Daniel W. Uresk

Flora and fauna associated with prairie dog colonies and adjacent ungrazed mixed-grass prairie in western South Dakota.

Vegetation, small rodents, and birds were sampled during the growing seasons of 2 years on prairie dog (Cynomys ludovicianus) colonies and adjacent mixed-grass prairie in western South Dakota. Prairie dog grazing decreased mulch cover, maximum height of vegetation, plant species richness, and tended to decrease live plant canopy cover compared to that on ungrazed mixed-grass prairie. Buffalograss @~~&educry~of&s) was the dominant plant on prairie dog towns and western wheatgrass (Agropyron smithii) and blue grama (Boutelouugrucilis) were most common on mixedgrass prairie sites. Prairie dog towns supported greater densities of small rodents but significantly fewer species compared to undisturbed mixed-grass sites. Deer mice (Peromyscus maniculatus) and northern grasshopper mice (Onychomys leucogaster) were more abundant on prairie dog towns than on undisturbed mixedgrass sites. Density and species richness of birds were significantly greater on prairie dog towns. Horned larks (Eremophila a&es&i@ were most common on prairie dog towns, whereas western meadowhuks (Sturneihz neglecta) were most common on mixed-grass prairie.

Understory-overstory relationships in ponderosa pine forests, Black Hills, South Dakota

Under-story-overstory relationships were examined over 7 difdifferent growing stock levels(GSLs) of 2 size classes(saplings,8-10 cm d.b.h. and poles, 15-18 cm d.b.h.) of ponderosa pine (Pinus ponderosa) in the Black Hills, South Dakota. Generally, production of graminoids, forbs, and shrubs was similar between sapling and pole stands. Trends among GSLs were also similar between these tree size classes. Graminoids and forbs were most abundant in clearcuts and the 5 m2/ha basal area. Intermediate amounts were produced at GSLs of 14-23 m2/ha and lowest in unthinned stands which had basal areas ranging from 27-33 m2/ ha and 37-40 m2/ha in sapling and pole stands, respectively. Total understory production followed the same trends. Shrubs, however, appeared to produce most at intermediate stocking levels but were variable. Grainoid and forb production were est estimatd by the model logY=a+bX. Relationships for total production were better described by Y=a+bX. However, variability of shrub production precluded selection of a single model; the best model varied between tree size classes. Standard errors of the estimate indicate that reasonably good predictive models can be developed for pole and sapling stands considered separately or combined. When years were combined, however, SEs increased markedly, indicating less reliable models.

Prairie Dogs: An Ecological Review and Current Biopolitics

Abstract In recent years, people have interpreted scientific information about the black-tailed prairie dog (Cynomys ludovicianus) in various, and sometimes conflicting, ways. Political complexity around the relationship among black-tailed prairie dogs, agricultural interests, and wildlife has increased in recent years, particularly when prairie dogs occur on publicly owned lands leased to private entities for livestock grazing. Some have proposed that estimates of prairie dog (Cynomys spp.) numbers from 1900 are inflated, that prairie dog grazing is not unique (other grazers have similar affects on vegetation), and that prairie dogs significantly reduce carrying capacity for livestock and wildlife. We address all these issues but concentrate on the degree of competition between prairie dogs and ungulates because this motivates most prairie dog control actions. We conclude that the available information does not justify holding distribution and numbers of prairie dogs at a level that is too low to perform their keystone ecological function. We further conclude that it is especially important that prairie dogs be sufficiently abundant on public lands to perform this function.

Black-Tailed Prairie Dog Food Habits and Forage Relationships in Western South Dakota

Four plants made up 65% of items in fecal pellets of the blacktailed prairie dog in western South Dakota. These important forages in order of significance were sand dropseed, sun sedge, blue grama and wheatgrasses. Grasses made up 87% of the total diet, while forbs comprised 12%. Shrubs, arthropods, and seeds made up 1% or less of the diet. Preference indices were highest for ring muhly, green needlegrass, and sand dropseed. Relationships of diets to available forage was weak, having an average similarity of 25%; rank-order correlations were nonsignificant, indicating that black-tailed prairie dogs are selective feeders. Black-tailed prairie dogs (Cynomys ludovicianus) are common herbivores on western rangelands. Much attention, since the 1800s, has focused on forage competition between livestock and prairie dogs. Widespread control programs for prairie dogs were begun in the late 1800’s and early 1900’s on the Great Plains, when it was estimated that 256 prairie dogs would eat as much forage as 1 cow (Merriam 1902). The concern over livestock and prairie dog grazing competition still exists; large-scale control programs for prairie dogs are being conducted even with costs as high as

Spatial optimization of prairie dog colonies for black-footed ferret recovery

6/acre on land which generates grazing fees of

An economic analysis of black-tailed prairie dog (Cynomys ludovicianus) control.

2.95/acre (Collins et al. 1984). Dietary information is essential t o assess the role of the prairie dog in prairie ecosystems. Since Kelso ( 1939) first presented general data on black-tailed prairie dog diets, research has been conducted in Colorado (Tileston and Lechleitner 1966, Bonham and Lerwick 1976, Hansen and Gold 1977); Montana (Fagerstone et al. 1977); and South Dakota (Summers and Linder 1978, Fagerstone et al. 198 1). Dietary information is presented in these studies; however, data on diet-forage relationships and preference indices are generally lacking. Most of these studies were conducted in National Parks or in areas with limited grazing by cattle. Dietary information by species will vary from region to region even though major categories consumed by prairie dogs (grasses, forbs, shrubs) are similar. Intensive management of our rangelands must be based on plant species consumed by herbivores in the area of interest. The purpose of this study was to estimate the diets of blacktailed prairie dogs as related to the availability of range vegetation on pastures grazed by cattle, and to determine preference indices for commonly consumed plants in western South Dakota.

