site on Ponza Island.

Our results show that LCC significantly decreased during the acute stress response, which implies high-stress levels and a diminished capacity to recover after a stressful event. This outcome further confirms that the LCC method is a useful tool to extend our understanding of stress and the ability of migrating birds to cope with it.

If you want to learn more about the Leukocyte coping capacity and how it relates to the classical corticosterone stress protocol and the energetic condition of these migratory birds, you can access the paper following this link.

Nikolaus HuberVirginie Canoine, Jessica S. Cornils, Ivan Maggini, Massimiliano Cardinale, Thomas Ruf & Leonida Fusani. Leukocyte coping capacity as a complementary stress metric in migrating birds. J Ornithol (2020). https://doi.org/10.1007/s10336-020-01774-9

Our study on courtship featured in ‘Der Standard’

The newspaper “Der Standard” has published an article by Susanne Strnadl featuring our ongoing project Comparative Aesthetics funded by the WWTF. You can read the full article (in German) by following this link.

Lean migratory songbirds move more when food is scarce

During spring migration, stopover sites play a determinant role for migratory songbirds’ survival. In a paper published on Scientific Reports, we investigated how food availability, an indicator of stopover site quality, shapes the behaviour of energetic challenged migratory songbirds after crossing the Mediterranean.


Our results suggest that birds with low energy reserves search for refuelling opportunities when food availability is low. In addition to improving our understanding of migratory strategies, our results are relevant for the protection of stopover areas, currently is one of the major concerns for the conservation of migratory birds.

If you want to learn more about the influence of food availability on stopover behaviour, you can access the paper following this link.

Energy reserves but not oxidative balance influence sleep

Several functions have been hypothesized for sleep, such as energy conservation and clearance of free radicals. In our study published in Integrative Organismal Biology, we investigated the relationship between sleep behavior, food intake and two markers of physiological condition – the amount of energy reserves and oxidative status – in two migratory songbird species, the Garden Warbler and the Whitethroat.

Although sleep posture preference resulted to be a common energy saving strategy, our results suggests that different species might use different strategies to manage their energy during stopover. In addition, it raises the possibility that migrants have evolved physiological adaptations to deal with oxidative damage produced during migration.

If you want to learn more about this study, you can access the paper by following this link.


MSc project available: How personality and sex influence problem solving in a highly social fish

We are looking for a motivated student interested in a Master’s project in Behavioural Biology and Cognition using a social cichlid (Neolamprologus pulcher) from Lake Tanganyika. The thesis will be part of the WWTF funded project: “Coping with change: Investigating the relationships between behavioural flexibility, stress and early environment”.

We are particularly interested in a student with a keen interest in scientific questions, that would like to research fish behaviour and cognition, is able to work independently and in a team. Our daily communications are in English and the student is required to have good knowledge of English and, preferably, the thesis should be written in English. The work will be based at the Konrad Lorenz Institute for Ethology which is located on Wilhelminenberg in the 16th district.

To know more and express interest in this project, please contact Stefan Fischer


+43 1 250 77 7404


MSc projects in migratory bird physiology available for spring 2020

We are currently recruiting two MSc students for exploring physiological and behavioural aspects of bird migration in spring 2020. The project will start in February 2020 and the students’ availability for continuous fieldwork on the island of Ponza in Italy from March to May 2020 is required. Spring research will involve studies on the physiological and hormonal control of migration, decision making during stopover and behavioural changes experienced during migratory season. The students should be ready to stay in Vienna and work on their Master project after returning from fieldwork to help with laboratory and data analysis.

We are seeking highly motivated candidates, who are keen on spending the entire fieldwork season together with other researchers at our field site on the island of Ponza. The ideal candidates should be team players and willing to be involved in intense team work throughout the field season. Furthermore, she/ he should be comfortable with spending some possibly long working days in the field and at our on-site laboratory. Honest motivation and commitment to the project are essential. The working language is English and knowledge of the language is necessary. Previous experience with bird related field work is very welcome but not a must.

We offer students an extensive bird migration field work experience in an international environment. Students will learn the catching and handling of wild birds, will be taught how to conduct field experiments and process the samples collected therein. Birds will be held in short-term captivity in our on-site laboratory giving students the opportunity to learn the use of different methods and apparatuses (e.g. respirometer) in migratory bird research with a focus on physiological processes. Furthermore, students will be able to expand their team work and independent field work skills and gain a wide range of knowledge on different topics of avian migration.

If you are interested in joining our team in spring 2020, please apply by sending your CV including a reference to Julia Slezacek by emailing to julia.slezacek@vetmeduni.ac.at. Interviews will be held until January 2020. For more information please do not hesitate to contact Julia or Prof. Leonida Fusani (leonida.fusani@univie.ac.at). Involvement in the project through conduction of an internship can be discussed. For more information about the ringing station on site please visit https://www.inanellamentoponza.it/about.

We are looking forward to receiving your applications!

Bald Ibis: Migration and data collection successfully completed

The human-led migration of the Northern bald ibis led by the Waldrappteam has taken place and with it also my data collection. The preparation for this data collection was a long process, mainly because in my case there is no second chance: the migration is only once a year and there is little room for mistakes.

The migration was really fast, from the 14th to the 26th of August. This year it went from Heiligenberg, in Baden-Württemberg (DE) to the WWF Oasis of Orbetello, in Tuscany (IT). It was divided into six bouts, four of which were also suitable for data collection.

Data on V-formation flights

My work consisted in equipping all the 29 hand-raised juveniles of Northern bald ibis with GNSS receivers to study how they fly in a V-formation. Many of you may ask, what are GNSS receivers? Well, basically these loggers are able to receive the signal from different satellite constellations, which in my case were GPS, Galileo, and GLONASS. The benefit of using different satellites systems is to be able to calculate the position with higher accuracy. However, the true speciality of these loggers stays in other two features:

  1. They collect and store raw satellite data: this means that the loggers themselves do not calculate the position of the bird (as any receivers would do, think about when you navigate with your smartphone and Maps), but collect and store the stream of information coming from the satellites. The data can then be downloaded and post-processed to calculate the position. This type of data collection is surely more complicated and time-spending, however, it allows to reach cm-level accuracy in the calculation of the position. This is fundamental in my project, as birds fly quite close to each other in a formation and normal accuracy (1-3 m) is not enough.
  2. They are small and light-weighted: all my loggers weight on average 20 g and their design was a real challenge. Such “GNSS loggers that collect raw data” are already existing on the market but usually, they are big and too heavy to be carried by a bird. Therefore, we had to create our own. In collaboration with the company RTK Consultants LLC, we came up with these receivers, which suited all my purposes.

All the birds in the group have to be equipped with a receiver to have a comprehensive view of the V-formation. Juveniles carried the loggers on the back by means of a leg-loop harness and 3D-printed plastic housing.

Behavioural observation

My data collection does not only consists of raw satellite data, but I also carry on behavioural observation. In particular, I am interested in seeing whether the social dynamics in the group are reflected in the flight formation or vice-versa. To achieve this, I conducted affiliative and aggressive behaviour observations before, during and after the migration.

Data collection went pretty good and the amount of data is huge. Now it is time to start with the data analysis!

Photo credits: Anne-Gabriela Schmalstieg. Waldrappteam, LIFE Northern Bald Ibis.

Andrea Ferretti wins prize for best talk

Andrea Ferretti has been awarded the prize for the best oral presentation at the 12th Meeting of the European Ornithologists’ Union in Cluj-Napoca, Romania. Andrea presented a talk entitled “The sleep dilemma of nocturnal migrants” in which he illustrated the results of his PhD research, recently published in Current Biology.