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.

Why birds sleep with their head tucked in

Most songbirds migrate at night and need to recover sleep at stopover sites. In a paper published in Current Biology, we found that birds choose their sleep posture depending on their condition. Sleeping with the head tucked in the scapular feathers is associated with a lower energy consumption but also with a reduced alertness. Therefore, birds in good conditions prefer to take less risks and sleep with the head facing forward.

The project involved researchers from Austria, Germany, Sweden, and the United States. The study unveiled a new function for sleep in birds and opened new perspectives on the role of sleep in migratory strategies. If you want to learn more about how songbirds sleep during migration, follow this link.

Review paper on multimodal courtship displays

We’re happy to announce that our review about the evolution and function of multimodal courtship displays is now published with Open Access in Ethology.

If you want to learn more about the current state of the art regarding how and why complex and multisensory courtship displays occur, follow this link.

Mitoyen, C., Quigley, C., & Fusani, L. Evolution and function of multimodal courtship displays. Ethology (2019). https://doi.org/10.1111/eth.12882

Stopover Strategies in the Sahara

Yasmina is a humble dry lake at the base of the impressive Erg Chebbi Dunes, on the northern fringe of the Sahara Desert in Morocco. It is in a relatively remote area in the heart of the Maghreb, attracting tourism for camel caravans and for wayfaring birders with a taste for sandstorms. An early spring inspection of the tamarisk trees bordering Yasmina’s shores will reveal a great assemblage of Phylloscopus and Sylvia warblers nervously hopping around the trees and understory. They are here making a migratory stopover- a stop of a few days to weeks to replenish energy reserves after having just crossed the formidable Sahara. Upon successfully refueling fat and muscle reserves at Yasmina, the birds then continue their journey to European breeding grounds.


A keen observer would notice a great deal of the Subalpine Warblers (Sylvia cantillans) are wearing colorful plastic rings on their legs. This species is particularly interesting to me because they obtain and aggressively defend small transient territories. Subalpine Warblers are often heard broadcasting their chattering songs signaling to their neighbors the boundaries of their territories. If these boundaries are intruded upon, a chase or physical altercation often ensues. But again, this is not their breeding site, so why are these birds spending valuable time and energy (both are limiting currencies for migration and subsequently for life history strategies) where there is no mate to defend in a location that is still far from their breeding areas? To begin elucidating this phenomenon I am examining the interactions between stopover behavior, refueling performance and hormonal programs. Every day I map each individual’s home range (by sighting their individualized color-ring combinations) and assess territoriality with playback experiments and hormone analysis.

However, now in the later part of spring, a new suite of species dominates the stopover site. The Reed, Isabelline, Saharan Olivaceous, and Melodious Warblers are some of the commoner tenants in our nets. These four members of the Acrocephalidae family, exhibit markedly diverse stopover strategies. For example, upon arrival, some spend the entire day hidden in the shade of a tree to conserve energy and immediately leave when night falls- while others actively forage in the heat and stay for weeks. In addition these species spend winters in different habitat types- therefore adaptations to desert conditions may vary. Here, along with Ivan Maggini, I am examining the relationship between stopover strategy, physiology and habitat adaptations. We are measuring physiological output with a respirometry device and collecting tissues for stable isotope analysis that provide us with information about each individual’s wintering habitat. These birds are then fitted with activity tags that send signals to an antenna and are stored on a hard drive. From the changes in tag signal strength we can infer movement patterns and calculate activity budgets. We hope to understand how activity levels in a dry and hot desert are influenced by physiology and non-migratory habitat adaptations.

Whether from hyper aggressive territoriality, or physiological adaptations, birds display a great diversity of strategies to make use of desert stopover sites every year on their incredible trans-continental journeys. A worthwhile phenomenon to study in further detail!


Ponza 2019 started!

Ponza view

We are happy to announce that the data collection for this year’s spring migratory field season on the island of Ponza has officially started in the beginning of April! PhD students Andrea Ferretti and Julia Slezacek and Master students Benjamin Kostner and Caroline Denechaud have spent the beginning of this month setting up the field site laboratory and field equipment to kick off this year’s data collection. Indeed, the preparatory work has already paid off and we have been able to collect the first samples and host the first Garden Warblers (Sylvia borin) and Common Whitethroats (Sylvia communis) in our registration cages for this season’s studies. This year we are investigating the influence of gut hormones on behaviour and physiology during stopover with a great focus on the hormone ghrelin and the genetics of the bird ghrelin system. In addition, we continue collecting data on sleep behaviour and have started a novel project on bird gut microbiota during migration.

For detailed information on the ringing activities and regular updates on the progress of the ringing season please check out our collaborator’s and local ringing station’s website.

If you would like to get involved in our research on migration physiology next spring season 2020, please contact Julia Slezacek for more information.

Ponza 2019 team
from left to right: Caroline Denechaud, Benjamin Kostner, Andrea Ferretti, Julia Slezacek

Crowdfunding campaign for an exciting project on migration flights!

Hi, I am Elisa Perinot, I am launching a crowdfunding campaign on Experiment.com to collect funds to buy several GNSS loggers for my project on costs and benefits of flight formation. These loggers are necessary to track the birds while flying and I will use them to collect data during my next field season, in the summer.  

You can help me to conduct my research by funding my project (see in the link)! Moreover, you can also share the campaign, so that I reach out to more people. For any question or curiosity, you are welcome to contact me.

Thank you very much!