269 research outputs found

    SAVING THE WORLD’S GRASSLANDS: AN INTRODUCTION

    Get PDF
    Grasslands cover a large portion of the world’s land surface but increasingly suffer from numerous threats. Temperate grasslands are the most endangered and least protected biome in the world (Hoekstra et al. 2005; Henwood, this issue). Grasslands suffer from the twin dangers of seeming to lack charismatic features deserving of protection (the Great Plains, one of the world’s great grasslands, has sometimes been dismissed as “the Great Empty” because it lacks mountains or coastal areas) and of being prime land for conversion to crop agriculture. As a result, people converted or destroyed much of the original Great Plains grassland and devastated much of its amazing biodiversity. While estimates differ, it appears that in the northern Great Plains only about 1% to 3% of the original tallgrass prairie remains intact, perhaps 20% to 30% of the mixed-grass prairie, and 40% to 70% of the shortgrass prairie (Bragg and Steuter 1996; Steinauer and Collins 1996; Weaver et al. 1996; Licht 1997). Through this process the nation lost a substantial proportion of the region’s biodiversity, although no overall inventory of the loss appears to be available. Much of the surviving grasslands remain in private hands, so private landowners will largely determine the fate of biodiversity conservation on this open, sweeping landscape

    Attributes of Black-Tailed Prairie Dog Colonies in Northcentral Montana

    Get PDF
    We examined several characteristics of black-tailed prairie dog (Cynomys ludovicianus) colonies in Phillips County, Montana, including slope, aspect, soils, land tenure, and distance from roads using a geographic information system (GIs). Colonies exhibited significantly smaller slopes, but not significantly different aspects than did randomly located polygons. In addition, colonies were more prevalent than expected on well drained clay-loam and loam soils and on U.S. Bureau of Land Management (BLM) land than on other soil types or on private land. Although prairie dogs commonly use roads for dispersal, distance to nearest road was not related to prairie dog density nor to colony area. These findings could be used to develop a cartographic model of preferred black-tailed prairie dog habitat useful for prairie dog monitoring and management, and for estimating prairie dog expansion potential for possible black-footed ferret (Mustela nigripes) reintroduction sites

    Attributes of Black-Tailed Prairie Dog Colonies in Northcentral Montana

    Get PDF
    We examined several characteristics of black-tailed prairie dog (Cynomys ludovicianus) colonies in Phillips County, Montana, including slope, aspect, soils, land tenure, and distance from roads using a geographic information system (GIs). Colonies exhibited significantly smaller slopes, but not significantly different aspects than did randomly located polygons. In addition, colonies were more prevalent than expected on well drained clay-loam and loam soils and on U.S. Bureau of Land Management (BLM) land than on other soil types or on private land. Although prairie dogs commonly use roads for dispersal, distance to nearest road was not related to prairie dog density nor to colony area. These findings could be used to develop a cartographic model of preferred black-tailed prairie dog habitat useful for prairie dog monitoring and management, and for estimating prairie dog expansion potential for possible black-footed ferret (Mustela nigripes) reintroduction sites

    Estimates of Toad Headed Agama Density in Three Steppe Habitats of Mongolia

    Get PDF
    The toad headed agama (Phrynocephalus versicolor) ranges across the arid steppe regions of southern and western Mongolia and represents one of the most common reptiles in the country. However, few details of the species’ population characteristics exist, which may be important for evaluating population trends and assessing its conservation status. We estimated toad headed agama density in Ikh Nart Nature Reserve, Mongolia based on surveys conducted in the summers (June-September) of 2005, 2006, 2008, and 2009. We conducted surveys in three steppe habitats including tall grassland (n = 7), shrub-steppe (n = 7), and semi-shrub steppe (n = 8), and calculated density using Distance methods. Mean density across all surveys was 66 agamas/ha (95% C.I. = 48-92; range: 24/ha to 112/ha). Agamas occurred in highest density in shrub-steppe and lowest in semi-shrub across years. Density was similar between shrub-steppe and tall grassland. However, density in these habitats was significantly higher than in semishrub steppe. Our results provide baseline estimates of toad headed agama density, and indicate that agamas are capable of reaching higher density than previously recorded. Our results also suggest that agamas benefit from the cover afforded by more structurally complex vegetation communities like those found in shrub-steppe and tall grassland habitats

    Estimates of Toad Headed Agama Density in Three Steppe Habitats of Mongolia

    Get PDF
    The toad headed agama (Phrynocephalus versicolor) ranges across the arid steppe regions of southern and western Mongolia and represents one of the most common reptiles in the country. However, few details of the species’ population characteristics exist, which may be important for evaluating population trends and assessing its conservation status. We estimated toad headed agama density in Ikh Nart Nature Reserve, Mongolia based on surveys conducted in the summers (June-September) of 2005, 2006, 2008, and 2009. We conducted surveys in three steppe habitats including tall grassland (n = 7), shrub-steppe (n = 7), and semi-shrub steppe (n = 8), and calculated density using Distance methods. Mean density across all surveys was 66 agamas/ha (95% C.I. = 48-92; range: 24/ha to 112/ha). Agamas occurred in highest density in shrub-steppe and lowest in semi-shrub across years. Density was similar between shrub-steppe and tall grassland. However, density in these habitats was significantly higher than in semishrub steppe. Our results provide baseline estimates of toad headed agama density, and indicate that agamas are capable of reaching higher density than previously recorded. Our results also suggest that agamas benefit from the cover afforded by more structurally complex vegetation communities like those found in shrub-steppe and tall grassland habitats

