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Goffin’s cockatoos, a parrot species endemic to the Tanimbar Islands in Indonesia, demonstrate remarkable cognitive skills across various technical tasks. These neophilic extractive foragers explore objects with their beak and feet, and are skilled in several modes of tool use. In this study, we confronted the animals for the first time with a vertical string-pulling setup, including a set of classic and novel controls. Nine of the 12 subjects, two of which were subadults, immediately interacted with the single-string task, with seven individuals successfully obtaining the reward on their very first attempt. Four different double string discrimination tests with varying spatial relations were used to assess the Goffin’s cockatoos’ apprehension of basic physical task properties. We found significant differences in performance between the respective experimental conditions, as well as the development of side biases. The results suggest that while the birds seem to consider simple cause–effect relationships, there is no evidence for a mental representation of the causal mechanisms underlying the string-pulling tasks, as subjects failed the crossed strings condition out of immediate sight. Finally, we provide suggestions on improving the methodology, and discuss our findings in regard to the Goffin’s cockatoo’s ecology.

Problem-solving tasks are commonly used to investigate technical, innovative behavior but a comparison of this ability across a broad range of species is a challenging undertaking. Specific predispositions, such as the morphological toolkit of a species or exploration techniques, can substantially influence performance in such tasks, which makes direct comparisons difficult. The method presented here was developed to be more robust with regard to such species-specific differences: the Innovation Arena presents 20 different problem-solving tasks. All tasks are presented simultaneously. Subjects are confronted with the apparatus repeatedly, which allows a measurement of the emergence of innovations over time - an important next step for investigating how animals can adapt to changing environmental conditions through innovative behavior. Each individual was tested with the apparatus until it ceased to discover solutions. After testing was concluded, we analyzed the video recordings and coded successful retrieval of rewards and multiple apparatus-directed behaviors. The latter were analyzed using a Principal Component Analysis and the resulting components were then included in a Generalized Linear Mixed Model together with session number and the group comparison of interest to predict the probability of success. We used this approach in a first study to target the question of whether long-term captivity influences the problem-solving ability of a parrot species known for its innovative behavior: the Goffin´s cockatoo. We found an effect in degree of motivation but no difference in the problem-solving ability between short- and long-term captive groups.

Complex novel tasks are often used in animal cognition research to allow discrimination between various learning mechanisms. Successful performance relies on the capacity to identify informational cues from features in the environment. Additionally, observational learning is often considered more beneficial for survival than individual learning. Despite the importance of controlling task complexity, it can often be challenging to operationalize. This study investigated whether jackdaws, a highly social corvid species, can learn to drop stones inside a tube to release a reward after observing a trained conspecific. Additionally, it aimed to identify the underlying learning mechanisms and to detect the informational cues triggering learning. A research design was developed to highlight different aspects of the required action sequence. Experimental conditions included a conspecific model demonstrating the full sequence, parts of the sequence, consuming the reward without solving the task, and consuming the reward after the solution was demonstrated without a visible model. None of the 12 naïve jackdaws solved the task in pretests. Two subjects started solving in test sessions and they developed modified versions of the demonstrated action. Observing the full action sequence performed by a conspecific seemed to trigger learning. The majority of the subjects exhibited changes in their stone-oriented behavior, most likely due to stimulus and/or local enhancement. As predicted, jackdaws were influenced by conspecific model demonstrations when manipulating a complex novel foraging task. Factors contributing to the apparent task difficulty and directions for future studies are discussed within a tri-dimensional framework including the task, setup, and individuals.

Paying attention to weight is important when deciding upon an object's efficacy or value in various contexts (e.g. tool use, foraging). Proprioceptive discrimination learning, with objects that differ only in weight, has so far been investigated almost exclusively in primate species. Here, we show that while Goffin's cockatoos learn faster when additional colour cues are used, they can also quickly learn to discriminate between objects on the basis of their weight alone. Ultimately, the birds learned to discriminate between visually identical objects on the basis of weight much faster than primates, although methodological differences between tasks should be considered.

