The humble Australian magpie is the star of new research that suggests social interaction is key to the development and evolution of intelligence in animals.

And when it comes to developing smarts, it seems the more birds in the group, the merrier.

In a study published by the journal Nature on Wednesday, researchers from the University of Western Australia and the University of Exeter, UK, found magpies living in larger groups appeared to be smarter than those in smaller groups.

The study also found clever female birds made better mothers, with a higher success rate when it came to both hatching their eggs and raising their young.