Since Gallup’s pioneering study of chimpanzees¹ and Amsterdam’s later adaptation for children², the mirror self-recognition (MSR) test has been widely regarded as the primary method for assessing self-awareness across species. Although the MSR task has been highly influential, its comparative value has been widely disputed because it relies heavily on vision and may therefore be less ecologically valid for species with different dominant sensory modalities. Moreover, reports of impressive MSR-like behavior in a relatively small-brained animal such as the cleaner wrasse (Labroides dimidiatus)³ have sparked debate over what the test actually captures. This prompted a shift towards a gradualist, modular framework that accounts for species-specific sensory modalities and ecological contexts^4,5,6. As de Waal argued, animals must represent the affordances of their own bodies in relation to the physical and social environment, suggesting that mirror responses alone should not remain the sole benchmark for studying self-awareness⁶. A highly promising complementary approach is the “body-as-an-obstacle” (BAO) task. Unlike MSR, which focuses on visual self-recognition, BAO assesses whether subjects treat their own body as a causal obstacle during goal-directed action.

The BAO task measures an individual’s ability to recognize parts of their own body as an impediment to achieving a goal, thereby assessing body-related self-representation. Developed for human infants^7,8, the task requires subjects to hand over an object while standing on a mat directly attached to the object; success requires stepping off the mat to eliminate their own body weight as the source of obstruction. In a control condition, the obstruction is external (e.g., a heavy object), so stepping off is unnecessary. In humans, BAO performance emerges at roughly the same age as MSR (18–24 months) and correlates moderately with it^7,9. Cross-cultural work shows that infants from autonomy-oriented cultures tend to pass MSR earlier, whereas those from relatedness-oriented cultures succeed earlier on BAO⁹. These findings indicate that MSR and BAO follow distinct developmental trajectories and rely on distinct processes. At the same time, they represent different modes of self-representation. Because BAO targets the embodied self, it offers a valuable alternative for species in which vision is not the dominant sensory modality.

From a cognitive standpoint, both MSR and BAO require causal reasoning, but they differ in sensory demands. MSR depends on recognizing visual contingencies and features, whereas BAO relies on awareness of direct body-environment interaction without requiring an external visual representation^7,9. Because BAO lacks visual prerequisites, it does not require prior mirror experience or visual inspection of the body, which may render it more ecologically valid for animals that rely primarily on non-visual modalities¹⁰. These advantages have motivated recent applications of BAO to non-human species.

Researchers have increasingly used the BAO paradigm to assess body awareness in nonhuman animals, with positive results in elephants, dogs, chimpanzees, and lowland gorillas^10,11,12. Because elephants’ size and strength precluded an “impossible” control, Dale and Plotnik included an unattached control and a foot-discomfort control; elephants stepped off the mat significantly more often in the test than in either control, whereas the two controls did not differ significantly from one another¹¹. In dogs, Lenkei et al. implemented both controls and an attached-to-ground condition, and dogs again left the mat more often and sooner in the test than in the critical attached control, including in the first trial¹⁰. Vanhooland et al. later adapted BAO for great apes using a non-social design and a single control analogous to the unattached condition used in earlier studies¹².

Together, these three studies showed that success on BAO, although correlated with MSR in humans, can be passed independent of having passed MSR in these animals. Adult Asian elephants and great apes have demonstrated MSR under certain conditions (e.g., after appropriate prior experience;^13,14,15), whereas dogs have not¹⁶, suggesting that body awareness may be evolutionarily widespread and may represent a fundamental, ecologically relevant component of self-representation.⁴

Although BAO has not yet been adapted for birds, there are strong reasons to do so. Birds, particularly parrots and corvids, have demonstrated a cognitive toolkit comparable to that of great apes^17,18, yet they have often yielded inconsistent evidence under MSR paradigms (e.g., replication attempts have yielded different results^19,20). This evidence, together with behavioral and neuroanatomical findings often linked to MSR in mammals^21,22,23, has led several authors to advocate avian species as compelling non-primate candidates for testing self-awareness using better-adapted methodology⁵.

Goffin’s cockatoos (Cacatua goffiniana) are highly innovative problem-solvers: they flexibly manufacture, modify, and use tools, and they engage extensively in haptic exploration with their beak and feet^18,24,25,26. This tactile interaction style aligns well with the embodied, action-based demands of BAO. Like other parrots tested thus far, Goffin’s cockatoos have failed in attempts to test MSR²⁷.

However, sulfur-crested cockatoos have been observed opening rubbish bins in a manner reminiscent of BAO-type problem-solving²⁸, although the learning mechanism remains unknown: they have learned to step off the lid of a rubbish bin onto the rim of the bin, avoiding the impediment of their own body weight for opening the lid.

These observations suggest that other, highly flexible white Cacatua species, such as the Goffin’s cockatoos, are strong candidates for BAO testing.

Here, we present the first avian adaptation of the BAO paradigm, using Goffin’s cockatoos as a model species (Fig. 1; Supplementary Video S1). We employ a “give-me” command to preserve the social element of the original design and include the key control comparisons used in mammalian BAO studies (unattached and attached-to-ground), plus a pre-test controlling for foot discomfort. We conceal visual differences between test and control conditions to prevent cue-based anticipation, and we focus the analysis on the first test session to reduce the likelihood that the main condition effect reflects repeated exposure across sessions. We hypothesize that Goffin’s cockatoos would be able to treat their own body as a causal obstacle to task completion in a body-as-obstacle task.