Recent research has tried to determine whether and under which conditions domestic dogs (Canis familiaris) engage in prosocial and potentially altruistic behaviour. A common paradigm used to test this is the so-called prosocial choice test. This is a task in which the animal can choose to operate an apparatus based on the outcome. For example, this could involve delivering food to themselves, to another individual, to both, or to neither. The aim of the current study was to investigate dogs' collaborative tendencies with humans, with the use of a novel prosocial choice test paradigm. This paradigm was designed to take into account the fact that predators may have a more natural tendency to pull vertically rather than horizontally. Our paradigm is based on pulleys that are operated by the dogs, an action which dogs mastered without extensive training. All dogs (N = 16) participated in three experimental conditions (selfish-, prosocial- and altruistic condition) and two control conditions (no-reward- and partner-absent control). We further tested to what extent the between subjects' familiarity with the human partner (owner vs. stranger) mattered to the dogs. The dogs were more likely to operate the apparatus when they received a reward (selfish- and prosocial condition) than when they did not (altruistic- and no-reward condition). In addition, the absence of a partner, owner or stranger only marginally affected the dogs' tendency to pull. Based on our findings, we cannot conclude that dogs make altruistic or prosocial choices; rather, they appear motivated by selfish interests. We discuss the possibility that even small procedural changes can have large implications on the behaviour of the dogs during the tests.

Identifying associations between ecological strategy and cognitive and behavioral traits is essential in predicting species sensitivity or persistence in the face of environmental change. Ecological generalists with a larger niche breadth are expected to exhibit high levels of behavioral flexibility, whereas specialists are likely to show increased performance of cognitive traits directly related to specific ecological challenges. To explore how ecological niche breadth is associated with cognitive and behavioral traits, we compared risk-taking, motivation, activity, and inhibitory control between two sister species of Gambusia that differ in ecological strategy: Gambusia affinis is an ecological generalist occupying a wide range of habitat types, and Gambusia geiseri is a specialist. Using a detour task and behavioral tracking, we evaluated cognitive and behavioral traits in both species from sympatric populations collected at two sites: one on the San Marcos River where G. geiseri dominates, and another on the Comal River characterized by more variable environmental conditions and roughly equal abundance of G. geiseri and G. affinis. We found that the generalist species, G. affinis was more likely to complete the detour task and was faster to exit a refuge indicating higher risk-taking behavior in this species. Gambusia geiseri from the variable habitat showed reduced solving success and slower solving speed which suggests that inhibitory control is associated with species identity and ecological niche breadth. Activity levels differed significantly across species and habitat type. We found a species by population interaction where G. affinis had a higher swimming velocity than G. geiseri in the Comal River, but a lower swimming velocity than G. geiseri in San Marcos River. Our findings highlight how cognitive and behavioral traits differ between generalist and specialist strategies and underscore these associations as drivers of species resilience to environmental change.

Cognitive flexibility - the ability to adjust previously learned associations given novel information - is hypothesized to allow animals to respond to variable conditions. While cognitive flexibility is thought to primarily rely on executive control, previous experiences may interfere with learning. In this study, we tested the hypothesis that strength of associations should improve cognitive flexibility and that birds given more time to learn different spatial associations would perform better in a serial reversal task with multiple, not binary, choices. Wild chickadees were subjected to one of three spatial learning tasks that differed in the number and duration of learned associations and then completed a serial reversal task using eight-feeder arrays. All birds learned the locations of two rewarding feeders sequentially. The control group then started the serial reversal task with reward alternating daily between those two feeders. The two experimental groups had to sequentially learn an additional two locations but differed in the time allowed to learn these associations – one day for the short exposure group and three days for the long exposure group. This was followed by the serial reversal task which involved daily alternations between these two additional feeder locations. The birds in the long exposure group showed fewer location errors and learned the reversal rule faster than birds in the short exposure group. Our results demonstrate that increased experience with specific associations improves cognitive flexibility involving these associations when animals have multiple choices.

Bees are flexible and adaptive learners, capable of learning stimuli seen on arrival and at departure from flowers where they have fed. This gives bees the potential to learn all information associated with a feeding event, but it also presents the challenge of managing information that is irrelevant, inconsistent, or conflicting. Here, we examined how presenting bumblebees with conflicting visual information before and after feeding influenced their learning rate and what they learned. Bees were trained to feeder stations mounted in front of a computer monitor. Visual stimuli were displayed behind each feeder station on the monitor. Positively reinforced stimuli (CS +) marked feeders offering sucrose solution. Negatively reinforced stimuli (CS−) marked feeders offering quinine solution. While alighted at the feeder station the stimuli were likely not visible to the bee. The “constant stimulus” training group saw the same stimulus throughout. For the “switched stimulus” training group, the CS + changed to the CS− during feeding. Learning was slower in the “switched stimulus” training group compared to the constant stimulus” group, but the training groups did not differ in their learning performance or the extent to which they generalised their learning. The information conflict in the “switched stimulus” group did not interfere with what had been learned. Differences between the “switched” and “constant stimulus” groups were greater for bees trained on a horizontal CS + than a vertical CS + suggesting bees differ in their processing of vertically and horizontally oriented stimuli. We discuss how bumblebees might resolve this type of information conflict so effectively, drawing on the known neurobiology of their visual learning system.

