Corvid Lab

Corvids are large-brained birds, commonly referred to as 'primates of the sky' or 'feathered apes'. We want to understand what their large brains are good for and how they work. Hence, we study corvids under field conditions as well as under controlled conditions in the lab, asking questions like

i) how do birds solve problems posed in daily life,

ii) which cognitive skills underlie that problem solving,

iii) how are these skills acquired and transmitted,

iv) how do these skills differ between closely related species and

v) how do the abilities of corvids compare to those of other large-brained animals like parrots, primates and carnivors.

Our main model system is the common raven Corvus corax, which is the largest member of the corvid family showing a worldwide distribution in the Northern hemisphere. Since 2010, we also work on its smaller sister species in Europe, the carrion crow and hooded crow Corvus corone corone and Corvus corone cornix (two subspecies with a hybridization zone exactly around Vienna). Like ravens, crows are feeding generalists and territorial breeders. In contrast to ravens, they seem to be less specialized on scavenging but to more readily engage in cooperative breeding. We study wild ravens and crows in comparable environments (ravens in the Cumberland Wildpark Grünau and crows in the Tiergarten Schönbrunn, where they snatch food from the zoo animals); in each population, we can recognize around 300 birds individually with the help of rings and wing tags. In addition, we keep captive colonies of ravens and crows at our two outdoor stations (Konrad Lorenz Forschungsstelle, Forschungsstation Haidlhof). Most of the captive birds are very tame, they all know their name and are highly motivated to work in our behavioural experiments.

We use a mix of biological and psychological approaches and techniques, depending on the research questions and ecological relevance. For our current projects on cooperation, for instance, we apply matched-controlled observations, choice experiments and non-invasive hormone sampling via feces and saliva. For our research line on social knowledge and 'politics', we combine radio- and GPS tracking, social network and kinship analyses with acoustical playback experiments and operant learning paradigms on touch screen computers. And for the research on information transmission, we use social learning and group diffusion paradigms, personality tests, video demonstrations and operant problem solving tasks.

Our latest addition to the lab is a captive group of azure-winged magpies Cyanopica cyanus, which has been established in 2014 for studying prosocial behaviour in a cooperatively breeding corvid.

Ongoing and finished projects:

The evolution of pro-social concern FWF (P26806): 2014-2017, PI Jorg Massen

In an attempt to better understand evolution of altruism, there has been a recent surge in studies on prosocial behaviours like helping. Next to humans a variety of animals has been tested in experiments on prosociality, with however, rather inconsistent results within and between species and across context. This raises questions about the evolutionary pressures (e.g. aspects of social life) and motivations behind prosocial behaviour (e.g. need, sympathy). Therefore, the aim of the current proposal is twofold: The first aim is to test two main hypotheses about the evolution of prosocial behaviour, namely the cooperative breeding hypothesis and the social bonding hypothesis, by making use of the comparative approach, including species with two distinct social features (cooperative breeding (CB) and social bonds (SB)). To control for effects of common ancestry, next to humans I will include two species per two phylogenetical different lineages (primates: common marmosets (CB) vs. long tailed macaques (SB); and corvids: Iberian magpies (CB) vs. common ravens (SB)). The second aim of the proposal is to test underlying motivation of prosocial behaviour, by confronting all five species with a series of experiments that vary across necessity and costs of prosocial behaviour.

The Evolutionary Roots of Social Comparison DSF, Research Unit (FOR 2150): 2015-2017, PI Julia Fischer, Co-PIs Bugnyar and Thomas Mussweiler

Social comparison processes are a fundamental characteristic of human behavior, and the underlying psychological mechanisms and processes have been intensively investigated in the last decades. Yet, until now, relatively little is known about the evolutionary foundations of social comparisons. Do non-human animals also engage in self-other comparisons or are these extensive social comparisons restricted to humans? Studies on non-human primates indicate that animals may be sensitive to the actions of others and adjust their responses. Chimpanzees and capuchin monkeys, for example, refuse to participate in experiments, if a partner animal is receiving better rewards for the same task. Crows and ravens also show this 'inequity aversion'. These studies suggest that there may be an evolutionary basis for social comparisons, but until now the underlying mechanisms have never been explored systematically. In an attempt to fill this important gap in understanding, the present project aims to elucidate the evolutionary roots of social comparisons. We will adopt a comparative approach and combine experimental paradigms from social psychology with animal behavior research methods. Specifically, in an analogy to classic research on social comparison processes in humans, we will examine how the performance of a partner influences subjects' performance behavior in monkeys (long-tailed macaques, Macaca fascicularis) and birds (carrion crows, Corvus corone). These species are particularly skilled at social tasks and thus ideally suited for our comparative research endeavor. More specifically, to examine whether specific features of social comparisons are already evident in non-human animals, we will use classic paradigms that have been developed to examine the underlying mechanisms of social comparisons in humans. Using parallel performances on touch-screen setups, we will investigate whether social comparisons in monkeys and birds are influenced by the relative difference between the subject's and the co-actor's performance as well as the personal relationship between them (Line 1), the social status of the subject within its group (Line 2) as well as prior priming procedures to shift the focus to similarity or dissimilarity features, respectively (Line 3). To validate the comparative approach we will conduct the experiments of Line 1 and 3 with human participants, too. Furthermore, experiments of Line 2 are in close collaboration to P7 reflecting our ambition to strive for a truly interdisciplinary approach.

