Some consider Kakadu National Park to be Australia's answer to the Serengeti, because it supports such a wealth of wildlife. In addition to the birds, crocodiles, dingoes, snakes, turtles, lizards, and other animals seen in the NATURE program THE CALL OF KAKADU, the park's 6,600 square miles of woodlands, wetlands, and floodplains are home to an amazing array of wildlife, including more than 300 species of birds (a third of all the bird species in Australia), 75 species of reptiles, 50 species of mammals, 1,500 species of butterflies and moths, 50 species of fish, 25 species of frogs, and thousands of species of plants, many of which remain unclassified.

The most prominent physical feature in Kakadu is the Arnhem Land Escarpment, a 1.6 billion-year-old sandstone cliff that stretches for miles across the park. The cliff, which hosts many waterfalls, is surrounded by towers of sandstone, rainforests, and swamps. The watery billabong, or pond, that is home to the animals featured in THE CALL OF KAKADU lies at the base of the Escarpment.

Not much was known about the blue-winged kookaburra before Curl began studying it. "Every day I would see new things, like feeding behaviors and how they interact," he says. "They have fabulous fights among themselves -- quite extraordinary, really. One bird dives at another on its perch. They lock beaks and with their wings partially outstretched, plummet to the ground, still locked together. It's done to establish a hierarchy, but watching it, it's hard to tell who won."

The birds also have an odd way of preparing dinner. "When they catch some food, such as a lizard or a snake," says Curl, "they fly to a perch and thwack it on a branch to kill it or stun it. With snakes, they aren't sure which end is the head, so they just make darn sure to kill both ends."

The frill-necked lizard is also "a fabulous character," Curl notes. "They run around the forest looking like some creature from a Steven Spielberg movie," he laughs, recalling how these prehistoric-looking reptiles scurry about on their two back legs. The lizard puff out its characteristic frill, an umbrella-like flap that normally lies flat against the neck, in order to claim its territory. "No one is sure why the frill evolved, other than for display purposes," says Curl. "It might be a cooling mechanism, similar to elephant ears." The frill is supported by a set of rods, much like the spines of an umbrella, that hold it out when the lizard opens its mouth.

Curl also spent quite a lot of time filming in the water. "The crocodiles didn't scare me," he says. "You get to know how they behave." Instead, what Curl found most frightening "was standing out on the floodplains, watching the lightning storms approach. That is really asking for trouble, because you are the only tall thing out there. It's prime habitat for death adders, the mosquitoes carry Ross River fever, and the lightning is coming nearer and nearer!" The thrill of observing these storms sweep towards him was so exhilarating, Curl says, that he now considers himself a lightning storm "addict."