Mysteries of the elusive flying reindeer will be revealed when Oregon Zoo Director and flying-reindeer expert Tony Vecchio shares his many reindeer theories with children the day before Christmas.

KGW/Oregon Zoo photo

Oregon Zoo Director Tony Vecchio stands next to a Roosevelt elk, a lesser known relative of reindeer, now visiting the zoo.

The event will take place at the zoo's Elk Meadow, Monday, Dec. 24, from 10 a.m. to 10:30 a.m. The "Mystery of Flying Reindeer" discussion is free with zoo admission.

Vecchio has studied flying reindeer for more than a decade and hopes to gather new data this month during the elusive creatures' annual journey.

He has been asking children around the world to report their sightings by visiting this Web site and clicking on the Flying Reindeer 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."

All reported sightings will be documented on a map located on the zoo's Web site. Visitors can watch a video of Vecchio discussing his theories while feeding the flying reindeer's cousin, the Roosevelt elk, by clicking here.

Vecchio 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.