It was a time of new beginnings at the National Zoo.

At 7:30 a.m., a baby wildebeeste, sex undertermined, raised its tiny head and announced its arrival with a sharp squeak.

And at 11:30 a.m., officials and guests raised their balloons to the sky and announced the arrival of the Zoo's new trail system.

All around, it was a festive day.

Modernistic totem poles decorated with large graphic designs point the way to the zebra, elephant, lion, duck, crowned crane or polar bear trails. Over-sized animal footprints give zoo visitors step-by-step directions to the different exhibits.

And after the ceremonial ribbon was cut (black plastic leaf bags taped together), about 100 people trudged up Crowned Crane Trail led by Dillon Ripley, secretary of the Smithsonian Institution, and followed by a piper playing "When the Saints Go Marching In" on the clarinet.

Children ran squealing between adult legs and balloons got tangled around their knees. Some tripped. All laughed.

A little boy, one of 75 campers from Camp Shalom in Silver Spring, Md., sat on the pavement and traced a crane footprint with his toe. His eyes were wide. "Are the birds really this big?" he asked.

"Now we're going to be able to find our way around because of good design," said Nancy Hanks, chairman of the National Endowment for the Arts, who is given much of the credit for the system's success.

The NEA and the Smithsonian financed the project, which began four years ago to simplify and centralize the existing hodge-podge of directions.

But until a week ago, there was little evidence in the zoo that a new graphic trail system was finished. Or even started.

But then work crews hit the trails like a swarm of locusts. They pounded and plastered and put up signs for a week.

There was a rumor about the wildebeeste at the champagne luncheon yesterday. A suggestion, really, about a way to connect the two great events of the day.

The new wildebeeste, with the screechy voice and the wobbley knees, may just be named "Nancy Hanks."

"Well," said one by-stander, "We're not sure yet, but Nancy if it's a girl, Hank if it's a boy."