Cognition, how individuals perceive, store, process and respond to information, influences decision-making. However, biases in cognitive processes can distort behavioural outcomes. Judgement bias occurs when individuals infer information to be more positive, or negative than it is. For captive animals, judgement bias is typically measured by testing behavioural responses to ambiguous cues that are intermediate to cues with learned valence (positive and negative). However, these tests have rarely been used in the wild. We therefore examined if a behavioural test of judgement bias commonly used in captive animals could be adapted to test a wild bird, the toutouwai (North Island robin, Petroica longipes). Toutouwai were faster to approach ambiguous cues that were more similar to a learned positive cue, compared to a learned negative cue. This positive bias mirrors behavioural response patterns observed across a range of species in captivity, including other birds. Responses toward ambiguous cues were repeatable over a short timespan, indicating there was consistent individual variation among our test birds in their degree of bias when judging ambiguous cues. Males tended to approach cues more quickly than females. Our results demonstrate that judgement bias can be tested for in situ in wild birds. However, as is typical of many island species, toutouwai are bold and fearless, which facilitated their participation in our experiment. Therefore, to enable research examining the ecological correlates of judgement biases in nature, we must develop tests of cognitive biases that can be used with a wider range of species in the wild.Supplementary InformationThe online version contains supplementary material available at 10.1007/s10071-025-02004-6.

When quantifying animal cognition, memory represents one of the most tested domains and is key to understanding cognitive evolution. Memory tests thus play an important role in comparative cognitive research, yet slight variations in the experimental settings can substantially change the outcome, questioning whether different memory tests tap into different memory systems or whether they test memory at all. Here, we first assessed memory performance of 16 common marmosets (Callithrix jacchus) in two distinct paradigms varying in their format and delay. First, we examined marmoset memory in a 24-h delay memory test (24 h-DMT) in which they could freely explore an environment with three novel objects of which one contained food. We examined their retention the day after, and the procedure was iterated cumulatively with previous objects remaining in the enclosure until the marmosets had to choose the correct out of 30 objects. Second, we administered a classical delayed response test (DRT) in the same animals with three objects and a maximum delay of 30 s. In the DRT, marmoset performance was poor and not better than chance after 15 s already. However, individuals excelled in the 24 h-DMT, performing above chance level after 24 h even with tenfold the number of objects to choose from compared to the DRT. Moreover, individual performances in the two tests were not correlated, and typical age effects on memory could not be detected in both experiments. Together, these results suggest that the two tests explore different domains, and that the 24 h-DMT examines long-term memory. The outcome of the DRT is more difficult to assign to memory since individuals performed only moderately even in the 0-s delay condition. This puts into question whether this task design indeed tests memory or other cognitive processes.

Complex displays that comprise multiple behavioral elements play an essential role in the communication of group-living animals. One of them is a greeting display. Greeting is performed during the reunion after a separation, and is known for maintaining social bonds in mammals and pair bonds in monogamous fish. Greeting displays have been documented in birds, but lack functional studies. Java sparrows (Lonchura oryzivora) are gregarious and long-term monogamous songbird species, exhibiting a complex greeting display consisting of a sequence of four repetitive behavioral elements. We hypothesized that Java sparrow greetings function as between-pair communication in social contexts. In particular, we expected that pair-bonded partners would greet more after experiencing longer separation. In addition, we also predicted that they greet more when other conspecific individuals are nearby; as it is more important for them to confirm and advertise their commitment relationships. To test these ideas, we conducted separation-reunion tests using pair-bonded Java sparrows with different separation times (long vs. short) and different social conditions (with vs. without the presence of conspecifics). We calculated and compared the sequential complexity of the greeting displays. We showed that subject pairs performed a greater number of greeting display bouts after longer separation times. In the presence of conspecifics, greeting displays were more frequent, longer, and more complex. Our finding supports the idea that greeting displays in birds are crucial to pair-bond maintenance, contributing to understanding the evolution of complex communications in birds.

Animals can form reputations of individuals through direct interactions or by observing interactions with a third party, known as eavesdropping. Given their cooperative relationship with humans, considerable interest has focused on whether dogs (Canis lupus familiaris) can socially evaluate humans, though findings remain mixed. To assess whether this ability develops during ontogeny, we investigated whether dogs of different ages (young, adult, and senior) can form reputations of humans after observing them interact with a conspecific or through direct interactions in a food-giving situation. Forty pet dogs participated in the experiment. In the eavesdropping condition, dogs observed two humans interact with a dog demonstrator—one was generous and fed the dog, while the other was selfish and withheld food. In the direct experience condition, dogs interacted with the two partners directly. We analysed dogs’ first choice and time spent exhibiting affiliative behaviours towards each partner. Results showed that dogs across all age groups did not significantly prefer the generous partner compared to the selfish partner, nor did their behaviour exceed chance levels following indirect or direct experience. These findings do not provide support for dogs showing reputation formation and highlight the methodological complexities of studying this phenomenon.