    Temporal Dynamics of Group Size and Sexual Segregation in Ibex

    Get PDF
    Group size is an important variable describing behavioral ecology of animals. A variety of factors such as habitat characteristics, life history, spatio-temporal resource dynamics, population density, predation risk, competition with kin, and social learning often determine group size in large mammals. We studied temporal dynamics of group size in Siberian ibex (Capra sibirica) in a protected area in Mongolia. We measured monthly and yearly variations in typical group size and used the sexual segregation and aggregation statistic to assess sexual segregation. Ibex formed the largest groups in November and smallest groups in July. However, group sizes did not significantly differ between the sexes. There was marked sexual segregation during the summer months and within all years segregation increased with temperature. We show that grouping behavior is a complex phenomenon and is probably determined by a combination of factors, such as species’ life history, habitat and environmental characteristics, and behavioral strategy against predation risk

    Comparative Morphology of Two Sympatric Species of Hedgehog in Ikh Nart Nature Reserve, Mongolia

    Get PDF
    Daurian hedgehog (Mesechinus dauuricus) and long-eared hedgehog (Hemiechinus auritus) inhabit Ikh Nart Nature Reserve, Mongolia and both species appear to occupy similar niches. We gathered morphological measurements to test for differences between species and sexes. We hoped to gain insight into the mechanisms that allow the species to coexist. We collected morphometric data from 10 long-eared hedgehogs (6 male, 4 female) and 18 Daurian hedgehogs (10 male, 7 female, and 1 unknown sex). Only total body length in Daurian hedgehogs differed significantly between males and females. Otherwise, we found no significant differences between morphometric measures of male and female hedgehogs of either species. Daurian hedgehogs were larger than long-eared hedgehogs for every measurement except for ear length; however, only girth, weight, and length of ear differed significantly. A general linear model found that animal girth best differentiated the two species. Coexistence of species that occupy similar niches generally occurs through the differential use of resources and may be inferred from morphological differentiation. We plan continued research to better explore resource partitioning between the two species

    Comparative Morphology of Two Sympatric Species of Hedgehog in Ikh Nart Nature Reserve, Mongolia

    Get PDF
    Daurian hedgehog (Mesechinus dauuricus) and long-eared hedgehog (Hemiechinus auritus) inhabit Ikh Nart Nature Reserve, Mongolia and both species appear to occupy similar niches. We gathered morphological measurements to test for differences between species and sexes. We hoped to gain insight into the mechanisms that allow the species to coexist. We collected morphometric data from 10 long-eared hedgehogs (6 male, 4 female) and 18 Daurian hedgehogs (10 male, 7 female, and 1 unknown sex). Only total body length in Daurian hedgehogs differed significantly between males and females. Otherwise, we found no significant differences between morphometric measures of male and female hedgehogs of either species. Daurian hedgehogs were larger than long-eared hedgehogs for every measurement except for ear length; however, only girth, weight, and length of ear differed significantly. A general linear model found that animal girth best differentiated the two species. Coexistence of species that occupy similar niches generally occurs through the differential use of resources and may be inferred from morphological differentiation. We plan continued research to better explore resource partitioning between the two species

    Wild Bactrian Camel Conservation

    Get PDF
    The wild Bactrian camel (Camelus bactrianus ferus) is critically endangered throughout its range in China and Mongolia. Yet, wild camels remain poorly understood, with knowledge derived primarily from a few short studies and anecdotal information. We initiated a wild camel conservation project to determine the reasons for camel decline and to develop a program to address those problems. We are employing satellite telemetry to gather data on wild camel movement patterns, home ranges, habitat use, and sources of mortality. We are also collecting feces from camels and wolves to determine important forage plants and to begin to assess predation levels, respectively. In addition, steroid fecal analysis may help us evaluate wild camel reproductive physiology. Finally, we are directly observing wild camels to study their behavior. Thus far, we successfully collared two wild camels (one male, one female). We received one year’s data on the cow before her Doppler satellite collar failed and are receiving only sporadic data from the GPS satellite collar on the bull. Over one year, the cow covered a minimum distance of 4,527 km and her 100% minimum convex polygon (MCP) home range was 17,232 km2. Her kernel home range sizes covered 8,696 km2 for 95%, 4,031 km2 for 75%, 2,284 km2 for 55%, and 612 km2 for 25% kernels. We received only 20 GPS locations on our bull from October 10, 2003 to March 22, 2004. During that time, he travelled a minimum of 683 km and his 100% MCP home range extended over 9,191 km2. His kernel home ranges covered 7,255 km2 for the 95%, 3,741 km2 for the 75%, 1,346 km2 for the 50%, 585 km2 for the 25%, and 115 km2 for the 5% kernel. Over the past few autumns, mean group size was 10.07±1.82 wild camels/group. We are currently analyzing the behavioral data and plan to evaluate the fecal samples once we have sufficient samples. We hope to use the knowledge derived from our work to develop a proactive conservation program working in close cooperation with the Mongolian government and other scientists and conservationists
    • …
    corecore