According to a new book, The Australian Magpie by the University of New England animal behaviouralist Professor Gisela Kaplan, magpies lead much more complicated lives than we ever thought. Kaplan says her book, due for release this week, is the first to comprehensively deal with the bird's biology and behaviour. While magpies might all look very similar to the casual observer, no two act the same, says Kaplan, who has studied them for nearly a decade.

Behind almost every one of their actions and rituals is a depth of complexity which is not yet fully understood, she says. Magpies may have capabilities comparable to a dog's, or perhaps even a primate's, and are at least as smart as the raven - another bird whose mind becomes more impressive the closer researchers look. "Magpies are certainly outstanding communicators and they keep surprising me with their ability to solve problems, suggesting a cognitive framework that is probably in the higher domain," says Kaplan. The more we study them, the more likely it seems magpies even have a rudimentary vocabulary allowing them to distinguish between a ground and an air predator, she says.

"They have incredible ability, flexibility and range in the sheer number of songs and calls they can make - there are at least seven or eight different alarm calls alone." Kaplan has observed "inexplicable altruism" in the birds, witnessing events such as the intervention of a group of magpies to save the life of a crested pigeon under attack from a Little Eagle.

Along with their distinctive appearance and cheeky nature, magpies are most famous for their calls, especially their carolling which has been measured by Kaplan at up to 127 decibels - similar in noise to a motorbike at full pelt. Carolling is the magpie's answer to almost every property dispute. It is so potent that scientific studies have shown that playing a recording of a dominant mapgie's song - after the magpie has been removed - is enough to enforce its territory. However, the quiet warbling sometimes practised by an individual probably has no significance in terms of breeding or territory protection, says Kaplan. It may actually be not unlike a human humming a tune. "The context in which sub-song appears makes me tempted to designate it as a leisure activity," writes Kaplan in her book.

"To call magpie song a 'leisure activity', is to describe a function that is generally not acceptable in science. All behaviour is meant to have a function by contributing to the survival of the species. However, humans have leisure time, free time beyond the demands of survival." Kaplan has also discovered that coupling or "pair bonding" between magpies varies as much as it does in humans. There are monogamous magpies and others who are hopelessly promiscuous. One similarity among all magpie males, however, seems to be a thriftiness in the courtship stakes. The blokes rarely partake of anything more than the most cursory of foreplay.

Kaplan even believes the birds have behavioural mechanisms for breaking up. "Although there is no published evidence of magpie 'divorces' - let alone the possible reason for them - my own anecdotal evidence suggests that they do exist," Kaplan writes. Another trait setting them apart from most other Australian birds is their playfulness. "Play is normally associated with mammals to hone their skills that they need later for survival." Magpies are regularly observed on their backs during play, a behaviour also found as submission in subordinate adults. "They roll around, breast bump each other, pull on wings, run after each other, hide, crouch, engage each other with legs, play fight, peck, grasp, jump and even play hide-and-seek."

In one other respect, magpies show behaviours we recognise: young birds are forbidden from carolling and warbling when the adults are around, Kaplan says. "They seem to have an adage that kids should be seen and not heard," she says.