COBRA (Cognition and Brains) EU, FP7-People (Marie Curie Actions IRSES): 2013-2015, PI Bugnyar

The joint exchange program involved the movement of three experienced researchers between the Universities of Vienna, Austria, University of St Andrews, UK, Ruhr University in Bochum, Germany, and University of Newcastle, Australia. Specifically, a researcher from Newcastle spent 6 months in Europe, split between St Andrews, Vienna, and Bochum. Researchers from Bochum and Vienna visited Newcastle for 6 months. At both their home institution and during each secondment, exchange researchers have collected data towards a geographically global research project that aims to use a collection of avian species as model systems to understand: 1. The role of behavioural flexibility in species' adaptation to urbanization, and 2. The extent to which behavioural flexibility is associated with changes in brain anatomy. The program was structured along four work packages (WP1-4). While WP1 concerned the project management and coordination, WP2-4 concerned the empirical studies on Indian mynahs (WP2), European crows (WP3) and European songbirds like house sparrows and great tits (WP4). Birds were tested in the field with simple problem solving tasks for their behavioural flexibility along a rural to urban gradient. For instance, they had to remove a cork that was blocking the access to food at a known feeder. By examining several species, in several geographical locations, using several different measures of behavioural flexibility, and describing associated brain changes, we find support for the hypothesis that increasing behavioural flexibility in increasingly urbanized environments is a general effect. Specifically, urban birds tend to be more exploratory and more risk taking than rural birds, but they do not show any differences in innovativeness, sociality, or responses to predators. These findings clearly demonstrate what factors makes urban birds 'special' and provide hints for when to expect species differences. The results likely have implications for conservation attempts of declining species and the management of invasive species. They also highlight the importance of comparative studies at different places that could only be achieved by close collaboration between different researchers and their working groups.

Modeling Social Transmission in Corvids WWTF (CS 11-008): 2012-1015, PI Christine Schwab, Co-PI Bugnyar

Humans are experts when it comes to learning from others. We learn by observing and imitating a wide range of other persons, starting with family members and expanding to teachers, friends, peers, or even unfamiliar persons. Further, an important learning strategy in humans is to conform with others, i.e. performing the same behaviour as the majority and/or trustable persons. In this project we investigate if crows, Corvus corone, and ravens, Corvus corax, apply similar social learning strategies. These two species are exceptionally suitable because, similar to humans, they exhibit a social system comprising on one side long-term partnerships and on the other side (sub-) group formation with high degrees of fission-fusion dynamics. Also, they maintain qualitatively different relationships with conspecifics. We will investigate how these various social networks influence the patterns of how social information spreads through populations of wild and captive birds. The results from our project will help us understanding the general principles underlying (human) culture.

Raven Politics: Understanding and Use of Social Relationships FWF, START (Y366-B17): 2008-1014, PI Bugnyar

Social life has been suggested as one of the main driving forces for the development of higher cognitive abilities in non-human, and human, primates. Yet there are open questions concerning the mechanisms underlying 'intelligent' behaviour and the socio-ecological conditions that promote investment in cognitive skills. Recently, the idea of the bird family Corvidae representing a mirror group to the primates in respect to cognitive capacities has gained momentum. Understanding the social life of corvids may thus be critical in our attempt to understand primate cognition, since comparison between these groups may offer the unique opportunity to identify which cognitive abilities are common to social living irrespective of phylogeny and how selection has acted to produce these solutions. The intend in this proposal is therefore to investigate social complexity as driving force for brain evolution in corvids and to provide a comprehensive study on the use of social knowledge in an avian model system, the common raven Corvus corax. Ravens show striking abilities in judging and manipulating competitors but also engage in referential communication, social learning, and various forms of cooperation on the basis of social relationships. This makes them promising candidates to examine their 'political' skills from a Machiavellian and a Vygotskian point of view. Hence, this proposal aims at testing what ravens know about other individuals and their social relations and how they make use of their knowledge in daily life. Studies shall follow two parallel lines of research, building blocks (i) on individual recognition and understanding of dyadic and triadic relations and (ii) on the formation, regulation, and use of valuable relations under fission-fusion dynamics. Furthermore, studies shall feature a combination of laboratory and field work by utilizing our unique captive colony of hand-raised adult birds, their yearly offspring that will be observed first in captivity and then in the field, and habituated wild birds. Finally, studies shall be conducted in collaboration with leading experts in primatology, experimental psychology and behavioural biology, enabling me to utilize a variety of methods (e.g. operant procedures, playbacks, matched-controlled observations, hormonal correlates) on one model system and to selectively conduct comparative studies with closely related species to address effects of phylogeny and ecology. The integrative aspect of the proposed project shall open new possibilities in the research on avian cognition and is expected to have both an impact on current hypotheses on mental evolution and a strong outreach component to lay persons. If birds with a radically different neurobiology and evolutionary trajectory to that of primates come to understand, and use, their social world in a similar way to primates, this would provide strong support for the idea of a convergent evolution and help us understand the selection pressures that may have boosted the evolution of sophisticated mental skills in non-human, and human, primates.

