What do corvids, parrots, and hornbills have in common? They are all members of a select group of bird species that possess remarkable cognitive abilities, rivaling those of apes.

This is the conclusion of a groundbreaking study conducted by two animal behaviorists at the National University of Singapore, who revealed that Oriental pied hornbills have a sophisticated understanding of object permanence - the ability to remember or know that something still exists even when it is hidden from view.

A Breakthrough Discovery in Avian Cognition

Object permanence is considered a key indicator of intelligence, as it requires mental representation, memory, and inference. It is also a prerequisite for more complex cognitive skills, such as causal reasoning, planning, and deception.

Until recently, only two bird groups - corvids (crows, ravens, magpies, etc.) and parrots - were known to exhibit object permanence levels comparable to apes.

However, the new study by Ruitong Yao and Elias Garcia-Pelegrin, published in the journal Animal Cognition, adds a third group to this exclusive club: hornbills.

Yao and Garcia-Pelegrin tested the object permanence abilities of four captive Oriental pied hornbills, using a series of tasks that involved hiding food items under cups, boxes, or cloth.

The tasks varied in difficulty, from simple visible displacements (where the food was hidden in plain sight) to invisible displacements (where the food was hidden out of sight).

The researchers found that the hornbills performed exceptionally well, solving all the tasks with high accuracy and speed. They also showed evidence of inferential reasoning, as they were able to track the location of the food even when it was moved between different hiding places.

The researchers were surprised by the hornbills' performance, as they had expected them to struggle with the more difficult tasks.

They attributed their success to their natural history and ecology, as hornbills are highly social, long-lived, and adaptable birds that face various challenges in their environment, such as finding food, avoiding predators, and competing for mates.

These factors may have favored the evolution of advanced cognitive abilities in hornbills, as they have in corvids and parrots.

Implications for Conservation and Education

The discovery of hornbill intelligence is not only a scientific breakthrough, but also has important implications for conservation and education.

Hornbills are among the most threatened bird groups in the world, due to habitat loss, hunting, and poaching.

Understanding their cognitive abilities can help design more effective conservation strategies, such as providing them with suitable habitats, food sources, and enrichment activities.

It can also help raise awareness and appreciation for these magnificent creatures, which are often overlooked or misunderstood by the public.

Furthermore, the study can also inspire and educate future generations of scientists, as it demonstrates the power of curiosity, creativity, and collaboration in scientific inquiry.

Yao and Garcia-Pelegrin are both young researchers who pursued their passion for animal behavior and cognition, despite the challenges and uncertainties of the field.

They also collaborated across disciplines and cultures, as Yao is a Chinese national who studied in Singapore, while Garcia-Pelegrin is a Spanish national who studied in the UK.

Their work showcases the diversity and richness of scientific research, as well as the potential for new discoveries and insights in the study of animal minds.

The study by Yao and Garcia-Pelegrin is a milestone in the field of avian cognition, as it reveals the hidden intelligence of hornbills, and challenges our assumptions and stereotypes about bird brains.

It also opens up new avenues for further research, as there may be many more bird species that possess similar or even greater cognitive abilities than hornbills. As the researchers conclude, "the sky is the limit" for exploring the minds of birds.