The only natural whooping crane flock reached a record population of 266 in December 2007, continuing its average annual growth rate of 4%.  This flock had been reduced to only 15 birds by 1941.  It migrates 2,400 miles each spring and fall between Aransas National Wildlife Refuge on the Texas Coast and Wood Buffalo National Park in the Northwest Territories, Canada.  An excellent production year in Canada in 2008 totaling 41 fledged chicks from a record 66 nests should lead to a substantial population increase in the flock in the 2008-09 winter.  However, threats to the flock including water and land development in Texas, wind farm and power line construction in the migration corridor, and tar sands waste ponds in Canada all increased in 2008.

The safety net for the Aransas flock currently lies in 151 whooping cranes held in captivity at five breeding centers and six zoos.  The captive flocks had a good production season in 2008 which help lift the total population of wild (n=387) and captive (n=151) whooping cranes to 538.

Reintroduced flocks in the eastern U.S. are struggling to be self-sustaining.  In 2008, production in the wild from both reintroduced flocks was a disappointing “zero”.  In Wisconsin, all 11 nesting pairs abandoned their nests just prior to expected hatching.  Twenty-two captive chicks are expected to be reintroduced into the eastern migratory population in the fall of 2008, bringing that flock to 91 total birds.  In the Florida non-migratory flock, five chicks hatched from a total of three first nests and two re-nests, but none of the chicks survived past 25 days of age.  The Whooping Crane Recovery Team has recommended not putting any more birds into the non-migratory Florida flock since that flock has experienced high mortality and low production since its inception in 1993.