Sustainable elk harvests in Alberta with increasing predator populations

Large predators often are believed to cause declines in hunter harvests of ungulates due to direct competition for prey with hunters. In Alberta, predators of elk (Cervus elaphus), including grizzly bear (Ursus arctos), cougar (Puma concolor), and wolf (Canis lupus), have increased in recent years. We used trend analysis replicated by Wildlife Management Unit (WMU) to examine regional trends in elk harvest and hunter success. Over a 26-yr period, average harvest of elk increased by 5.46% per year for unrestricted bull and by 6.64% per year for limited-quota seasons. Also, over the same time frame, average hunter success increased by 0.2% per year for unrestricted bull and by 0.3% per year for limited-quota seasons, but no trend was detected in hunter effort (P>0.05). Our results show that increasing large-predator populations do not necessarily reduce hunter harvest of elk, and we only found evidence for this in Alberta's mountain WMUs where predation on elk calves has reduced recruitment. Furthermore, data indicate that Alberta's elk harvest management has been sustainable, i.e., hunting has continued while populations of elk have increased throughout most of the province. Wildlife agencies can justify commitments to long-term population monitoring because data allow adaptive management and can inform stakeholders on the status of populations.

Methods for Postdisaster Impact Assessment: A Case Study of the Impacts of the Fundão Dam Failure on Terrestrial Species Threatened with Extinction

The Fundão tailings dam held back approximately 50 million cubic meters of tailings from an Fe ore mine in the state of Minas Gerais, Brazil. The dam failed on 5 November 2015, releasing tailings into the Rio Doce watershed and causing an environmental disaster in a biodiversity hotspot. To guide conservation action following the event, Brazilian authorities demanded an impact assessment focused on terrestrial species threatened by extinction. Postdisaster impact assessment is substantially more challenging than predevelopment impact assessment. Predisaster baseline data were sparse, and much was unknown about how the Fundão dam failure impacted terrestrial species threatened with extinction. Baseline reconstruction and impact pathway validation and characterization was critical. Ecosystem reconstruction revealed that 1580 ha of terrestrial ecosystems were destroyed, including approximately 480 ha of Atlantic rainforest. Collaboration with local experts identified 346 species of vertebrates, invertebrates, and vascular plants threatened with extinction that were impacted or potentially impacted. Species composition and impacts varied within 4 distinct segments of the Rio Doce watershed. Nine potential impact pathways were identified using data and literature review combined with information provided by regulators, experts, and media. Not all were valid. Validating and characterizing each pathway within each watershed segment involved data evaluation, an ecological risk screening, and field assessments. Impact pathway evaluation proved critical to dispelling misconception, accurately understanding postdisaster impacts, and directing conservation action; the importance of this step cannot be overemphasized. Integr Environ Assess Manag 2020;16:676-680. © 2020 SETAC.