Spatial patterns in relative primary productivity and gazelle migration inthe Eastern Steppes of Mongolia

The Mongolian gazelle (Procapra gutturosa) of the Eastern Steppes of Mongol ia shows seasonal migrations to traditional winter and calving grounds with diffuse movements during the intervening periods. We used a normalized dif ference vegetation index (NDVI), derived from coarse-resolution satellite i magery, to map relative primary productivity of steppes between April 1992 and December 1995. Productivity peaks were variable between years, but wint er, and calving grounds had highest NDVI scores during periods of use by ga zelles. Gazelle movements to these areas track shifts in primary productivi ty across the steppe. Diffuse movements in summer were not matched to peaks in productivity. Productivity 'hotspots' utilized by gazelles during criti cal periods in their life cycle should be first priority for conservation a nd the impact of livestock grazing on these areas should be evaluated. (C) 2001 Elsevier Science Ltd. All rights reserved.