Tool use research has suffered from a lack of consistent theoretical frameworks. There is a plethora of tool use definitions and the most widespread ones are so inclusive that the behaviors that fall under them arguably do not have much in common. The situation is aggravated by the prevalence of anecdotes, which have played an undue role in the literature. In order to provide a more rigorous foundation for research and to advance our understanding of the interrelation between tool use and cognition, we suggest the adoption of Fragaszy and Mangalam's (2018) tooling framework, which is characterized by the creation of a body-plus-object system that manages a mechanical interface between tool and surface. Tooling is limited to a narrower suite of behaviors than tool use, which might facilitate its neurocognitive investigation. Indeed, evidence in the literature indicates that tooling has distinct neurocognitive underpinnings not shared by other activities typically classified as tool use, at least in primates. In order to understand the extent of tooling incidences in previous research, we systematically surveyed the comprehensive tool use catalog by Shumaker et al. (2011). We identified 201 tool use submodes, of which only 81 could be classified as tooling, and the majority of the tool use examples across species were poorly supported by evidence. Furthermore, tooling appears to be phylogenetically less widespread than tool use, with the greatest variability found in the primate order. However, in order to confirm these findings and to understand the evolution and neurocognitive mechanisms of tooling, more systematic research will be required in the future, particularly with currently underrepresented taxa.

One hallmark in the evolution of cooperation is the ability to evaluate one's own payoff for a task against that of another person. To trace its evolutionary history, there has recently been a surge in comparative studies across different species. In non-human animals, evidence of inequity aversion has so far been identified in several primate species, dogs, and rats. Research in birds revealed mixed findings so far: among corvids, crows and ravens did react sensitively to unequal payoffs and work-effort, while New Caledonian crows did not. Among psittacids, kea were studied so far: Yet, despite the fact that they live in large, hierarchically organized social groups that show complex interactions, they did not show a significant reaction to inequitable payoffs. Here we tested for the first time a Cacatua, the Goffin's cockatoo, using a standardized token exchange paradigm in which first the partner and then the subject could exchange a token for a food reward. Our results show that subjects did not react to unequal reward distributions. However, in comparison to the Equity Condition, the likelihood to exchange was lower in the condition in which the partner received the same reward as a gift (without having to work for it) whereas the subject had to perform a task involving substantial work-effort, suggesting that the Goffin's cockatoos do react aversively to work-effort inequity. In a follow-up experiment, subjects never received a reward but observed a conspecific receive a high-quality reward depending on condition. We found again no evidence for an aversion for the unequal reward distribution, but only that, independent of condition, subjects quickly lost their motivation to participate due to not receiving a reward. In summary, Goffins showed some sensitivity to increased unequal work-effort, but did not react to unequal reward distribution.

Experimental work on captive Goffin’s cockatoos (Cacatua goffiniana) has highlighted the remarkable cognitive abilities of this species. However, little is known about its behavior in the natural habitat on the Tanimbar Archipelago in Indonesia. In order to fully understand the evolutionary roots leading to cognitively advanced skills, such as multi-step problem solving or flexible tool use and manufacture, it is crucial to study the ecological challenges faced by the respective species in the wild. The three-month expedition presented here aimed at gaining first insights into the cockatoos’ feeding ecology and breeding behavior. We could confirm previous predictions that Goffin’s cockatoos are opportunistic foragers and consume a variety of resources (seeds, fruit, inflorescence, roots). Their breeding season may be estimated to start between June and early July and they face potential predation from ground and aerial predators. Additionally, the observational data provide indications that Goffin’s cockatoos are extractive foragers, which together with relying on multiple food sources might be considered a prerequisite of tool use.

