Researchers have discovered that New Caledonian crows and kea parrots can learn about the usefulness of objects by playing with them -- similar to human baby behaviour.

The study, led by researchers at the Universities of York and St Andrews, demonstrated that two types of bird were able to solve tasks more successfully if they had explored the object involved in the task beforehand.

It has long been thought that playful exploration allows animals to gather information about their physical world, in much the same way that human infants learn about their world through play.

In one of the first direct tests of this hypothesis, scientists studied two bird species, the New Caledonian crow and the kea parrot, to understand how they interact with objects before, during and after a task involving that object.

Dr Katie Slocombe, from the University of York's Department of Psychology, said: "Both species of bird are known for exploring objects in different ways. The New Caledonian crow use objects in the wild and the kea parrot is known for often being destructive in its play back in its native New Zealand.

"We found that both species were better at selecting the correct tools to solve a task if they had the opportunity to explore them beforehand, suggesting that they were learning something about the properties of them as they interacted with them."

The team presented the birds with blocks and ropes of different colours, weights and patterns to explore and play with, before presenting a task where they had to collapse a platform with a ball and retrieve a reward from a pipe with a stick. The ball and stick where later replaced with the blocks and ropes to see whether they could choose the right tool from their earlier play session to complete the task.

The team suggests that applying this simple test to other species may shed more light on the different functions of play and exploration and its relation to tool use and physical problem solving.

Megan Lambert, PhD student at the University of York, said: "This type of 'latent learning', which occurs without any reinforcement, is thought to be particularly important for animals to be able to use objects as tools in a variety of contexts for creative problem-solving.

"Although the birds appeared to learn from their exploration, we found no evidence that the birds changed the way they interacted with the objects after learning they could be used as tools.

"This means that the birds did not appear to explicitly seek information about the objects, but rather learned about their properties incidentally through exploring them."