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Animal movement is predicted to be nomadic in areas with low temporal predictability of environmental conditions, but it remains unclear whether the costs of nomadic movement outweigh the benefits received. To examine the spring movement strategy of Mongolian gazelles (Procapra gutturosa) in Mongolia, where predictability of vegetation conditions is relatively low, we identified the type of each movement, evaluated the preferred vegetation conditions for gazelles, and quantified the benefit achieved through each spring movement. The surveyed gazelles continuously preferred areas with intermediate normalized difference vegetation index (NDVI) values from May to July, and spatial and temporal shifts of the distribution of preferred areas explain the long-distance movements of many gazelles in spring. Three movement types, sedentary, linear, and nomadic movement, were identified. The period when benefit varied most greatly among individuals differed between the linear and nomadic movement types. During the spring movement period, the variance of benefit was larger for the nomadic movement type, whereas during the summer it was larger for the linear movement type, suggesting the existence of different movement strategies in the Mongolian gazelle. Linear long-distance movements over a short period in the linear movement type suggest the so-called jumper strategy, whereas other movement patterns might represent the searcher strategy. Benefit loss through movements of individuals in both strategies indicate low interannual predictability of vegetation conditions in the study area, and it would explain the co-existence of multiple movement types or strategies used by Mongolian gazelles in spring.

The forage maturation hypothesis (FMH) states that energy intake for ungulates is maximised when forage biomass is at intermediate levels. Nevertheless, metabolic allometry and different digestive systems suggest that resource selection should vary across ungulate species. By combining GPS relocations with remotely sensed data on forage characteristics and surface water, we quantified the effect of body size and digestive system in determining movements of 30 populations of hindgut fermenters (equids) and ruminants across biomes. Selection for intermediate forage biomass was negatively related to body size, regardless of digestive system. Selection for proximity to surface water was stronger for equids relative to ruminants, regardless of body size. To be more generalisable, we suggest that the FMH explicitly incorporate contingencies in body size and digestive system, with small-bodied ruminants selecting more strongly for potential energy intake, and hindgut fermenters selecting more strongly for surface water.

Environmental disturbances owing to human activity and habitat fragmentation are considered as threats to wildlife populations and migrations. The construction of railroads in southern Mongolia could lead to further habitat fragmentation that could disrupt the long-distance movement of ungulates such as the Mongolian gazelle (Procapra gutturosa). In this study, we used tracking and environmental data to construct habitat suitability maps for wintering Mongolian gazelles to analyze the spatiotemporal changes in habitats for regions that could be fragmented by the presence of new railroads. Habitat suitability in winter was high in areas with a short duration of snow cover and a high normalized difference vegetation index (NDVI). We noted significant interannual variability in the spatial distribution of winter habitat suitability in the potentially fragmented area, which suggests a serious threat posed by railroad construction, although the tracked gazelles had not crossed the area of planned railroads during the entire one-year tracking period. Maintaining accessibility to habitat by creating enough accessible animal crossings over the new railroad area would be crucial for wild ungulate conservation in this region.

The impact of increasing numbers of livestock on wild ungulates has been a concern in Mongolia. We used DNA barcoding via next generation sequencing to reveal detailed food habits and assess the extent of potential resource competition among ungulates in the desert steppe of southern Mongolia. From feces of 2 wild (Mongolian gazelle [Procapra gutturosa], Asiatic wild ass [Equus hemionus]) and 4 domestic (sheep [Ovis aries], goat [Capra hircus], horse [Equus caballus], camel [Camelus bactrianus]) ungulates collected in June 2014, we identified 25 plant families (39 to genus and 18 to species). Dietary diversity was the highest for sheep (Levins' standardized index = 0.351), followed by goats (0.342), and the lowest for gazelles (0.220). Gazelles had a high dietary overlap with goats (Pianka's index = 0.654) and sheep (0.630). Wild asses had the highest dietary overlap with horses (0.847), followed by goats (0.727) and sheep (0.719). The high dietary overlaps may be explained by similar digestive systems and body sizes among gazelles, sheep, and goats and between wild asses and horses, and by the high dietary diversity of sheep and goats. The present study shows more diverse food compositions than previous studies, suggesting that because of the high dietary diversity of sheep and goats and their overlap with wild species, their increasing number is a potential risk for the survival of wild ungulates.

