Evaluating the summer landscapes of predation risk and forage quality for elk (Cervus canadensis)

The recovery of carnivore populations in North American has consequences for trophic interactions and population dynamics of prey. In addition to direct effects on prey populations through killing, predators can influence prey behavior by imposing the risk of predation. The mechanisms through which patterns of space use by predators are linked to behavioral response by prey and nonconsumptive effects on prey population dynamics are poorly understood. Our goal was to characterize population‐ and individual‐level patterns of resource selection by elk (Cervus canadensis) in response to risk of wolves (Canis lupus) and mountain lions (Puma concolor) and evaluate potential nonconsumptive effects of these behavioral patterns. We tested the hypothesis that individual elk risk‐avoidance behavior during summer would result in exposure to lower‐quality forage and reduced body fat and pregnancy rates. First, we evaluated individuals'' second‐order and third‐order resource selection with a used‐available sampling design. At the population level, we found evidence for a positive relationship between second‐ and third‐order selection and forage, and an interaction between forage quality and mountain lion risk such that the relative probability of use at low mountain lion risk increased with forage quality but decreased at high risk at both orders of selection. We found no evidence of a population‐level trade‐off between forage quality and wolf risk. However, we found substantial among‐individual heterogeneity in resource selection patterns such that population‐level patterns were potentially misleading. We found no evidence that the diversity of individual resource selection patterns varied predictably with available resources, or that patterns of individual risk‐related resource selection translated into biologically meaningful changes in body fat or pregnancy rates. Our work highlights the importance of evaluating individual responses to predation risk and predator hunting technique when assessing responses to predators and suggests nonconsumptive effects are not operating at a population scale in this system.     

Characterization of 11 polymorphic tetranucleotide microsatellites for forensic applications in California elk (Cervus elaphus canadensis)

Eleven polymorphic tetranucleotide microsatellite loci have been developed for forensic use in the protection of California elk. Based on a reference sample of elk taken from three races throughout California, the loci consist of 4–9 alleles (average 6.125). Probabilities of identity ( Paetkau et al. 1995 ) range from 0.079 to 0.288, with an overall probability of identity of 1.3 × 10^?9 (one in 7.8 × 10⁸).     

Behavioral responses of male elk to hunting risk

Prey respond to predation risk with a range of behavioral tactics that can vary based on space use and hunting mode of the predator. Unlike other predators, human hunters are often more spatially and temporally restricted, which creates a period of short-duration, high-intensity predation risk for prey. Consequently, identifying the roles different hunting modes (i.e., archery and rifle), hunts for targeted and non-targeted species, and landscape features play in altering spatial and temporal responses of prey to predation risk by humans is important for effective management of harvested populations. From 2009 to 2016, we used a large-scale experiment including 50 animal-years of location data from 38 unique male elk (Cervus canadensis) to quantify changes in movement and resource selection in response to hunters during 3 separate 5-day controlled hunts for antlered males (elk archery, deer [Odocoileus spp.] rifle, and elk rifle) at the Starkey Experimental Forest and Range in northeast Oregon, USA. We evaluated competing hypotheses regarding elk responses to varying levels of prey risk posed by the different hunt types. We predicted that the strength of elk behavioral responses would increase with perceived hunter lethality (i.e., weak response to elk archery but similar response to elk and deer rifle hunts) and that prey response would be closely associated with hunter activity within the diel cycle (greater during diurnal than nocturnal hours) and across hunting seasons. Elk responses were strongest during diurnal hours when hunters were active on the landscape and were generally more pronounced during both rifle hunts than during the archery hunt (supporting our perceived lethality hypothesis). Male elk avoided open roads across all periods except during nocturnal hours of the breeding season and alternated between avoidance of areas with high canopy cover during nocturnal hours and selection during diurnal hours. In combination these patterns led to distinct distributional changes of male elk from pre-hunt to hunt periods. Patterns of male elk selection highlight the importance of managing for heterogeneous landscapes to meet a variety of habitat, harvest, hunter satisfaction, and escapement objectives.     

Predation risk sensitivity and the spatial organization of primate groups: A case study using GIS in lowland Woolly Monkeys (Lagothrix lagotricha poeppigii)

Predation risk is thought to be a potent force influencing intragroup cohesion, and the level of risk experienced by an individual is expected to vary with both group size and spatial position within a group. Smaller‐bodied and less‐experienced individuals are presumed to be more vulnerable to predators, suggesting that within‐group spatial organization should show size‐ and age‐dependent patterns in predator sensitive positioning. However, such effects have been difficult to evaluate for arboreal primates living in large groups. We conducted a preliminary study using a novel, spatially explicit method of assessing group spatial organization using GIS data in two groups of wild lowland Woolly monkeys, in which one group had a membership roughly twice as large as the second. In the larger group, group spread was more diffuse and large adult males were more frequently on the outskirts of the group than other age/sex classes, while immatures and females with dependents were more often in the center. Leaf cover around an individual—presumed to index an animal's perception of risk—increased significantly with distance from the group center for all immatures, although they were typically under lower leaf cover than adults; the number of groupmates in proximity also had an effect, but nearest neighbor distance did not. These differences were not detectable in the smaller group. This preliminary study suggests that thorough studies of spatial organization and predation risk sensitivity in arboreal primates are possible and could yield valuable information on how gregarious individuals offset ecological risks through social spacing. Am J Phys Anthropol 156:158–165, 2015 © 2014 Wiley Periodicals, Inc.     

