Ten surplus eggs are transferred each year from a number of zoos and breeding colonies in the U.S. to Khinganski Nature Reserve. According to National Aviary's Curator of Birds, James A. Bonner, the eggs are first carried to Pittsburgh in foam-lined plastic coolers using hot water bottles for heat. For the long trip to Siberia, the eggs are transported in an insulated plywood box with two chambers. The top contains the eggs cradled in foam. The bottom chamber holds two to three rubber hot water bottles that provide heat for the eggs.
Hot water is carried in a thermos to recharge the hot water bottles along the way.
As with any incubator, the temperature must be closely monitored and the eggs periodically turned for correct development. The trip takes a day and a half, first by plane through Seattle and Anchorage to Kharborov, Russia, then via the Trans-Siberian Railway to the nearest town to the reserve, but so far, all the eggs have arrived in good shape. In November of 1998, a white-naped crane from the 1996 transfer was spotted in Izumi, Japan. The sighting was the first evidence that one of the hand-raised cranes had migrated successfully.