To the casual human listener, the love song of a humpback whale sounds magnificently free-flowing and improvised. But fresh mathematical analysis of the song shows there are complex grammatical rules. Using syntax, the whales combine sounds into phrases, which they further weave into hours-long melodies packed with information.

Some whales, dolphins and porpoises are now so endangered they could vanish within a decade, scientists say.

Researchers have found six distinct groups of sperm whales. Groups that don't speak the same dialect don't appear to mix. One species of whale may speak many different dialects in different parts of the world, raising the likelihood that whales, like humans, have different nationalities and cultures that span vast areas.

Dolphins can recognise their own reflections, say researchers in the US. This shows a level of self-awareness never seen before in the animals. \"This is a very rare ability that up until now has only been shown in humans and great apes,\" says researcher Lori Marino of Emory University in Atlanta.

With brains second only to those of humans in relative size, superb memories, sonar systems more sophisticated than any Navy's, and complex social structures, dolphins are often considered geniuses of the seas. Clever mimics and quick learners, dolphins have an uncanny ability to confound researchers, those who have studied them in captivity and in the wild say. But in recent decades, scientists have made progress in unraveling the complexities of the dolphin's mind and social life, and have begun to create a detailed portrait of these remarkable animals. Now, two new, unrelated studies are reporting that dolphins are able to recognize themselves in mirrors -- often taken as a sign of self-awareness -- and of spontaneously grasping the thoughts of other individuals, in this case, humans.

Researchers at Sea Life Park Hawaii are working on a way to get humans even closer to our flipper friends: They\'re devising a common language of dolphin-like whistles. Already, dolphins recognize sounds for four words: ball, disk, leaf and barrel -- all of which are objects that the dolphins being tested are familiar with. \"We have developed a whistle word language -- words represented as whistles,\" said Dr. Ken Marten, director of the dolphin research initiative Project Delphis.

Wild dolphins greet each of their pals using individual whistle signatures. Until now this sort of behaviour has only been found in birds and humans. Previous research with captive dolphins shows that each one has a unique whistle and can mimic another dolphin's whistle perfectly after hearing it just once.

A transcript of an interview with two researchers who have examined the songs of Humpback whales and found that while they do have a grammatical structure, they do not seem to be conveying a significant amount of information.

The New Jersey State Aquarium in Camden recently unveiled Cyberfin, a virtual-reality attraction that simulates the experience of swimming with dolphins.
\"If you\'ve never swum with dolphins before, this is your chance to do it without getting wet. And it\'s one of the most relaxing experiences you can have ... a total experience, via sound, via motion, and via sight,\" said Christine Connell, sales manager for Aquathought Labs, the Florida company that developed the equipment.