Spring burning Japanese brome in a western wheatgrass community.

A discrete-time reaction-diffusion model for black-footed ferret release, population growth, and dispersal is combined with ferret carrying capacity constraints based on prairie dog population management decisions to form a spatial optimization model. Spatial arrangement of active prairie dog colonies within a ferret reintroduction area is optimized over time for maximum expected adult ferret population. This modeling approach is applied in an exploratory case study to a black-footed ferret reintroduction program in Badlands National Park and Buffalo Gap National Grassland, South Dakota. The model is currently being used to evaluate prairie dog population management alternatives and captive-bred ferret release locations for the Buffalo Gap National Grassland. This approach is also being adapted for use on other grasslands and with other species in the northern Great Plains.

Using multivariate techniques to quantitatively estimate ecological stages in a mixed grass prairie.

Black-tailed prairie dog (Cynomys ludovicianus) control by poisoning with zinc phosphide was not economically feasible in the Conata Basin of South Dakota. Economic analyses were conducted from U.S. Forest Service and rancher viewpoints. Control programs were analyzed with annual maintenance or complete retreatment of initially treated areas to prevent prairie dog repopulation and, except for annual maintenance at low repopulation rates, were unable to recover initial control costs. At a prairie dog repopulation rate of 30% per year (the most realistic projection), prairie dog control was not economically feasible and annual maintenance control costs were greater than the annual value of forage gained. Control benefit was forage gained on treated areas. With an increase of approximately 51 kg/ha of cattle forage, over 7 ha of initial prairie dog control were required to gain 1 AUM per year for the life of the treatment. Prairie dogs have been controlled on western rangelands for many years (Merriam 1902), yet there has never been an economic analysis of any control method. While control has sometimes been justified on the basis of reducing the potential of a plague outbreak among prairie dog populations, competition between domestic livestock and prairie dogs for range forage has been the main justification for control. Research efforts have investigated this competition (Taylor and Loftfield 1924, Hansen and Gold 1977), but no effort has been made to evaluate the costs and benefits of eliminating or decreasing prairie dog populations. Early literature on prairie dog-livestock competition was negative. Merriam ( 1902) and Bell (1920) described losses in crops and range forage due to prairie dogs and recommended prairie dog elimination. In northern Arizona, Zuni prairie dogs (C. gunnisoni zuniensis) reportedly consumed 80% of the total annual forage production and seriously competed with cattle for available forage, especially during droughts (Taylor and Loftfield 1924). Recent information suggests that black-tailed prairie dogs (Cynomys Zudovicianus) compete with cattle for forage, but possibly not enough to warrant control measures (Klatt and Hein 1978). Most plants consumed by black-tailed prairie dogs are potential cattle forage (Kelso 1939, Bonham and Lerwick 1976). Summers and Linder (1978) stated that important food species for blacktailed prairie dogs in the Conata Basin of South Dakota were buffalograss (Buchloe dactyloides), scarlet globemallow (Sphaeralcae coccinea), threadleaf sedge (Carex filifolia), blue grama (Bouteloua gracilis), and western wheatgrass (Agropyron smithii). Hansen and Gold (1977) found sedges made up the largest percentage of the diet for black-tailed prairie dogs in northeastern Colorado and the second largest percentage in cattle diets. In their study, cattle and prairie dog diets were most similar during spring. Hansen and Gold (1977) estimated that prairie dogs consumed

COYOTE FOODS IN THE BLACK HILLS, SOUTH DAKOTA

Plots dominated by Japanese brome (Bromus japonicus) and western wheatgrass (Agropyron smithii) were burned in Badlands National Park, South Dakota, in April 1983 and/or 1984. Standing crop of all species and tiller densities of the 2 dominate species were determined for 4 years. Burning favored western wheatgrass and reduced Japanese brome tiller density and standing crop for at least 1 growing season. In years where no burning occurred, Japanese brome standing crop and tiller density were dependent on the presence of litter on the soil surface. Burning in April killed Japanese brome seedlings for 1 growing season and reduced subsequent generations by reducing surface litter accumulations, with the effect being greatest when autumn precipitation was below average. April burning reduced the standing crop of green needlegrass (Stipa viridula) for at least 3 growing seasons after burning but increased standing crop of buffalograss (Buchloe dactyloides) and sand dropseed (Sporobolus cryptandrus) for 3 to 4 years after burning. Threadleaf sedge (Carexfilifolia) standing crop was not significantly affected by burning.

Diets of the Black-tailed Hare in Steppe Vegetation

Cluster analysis followed by stepwise discriminant analysis was used to delineate ecological stages on a mixed grass prairie in western South Dakota. Forty-seven variables were analyzed for 48 sites ranging from potential vegetation to early seral stages. A cover-frequency index for western wheatgrass (Agropyron smithii), blue grama (Bouteloua gracilis), and buffalograss (Buchloe dactyloides) was the most valuable in identifying 4 different (P<0.0001) ecological stages. Ecological stage classification was estimated to be 95% accurate. The methods presented are quantitative, precise, easy, time-efficient, and meet the goals of resource managers with a minimum of bias.