RATIONALE, GOAL AND OBJECTIVES. COMPETITION BETWEEN LIVESTOCK AND PRAIRIE DOGS IS A WIDELY DISCUSSED, BUT POORLY UNDERSTOOD BARRIER TO LIVESTOCK PRODUCTION IN WESTERN NORTH AMERICAN RANGELANDS. WILDLIFE CONSERVATION EFFORTS HAVE LED TO INCREASES IN PRAIRIE DOG POPULATIONS ACROSS PUBLIC AND PRIVATE RANGELANDS IN WESTERN RANGELANDS OVER THE PAST TWO DECADES. FOR LAND MANAGERS STRIVING TO BALANCE DUAL OBJECTIVES OF LIVESTOCK PRODUCTION AND CONSERVATION, THERE IS AN URGENT NEED FOR QUANTITATIVE MEASURES OF PRAIRIE DOG IMPACTS ON LIVESTOCK PRODUCTION. ONE OF THE ONLY QUANTITATIVE STUDIES ON THIS SUBJECT FOUND THAT PRAIRIE DOGS CAN REDUCE LIVESTOCK VALUE BY UP TO $38 PER STEER AND $5.58 PER HECTARE FOR THE SUMMER GRAZING SEASON (DERNER ET AL. 2006, FRONTIERS IN ECOLOGY AND THE ENVIRONMENT). YET, OTHER ANALYSES INDICATE PRAIRIE DOGS CAN ENHANCE LIVESTOCK PERFORMANCE UNDER CERTAIN WEATHER AND VEGETATION CONDITIONS. A COMPREHENSIVE REVIEW OF THE SUBJECT CONCLUDED: LARGE-SCALE FIELD STUDIES - INVOLVING NUMEROUS PASTURES, WITH AND WITHOUT PRAIRIE DOGS, ARE NECESSARY TO CLARIFY THE EFFECTS OF PRAIRIE DOGS ON DOMESTIC LIVESTOCK. WITH SO MUCH CONTROVERSY AND SO MANY ECONOMIC IMPLICATIONS, THE PAUCITY OF SUCH STUDIES IS DISAPPOINTING (DETLING 2006, IN BOOK:CONSERVATION OF THE BLACK-TAILED PRAIRIE DOG). WE PROPOSE AN INTEGRATED, PARTICIPATORY RESEARCH APPROACH TO QUANTIFY PRAIRIE DOG EFFECTS ON LIVESTOCK PRODUCTION, AND DEVELOP TRUSTED DECISION-SUPPORT TOOLS FOR MANAGERS AND STAKEHOLDERS THAT OPTIMIZE BOTH LIVESTOCK PRODUCTION AND GRASSLAND ECOSYSTEM CONSERVATION. OUR SPECIFIC OBJECTIVES ARE TO: 1) INTEGRATE LIVESTOCK PRODUCERS IN THE DESIGN, IMPLEMENTATION, AND EXECUTION OF RESEARCH ON THE CRITICAL STAKEHOLDER-IDENTIFIED ISSUE OF PRAIRIE DOG-LIVESTOCK COMPETITION; 2) QUANTIFY RELATIONSHIPS BETWEEN CATTLE WEIGHT GAINS AND PRAIRIE DOG ABUNDANCE AT PASTURE SCALES, ACROSS MULTIPLE YEARS; 3) EVALUATE WHETHER THE SPATIOTEMPORAL PATTERN OF LIVESTOCK GRAZING CAN MECHANISTICALLY EXPLAIN HOW PRAIRIE DOG ABUNDANCE AND DISTRIBUTION AFFECT LIVESTOCK WEIGHT GAINS; 4) DETERMINE IF STAKEHOLDER PARTICIPATION IN OUR RESEARCH DESIGN AND EXECUTION ALTERS THEIR TRUST IN, AND PERCEPTIONS OF, THE SCIENTIFIC RESULTS FROM THIS RESEARCH; AND 5) CO-CREATE WITH STAKEHOLDERS DECISION SUPPORT TOOLS.GENERAL APPROACH. BETWEEN 2013 AND 2016, AREA OCCUPIED BY BLACK-TAILED PRAIRIE DOGS INCREASED BY 230% ON THE THUNDER BASIN NATIONAL GRASSLAND AND SURROUNDING PRIVATE RANCHES IN NORTHEAST WYOMING. THE CURRENT DISTRIBUTION OF PRAIRIE DOGS PROVIDES AN IDEAL OPPORTUNITY TO QUANTIFY PRAIRIE DOG EFFECTS ON LIVESTOCK PRODUCTION AT SPATIAL SCALES RELEVANT TO RANCHING ENTERPRISES IN A REGION WHERE SOLUTIONS TO PRAIRIE DOG-LIVESTOCK CONFLICT ARE URGENTLY NEEDED. WE WILL WORK WITH 10 PRODUCERS ON AT LEAST 20 PASTURES (2 PER PRODUCER) STRATIFIED ALONG GRADIENTS OF PRAIRIE DOG OCCUPANCY, COLONY AGE, AND TOPOEDAPHIC CHARACTERISTICS. WE WILL USE GPS COLLARS TO MEASURE CATTLE FORAGING BEHAVIOR IN RELATION TO THE,QUANTITY, QUALITY, AND SPATIAL DISTRIBUTION OF FORAGE. LIVESTOCK WEIGHT GAINS WILL BE ASSESSED BY WEIGHING CATTLE BEFORE AND AFTER PASTURE USE. HALF OF THE PRODUCERS WILL BE ACTIVELY INVOLVED IN DESIGNING AND IMPLEMENTING RESEARCH, WHILE THE OTHERS WILL ALLOW ACCESS AND BE PROVIDED WITH RESEARCH RESULTS. PRODUCERS WILL BE INTERVIEWED BEFORE/AFTER THE PROJECT TO ASSESS LEVELS OF TRUST IN THE FINDINGS.IMPACTS AND OUTCOMES. OUR ANALYSES WILL GENERATE A PREDICTIVE STATISTICAL MODEL THAT ESTIMATES COSTS OF PRAIRIE DOGS ON A GIVEN LANDSCAPE FOR LIVESTOCK PRODUCTION, THEREBY HELPING PRODUCERS AND MANAGERS DETERMINE WHERE, WHEN, AND HOW TO BEST MANAGE PRAIRIE DOGS. THIS WORK WILL PROMOTE LIVESTOCK NUTRITION, ECONOMIC VIABILITY OF RANCHING, RURAL COMMUNITY SUSTAINABILITY, GRASSLAND ECOSYSTEM HEALTH, AND ENHANCE TRUST IN SCIENCE AND FEDERAL PARTNERS, WITH BROAD IMPLICATIONS FOR ADDRESSING COMPLEX CONSERVATION AND MANAGEMENT ISSUES THROUGH PARTICIPATORY RESEARCH, NOT ONLY REGIONALLY, BUT ALSO NATIONALLY AND INTERNATIONALLY.