Die Fahigkeit, die Hilfsmittel fur eine Aufgabe auszuwahlen um an eine Belohnung zu gelangen, wahrend der Aufgabenort oder die jeweiligen Werkzeuge zu dem Zeitpunkt nicht sichtbar sind, deutet auf eine einfache Form der Planung hin. Hier untersuchten wir, ob und wie nicht spezialisierte werkzeuggebrauchende Vogel, Goffin’s Kakadus prospektiv oder retrospektiv das funktionelle Werkzeug in einer problemlosenden Aufgabe auswahlen konnen. Das Experiment beinhaltete zwei verschiedene Apparaturen und zwei verschiedene Werkzeuge. Jede Apparatur konnte nur mit einem spezifischen Typ von Werkzeug verwendet werden. Die Versuchstiere waren nie in der Lage, die Werkzeuge und die Apparatur zur gleichen Zeit zu sehen bevor sie eine binare Wahl treffen durften. In der prospektiven Bedingung wurde die Apparatur und in der retrospektiven Bedingung wurden die Werkzeuge vor jeder Wahl verdeckt. Die Ergebnisse zeigten, dass Goffin’s Kakadus fahig sind prospektiv aber nicht retrospektiv das richtige Werkzeug auszuwahlen. Daraus schliesen wir, dass die Leistung der Versuchstiere davon abhangig war, in welcher Reihenfolge die Aufgabe und die Werkzeuge prasentiert wurden. Diese Ergebnisse sind vergleichbar mit denen, die bei Affen gefunden wurden und zeigen zumindest eine einfache Form von zukunftsorientierter Kognition in einer von Primaten weit entfernten verwandten Spezies.

When tested under laboratory conditions, Goffin’s cockatoos (Cacatua goffiniana) demonstrate numerous sophisticated cognitive skills. Most importantly, this species has shown the ability to manufacture and use tools. However, little is known about the ecology of these cockatoos, endemic to the Tanimbar Islands in Indonesia. Here we provide first insights into the feeding- and socio-ecology of the wild Goffin’s cockatoos and propose potential links between their behaviour in natural settings and their advanced problem-solving capacities shown in captivity. Observational data suggests that Goffin’s cockatoos rely on a large variety of partially seasonal resources. Furthermore, several food types require different extraction techniques. These ecological and behavioural characteristics fall in line with current hypotheses regarding the evolution of complex cognition and innovativeness. We discuss how the efficiency of (extractive) foraging may preclude tool use in wild Goffin’s cockatoos, even though the corresponding cognitive and ecological prerequisites seem to be present.

Parrots are renowned for their intelligence and ability to imitate human speech ever since they have been kept as pets. Despite of impressive pioneering work on the cognitive abilities of parrots, research on parrot cognition has only recently gained momentum, probably given the new wave of interest in possible convergent evolution of complex cognition within the vertebrates. Together with corvids, they often parallel primates if not great apes in cognitive performance and have become important model systems to study the evolution of cognition. We briefly review the history of parrot cognition within the field of comparative cognition and introduce some of the laboratories that have contributed to this special issue as well as the studies they present.

So far only one bird species, a corvid, passed the mark test for mirror self-recognition (MSR) although the results have been questioned. We examined the capacity for MSR in another large-brained avian taxon, parrots, with keas (Nestor notabilis) and Goffin’s cockatoos (Cacatua goffini). After several weeks of mirror habituation, they were subjected to the mark test using different marks and mark placements while facing horizontal and vertical mirrors simultaneously. The keas had an additional control condition in which their reaction towards a marked or non-marked conspecific behind a transparent partition was compared to their own reflection. No evidence of MSR was found in either species. Keas responded to their reflection comparably to a conspecific behind a clear separation. Goffin’s cockatoos showed fewer social responses towards their horizontal reflection compared to their vertical reflection, suggesting that they may interpret them differently.

