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.

A barragem de Fundão armazenava milhões de metros cúbicos de rejeitos de uma mina de ferro no estado de Minas Gerais, Brasil. A barragem se rompeu em 5 de novembro de 2015, liberando rejeitos para a bacia do rio Doce, provocando um desastre ambiental em um hotspot de biodiversidade. Visando orientar ações de conservação após o evento, autoridades ambientais brasileiras demandaram uma avaliação de impactos com foco em espécies ameaçadas de extinção. Avaliações de impacto pós-desastre são substancialmente mais desafiadoras do que avaliações padrão, que antecedem a execução de empreendimentos. No caso de Fundão, dados da linha de base anterior ao desastre eram escassos, e pouco se sabia a respeito de como os vetores de impacto relacionados ao rompimento poderiam ter afetado a biodiversidade terrestre, incluindo a sua magnitude, duração e abrangência espacial. Consequentemente, a reconstrução da linha de base e a validação e caracterização dos potenciais vetores de impacto foram os primeiros passos essenciais. A reconstrução da linha de base para ecossistemas, feita a partir de imagens de satélite, revelou que aproximadamente 1580 ha de ecossistemas terrestres foram suprimidos, incluindo ~480 ha de mata atlântica. Por meio de colaboração com especialistas na biodiversidade local e utilizando fontes diversas de dados e literatura, foram identificadas 346 espécies de vertebrados, invertebrados e plantas vasculares ameaçadas de extinção ocorrentes ou potencialmente ocorrentes nas áreas afetadas. A composição em espécies variou entre quatro distintos segmentos da bacia do rio Doce, assim como os impactos incidentes. Nove potenciais vetores de impacto foram identificados utilizando-se dados e revisões da literatura, além de informações fornecidas por órgãos ambientais e especialistas, e pela mídia. A validação e caracterização de cada vetor de impacto em cada segmento da bacia envolveu a avaliação de dados, uma análise preliminar de risco ecológico, e avaliações em campo. A avaliação de vetores de impacto mostrou-se fundamental para dirimir equívocos de interpretação e acuradamente entender os impactos pós-desastre; a importância desta etapa não pode ser menosprezada. O cruzamento de características biológicas e ecológicas das espécies terrestres ameaçadas de extinção, em cada segmento da bacia, com a caracterização dos vetores de impacto, permitiu a atribuição de consequências dos impactos, constituindo uma maneira efetiva de priorizar medidas mitigadoras com vistas ao alcance de metas de conservação pós-desastre. Integr Environ Assess Manag 2020;16:676-680.

Temporal autocorrelation functions for movement rates from global positioning system radiotelemetry data.

Autocorrelation has been viewed as a problem in telemetry studies because sequential observations are not independent in time or space, therefore violating assumptions for statistical inference. Yet nearly all ecological and behavioural data are autocorrelated in both space and time. We argue that there is much to learn about the structure of ecological and behavioural data from patterns of autocorrelation. Such patterns include periodicity in movement and patchiness in spatial data, which can be characterized by an autocorrelogram, semivariogram or spectrum. We illustrate the utility of temporal autocorrelation functions (ACFs) for analysing step-length data from GPS telemetry of wolves (Canis lupus), cougars (Puma concolor), grizzly bears (Ursus arctos) and elk (Cervus elaphus) in western Alberta. ACFs often differ by season, reflecting differences in foraging behaviour. In wilderness landscapes, step-length ACFs for predators decay slowly to apparently random patterns, but sometimes display strong daily rhythms in areas of human disturbance. In contrast, step lengths of elk are consistently periodic, reflecting crepuscular activity.

Observed case of infanticide committed by a resident male central American black howler monkey (Alouatta pigra).

Although infanticide has been witnessed in other species of howler monkey, and has been inferred for Alouatta pigra, an observed case of infanticide has not previously been recorded for this species. Here we describe the killing of a 2-week-old infant by the resident male of a small social group in southern Belize. The infanticide was witnessed as part of an intensive observational study that began in January 2003. The male was known to have resided in the group for at least 4 months, but it is not known whether he was the father of the infant. The literature proposes three main explanations for infanticide: two adaptive hypotheses (sexual selection and resource competition), and one nonadaptive hypothesis (social pathology). Individual cases of infanticide such as this one are important for comparative purposes, but when examined on their own they are difficult to interpret in relation to established theoretical frameworks. The data presented here show some consistency with the sexual-selection and resource-competition hypotheses, but the lack of critical information (i.e., as to paternity) makes it impossible to draw firm conclusions.

Diet and activity in black howler monkeys ( Alouatta pigra) in southern Belize: does degree of frugivory influence activity level?

This study reports on the diet and activity budgets of Central American black howling monkeys ( Alouatta pigra) at Monkey River, Belize. This is a previously unstudied population, close to the southern boundary of the species range, and it provides comparative data on A. pigra from a new study site. Both diet and activity are within the ranges reported for other A.pigra sites and for mantled howlers ( A. palliata). No age-sex differences could be discerned in either diet or activity, though monthly variation was apparent. The monkeys switch from consuming leaves 86% of the time in January to March to consuming 67% fruit in April to July. This difference was statistically significant, and provided the opportunity to compare activity levels of the monkeys over two dietary periods, one characterized primarily by folivory, the other by frugivory. Howlers are often seen as a relatively inactive species, something that is associated with a low quality, folivorous diet. However, A. pigra have been described as being as frugivorous as possible and as folivorous as necessary. Yet, despite the opportunistic consumption of large quantities of high-energy foods, A. pigra has been observed as conforming to the howler lifestyle, resting as much as 80% of the day. The data in this paper support both of these reports. Black howlers at Monkey River Belize are typically inactive, maintaining high levels of inactivity even during months characterized by frugivory, suggesting that diet is more flexible and varied than is behavior and calling into question the assumption that howler inactivity is due to the digestion of large quantities of leaves.