Use of Natural Vegetative Barriers to Limit Expansion of Blacktailed Prairie Dog Towns

Prairie dog (Cynomys ludovicianus) control has historically consisted of lethal methods to maintain, reduce, or eliminate populations in South Dakota and throughout the species range. Non-lethal methods of control are desired to meet changing management objectives for the black-tailed prairie dog. The use of naturally occurring buffer strips as vegetative barriers may be effective in limiting prairie dog town expansion. The objectives of this study were: 1) to evaluate effective width of vegetative barriers in limiting prairie dog towns expansion in western South Dakota; and 2) to document effect native vegetation height on expansion of prairie dog towns in western South Dakota. Five study sites were established in western South Dakota on rangelands containing prairie dog towns of adequate size. Electric fences were constructed for the purpose of excluding cattle and creating buffer strips of native grasses and shrubs. Prairie dogs were poisoned to create a prairie dog free buffer zone adjacent to active prairie dog towns. Grazing was allowed on both sides of the buffer strip. When grazing pressure was not sufficient, mowing was used to simulate grazing. Buffer strips were 100 meters long and 10, 25, and 40 meters in width. A zero meter control was included on all study sites. Quadrats (25) were randomly distributed throughout the buffer strips. Evaluation of study sites included visual obstruction, vegetation cover, vegetation frequency, vegetation height, and vegetation identification. Barrier penetration was evaluated by the presence of new active burrows behind vegetative barriers. Significant relationships were documented for both VOR and vegetation height. No significant difference was found between frequency of breakthroughs and buffer widths.

Feral swine damage and damage management in forested ecosystems

Invasive feral swine (Sus scrofa) cause deleterious impacts to ecosystem processes and functioning throughout their worldwide distribution, including forested ecosystems in the United States. Unfortunately, many feral swine damage management programs are conducted in a piecemeal fashion, are not adequately funded, and lack clearly stated or realistic objectives. This review paper identifies damage caused by feral swine to forest resources and presents techniques used to prevent and control feral swine damage. Concluding points related to planning a feral swine damage management program are: (1) the value of using a variety of techniques in an integrated fashion cannot be overstated; (2) there is value in using indices for both feral swine populations and their damage pre and post management activities; (3) innovative technologies will increasing be of value in the pursuit of feral swine damage reduction; and (4) though not appropriate in every situation, there is value in involving the public in feral swine damage management decisions and activities.

Overabundant deer: Better management through research

Overabundance of white-tailed deer (Odocoileus virginianus) continues to challenge wildlife professionals nationwide, especially in urban settings. Moreover, wildlife managers often lack general site-specific information on deer movements, survival, and reproduction that are critical for management planning. We conducted radio-telemetry research concurrent with deer culling in forest preserves in northeastern Illinois and used empirical data to construct predictive population models. We culled 2,826 deer from 16 forest preserves in DuPage County (1992-1999) including 1,736 from the 10 km2 Waterfall Glen Forest Preserve. We also radio-marked 129 deer from 8 preserves in DuPage and adjacent Cook County (1994-1998). Recruitment was inversely associated with deer density suggesting a classic density-dependent response. Female deer were philopatric and 20% of adult males dispersed. Survival was high for all sex and age classes, and deer-vehicle collisions accounted for >55% of known mortalities. Based upon data from other areas, early attempts to apply population models to deer at Waterfall Glen Forest Preserve were not useful. The subsequent quantification of the density-dependent recruitment response and use of other empirical data strengthened the predictive capability of models. Our experience illustrates the importance of understanding demographics of overabundant deer in order to set realistic objectives and make sound management decisions.