Alice M. I. Auersperg

Flexibility in Problem Solving and Tool Use of Kea and New Caledonian Crows in a Multi Access Box Paradigm

Parrots and corvids show outstanding innovative and flexible behaviour. In particular, kea and New Caledonian crows are often singled out as being exceptionally sophisticated in physical cognition, so that comparing them in this respect is particularly interesting. However, comparing cognitive mechanisms among species requires consideration of non-cognitive behavioural propensities and morphological characteristics evolved from different ancestry and adapted to fit different ecological niches. We used a novel experimental approach based on a Multi-Access-Box (MAB). Food could be extracted by four different techniques, two of them involving tools. Initially all four options were available to the subjects. Once they reached criterion for mastering one option, this task was blocked, until the subjects became proficient in another solution. The exploratory behaviour differed considerably. Only one (of six) kea and one (of five) NCC mastered all four options, including a first report of innovative stick tool use in kea. The crows were more efficient in using the stick tool, the kea the ball tool. The kea were haptically more explorative than the NCC, discovered two or three solutions within the first ten trials (against a mean of 0.75 discoveries by the crows) and switched more quickly to new solutions when the previous one was blocked. Differences in exploration technique, neophobia and object manipulation are likely to explain differential performance across the set of tasks. Our study further underlines the need to use a diversity of tasks when comparing cognitive traits between members of different species. Extension of a similar method to other taxa could help developing a comparative cognition research program.

Spontaneous innovation in tool manufacture and use in a Goffin's cockatoo.

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 Goffins 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.

Goffin cockatoos wait for qualitative and quantitative gains but prefer 'better' to 'more'.

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.

Explorative Learning and Functional Inferences on a Five- Step Means-Means-End Problem in Goffin's Cockatoos (Cacatua goffini)

To investigate cognitive operations underlying sequential problem solving, we confronted ten Goffin’s cockatoos with a baited box locked by five different inter-locking devices. Subjects were either naïve or had watched a conspecific demonstration, and either faced all devices at once or incrementally. One naïve subject solved the problem without demonstration and with all locks present within the first five sessions (each consisting of one trial of up to 20 minutes), while five others did so after social demonstrations or incremental experience. Performance was aided by species-specific traits including neophilia, a haptic modality and persistence. Most birds showed a ratchet-like progress, rarely failing to solve a stage once they had done it once. In most transfer tests subjects reacted flexibly and sensitively to alterations of the locks’ sequencing and functionality, as expected from the presence of predictive inferences about mechanical interactions between the locks.

Navigating a tool end in a specific direction: stick-tool use in kea (Nestor notabilis)

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.

Object Permanence in the Goffin Cockatoo (Cacatua goffini)

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.

Flexible decision-making relative to reward quality and tool functionality in Goffin cockatoos (Cacatua goffiniana)

Decisions involving the use of tools may require an agent to consider more levels of relational complexity than merely deciding between an immediate and a delayed option. Using a new experimental approach featuring two different types of tools, two apparatuses as well as two different types of reward, we investigated the Goffin cockatoos’ ability to make flexible and profitable decisions within five different setups. Paralleling previous results in primates, most birds overcame immediate drives in favor of future gains; some did so even if tool use involved additional work effort. Furthermore, at the group level subjects maximized their profit by simultaneously considering both the quality of an immediate versus a delayed food reward (accessible with a tool) and the functionality of the available tool. As their performance levels remained stable across trials in all testing setups, this was unlikely the result of a learning effect. The Goffin cockatoos’ ability to focus on relevant information was constrained when all task components (both food qualities, both apparatuses and both tools) were presented at the same time.

A new approach to comparing problem solving, flexibility and innovation

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.

Goffin's cockatoos make the same tool type from different materials

Innovative tool manufacture is rare and hard to isolate in animals. We show that an Indonesian generalist parrot, the Goffins 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.

The temporal dependence of exploration on neotic style in birds

Exploration (interacting with objects to gain information) and neophobia (avoiding novelty) are considered independent traits shaped by the socio-ecology of a given species. However, in the literature it is often assumed that neophobia inhibits exploration. Here, we investigate how different approaches to novelty (fast or slow) determine the time at which exploration is likely to occur across a number of species. We presented four corvid and five parrot species with a touchscreen discrimination task in which novel stimuli were occasionally interspersed within the familiar training stimuli. We investigated the likelihood that an animal would choose novelty at different stages of its training and found evidence for a shift in the pattern of exploration, depending on neotic style. The findings suggest that faster approaching individuals explored earlier, whilst animals with long initial approach latencies showed similar amounts of exploration but did so later in training. Age rather than species might have influenced the amount of total exploration, with juveniles exploring more than adults. Neotic style varied consistently only for one species and seems to involve a strong individual component, rather than being a purely species-specific trait. This suggests that variation in behavioural phenotypes within a species may be adaptive.