We analyzed the effects of forage amount and its spatiotemporal heterogeneity on the annual range size of Mongolian gazelles by tracking 20 gazelles over a wide range of their distribution in Mongolia and by applying the normalized difference vegetation index (NDVI). Annual ranges were separated into four regions. The maximum individual annual range size was more than 40 times the minimum (range: 900–37 000 km2). Annual range size was increased with increasing forage amount and spatial heterogeneity and seasonal change in forage amount. Many tracked gazelles changed their range locations between summer and winter, and these ranges occupied only small parts of their annual ranges. The smaller annual range size in the areas with smaller forage amount was explained by the smaller seasonal change and spatial heterogeneity of forage amount. Knowledge of such variations of movements and environments in a continuous distribution can improve our understanding of movement ecology.

Studying nomadic animal movement across species and ecosystems is essential for better understanding variability in nomadism. In arid environments, unpredictable changes in water and forage resources are known drivers of nomadic movements. Water resources vary temporally but are often spatially stationary, whereas foraging resources are often both temporally and spatially variable. These differences may lead to different types of nomadic movements: forage- vs. water-driven nomadism. Our study investigates these two different types of nomadism in relation to resource gradients from mesic steppe to xeric desert environments in Mongolia’s Gobi-Steppe Ecosystem. We hypothesized that in the desert, where water is a key resource, animals are more water-dependent and may show water-driven nomadism with frequent revisits to spatially fixed resources, while in the steppe, animals are less water-dependent and may show forage-driven nomadism, tracking high-quality foraging patches with infrequent revisits to previously used resources. We utilized GPS movement data from 40 individuals of four ungulate species (Mongolian gazelle, goitered gazelle, saiga antelope, and Asiatic wild ass) in the Gobi-Steppe Ecosystem. We calculated displacement distances and recursion metrics and subsequently performed a principal component analysis to quantify the variation in movement patterns. The satellite-derived vegetation greenness served as a proxy for the resource gradient and was associated with variation in movement behaviors described by the first principal component, demonstrating that the variability in movements was closely related to the resource gradient from mesic to xeric habitats.We showed that ungulates in the resource-rich steppe tended to move long distances with few revisits (forage-driven nomadism), while ungulates in the resource-poor desert tended to move shorter distances with more revisits (water-driven nomadism). Our results suggest that xeric and mesic habitats promote different types of nomadic strategies. These results have important implications for conservation strategies: Forage-driven nomads primarily require a high degree of landscape-level permeability, and water-driven nomads additionally require the protection of ephemeral water bodies and actions to maintain the functional connectivity between them. animal movement; arid; forage; nomadism; recursion; resource; ungulate; water Variability in nomadism: environmental gradients modulate the movement behaviors of dryland ungulates

We aimed to ascertain the environmental determinants of the diets of Japanese macaques Macaca fuscata in relation to geographical variables (latitude and elevation) and environmental variables [annual rainfall, mean temperature, snow characteristics and normalized difference vegetation index (NDVI), a proxy for primary productivity] We collected dietary data from the entire range of Japanese macaques (29 study sites) and extracted each dietary component to determine spatial patterns over the species' range and between forest types. We then conducted model selection to identify the environmental determinants of staple diets and dietary diversity. Japanese macaques' diets were mainly composed of 1) foliage, 2) fruits and seeds, and 3) bark and leaf buds, throughout the entire range. Percentages of bark and buds were greater in deciduous forests than in evergreen forests; significant differences in the proportions of the other two major components and in dietary diversity were not observed in different forest types. Macaques inhabiting forests with higher NDVI and with less snow fed more on fruits and seeds, and a high dietary diversity was observed. In snowy forests, macaques inhabiting higher elevation fed more on foliage, while those inhabiting lower elevations fed mainly on bark and buds. When studying spatial patterns in the feeding behaviour of mammals, both environmental and geographical variables should be treated equally since the effect of environmental variables may be independent of the effect of geographical variables. In addition, more emphasis should be placed on snow characteristics, because snow cover leads to decreased availability of terrestrial food items and to increased energy costs (for locomotion and body temperature regulation), which can affect feeding behaviour and dietary diversity.

