Franklin Park's two pair are significant because they are the only Siberian cranes in a zoo that are proven breeders. However, they will almost certainly mate naturally as well. The eggs could be laid sometime in mid to late May, and would hatch after an incubation period of 28-30 days. If all goes well, the eggs will be naturally incubated and parentally reared. Zoo New England has again been asked to attempt to breed its two pair of Siberian crane, per direction of the Global Captive Action Plan, which includes Siberian crane experts from North America, Russia, India, China and Iran, as well as government officials from the crane's native habitats.
Siberian cranes are highly endangered for several reasons.
There are 39 known birds in captivity worldwide, and no more than 3,000 in the wild. Cranes migrate over wetlands, which have become increasingly threatened over the past several decades. The three distinct populations of the crane, all of which breed in remote areas of Siberia, have very separate wintering grounds. Each of these wintering grounds is subject to heavy encroachment and predation by man. The western population, which winters in Iran, has only nine birds.