Summary The use of different tools to achieve a single goal is considered unique to human and primate technology. To unravel the origins of such complex behaviors, it is crucial to investigate tool use that is not necessary for a species’ survival. These cases can be assumed to have emerged innovatively and be applied flexibly, thus emphasizing creativity and intelligence. However, it is intrinsically challenging to record tool innovations in natural settings that do not occur species-wide. Here, we report the discovery of two distinct tool manufacture methods and the use of tool sets in wild Goffin’s cockatoos (Cacatua goffiniana). Up to three types of wooden tools, differing in their physical properties and each serving a different function, were manufactured and employed to extract embedded seed matter of Cerbera manghas. While Goffin’s cockatoos do not depend on tool-obtained resources, repeated observations of two temporarily captive wild birds and indications from free-ranging individuals suggest this behavior occurs in the wild, albeit not species-wide. The use of a tool set in a non-primate implies convergent evolution of advanced tool use. Furthermore, these observations demonstrate how a species without hands can achieve dexterity in a high-precision task. The presence of flexible use and manufacture of tool sets in animals distantly related to humans significantly diversifies the phylogenetic landscape of technology and opens multiple avenues for future research. Video abstract Download : Download video (42MB)

Novel problems often partially overlap with familiar ones. Some features match the qualities of previous situations stored in long-term memory and therefore trigger their retrieval. Using relevant, while inhibiting irrelevant, memories to solve novel problems is a hallmark of behavioral flexibility in humans and has recently been demonstrated in great apes. This capacity has been proposed to promote technical innovativeness and thus warrants investigations of such a mechanism in other innovative species. Here, we show that proficient tool—users among Goffin's cockatoos—an innovative tool—using species—could use a relevant previous experience to solve a novel, partially overlapping problem, even despite a conflicting, potentially misleading, experience. This suggests that selecting relevant experiences over irrelevant experiences guides problem solving at least in some Goffin's cockatoos. Our result supports the hypothesis that flexible memory functions may promote technical innovations.

A recent article by Fayet et al. (1) reports two observations of wild puffins ( Fratercula arctica ) from two geographical locations touching different body parts with a stick. The behaviors are interpreted as unprecedented evidence of tool use in a seabird. However, there is another existing report of tool use in a wild seabird in a self-directed context as also pointed out in a commentary (2). From close by, Meyerriecks (3) observed a cormorant brushing its wings repeatedly with a loose feather. Each motion was preceded by dipping the feather’s tip to its preen gland. Due to its anecdotal nature, this remains a short note in an ornithological bulletin … [↵][1]1To whom correspondence may be addressed. Email: alice.auersperg{at}vetmeduni.ac.at. [1]: #xref-corresp-1-1

The ability to innovate, i.e., to exhibit new or modified learned behaviours, can facilitate adaptation to environmental changes or exploiting novel resources. We hereby introduce a comparative approach for studying innovation rate, the ‘Innovation Arena’ (IA), featuring the simultaneous presentation of 20 interchangeable tasks, which subjects encounter repeatedly. The new design allows for the experimental study of innovation per time unit and for uncovering group-specific problem-solving abilities – an important feature for comparing animals with different predispositions and life histories. We applied the IA for the first time to investigate how long-term captivity affects innovative capacities in the Goffin’s cockatoo, an avian model species for animal innovation. We found that fewer temporarily-captive wild birds are inclined to consistently interact with the apparatus in comparison to laboratory-raised birds. However, those that are interested solve a similar number of tasks at a similar rate, indicating no difference in the cognitive ability to solve technical problems. Our findings thus provide a contrast to previous literature, which suggested enhanced cognitive abilities and technical problem-solving skills in long-term captive animals. We discuss the impact and discrepancy between motivation and cognitive ability on innovation rate. Our findings contribute to the debate on how captivity affects innovation in animals.

