High associative neuron numbers could drive cognitive performance in corvid species.

Corvids possess cognitive skills, matching those of nonhuman primates. However, how these species with their small brains achieve such feats remains elusive. Recent studies suggest that cognitive capabilities could be based on the total numbers of telencephalic neurons.

Why do zoos attract crows? A comparative study from Europe and Asia.

Crows have successfully colonized many cities, and urban zoos have been important in this process. To evaluate why zoos attract crows, we quantified crow numbers and behavior in three zoos in Europe (Debrecen, Edinburgh, Vienna) and one in Asia (Sapporo). Data were collected in 445 surveys over 297 days in summer 2014 and winter 2014-2015.

Counting crows: population structure and group size variation in an urban population of crows.

Social complexity arises from the formation of social relationships like social bonds and dominance hierarchies. In turn, these aspects may be affected by the degree of fission-fusion dynamics, i.e.

Behavioural Type Affects Space Use in a Wild Population of Crows ().

While personality-dependent dispersal is well studied, local space use has received surprisingly little attention in this context, despite the multiple consequences on survival and fitness. Regarding the coping style of individuals, recent studies on personality-dependent space use within a habitat indicate that 'proactive' individuals are wider ranging than 'reactive' ones. However, such studies are still scarce and cover limited taxonomic diversity, and thus, more research is needed to explore whether this pattern generalises across species.

Responses of urban crows to con- and hetero-specific alarm calls in predator and non-predator zoo enclosures.

Urban animals and birds in particular are able to cope with diverse novel threats in a city environment such as avoiding novel, unfamiliar predators. Predator avoidance often includes alarm signals that can be used also by hetero-specifics, which is mainly the case in mixed-species flocks. It can also occur when species do not form flocks but co-occur together.

Social networks predict selective observation and information spread in ravens.

Animals are predicted to selectively observe and learn from the conspecifics with whom they share social connections. Yet, hardly anything is known about the role of different connections in observation and learning. To address the relationships between social connections, observation and learning, we investigated transmission of information in two raven (Corvus corax) groups.

Explorative innovators and flexible use of social information in common ravens (Corvus corax) and carrion crows (Corvus corone).

Innovation and social information use are influenced by individual characteristics, and are important for the creation and transmission of novel behavioral patterns. Here, we investigated which individual factors predict innovation rates and social transmission of information in a comparative study with identically reared common ravens (Corvus corax) and carrion crows (Corvus corone corone; Corvus corone cornix). In the innovation experiment (1), we presented the birds with a novel problem-solving task while alone, to determine which individuals would quickly solve ("innovators") or not solve ("noninnovators") this task.

Socially Driven Consistent Behavioural Differences during Development in Common Ravens and Carrion Crows.

Consistent individual differences in behaviour, or 'personality', are likely to be influenced by development, social context, and species ecology, though few comparative, longitudinal studies exist. Here, we investigated the role of development and social context on personality variation in two identically reared, social corvids: common ravens and carrion crows. We repeatedly presented subjects with a variety of novel food and objects, while alone and in a primarily sibling subgroup, from fledging to sub-adulthood.

Loner or socializer? Ravens' adrenocortical response to individual separation depends on social integration.

Non-breeding common ravens (Corvus corax) live in complex social groups with a high degree of fission-fusion dynamics. They form valuable relationships and alliances with some conspecifics, while taking coordinated action against others. In ravens, affiliates reconcile their conflicts, console each other after conflicts with a third party, and provide each other with social support - all behaviors that presumably reduce corticosterone levels and alleviate stress.

Differences in exploration behaviour in common ravens and carrion crows during development and across social context.

Exploration is particularly important for young animals, as it enables them to learn to exploit their surroundings. It is likely to be affected by species ecology and social context, though there are few comparative, longitudinal studies that control for effects of early experience. Here, we investigated group level exploration behaviour in two closely related and identically reared, generalist corvid species: common ravens () and carrion crows (, ), during development and across social context.

Tolerance and Social Facilitation in the Foraging Behaviour of Free-Ranging Crows ().

Social foraging provides animals with opportunities to gain knowledge about available food. Studies indicate that animals are influenced by social context during exploration and are able to learn socially. Carrion and hooded crows, which are opportunistic generalists with flexible social systems, have so far received little focus in this area.

Pair bond characteristics and maintenance in free-flying jackdaws : effects of social context and season.

Most birds rely on cooperation between pair partners for breeding. In long-term monogamous species, pair bonds are considered the basic units of social organization, albeit these birds often form foraging, roosting or breeding groups in which they repeatedly interact with numerous conspecifics. Focusing on jackdaws , we here investigated 1) the interplay between pair bond and group dynamics in several social contexts and 2) how pair partners differ in individual effort of pair bond maintenance.

Recipients affect prosocial and altruistic choices in jackdaws, Corvus monedula.

Other-regarding preferences are a critical feature of human cooperation but to what extent non-human animals exhibit these preferences is a matter of intense discussion. We tested whether jackdaws show prosocial behaviour (providing benefits to others at no cost to themselves) and altruism (providing benefits to others while incurring costs) with both sibling and non-sibling recipients. In the prosocial condition, a box was baited on both the actor's and the recipient's side (1/1 option), whereas another box provided food only for the actor (1/0 option).

Network measures for dyadic interactions: stability and reliability.

Social network analysis (SNA) is a general heading for a collection of statistical tools that aim to describe social interactions and social structure by representing individuals and their interactions as graph objects. It was originally developed for the social sciences, but more recently it was also adopted by behavioral ecologists. However, although SNA offers a full range of exciting possibilities for the study of animal societies, some authors have raised concerns about the correct application and interpretation of network measures.

Preferential learning from non-affiliated individuals in jackdaws (Corvus monedula).

It has been suggested that affiliated social relations may facilitate information transfer between individuals. We here tested this rarely examined hypothesis with juvenile and adult jackdaws (Corvus monedula) in three stimulus enhancement tasks, both in a non-food context (experiment 1) and in a food context (experiments 2 and 3). We first show that siblings and pair partners maintain stronger bonded social relations than do non-siblings and non-pair partners.

Enhanced social learning between siblings in common ravens, .

It has been suggested that social dynamics affect social learning but empirical support for this idea is scarce. Here we show that affiliate relationships among kin indeed enhance the performance of common ravens, , in a social learning task. Via daily behavioural protocols we first monitored social dynamics in our group of captive young ravens.

Ravens judge competitors through experience with play caching.

Complex social behavior builds on the mutual judgment of individuals as cooperation partners and competitors [1]. Play can be used for assessing the others' dispositions in humans and nonhuman mammals [2], whereas little is known about birds. Recently, food-caching corvids have been found to rival primates in their ability to judge the behaviors and intentions of others in competition for hidden food [3].

Obey or not obey? Dogs (Canis familiaris) behave differently in response to attentional states of their owners.

Sixteen domestic dogs (Canis familiaris) were tested in a familiar context in a series of 1-min trials on how well they obeyed after being told by their owner to lie down. Food was used in 1/3 of all trials, and during the trial the owner engaged in 1 of 5 activities. The dogs behaved differently depending on the owner's attention to them.