breeding and wintering grounds was announced by the
Ministry of the Environment, and the ultimate aim was to
extend their distribution to their former habitats on the
Honshu Island. The successful establishment of several
wintering grounds will effectively mitigate the risk of
disease spread.
Achieving this goal implies that additional artificial
feeding sites will be needed in other areas because of the
lack of appropriate natural foraging sites during winter;
however, this is not concordant with another important
management goal of enabling cranes to survive without
artificial feeding during winter. The artificial feeding, ini-
tiated in the 1950s, has greatly contributed to population
recovery; however, now wildlife management must con-
sider how this population will persist without human
intervention (Masatomi and Masatomi 2009). This task will
be a significant challenge because extensive and long-term
management efforts are required such as restoration of the
wetland ecosystem, creation of natural foraging sites, and
development of adequate measures for the prevention of
agricultural damage caused by cranes (Masatomi and
Masatomi 2009; Masatomi et al. 2007). Dispersing cranes
into unoccupied areas along with improving and restoring
their foraging habitat will be crucial for the persistence of
cranes in Japan.
This study is the first to investigate the genetic structure
of the non-migratory red-crowned cranes in Hokkaido. Our
findings suggest that natal philopatry plays an important
role in shaping the genetic structure, which should be
considered when developing management strategies. It is
possible that a few newly built nests in northern Hokkaido
may be comprised of closely related individuals due to
natal philopatry. It is needed to monitor the individual
exchange between northern and eastern Hokkaido, and if
the northern group is demographically isolated, manage-
ment actions that facilitate gene flow between the two
regions will be needed. The present study highlights the
need for further research into the mechanism underlying
pair formation and the dispersal patterns of a greater
number of individuals. First-time pair formation and natal
dispersal are probably important for the genetic structure,
considering the high adult survival rates (Masatomi et al.
2007), strong pair bonds, and strong fidelity to nest sites
exhibited by the breeding pairs. The accumulation of
observational data on banded individuals or GPS tracking
data (Masatomi et al. 2008) will help to better understand
the mechanisms shaping the genetic structure and predict
population expansion into unoccupied areas.