International audience; Allogrooming in primates serves not only a hygienic function, but also plays a crucial role in maintaining strong affiliative bonds between group members, which in turn, underpin the emergence of cooperative behavior. In contrast, although allopreening occurs in many avian species, we know little about its social functions. Our study addresses this issue by investigating allopreening in a broad comparative data set including six corvid and nine parrot species. We assessed whether rates of allopreening initiations, proportion of time spent allopreening, and the number of grooming partners in captive group-housed birds were comparable to patterns observed in captive chimpanzees and bonobos. While parrots and corvids were found to have similar rates of social grooming to bonobos and chimpanzees, Pan species dedicated significantly more time to social grooming. Animals in larger groups had more grooming partners, but when controlling for the number of potential partners, birds tended to have fewer grooming interaction partners than Pan species. We then investigated whether allopreening in parrots and corvids was predicted by behavioral markers of affiliative social bonds (close physical proximity, active feeding, and low levels of agonistic behavior). Results revealed that providing allopreening to a partner was significantly predicted by often being in close proximity, but not engagement in active feeding or agonistic behavior. We examined the region allopreened in a subset of species and found that preening a partner's head was predicted by both close physical proximity and active feeding, while body allopreening was only predicted by close physical proximity. Head preening may confer more hygienic benefits to recipients, and thus, may be more selectively provided to valued partners. Results support the hypothesis that allopreening in corvids and parrots helps maintain social bonds with an individual's most important social partners, showing some similarities to allogrooming in primates.

In captivity, the Goffin’s cockatoo (Cacatua goffiniana) has shown the capacity for flexible tool use and manufacture to a degree that rivals some habitually tool using birds. Although these skills make it an important avian model species for studying physical cognition, there are no scientific records of this species using objects as tools in the wild. We hereby report a single observation of a feral individual, showing an object related foraging behavior not previously described. The bird directly and repeatedly combined plant material (alternating between stiff stalks and flimsy leaves) with the inside of a foraging source (open coconuts) in a continuous and very persistent way. Here we analyze the observation and discuss how a psychological motivation for combining objects, particularly with food sources, may represent a potential new path to the onset of avian tool use. We evaluate the possibility that this particular case may already represent tool use and highlight the theoretical importance of this finding to our present state of knowledge about the technical abilities of this species.

Play behaviour may be subdivided into social play, locomotor play and object play. Object play has been proposed to constitute an important factor in developing skills concerned with physical problem solving. Especially tool using species seem to benefit from object play during their ontogeny. However, object play is not easily distinguished from exploration as both behaviours seem to serve no immediate benefit. Here we try to discuss proposed definitional differentiations and their implications. Further, we provide examples of how object play might be adaptive for problem solving proficiency in some bird species, indicating similar ecological factors driving the evolution of object play in primates and birds.

Tool use in animals can be costly as foraging tools need to be actively searched for or manufactured. Consequently, some habitually tool-using species keep their tools safe and ‘recycle’ them for further use. We tested the Indonesian Goffin's cockatoo, a parrot with the capacity but no apparent adaptive specialization for tool use to investigate how tool safekeeping can arise innovatively. In this case, we further intended to test whether and how such safekeeping changes in different feeding contexts. We demonstrate that, in a set-up allowing for tool losses, the birds quickly started to keep their tools safe in between tool-using events. They used different individual strategies, suggesting that the behaviour was a product of innovation rather than inherited predispositions. The frequency of safekeeping improved over time indicating individual learning. Furthermore, the birds flexibly adjusted their performance depending on different contexts: paralleling previous results in the habitually tool-using New Caledonian crow, Corvus moneduloides, the cockatoos saved their tools more often when the foraging site was elevated and when the food item was easy rather than difficult to process. Furthermore, when feeding at heights, the birds tended to use a different safekeeping mode than when the foraging site was low.

This work was supported by the University of St Andrews and the Max Planck Institute for Evolutionary Anthropology. Isabelle Laumer was supported by a uni:docs fellowship of the University of Vienna, Alice Auersperg was supported by by FWF grants J 3404-B19 and P 29084, and Thomas Bugnyar by Y366-B17. Making economic decisions in a natural foraging situation that involves the use of tools, may require an animal to consider more levels of relational complexity than merely deciding between an immediate and a delayed food option. We used the same method previously used with Goffin´s cockatoos to investigate the orangutans’ flexibility for making the most profitable decisions when confronted with five different settings that included one or two different apparatuses, two different tools and two food items (one more preferred than the other). We found that orangutans made profitable decisions relative to reward quality, when the task required the subjects to select a tool over an immediately accessible food reward. Furthermore, most subjects were sensitive to work-effort when the immediate and the delayed option (directly accessible by using a tool) led to the same outcome. Most subjects continued to make profitable decisions that required taking into account the tool functionality. In a final multidimensional task design in which subjects had to simultaneously focus on two apparatuses, two reward qualities and two different tools, the orangutans chose the functional tool to access the high quality reward. Publisher PDF