A simple way to unify multicriteria decision analysis (MCDA) and stochastic multicriteria acceptability analysis (SMAA) using a Dirichlet distribution in benefit–risk assessment

Quantitative methodologies have been proposed to support decision making in drug development and monitoring. In particular, multicriteria decision analysis (MCDA) and stochastic multicriteria acceptability analysis (SMAA) are useful tools to assess the benefit–risk ratio of medicines according to the performances of the treatments on several criteria, accounting for the preferences of the decision makers regarding the relative importance of these criteria. However, even in its probabilistic form, MCDA requires the exact elicitations of the weights of the criteria by the decision makers, which may be difficult to achieve in practice. SMAA allows for more flexibility and can be used with unknown or partially known preferences, but it is less popular due to its increased complexity and the high degree of uncertainty in its results. In this paper, we propose a simple model as a generalization of MCDA and SMAA, by applying a Dirichlet distribution to the weights of the criteria and by making its parameters vary. This unique model permits to fit both MCDA and SMAA, and allows for a more extended exploration of the benefit–risk assessment of treatments. The precision of its results depends on the precision parameter of the Dirichlet distribution, which could be naturally interpreted as the strength of confidence of the decision makers in their elicitation of preferences.     

甜菜夜蛾对虫酰肼的抗性选育、风险评估及交互抗性

虫酰肼是目前防治甜菜夜蛾Spodoptera exigua（Hübner）的一种主要杀虫剂,为评估其抗性风险,在室内进行了抗性筛选和交互抗性的研究。采用饲料感染法,在甜菜夜蛾饲养75代期间用虫酰肼筛选62代,与起始种群相比抗性上升39.2倍,与室内敏感品系相比抗性上升141.3倍。在筛选的早、中、后期,现实遗传力h²分别为0.1075（F₀～F₂₅）、0.2780（F₂₆～F₅₀）和0.0538（F₅₁～F₇₅）,整个筛选62代现实遗传力为0.1556。抗性种群筛选43次（F55）后停止用药筛选,饲养21代后,与敏感品系相比,抗性水平由63.5倍下降到21倍,抗性下降3倍。说明甜菜夜蛾具有对虫酰肼产生抗性的风险,且抗性衰退缓慢,短期内很难恢复到敏感水平。交互抗性测定结果表明,上述室内选育的抗性品系对甲氧虫酰肼具有71.4倍的高水平交互抗性,对阿维菌素具有13.1倍的中等水平交互抗性,对甲维盐、茚虫威和呋喃虫酰肼分别具有7.0、8.4和4.7倍的低水平交互抗性,但对溴虫腈交互抗性不明显（1.9倍）。结果提示： 间断交替使用虫酰肼可以延缓抗性的发展,但除溴虫腈外,虫酰肼和其他几种新型杀虫剂之间的轮用可能不是甜菜夜蛾抗性治理的有效策略。     

Multi‐methods approach to characterizing the magnitude,impact, and spatial risk of Irrawaddy dolphin (Orcaella brevirostris) bycatch in small‐scale fisheries in Malampaya Sound,Philippines

Addressing the urgent conservation threat of marine mammal bycatch in small‐scale fisheries requires information on bycatch magnitude, gear types, population impacts, and risk. However, data on these proximate attributes are widely lacking in developing countries. This study used a multi‐methods approach integrating boat surveys and interviews with fishermen (n = 526) to assess proximate attributes of bycatch for the Critically Endangered subpopulation of Irrawaddy dolphins (Orcaella brevirostris) in Malampaya Sound, Philippines. Given an updated population estimate of 35 individuals (CV = 22.9%), the estimated rate of bycatch fatalities exceeds the potential biological removal rate. Spatial overlap scores were calculated to characterize overlap between dolphins and fisheries as a proxy of bycatch risk. These scores identified particularly high risk areas that could be prioritized for gear bans. However, completely reducing bycatch risk would require more widespread bans beyond these high risk areas. Implementing gear restrictions will be immensely challenging, given serious obstacles to fisheries management at this site. The multi‐methods approach describes the urgency of the bycatch problem and the changes required for mitigation, setting the stage for identifying and evaluating potential solutions. It can be readily applied to developing country sites to guide more efficient and complete data collection and conservation efforts.     

Ecological niche modeling and geographic distribution of the genus <Emphasis Type="Italic">Polianthes</Emphasis> L. (Agavaceae) in Mexico: using niche modeling to improve assessments of risk status

The genus Polianthes (Agavaceae) is endemic to Mexico and is important at the scientific, economical, and cultural level since prehispanic times. Habitat destruction is one of the main factors affecting populations of Polianthes species, yet little is known about the geographic distribution of this genus, and thus its vulnerability to habitat change. We compared three different approaches to measure the Polianthes species area of distribution to assess the risk of species extinction applying the MER (Method of Evaluation of Risk extinction of wild species for Mexico): area of occupancy, extent of occurrence, and ecological modeling. We also found the richness areas of distribution of this genus. We compared the species distributions with Terrestrial Protected Regions (TPR) and Natural Protected Areas (NPA). Although the three methods used to calculate the species area of distribution agree about the highly restricted nature of Polianthes species. The area of occupancy sub-estimate the species distribution, while the extent of occurrence over-estimate it for species with disjoint distribution. Thus, we recommend the use of ecological modeling to improve the assessment of the current species distribution area to apply the MER. Most Polianthes species are distributed in the Sierra Madre Occidental and Transvolcanic Belt. Three species do not occur in any of the NPA or TPR, one species has suitable habitat in three TPR but has not been recorded there, and one species, P. palustris, is likely extinct.