Recent developments in parrot cognition: a quadrennial update.

Psittacines, along with corvids, are commonly referred to as 'feathered apes' due to their advanced cognitive abilities. Until rather recently, the research effort on parrot cognition was lagging behind that on corvids, however current developments show that the number of parrot studies is steadily increasing. In 2018, M.

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 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.

Inference by Exclusion in Goffin Cockatoos (Cacatua goffini).

Inference by exclusion, the ability to base choices on the systematic exclusion of alternatives, has been studied in many nonhuman species over the past decade. However, the majority of methodologies employed so far are hard to integrate into a comparative framework as they rarely use controls for the effect of neophilia. Here, we present an improved approach that takes neophilia into account, using an abstract two-choice task on a touch screen, which is equally feasible for a large variety of species.

Unrewarded Object Combinations in Captive Parrots.

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.

Combinatory actions during object play in psittaciformes (Diopsittaca nobilis, Pionites melanocephala, Cacatua goffini) and corvids (Corvus corax, C. monedula, C. moneduloides).

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.

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).

Explorative learning and functional inferences on a five-step means-means-end problem in Goffin's cockatoos (Cacatuagoffini).

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.

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.

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.

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.

Kea (Nestor notabilis) consider spatial relationships between objects in the support problem.

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.