The construction of novel compound tools through assemblage of otherwise non-functional elements involves anticipation of the affordances of the tools to be built. Except for few observations in captive great apes, compound tool construction is unknown outside humans, and tool innovation appears late in human ontogeny. We report that habitually tool-using New Caledonian crows (Corvus moneduloides) can combine objects to construct novel compound tools. We presented 8 naïve crows with combinable elements too short to retrieve food targets. Four crows spontaneously combined elements to make functional tools, and did so conditionally on the position of food. One of them made 3- and 4-piece tools when required. In humans, individual innovation in compound tool construction is often claimed to be evolutionarily and mechanistically related to planning, complex task coordination, executive control, and even language. Our results are not accountable by direct reinforcement learning but corroborate that these crows possess highly flexible abilities that allow them to solve novel problems rapidly. The underlying cognitive processes however remain opaque for now. They probably include the species’ typical propensity to use tools, their ability to judge affordances that make some objects usable as tools, and an ability to innovate perhaps through virtual, cognitive simulations.

The ability to move an object in alignment to a surface develops early in human ontogeny. However, aligning not just your own body but also the object itself in relation to a surface with a specific shape requires using landmarks rather than the own body as a frame of reference for orientation. The ability to do so is considered important in the development of tool use behaviour in human and non-human animals. Aside from humans, with the exception of a single study on habitually tool using primates, shape-frame matching abilities remain largely unstudied. The Goffin's cockatoo is a generalist parrot, and not a specialised tool user but has shown the capacity to innovate and use different types of tools under controlled settings. We tested these parrots in a tool selection and tool use task featuring objects and their corresponding substrate grooves in a number of shapes with different levels of symmetry. Subjects had to choose the correct 'key' to insert into a box, and align its shape to fit into the corresponding 'keyhole' in the box. The parrots were able to select the correct key above chance level from early on in the experiment. Despite their lack of hands, they required fewer placement attempts than primates to insert simple object shapes into corresponding grooves. For complex shapes, they reduced their insertion effort by rotating shapes in their beak while avoiding as many protrusions as possible. Unrewarded play experience with similar object shapes was provided to some of the subjects previously to testing, but did not seem to have an effect on the number of correct choices or on insertion effort.

The spontaneous crafting of hook-tools from bendable material to lift a basket out of a vertical tube in corvids has widely been used as one of the prime examples of animal tool innovation. However, it was recently suggested that the animals' solution was hardly innovative but strongly influenced by predispositions from habitual tool use and nest building. We tested Goffin's cockatoo, which is neither a specialized tool user nor a nest builder, on a similar task set-up. Three birds individually learned to bend hook tools from straight wire to retrieve food from vertical tubes and four subjects unbent wire to retrieve food from horizontal tubes. Pre-experience with ready-made hooks had some effect but was not necessary for success. Our results indicate that the ability to represent and manufacture tools according to a current need does not require genetically hardwired behavioural routines, but can indeed arise innovatively from domain general cognitive processing.

Different types of social relationships can influence individual learning strategies in structured groups of animals. Studies on a number of avian species have suggested that local and/or stimulus enhancement are important ingredients of the respective species’ exploration modes. Our aim was to identify the role of enhancement during object manipulation in different social contexts. We used focal observations to identify a linear dominance hierarchy as well as affiliative relationships between individuals in a group of 14 Goffin’s cockatoos (Cacatua goffiniana, formerly goffini). Thereafter, in an unrewarded object choice task, several pairs of subjects were tested for a possible influence of social enhancement (local vs. stimulus) in three conditions: dominance, affiliation, and kinship. Our results suggest strong individual biases. Whereas previous studies on ravens and kea had indicated that enhancement in a non-food-related task was influenced by the social relationship between a demonstrator and an observer (affiliated – nonaffiliated), we found no such effects in our study group. In this context, Goffin’s cockatoos’ object learning seems to take place more on an individual level, despite their generally high motivation to manipulate nonfood items. Electronic supplementary material The online version of this article (doi:10.3758/s13420-016-0235-0) contains supplementary material, which is available to authorized users.

