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POTENTIAL NESTING SITE ANALYSIS OF RED-CROWNED CRANES USING GIS 
Hiroshi MURAKAMI 
Geographical Survey Institute, Japan 
and 
Koichi HIRATA 
PASCO Corporation, Japan 
Commission IV, Working Group 1 
KEY WORDS: GIS, Modeling, Analysis, Spatial, Environment, Spatial Analysis, Potential Habitat Analysis. 
ABSTRACT: 
Red-crowned cranes (Grus japonesis), once considered extinct, has been increasing in number in eastern Hokkaido, 
anorthern island of Japan. One of the recent concerns about the cranes has been that the habitat in eastern 
Hokkaido may not be large enough to accommodate the increasing number of cranes. This study focuses on the 
breeding areas, especially the nesting areas of the cranes to develop a simple nesting site selection model using 
GIS so that the model will be used to help find suitable nesting areas in other parts of the island. 
Geographic features in 1:25,000 scale maps and existing nest location points were digitized and a nesting site 
selection model developed for Kushiro Wetland with GIS. Potential nesting areas located by applying this model 
were small and existed only along the edge of the wetland. The result was consistent with the understanding of 
experts on the cranes whose breeding environment is becoming undesirable. It is expected that GIS will be also 
useful for the subsequent analyses required to find new nesting areas other than eastern Hokkaido. 
1. INTRODUCTION 
Red-crowned cranes (Grus japonesis), called Tancho in 
Japanese, inhabit Hokkaido, a northern island of Japan. 
They were once considered extinct about 80 years ago, 
because of overhunting and loss of habitats (Masatomi, 
1993). However, in the 1920s, a few cranes were found 
to exist in Kushiro Wetland located in eastern Hokkaido 
(Saito, 1926). Since then they have been well protected, 
designated as a special national natural monument by 
the Japanese Government, and increasing in number. 
Especially, local people's effort to feed them during 
winter greatly helped the cranes survive and increase. 
The number of cranes has been counted in winter 
through annual crane census since 1952. Now, about 
600 cranes are identified in eastern Hokkaido. Although 
the crane population is steadily increasing, its habitats, 
especially, the breeding areas, are decreasing. 
Agricultural, industrial and residential development 
have reduced one-third of the Kushiro Wetland, the 
largest wetland in Japan, during the last 20 years, and 
the crane population density in the wetland doubled 
between 1988 and 1992 (Masatomi, 1993). 
Surveys on the crane nesting sites have indicated that 
most of the cranes in Kushiro Wetland select their 
nesting sites in low moor and use decaying reeds to 
make their nests. But the cranes are very adaptable in 
their nesting site selection, and those nesting in other 
wetlands such as Nemuro and Tokachi areas make 
their nests in near open marshes, and mud flats. 
Consequently, it is difficult to tell what environment 
should be preserved (Masatomi, 1993). Herr and 
Queen (1993) also indicated the difficulty of modeling 
the nesting habitat of greater sandhill cranes in 
northwestern Minnesota using GIS. 
Recognizing the steady increase in the number of the 
cranes and continuing development pressure on their 
habitats, however, it is practical to assume that the 
current breeding areas in eastern Hokkaido will 
someday be oversaturated for the cranes. Masatomi 
(1993) pointed out that the nesting sites are increasing 
in peripheral zones of the Kushiro Wetland where the 
accessibility to predators such as minks and foxes are 
high. High vulnerability of chicks and juveniles to such 
predators creates great concern about the future 
population of the cranes. Experts agree that the current 
number, about 600, is not enough to maintain the 
species against diseases and natural disasters and at 
least over 1,000 cranes are necessary. In that case, 
new habitat areas other than eastern Hokkaido need to 
be found for the cranes. 
The goal of this research is to find suitable nesting 
areas for red-crowned cranes in Hokkaido other than 
eastern part using GIS. To attain this goal, the research 
was divided into three stages: (1) spatial analysis of 
existing nesting sites in a study area to develop a 
simple model on the nesting conditions; (2) same 
analysis as (1) for whole eastern Hokkaido in which 
there exist a variety of natural environments from 
ordinary wetlands to coastal areas including open 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B4. Vienna 1996