Mongolian gazelles (Procapra gutturosa) are among the last remaining abundant and wide-ranging grassland ungulates, although they have experienced a 75% decline in habitat historically. The effect of their mobility on their genetic structure has not been fully investigated, especially given recent anthropological disturbances. We carried out a molecular study of Mongolian gazelles along the international railroad in the eastern Gobi-steppe of Mongolia using mitochondrial control region sequences and microsatellite markers. Both markers had high genetic diversity with no evidence of a population bottleneck. Genealogies using control region sequences revealed two distinct genetic lineages; however, they were unrelated to geographic location. No significant population genetic structure was found with mtDNA or microsatellites; no isolation-by-distance was detected in our study. Our results suggested that the large population and high mobility of the animals has allowed sufficient gene flow to maintain a homogenous population, and detectable genetic differentiation has not been caused in spite of the anthropologic disturbances including the railroad.

Department of Zoology, School of Biology and Biotechnology, National University of Mongolia, University Avenue-1, Ulaanbaatar,Mongolia†Mongolia Program, Wildlife Conservation Society, Amar Street-3, “Internom” Bookstore Building, 3rd Floor, Ulaanbaatar, Mongolia‡Ochir-WWF Mongolia Program, Amar Street-4, P.O. Box 115, PO-20A, Ulaanbaatar, Mongolia§The Nature Conservancy Mongolia Program Office, Amar Street-4, 2nd floor, Ulaanbaatar, Mongolia¶Protected Areas Administration, Mongolia, Great Gobi B Strictly Protected Area, Khovd, Mongolia

To examine the effects of interannual variations in environmental conditions on the seasonal range selection and movement pattern of Mongolian gazelles Procapra gutturosa , we compared the summer and winter ranges of satellite tracked gazelles among 3 years, and we analyzed the environmental conditions in the gazelles' seasonal ranges by using a satellite-derived normalized difference vegetation index (NDVI). The movement pattern of the tracked Mongolian gazelles was not regular migration between specific seasonal ranges. The locations of the summer ranges in 2003 and 2004 were similar for all gazelles, but in 2005, when the NDVI values were lower, the animals ranged about 30–70 km farther north, suggesting that the gazelles used areas of similar vegetation availability with former 2 years. The winter ranges were widely separated among years; the longest distance between winter ranges of the same individual in different years was about 340 km. During winter, the NDVI values of the winter ranges of tracked gazelles were almost always higher than or not significantly different from the mean of the 3-year range. Conservation strategies to allow access to wide ranges containing suitable areas in each year for gazelles, which location is changing interannually, are important.

Climate and grazing are the main drivers of plant community composition and species richness in arid environments. This study aimed to examine the vegetation response to a spatial precipitation gradient, interannual rainfall variability, and grazing pressure in Mongolia. To examine the effect of a spatial precipitation gradient, we compared species richness among six sites. To investigate the effects of interannual rainfall variability and grazing pressure, we compared species richness for 2 years at two sites, in desert-steppe and steppe areas. The regional gradient in annual precipitation showed positive and negative relationships with grass richness and shrub richness, respectively, although total species richness did not vary significantly. The proportions of the different functional groups were affected by grazing pressure and rainfall variability in both zones. In the desert-steppe zone, species richness was lower in the drier year but did not vary with grazing pressure. In the steppe zone, species richness varied significantly with grazing pressure but did not vary between years. Precipitation would be more important than grazing pressure on vegetation changes in drier areas with high rainfall variability.

We conducted a carcass census of Mongolian gazelles (Procapra gutturosa) along the Trans-Mongolian railroad in June 2005. We counted 241 gazelles that had died within the previous 12 months. Carcass numbers were greater on the southwestern side in the northern 3 zones, but we found carcasses only on the northeastern side in the southernmost zone. It suggests that impact of the railroad was stronger on one side and that the strength of this impact varied among regions.

The Mongolian gazelle ( Procapra gutturosa ) is often sympatric with livestock. After the political regime changed in 1990 in Mongolia, the human population and consequent livestock populations increased, resulting in overgrazing. If food preferences overlap and food supply is limited, ungulates may compete. We analyzed summer (2004) food habits of the Mongolian gazelle and sympatric livestock (sheep, goats, cattle, and horses) in three areas (Dornod, Dorno-Gobi, and Omno-Gobi) in eastern and southern Mongolia by the fecal analysis method. The food resource composition of the ungulates largely supported the prediction of the Jarman–Bell principle: the horse, a large nonruminant, was a grazer, the Mongolian gazelle and sheep/goats, small ruminants, were browsers, and cattle, large ruminants, were intermediate. The food composition of the Mongolian gazelle was consistent among the areas, and fed on more forbs and less grasses. The foods of sheep/goats varied greatly among the areas, suggesting their foods were strongly affected by herding. Food resource used by horses and cattle showed some variations among the areas. Since heavy grazing of livestock results in reductions in plant biomass, the similarity found in food resources strongly suggests the possibility of competition between Mongolian gazelle and sheep and goats.