In primates, complex object combinations during play are often regarded as precursors of functional behavior. Here we investigate combinatory behaviors during unrewarded object manipulation in seven parrot species, including kea, African grey parrots and Goffin cockatoos, three species previously used as model species for technical problem solving. We further examine a habitually tool using species, the black palm cockatoo. Moreover, we incorporate three neotropical species, the yellow- and the black-billed Amazon and the burrowing parakeet. Paralleling previous studies on primates and corvids, free object-object combinations and complex object-substrate combinations such as inserting objects into tubes/holes or stacking rings onto poles prevailed in the species previously linked to advanced physical cognition and tool use. In addition, free object-object combinations were intrinsically structured in Goffin cockatoos and in kea.

Innovative tool manufacture is rare and hard to isolate in animals. We show that an Indonesian generalist parrot, the Goffin's cockatoo, can flexibly and spontaneously transfer the manufacture of stick-type tools across three different materials. Each material required different manipulation patterns, including substrates that required active sculpting for achieving a functional, elongated shape.

Studies on advanced forms of tool use in birds have mainly been concentrated on corvids. In this study, captive kea, a neophilic New Zealand parrot species, produced different orders of spatial object relationships in a tube-lifting/object-inserting paradigm. Hence, we found that kea, which are neither natural tool users nor nest builders, could readily solve a second-order tool use task. They also learned to produce highly complicated meansemeanseend sequences in a short period of time.

Unusual niches as well as unpredictable or seasonal resources foster a broader spectrum of foraging techniques and often promote flexibility and physical innovations. This may lead to an increase in technical abilities, including enhanced cause–effect exploitation, the capacity to distinguish between functional and nonfunctional object properties and/or the use of physical concepts. Within birds, corvids and psittacines appear to be particularly promising candidate models for studies on physical cognition. Similarly to the great apes, corvids and parrots live in individualized social groups with complex hierarchical structures and face ecological problems such as spatially and temporally heterogeneous resources. Although their brain anatomy is different, their relative forebrain sizes resemble those of great apes’ prefrontal cortices. This chapter investigates the problem solving and innovative behavior of corvids and parrots.

The playful (i.e., not overtly functional) combination of objects is considered a potential ontogenetic and phylogenetic precursor of technical problem solving abilities, as it may lead to affordance learning and honing of mechanical skills. We compared such activities in 6 avian species: 3 psittaciforms (black-headed caiques, red-shouldered macaws, and Goffin cockatoos) and 3 corvids (New Caledonian crows, ravens, and jackdaws). Differences in the type and frequency of object combinations were consistent with species' ecology. Object caching was found predominately in common ravens, which frequently cache food. The most intrinsically structured object combinations were found in New Caledonian crows and Goffin cockatoos, which both stand out for their problem solving abilities in physical tasks. Object insertions prevailed in New Caledonian crows that naturally extract food using tools. Our results support the idea that playful manipulations of inedible objects are linked to physical cognition and problem-solving abilities.

The ability to represent hidden objects plays an important role in the survival of many species. In order to provide an inclusive synopsis of the current benchmark tasks used to test object permanence in animals for a psittacine representative, we tested eight Goffin cockatoos (Cacatua goffini) on Stages 3–6 of Piagetian object permanence as well as derivations of spatial transposition, rotation, and translocation tasks. Subjects instantly solved visible displacement 3b and 4a but showed an extended plateau for solving Stage 5a at a very late age (10 months). Subjects readily solved most invisible displacement tasks including double hidings and four angles (90°, 180°, 270°, and 360°) of rotation and translocations at high performance levels, although Piagetian Stage 6 invisible displacement tasks caused more difficulties for the animals than transposition, rotations, and translocation tasks.

