Reinforcement project and breeding cases of introduced endangered Red-crowned Cranes Grus japonensis in Yancheng National Nature Reserve, China

The Red-crowned Crane Grus japonensis is an endangered species in East Asia. The western flyway population in China has been in steady decline in recent years because of the loss and deterioration of the natural wetland habitat it requires. To enhance this migratory Red-crowned Crane population, a project was designed to return captive Red-crowned Cranes to the wild in 2013 and 2015 in the Yancheng National Nature Reserve (YNNR). This reserve is the most important wintering site for the continental migratory population. The survival rate of introduced Red-crowned Cranes was 40%. However, aggregation of introduced and wild individuals was not observed. Introduced individuals did not pair with wild individuals nor did they migrate to breeding areas with them. They remained in the core zone of the YNNR over summer. Here, we report the first breeding of introduced Red-crowned Cranes in the YNNR in 2017 and 2018. Suitable rearing methods and the use of aircraft to inform them of the migration route are necessary. Further research is necessary to confirm the migratory status of the cranes that are reared in the reserve.