Conservation and management are urgently required for Mongolian gazelles Procapra gutturosa inhabiting the Mongolian steppe. We captured and satellite-collared two adult females in Dornogobi Province and two adult females in Omnogobi Province and examined whether their seasonal migration corresponded to shifts in the normalized difference vegetation index (NDVI) in their habitat. The mean NDVI values of their annual, summer and winter ranges were calculated based on data acquired by the moderate-resolution imaging spectrometer (MODIS) onboard the Terra satellite. Satellite tracking of gazelles proved their ability to move long distances and provided details of their migration routes. In Omnogobi, the NDVI of the summer range was higher than those of annual and winter ranges during summer, but from October to November the NDVI of the summer range was lower than annual or winter ranges. The shift in NDVI values between summer and winter ranges corresponded with seasonal migrations of gazelles. In contrast, NDVI values were higher in the winter ranges than in both the summer and annual ranges throughout the year in Dornogobi. The results showed that the NDVI is a good indicator of gazelle habitat, but the NDVI alone cannot the explain seasonal migration of gazelles. It is important to evaluate the effectiveness and limitations of the NDVI as an indicator of habitat quality.

Much remains to be learned about how anthropogenic structures affect migration in large mammals. We examined the potential influence of the international railroad in Mongolia on migration in Mongolian gazelles (Procapra gutturosa). We examined gazelle movements and the normalized difference vegetation index (NDVI) on both sides of the railroad. The tracked gazelles never crossed the railroad, despite movements that mainly followed the railroad in winter and higher NDVI values on the opposite side. It is likely that the railroad had a barrier effect on gazelle migration because it split the gazelles' habitat. Our results, although based on an extremely small sample, have utility in indicating approaches that might be useful for examining migration in ungulates. Resumen: Falta mucho por conocer sobre el efecto de estructuras antropogenicas sobre la migracion de mamiferos mayores. Examinamos la potencial influencia del ferrocarril internacional en Mongolia sobre la migracion de gacelas de Mongolia ( Procapra gutturosa). Examinamos los movimientos de las gacelas y el indice de vegetacion de diferencia normalizada (IVDN) a ambos lados de la via ferrea. Las gacelas rastreadas nunca cruzaron la via ferrea, a pesar de que los movimientos mayormente seguian la via en invierno y que los valores de IVDN eran mayores del lado contrario. Es probable que la via ferrea produjera un efecto de barrera sobre la migracion de las gacelas porque dividio al habitat de las gacelas. Nuestros resultados, aunque basados en una muestra extremadamente pequena, son utiles para senalar estrategias que pueden ser utilizadas provechosamente para examinar la migracion de ungulados.

An extremely high-density (ca. 800 deer km−2) wild sika deer population uses a short-grass community dominated by Zoysia japonica on Kinkazan Island in northeastern Japan. To explain why the density of wild deer is quite high on the Zoysia community, (1) we quantified the seasonal productivity of the Zoysia community, (2) we compared food availabilities among the plant communities, and (3) we described the habitat selection by the deer in different seasons. Food availability was greater on the Zoysia community than in the forest understory from spring to fall. The productivity of the Zoysia community was high enough to support the actual high density of the deer (814 deer km−2) in summer. However, the productivity markedly decreased in winter, when the deer density decreased to less than half (358 deer km−2) of the summer value. In contrast, the deer density of the adjacent forests was highest in winter (154 deer km−2) and lowest in spring (19 deer km−2). These results suggest that the deer using the Zoysia community in summer left and were “absorbed” into the adjacent forest in winter. If such an adjacent community were absent, many deer would not survive, and consequently the deer density on the Zoysia community in summer would not be so high. This intercommunity movement is particularly important for the deer using a plant community like the Zoysia community, which is highly productive but has a small standing biomass.