Competition on the range: science vs. perception in a bison–cattle conflict in the western USA

摘要: Summary 1. Competition between livestock and wild ungulates is commonly perceived to occur on shared rangelands. In the Henry Mountains (HM) of Utah, a free-ranging population bison Bison has raised concerns among ranchers holding grazing permits these public lands. are most conspicuous potential competitors with cattle, but lagomorphs (mainly jackrabbits Lepus californicus) also abundant in this area. The local ranching community applying political pressure state federal agencies resolve ‘the problem’, relative impacts bison, cattle have not previously been quantified. 2. We constructed 40 exclosures (each 5� 95 m 2 ) conflict area: 20 excluded + (‘partial’) (‘full’). All exclosures, each paired open reference plot, were monitored for 1 year, above-ground plant production was measured. GPS telemetry (bison) scheduled (cattle) allowed visitation be quantified ungulate species based number ‘animal days’ Rancher perceptions wildlife–cattle interactions recorded questionnaire survey. 3. Ranchers as high-level competitor whereas low-level competitors. 4. Grazed plots yielded an average (� SE) 22� 7gm � 16) grass, compared 36� 5gm 7� 33) partial 43� 61) full exclosures. Exclusion large herbivores thus resulted 13� 8gm increase grass biomass (P =0 005), additional exclusion resulting further 18 g 048). 5. Overall, accounted 34� 1%, 7% 52� 3% total removed by all range. 6. Synthesis applications. Cattle face greater competitive challenge from than study This case illustrates need science-based management social–ecological systems which even long-term resource users might underestimate complexities trophic interactions. Attention should redirected at their main predators, coyotes Canis latrans, currently subject control. To reduce negative ranchers, options explored incorporate benefit-sharing into population.