ANALYSIS OF THE SEASONAL MIGRATIONS OF MONGOLIAN GAZELLE,
USING MODIS DATA
N. Miura* *, T, Y. Ito”, B. Lhagvasuren ©, D. Enkhbileg‘“, A. Tsunekawa ^ S. Takatsuki “, Z. Jiang‘, K. Mochizuki *
?* PASCO CORPORATION, 1-1-1 Higashiyama, Meguro-ku, Tokyo 153-0043 Japan, - naoko_miura(@pasco.co.jp
° Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-
8657 Japan
* Institute of Biology, Mongolian Academy of Science, Ulaanbaatar 51, Mongolia
4 The University Museum, The University of Tokyo, 7-3-1 Hong, Bunkyo-ku, Tokyo 113-0033 Japan
® Yamanashi Institute of Environmental Sciences, 5597-1 Kenmarubi, Kamiyoshida, Fujiyoshida, Yamanashi 403-0005
Japan
KEY WORDS: Ecology, Monitoring, GIS, Ecosystem, Satellite, Tracking
ABSTRACT:
Conservation and management for Mongolian gazelles (Procapra gutturosa), which inhabits steppes in Mongolia, northern China,
and southern Russia, are urgently required. The Mongolian gazelle migrates hundreds or thousands of kilometers seasonally,
however details of the migration routes are still unknown, because of difficulty in continuous tracking. The objectives in the present
study are to describe the migration routes of Mongolian gazelles using satellite tracking, and to examine whether their seasonal
migrations are influenced by change in normalized difference vegetation index (NDVI) in their habitat. We captured four gazelles in
Omnogobi Province and Dornogobi Province in Mongolia and tracked their location from October 2002 to October 2003. Satellite
tracking provided details of their migration routes, and their cumulative moving distances were more than 1000 km. Sift of NDVI
values derived from moderate resolution imaging spectrometer (MODIS) satellite image between summer and winter ranges
corresponded with seasonal migrations of gazelles in Omnogobi. In Dornogobi, NDVI values of the summer ranges were higher in
summer and lower in winter than those of overall average, although NDVI values of the winter ranges were higher than those of the
summer ranges almost throughout the year. The gazelles seem to migrate seasonally, depending on the seasonal change of habitat
quality between summer and winter ranges. NDVI was an effective indicator for evaluating the gazelle habitat. Therefore, it could
explain seasonal migrations of the gazelles. However, the seasonal migrations in some areas were not explained by the NDVI sifts
between the ranges. Thus, it is recommended to examine the effective extent and the limitation of NDVI as an indicator.
1. INTRODUCTION
Mongolian gazelles (Procapra gutturosa), which inhabit
steppes in Mongolia, northern China, and southern Russia, were
listed in the Red List of IUCN as Near Threatened (LR/nt)
(IUCN 1996), therefore conservation and management for them
are urgently required (Jiang et al., 1998; Reading et al., 1998) as
total population has decreased from about 1.5 million heads in
the 1940's to 300,000-500,000 at present (Lhagvasuren and
Milner-Gulland, 1997; Jiang et al, 1998). The Mongolian
gazelle migrates hundreds or thousands of kilometers seasonally,
however details of the migration routes are still unknown,
because of difficulty in continuous tracking.
To conserve the animals that migrate long distances, it is
necessary to know their migration routes and reasons why they
migrate on such routes. Although it is difficult to know the
migration routes of long distances, over the last decade, the
advent of reliable satellite tracking technology enabled the
study of such long-distance movements (Gillespie, 2001;
Akesson, 2002; Webster et al, 2002; Nathan et al, 2003).
Besides, Satellite imagery and remote sensing technology have
been widely used to assess habitat extent and quality in ungulate
studies (e.g. Unsworth et al., 1998; Bowyer et al., 1999).
* Corresponding author.
For ungulates inhabiting grasslands, above ground net primary
productivity is strongly correlated with habitat quality
(McNaughton, 1985, 1993; Frank and McNaughton, 1992). It is
possible to use the normalized difference vegetation index
(NDVI; Lillesand and Kiefer, 1999) calculated from satellite
image as an index for habitat quality. The NDVI represents the
difference in reflection between the near infrared and red parts
of the electromagnetic spectrum (Eidenshink and Faundeen,
1994) and works well in measuring plant biomass and
productivity because healthy green vegetation reflects strongly
in the near infrared but absorbs most light in the red. There are
good statistical relationships between the NDVI and biomass
and/or productivity (Cihar et al, 1991; Paruelo and Laurenroth,
1995: Paruelo et al, 1997), and NDVI has been used to
estimate the quality of the habitat of the Mongolian gazelle
(Leimgruber et al., 2001).
Leimgruber et al. (2001) shows that winter and calving grounds
had highest NDVI scores during period of use by gazelles in
eastern Mongolia, suggesting that gazelle movements track
shifis in primary productivity across the steppe. However they
just delineated the habitat types within the gazelle range (i.e.
winter, summer, and calving grounds) by literatures and expert
knowledge, not by actual migration data (Leimgruber et al.,
2001), due to lack of data of migration routes and habitat
selection of gazelles. If migration routes and habitat selection of
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