Cooperation, Collaborators, and Cognition FWF, Lise Meitner program for scientists from abroad (M1351-B17): 2012-1013, PI Jorg Massen, Co-PI and host Bugnyar

Cooperation is a useful strategy to gain benefits that cannot be obtained alone, yet is characterized by risky investments. To deal with these uncertainties several mechanisms may have evolved. It has been argued that among group members or known individuals cooperation is unconsciously mediated by emotions. Yet, when dealing with unfamiliar individuals or strangers, human cooperation is governed by complex cognitive decisions involving the calculation of costs/benefits and the understanding of roles and intentions of collaborating individuals. Whether non-human animals also employ different decision rules for cooperation with either known or unknown individuals remains unknown. This study tests experimentally which behavioural decision rules ravens use in their cooperative behaviour with conspecifics of different familiarity. Ravens interact regularly with both familiar and unfamiliar conspecifics and are renowned for advanced socio-cognitive skills. The experiments aim to conceive whether ravens have a preference for cooperation with familiar individuals, whether they prefer an equal distribution of rewards for their cooperative act and whether ravens can calculate costs and benefits of their cooperation and act accordingly. Moreover, the experiments are complimented with an observational study on wild ravens, investigating the contingency of exchange patterns for different commodities in either familiar or unfamiliar dyads.

COCOR (Cooperation in Corvids): Affiliate Relations and Cooperation in Ravens, Corvus corax ESF-EUROCORES framework TECT (I105-G11): 2007-2010, PI Bugnyar

Observational evidence suggests that corvid flocks represent individualized societies with members selectively exchanging low- and high-risks behaviours such as preening and coalition formation. Moreover, recent studies emphasize a crucial role of affiliate relationships that may form between siblings but also between non-related individuals. What is not yet clear is to what extent individuals make tactical use of their relations in cooperative interactions. The aim of the project is to 1) test if ravens' affiliate relationships work as alliances in conflicts, leading to a system of dependent ranks both within and between sexes, 2) determine if, and how, individuals maintain affiliate relations when their partners are experimentally prevented from retaliating social support and 3) examine the birds' willingness to share resources with 'reliable' and 'unreliable' partners.

Cooperation and economic behaviour in corvids EU, FP6-NEST (INCORE): 2007-2010, PI Bugnyar

Corvids have been suggested to show complex cognitive abilities similar to those of primates in the context of similar socio-ecological problems. One of the most fascinating aspects of their social life is the tactical and economical use of cooperative behaviour. Corvids are known to facultatively engage in helping at the nest (e.g. carrion crows), active recruitment of non-relatives to food sources (e.g. ravens), food sharing (e.g. jackdaws), coalitionary support between and within sexes (e.g. ravens, rooks), and post-conflict consolation (e.g. ravens, rooks). Taken together, results indicate a high flexibility in the birds' decision of whether or not to cooperate in certain situations, some knowledge about potential cooperation partners and the use of tools both in the social and technical domain. So far, issues related to corvid-cooperation have been investigated as isolated topics, focusing either on specific proximate or functional aspects. Extending the view of different programs, coordinating ongoing studies and adjusting already-used procedures pose technical and practical challenges and call for improved networking between the established labs in Austria (KL Research Station, Univ. Vienna), France (Univ. Strasbourg), Great Britain (Univ. Cambridge, Univ. Oxford), Spain (Univ. Valladolid) and Italy (Univ. Trieste). This work package is aimed to improve the exchange of information between the European corvid labs in order to coordinate their activities and integrate their ongoing work on cooperative behaviour into the broad framework of other European programs (GEBACO, TECT).