Evidence for flexible impulse control over food consumption is rare in non-human animals. So far, only primates and corvids have been shown to be able to fully inhibit the consumption of a desirable food item in anticipation for a gain in quality or quantity longer than a minute. We tested Goffin cockatoos ( Cacatua goffini ) in an exchange task. Subjects were able to bridge delays of up to 80 s for a preferred food quality and up to 20 s for a higher quantity, providing the first evidence for temporal discounting in birds that do not cache food.

Comparative cognition aims at unfolding the cognitive processes underlying animal behavior and their evolution, and is concerned with testing hypotheses about the evolution of the brain and intelligence in general. It is a developing field still challenged by conceptual and methodological issues. Systematic cross-species comparisons of cognitive abilities, taking both phylogeny and ecology into account are still scarce. One major reason for this is that it is very hard to find universally applicable paradigms that can be used to investigate the same cognitive ability or 'general intelligence' in several species. Many comparative paradigms have not paid sufficient attention to interspecific differences in anatomical, behavioral and perceptual features, besides psychological variables such as motivation, attentiveness or neophobia, thus potentially producing misrepresentative results. A new stance for future comparative research may be to establish behavioral and psychological profiles prior or alongside to comparing specific cognitive skills across species. Potentially revealing profiles could be obtained from examining species differences in how novel experimental (extractive foraging) tasks are explored and approached, how solutions are discovered and which ones are preferred, how flexibly multiple solutions are used and how much individual variation occurs, before proceeding to more detailed tests. Such new comparative approach is the Multi-Access-Box. It presents the animal with a novel problem that can be solved in several ways thus offering the possibility to examine species differences in all the above, and extract behavioral and perceptual determinants of their performance. Simultaneously, it is a suitable paradigm to collect comparative data about flexibility, innovativeness and problem solving ability, i.e., theoretical covariates of 'general intelligence', in a standardized manner.

Summary Accounts of complex tool innovations in animals, particularly in species not adaptively specialized for doing so, are exceedingly rare and often linked to advanced cognitive abilities in the physical domain [1], even though the relation between such capabilities and intelligence is poorly understood [2]. For this reason, discoveries of such capabilities transcend anecdotal value and contribute significantly to comparative cognition [3–5]. Among birds, there are several reports of tool innovations in corvids, but very few documented records in other families (for example [1,3–7]). Here, we report a case of spontaneous tool innovation in the Goffin's cockatoo ( Cacatua goffini ), a species endemic to the Tanimbar archipelago in Indonesia. Like most corellas, they live in social groups (∼10–100) in tropical dry forests, roost in simple tree holes, and feed mainly on a seed based diet (which occasionally causes interference with agriculture) [8]. There are no records of tool-related behavior in the wild. We report how a captive male named Figaro successfully, reliably and repeatedly made and used stick-type tools to rake in food, manufacturing them from two different materials and displaying different steps and techniques.

This study depicts how captive kea, New Zealand parrots, which are not known to use tools in the wild, employ a stick-tool to retrieve a food reward after receiving demonstration trials. Four out of six animals succeeded in doing so despite physical (beak curvature) and ecological (no stick-like materials used during nest construction) constraints when handling elongated objects. We further demonstrate that the same animals can thereafter direct the functional end of a stick-tool into a desired direction, aiming at a positive option while avoiding a negative one.

The ‘Support Problem’ is a benchmark test to investigate the understanding of spatial relationships between objects. We tested kea parrots' performance in a paradigm that has previously been studied in primates. Kea perform comparably well to tamarins when they are confronted with a choice between two support devices, one of which has a reward resting on it and the other slightly next to it, or when given a choice between a continuous and a disrupted support. Kea did better than chimpanzees in some tasks in which the perceptual connection of the food to the support was altered. The results indicate that kea are capable of assessing the spatial means–end relationships of this problem spontaneously and in a way that is comparable with primates.