PORTLAND, Ore. -- Children can track Santa's progress online and assist the Oregon Zoo with flying reindeer research this Christmas Eve. A toll-free number allows children to call in to a radar base in Colorado and get updates on Santa's whereabouts.

Closer to home, the Oregon Zoo is a world center for flying reindeer research. Oregon Zoo Director Tony Vecchio has studied flying-reindeer for more than a decade. He spoke on the "Mystery of Flying Reindeer" Wednesday at the zoo's Elk Meadow (left). | WATCH A VIDEO INTERVIEW

Vecchio hopes to gather new data this month during the elusive creatures' annual journey Christmas Eve. He is asking children around the world to report their sightings by visiting the Flying Reinder Report Center.

"The science of reindeer flight continues to evolve as new data pours in every Dec. 24, during their once-a-year migration," said Vecchio. "I'm asking anyone who sees flying reindeer to e-mail me with details, such as where they saw the reindeer, what time it was and how high they were in the sky."

Updates from NORAD

Deputy reindeer researchers can get a boost from the North American Aerospace Defense Command, or NORAD, at Peterson Air Force Base in Colorado.

Over 1,000 Santa tracker volunteers have signed on to cycle through the center answering telephone calls and e-mails from children around the world wanting to get a fix on Santa Claus' whereabouts.

A toll free number is available at 1-877-Hi-NORAD (1-877-446-6723) for children to call and personally speak to a Santa tracker on Christmas Eve. Children can also send an email to noradtrackssanta@gmail.com.

After Santa takes off from the North Pole early on Dec. 24, children can track him online with up-to-the-minute reports in Google Maps and Google Earth and can view video captured by NORAD's Santa cams from several key stops. All of this information is available on the Web site in English, French, German, Italian, Japanese, Spanish and Chinese.

NORAD serves millions of children around the world on Christmas Eve, even documenting how Santa avoids homes where children are not asleep.

"In years past, Santa has often times had to circle back around since many of the children were not asleep when he visited them the first time," said Maj. Stacia Reddish, NORAD Tracks Santa program manager.   

"The tradition of NORAD Tracking Santa began with an errant telephone call from a child, and that is why we continue the tradition", said Maj. Reddish.   "Although the Web site has a huge audience, many children still like to call the Operations Center to talk to a real person. In fact, last year, the Santa trackers answered about 40 calls per hour from children around the world."

Oregon Zoo director resident expert on reindeer

Vecchio from the Oregon Zoo began studying reindeer flight when he was asked to theorize the concept for Robert Sullivan's 1996 book "Flight of the Reindeer."

Sullivan, a senior editor at Life magazine, consulted with respected scientists, zoologists and Arctic explorers for his book, which aims to document and explain the mysterious phenomenon.

Learn more about flying reindeer in this video interview with Vecchio: