Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 40
Filtrar
1.
Mov Ecol ; 12(1): 33, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38671527

RESUMO

BACKGROUND: Prey are more vulnerable during migration due to decreased familiarity with their surroundings and spatially concentrated movements. Predators may respond to increased prey vulnerability by shifting their ranges to match prey. Moose (Alces alces) and white-tailed deer (Odocoileus virginianus) are primary gray wolf (Canis lupus) prey and important subsistence species for Indigenous communities. We hypothesized wolves would increase use of ungulate migration corridors during migrations and predicted wolf distributions would overlap primary available prey. METHODS: We examined seasonal gray wolf, moose, and white-tailed deer movements on and near the Grand Portage Indian Reservation, Minnesota, USA. We analyzed GPS collar data during 2012-2021 using Brownian bridge movement models (BBMM) in Migration Mapper and mechanistic range shift analysis (MRSA) to estimate individual- and population-level occurrence distributions and determine the status and timing of range shifts. We estimated proportional overlap of wolf distributions with moose and deer distributions and tested for differences among seasons, prey populations, and wolf sex and pack affiliations. RESULTS: We identified a single migration corridor through which white-tailed deer synchronously departed in April and returned in October-November. Gray wolf distributions overlapped the deer migration corridor similarly year-round, but wolves altered within-range distributions seasonally corresponding to prey distributions. Seasonal wolf distributions had the greatest overlap with deer during fall migration (10 October-28 November) and greatest overlap with moose during summer (3 May-9 October). CONCLUSIONS: Gray wolves did not increase their use of the white-tailed deer migration corridor but altered distributions within their territories in response to seasonal prey distributions. Greater overlap of wolves and white-tailed deer in fall may be due to greater predation success facilitated by asynchronous deer migration movements. Greater summer overlap between wolves and moose may be linked to moose calf vulnerability, American beaver (Castor canadensis) co-occurrence, and reduced deer abundance associated with migration. Our results suggest increases in predation pressure on deer in fall and moose in summer, which can inform Indigenous conservation efforts. We observed seasonal plasticity of wolf distributions suggestive of prey switching; that wolves did not exhibit migratory coupling was likely due to spatial constraints resulting from territoriality.

2.
Ecol Evol ; 13(11): e10658, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37915808

RESUMO

Investigating spatial patterns of animal occupancy and reproduction in peripheral populations can provide insight into factors that form species range boundaries. Following historical extirpation, American black bears (Ursus americanus) recolonized the western Great Basin in Nevada from the Sierra Nevada during the late 1900s. This range expansion, however, has not continued further into the Great Basin despite the presence of additional habitat. We aimed to quantify whether reduced reproduction toward the range edge contributes to this range boundary. We analyzed black bear detections from 100 camera traps deployed across black bear distribution in western Nevada using a multistate occupancy model that quantified the probability of occupancy and reproduction (i.e., female bears with cubs occupancy) in relation to changes in habitat type and habitat amount toward the range boundary. We detected a strong effect of habitat amount and habitat type on the probability of black bear occupancy and reproduction. At similar levels of landscape-scale habitat amount (e.g., 50%), estimated probability of occupancy for adult bears in piñon-juniper woodlands near the range boundary was 0.39, compared to ~1.0 in Sierra Nevada mixed-conifer forest (i.e., core habitat). Furthermore, estimated probability of cub occupancy, conditional on adult bear occupancy, in landscapes with 50% habitat was 0.32 in Great Basin piñon-juniper woodlands, compared to 0.92 in Sierra Nevada mixed-conifer forest. Black bear range in the western Great Basin conforms to the center-periphery hypothesis, with piñon-juniper woodland at the range edge supporting ecologically marginal habitat for the species compared to habitat in the Sierra Nevada. Further geographic expansion of black bears in the Great Basin may be limited by lower occupancy of reproducing females in piñon-juniper woodland. Center-periphery range dynamics may be common in large carnivore species, as their dispersal ability allows them to colonize low-quality habitat near range edges.

3.
Oncol Nurs Forum ; 49(4): 307-314, 2022 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-35788735

RESUMO

OBJECTIVES: To determine the relative predictive validity of personality and spirituality for mental health and salivary alpha-amylase (sAA) in breast cancer (BC) survivors. SAMPLE & SETTING: 23 BC survivors participated in a single-group, cross-sectional study. METHODS & VARIABLES: Predictor variables included personality and spiritual variables. Outcome variables included subjective physical and mental health outcomes and sAA, a neuroimmune biomarker. RESULTS: Hierarchical regressions indicated that (a) conscientiousness and forgiveness independently predict 38% and 11% of variance in mental health scores, respectively; and (b) conscientiousness and forgiveness independently predict 15% and 24% of the variance in sAA, respectively. Consistent with psychoneuroimmunology theory, personality and spiritual variables independently influence subjective mental health and neuroimmune activity in BC survivors. IMPLICATIONS FOR NURSING: Nurses should be aware of BC survivors' personality characteristics and spiritual dispositions so that distinct interventions can be offered to promote mental health and reduce stress-related neuroimmune inflammation.


Assuntos
Neoplasias da Mama , Sobreviventes de Câncer , alfa-Amilases Salivares , Feminino , Humanos , Estudos Transversais , Saúde Mental , Personalidade , Espiritualidade , Sobreviventes
4.
Conserv Physiol ; 10(1): coac009, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35492406

RESUMO

Conservation translocations-the intentional movement of animals to restore populations-have increased over the past 30 years to halt and reverse species declines and losses. However, there are many challenges translocated animals face that should be considered for restoration programs to be successful. Understanding how long it takes for translocated animals to acclimate to these challenges and their new landscape is a critical component of post-release population management. Physiological measures such as hormone responses are increasingly used to assess animal responses and acclimation to disturbances including translocation. We determined the physiological acclimation period of elk (Cervus canadensis) translocated to the Missouri Ozarks, USA, as part of a restoration effort. From 2011 to 2013, we translocated 108 GPS-radio-collared elk from Kentucky, USA, to Missouri, USA, and collected faecal samples for glucocorticoid metabolite extraction to use as an indicator of physiological acclimation. We modelled the response of population-wide faecal glucocorticoid metabolites (fGCMs) across the initial 9 years of the restoration in response to days following release and additional site-specific covariates. Presence of white-tailed deer (Odocoileus virginianus) hunts and monthly precipitation levels were positively and negatively associated with fGCM levels, respectively. Concurrent with influences from site-specific conditions on the release landscape, fGCM levels declined following release. We identified a breakpoint in fGCM decline at ~42 days following translocation releases suggesting elk acclimated physiologically relatively quickly compared to other species. The fast physiological acclimation by Missouri elk suggests effective use of temporary post-release management efforts. Determining how quickly animals acclimate following translocations allows researchers to tailor post-release management plans to each species' needs, thus maximizing the success of future translocation efforts while minimizing costs.

5.
Ecol Evol ; 11(9): 3685-3695, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33976768

RESUMO

Despite the key roles that dispersal plays in individual animal fitness and meta-population gene flow, it remains one of the least understood behaviors in many species. In large mammalian herbivores, dispersals might span long distances and thereby influence landscape-level ecological processes, such as infectious disease spread. Here, we describe and analyze an exceptional long-distance dispersal by an adult white-tailed deer (Odocoileus virginianus) in the central United States. We also conducted a literature survey to compare the dispersal to previous studies. This dispersal was remarkable for its length, duration, and the life history stage of the dispersing individual. Dispersal is typical of juvenile deer seeking to establish postnatal home ranges, but this dispersal was undertaken by an adult male (age = 3.5). This individual dispersed ~300 km over a 22-day period by moving, on average, 13.6 km/day and achieving a straight-line distance of ~215 km, which was ~174 km longer than any other distance recorded for an adult male deer in our literature survey. During the dispersal, which occurred during the hunting season, the individual crossed a major river seven times, an interstate highway, a railroad, and eight state highways. Movements during the dispersal were faster (mean = 568.1 m/h) and more directional than those during stationary home range periods before and after the dispersal (mean = 56.9 m/h). Likewise, movements during the dispersal were faster (mean = 847.8 m/h) and more directional at night than during the day (mean = 166.4 m/h), when the individual frequently sheltered in forest cover. This natural history event highlights the unpredictable nature of dispersal and has important implications for landscape-level processes such as chronic wasting disease transmission in cervids. More broadly, our study underscores how integrating natural history observations with modern technology holds promise for understanding potentially high impact but rarely recorded ecological events.

6.
Oecologia ; 196(1): 223-234, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33934223

RESUMO

Apex predators can shape communities via cascading top-down effects, but the degree to which such effects depend on predator life history traits is largely unknown. Within carnivore guilds, complex hierarchies of dominance facilitate coexistence, whereby subordinate species avoid dominant counterparts by partitioning space, time, or both. We investigated whether a major life history trait (hibernation) in an apex carnivore (black bears Ursus americanus) mediated its top-down effects on the spatio-temporal dynamics of three sympatric mesocarnivore species (coyotes Canis latrans, bobcats Lynx rufus, and gray foxes Urocyon cinereoargenteus) across a 15,000 km2 landscape in the western USA. We compared top-down, bottom-up, and environmental effects on these mesocarnivores using an integrated modeling approach. Black bears exerted top-down effects that varied as a function of hibernation and were stronger than bottom-up or environmental impacts. High black bear activity in summer and fall appeared to buffer the most subordinate mesocarnivore (gray foxes) from competition with dominant mesocarnivores (coyotes and bobcats), which were in turn released by black bear hibernation in winter and early spring. The mesocarnivore responses occurred in space (i.e., altered occupancy and site visitation intensity) rather than time (i.e., diel activity patterns unaffected). These results suggest that the spatio-temporal dynamics of mesocarnivores in this system were principally shaped by a spatial predator cascade of interference competition mediated by black bear hibernation. Thus, certain life history traits of apex predators might facilitate coexistence among competing species over broad time scales, with complex implications for lower trophic levels.


Assuntos
Carnívoros , Lynx , Ursidae , Animais , Clima , Raposas
7.
Support Care Cancer ; 29(11): 6421-6429, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33890163

RESUMO

PURPOSE: Chronic stress is associated with neuroimmune inflammation and adverse outcomes in breast cancer survivors. Some breast cancer survivors rely on religious and spiritual (R/S) variables to manage stress after breast cancer treatment. A spiritually based psychoneuroimmunological (PNI) model of health suggests that R/S variables influence neuroimmune activity; however, these associations are not well-established. A pilot study was conducted to assess the feasibility of studying associations between R/S variables and neuroimmune biomarkers in breast cancer survivors. METHOD: Salivary alpha-amylase (sAA) and interleukin-6 (IL-6) were sampled among women previously treated for breast cancer. The primary aim was to assess feasibility and acceptability of the sampling protocol. A secondary aim explored associations between sAA, IL-6, R/S variables, and health outcomes. RESULT: Forty-one women completed the study. Biomarker sampling yielded 246 acceptable specimens used for analysis. SAA was detectable in 96% of specimens and IL-6 was detectable in 44% of specimens. The R/S variables with the strongest associations to sAA were spiritual self-rank (rs = .39; p < .05) and forgiveness (rs = .40; p < .05). The R/S variable with the strongest association to salivary IL-6 was positive congregational support (rs = .42; p < .05). CONCLUSION: Feasibility and acceptability of the sampling protocol were confirmed. Reference ranges for sAA and IL-6 for female breast cancer survivors are presented. Results suggest that spiritual beliefs and religious practices are associated with neuroimmune activity, adding credence to a spiritually based PNI model of health. Findings lay the foundations for future R/S-based interventions to promote health and well-being in breast cancer survivors.


Assuntos
Neoplasias da Mama , Adaptação Psicológica , Estudos de Viabilidade , Feminino , Promoção da Saúde , Humanos , Projetos Piloto , Espiritualidade , Sobreviventes
8.
Cancer Nurs ; 44(4): 323-332, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32195710

RESUMO

BACKGROUND: Because of chronic emotional and psychosocial stressors following breast cancer (BC) treatment, BC survivors are at risk of neuroimmune dysfunction in survivorship. Rural BC survivors experience more health disparities than urban BC survivors. Rural-urban residence as a variable on neuroimmune activity in extended BC survivorship continuum has not been explored. OBJECTIVE: To report the feasibility of studying relationships between neuroimmune activity and perceived health in rural and urban BC survivors. METHODS: Data from a pilot study of BC survivors (n = 41) were analyzed. Participants were rural (n = 16) and urban (n = 25). Participants completed Medical Outcomes Study Short-Form Version 2 Health Survey questionnaires and provided salivary specimens for analysis of salivary α-amylase (sAA), cortisol, and interleukin 6 (IL-6). Rural-Urban Commuting Area Codes were used to determine rural or urban residence. RESULTS: Differences in immune activity were observed between rural and urban BC survivors (U = 34, P < .05). No rural-urban group differences in neuroendocrine activity were observed. Relationships were observed between perceptions of mental health and sAA (P < .05) in rural BC survivors and between perceptions of mental health and IL-6 (P < .05) in urban BC survivors. Interleukin 6 was positively associated with perceptions of physical health (P < .05) in rural BC survivors. CONCLUSION: Pilot data suggest rural-urban residence may be a factor in relationships between neuroimmune function (ie, sAA and IL-6) and perceived health status, particularly social functioning in women with BC. Additional studies with powered designs are indicated. IMPLICATIONS FOR PRACTICE: Although evidence is limited, data support the feasibility of studying relationships between sAA and IL-6 and perceptions of health in women with BC.


Assuntos
Biomarcadores/metabolismo , Neoplasias da Mama/metabolismo , População Rural/estatística & dados numéricos , Saliva/metabolismo , Sobrevivência , População Urbana/estatística & dados numéricos , Adulto , Idoso , Neoplasias da Mama/psicologia , Sobreviventes de Câncer/psicologia , Feminino , Humanos , Hidrocortisona/análise , Interleucina-6/análise , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Projetos Piloto , Inquéritos e Questionários , alfa-Amilases/análise
9.
MethodsX ; 7: 100953, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32612939

RESUMO

Epidemiological surveillance for many important wildlife diseases relies on samples obtained from hunter-harvested animals. Statistical methods used to calculate sample size requirements assume that the target population is randomly sampled, and therefore the samples are representative of the population. But hunter-harvested samples may not be representative of the population due to disease distribution heterogeneities (e.g. spatial clustering of infected individuals), and harvest-related non-random processes like regulations, hunter selectivity, variable land access, and uneven hunter distribution. Consequently, sample sizes necessary for detection of disease are underestimated and disease detection probabilities are overestimated, resulting in erroneous inferences about disease presence and distribution. We have developed a modeling framework to support the design of efficient disease surveillance programs for wildlife populations. The constituent agent-based models can incorporate real-world heterogeneities associated with disease distribution, harvest, and harvest-based sampling, and can be used to determine population-specific sample sizes necessary for prompt detection of important wildlife diseases like chronic wasting disease and bovine tuberculosis. The modeling framework and its application has been described in detail by Belsare et al. [1]. Here we describe how model scenarios were developed and implemented, and how model outputs were analyzed. The main objectives of this methods paper are to provide users the opportunity to a) assess the reproducibility of the published model results, b) gain an in-depth understanding of model analysis, and c) facilitate adaptation of this modeling framework to other regions and other wildlife disease systems.•The two agent-based models, MOOvPOP and MOOvPOPsurveillance, incorporate real-world heterogeneities underpinned by host characteristics, disease spread dynamics, and sampling biases in hunter-harvested deer.•The modeling framework facilitates iterative analysis of locally relevant disease surveillance scenarios, thereby facilitating sample size calculations for prompt and reliable detection of important wildlife diseases.•Insights gained from modeling studies can be used to inform the design of effective wildlife disease surveillance strategies.

10.
Ecol Modell ; 4172020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32189826

RESUMO

Epidemiological surveillance for important wildlife diseases often relies on samples obtained from hunter-harvested animals. A problem, however, is that although convenient and cost-effective, hunter-harvest samples are not representative of the population due to heterogeneities in disease distribution and biased sampling. We developed an agent-based modeling framework that i) simulates a deer population in a user-generated landscape, and ii) uses a snapshot of the in silico deer population to simulate disease prevalence and distribution, harvest effort and sampling as per user-specified parameters. This framework can incorporate real-world heterogeneities in disease distribution, hunter harvest and harvest-based sampling, and therefore can be useful in informing wildlife disease surveillance strategies, specifically to determine population-specific sample sizes necessary for prompt detection of disease. Application of this framework is illustrated using the example of chronic wasting disease (CWD) surveillance in Missouri's white-tailed deer (Odocoileus virginianus) population. We show how confidence in detecting CWD is grossly overestimated under the unrealistic, but standard, assumptions that sampling effort and disease are randomly and independently distributed. We then provide adjusted sample size recommendations based on more realistic assumptions. Wildlife agencies can use these open-access models to design their CWD surveillance. Furthermore, these models can be readily adapted to other regions and other wildlife disease systems.

11.
Front Vet Sci ; 7: 608235, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33585599

RESUMO

Continuing geographic spread of chronic wasting disease (CWD) poses a serious threat to the sustainable future of cervids and hunting in North America. Moreover, CWD has been detected in captive cervids in South Korea and, in recent years, in free-ranging reindeer in Europe (Norway). Management of this disease is limited by logistical, financial, and sociopolitical considerations, and current strategies primarily focus on reducing host densities through hunter harvest and targeted culling. The success of such strategies in mitigating the spread and prevalence of CWD only upon detection is questionable. Here, we propose a proactive approach that emphasizes pre-emptive management through purposeful integration of virtual experiments (simulating alternate interventions as model scenarios) with the aim of evaluating their effectiveness. Here, we have used a published agent-based model that links white-tailed deer demography and behavior with CWD transmission dynamics to first derive a CWD outbreak trajectory and then use the trajectory to highlight issues associated with different phases of the CWD outbreak (pre-establishment/transition/endemic). Specifically, we highlight the practical constraints on surveillance in the pre-establishment phase and recommend that agencies use a realistic detection threshold for their CWD surveillance programs. We further demonstrate that many disease introductions are "dead ends" not leading to a full epidemic due to high stochasticity and harvesting in the pre-establishment phase of CWD. Model evaluated pre-emptive (pre-detection) harvest strategies could increase the resilience of the deer population to CWD spread and establishment. We conclude it is important to adaptively position CWD management ahead of, rather than behind, the CWD front.

12.
Ecol Appl ; 29(8): e01993, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31400176

RESUMO

Modern forest management seeks to balance multiple social, economic, and ecological goals. Different management approaches create different types of disturbances in a forest ecosystem and thus also differ in their impacts on plants, animals, and insects. Understanding these impacts is important for conservation of forest ecosystem function, but challenging due to the large spatial and temporal scale over which management occurs. Most past research has focused on relatively small areas, short time scales, and/or a small number of species. To address this, we examined the effects of two common silvicultural systems (even and uneven aged) on abundance and richness of three vertebrate taxa (birds, small mammals, and herpetofauna) over a two-decade period in a temperate hardwood forest in Missouri, USA. The two systems removed a similar amount of biomass overall, but differed in the intensity, number, and configuration of harvests applied. We found that vertebrate population responses varied by taxa, occurred at multiple spatial scales, and were concentrated in the period following the first harvest entry. Birds generally had the largest changes in relative abundance, both positive and negative, following management. Small mammals and reptiles had smaller, but generally positive, responses; amphibians were mixed. Bird species tended to respond in the same way to both silvicultural systems, while small mammals and herpetofauna did not respond consistently. Thus, for birds, the total amount of harvest disturbance across the landscape drives population responses, while for others the size and configuration of individual harvests is likely more important. Synthesizing results across the vertebrate community at large spatial and temporal scales allows managers to better understand trade-offs when making decisions that will affect wildlife in contrasting ways.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , Animais , Biodiversidade , Aves , Florestas , Missouri
13.
PeerJ ; 7: e7185, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31293830

RESUMO

Percent of body fat and physiological stress are important correlates to wildlife demographics. We studied winter percent of body fat and physiological stress levels for a declining elk (Cervus canadensis nelsoni) population in South Dakota, 2011-2013. We obtained percent of winter body fat, pregnancy status, lactation status, and physiological stress data from 58 adult females (2+ years old). We compared physiological stress level data from 2011 with data collected from this same herd when elk densities were much higher (1995-1997). Our objectives were to determine percent of body fat during winter, examine if winter body fat was correlated with pregnancy and lactation status, and quantify and compare physiological stress hormone values from elk in the mid-1990s. Probability of being pregnant increased with higher winter nutritional condition, or percent of body fat; whereas females with a higher probability of previously lactating were lower in winter body fat. Mean fecal glucocorticoid metabolite (FGM) levels in 2011 (mean = 47.78 ng/g, SE = 2.37) were higher during summer compared to data collected in 1995-1997 (mean = 34.21 ng/g, SE = 3.71); however, mean FGM levels during winter did not differ between the two time periods. Although summer levels of FGM have significantly increased since the mid-1990s, we caution against any interpretation of increased FGM levels on elk fitness, as it may not infer biological significance. Mean winter percent of body fat of elk was lower when compared to other populations in the west but this difference does not appear to be limiting vital rates and population growth for this elk herd. We recommend future research focus on summer/autumn data collection to provide a more comprehensive understanding of percent of body fat for elk in our region.

14.
Ecol Evol ; 8(22): 10893-10901, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30519415

RESUMO

Examining the ways in which animals use habitat and select resources to satisfy their life history requirements has important implications for ecology, evolution, and conservation. The advent of radio-tracking in the mid-20th century greatly expanded the scope of animal-habitat modeling. Thereafter, it became common practice to aggregate telemetry data collected on a number of tagged individuals and fit one model describing resource selection at the population level. This convention, however, runs the risk of masking important individuality in the nature of associations between animals and their environment. Here, we investigated the importance of individual variation in animal-habitat relationships via the study of a highly gregarious species. We modeled elk (Cervus elaphus) location data, collected from Global Positioning System (GPS) collars, using Bayesian discrete choice resource selection function (RSF) models. Using a high-performance computing cluster, we batch-processed these models at the level of each individual elk (n = 88) and evaluated the output with respect to: (a) the composition of parameters in the most supported models, (b) the estimates of the parameters featured in the global models, and (c) spatial maps of the predicted relative probabilities of use. We detected considerable individual variation across all three metrics. For instance, the most supported models varied with respect to parameter composition with a range of seven to 17 and an average of 14.4 parameters per individual elk. The estimates of the parameters featured in the global models also varied greatly across individual elk with little conformity detected across age or sex classes. Finally, spatial mapping illustrated stark differences in the predicted relative probabilities of use across individual elk. Our analysis identifies that animal-habitat relationships, even among the most gregarious of species, can be highly variable. We discuss the implications of our results for ecology and present some guiding principles for the development of RSF models at the individual-animal level.

15.
Conserv Physiol ; 6(1): coy054, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30279991

RESUMO

Rapid climate and human land-use change may limit the ability of long-distance migratory herbivores to optimally track or 'surf' high-quality forage during spring green-up. Understanding how anthropogenic and environmental stressors influence migratory movements is of critical importance because of their potential to cause a mismatch between the timing of animal movements and the emergence of high-quality forage. We measured stress hormones (fecal glucocorticoid metabolites; FGMs) to test hypotheses about the effects of high-quality forage tracking, human land-use and use of stopover sites on the physiological state of individuals along a migratory route. We collected and analysed FGM concentrations from 399 mule deer (Odocoileus hemionus) samples obtained along a 241-km migratory route in western Wyoming, USA, during spring 2015 and 2016. In support of a fitness benefit hypothesis, individuals occupying areas closer to peak forage quality had decreased FGM levels. Specifically, for every 10-day interval closer to peak forage quality, we observed a 7% decrease in FGMs. Additionally, we observed support for both an additive anthropogenic stress hypothesis and a hypothesis that stopovers act as physiological refugia, wherein individuals sampled far from stopover sites exhibited 341% higher FGM levels if in areas of low landscape integrity compared to areas of high landscape integrity. Overall, our findings indicate that the physiological state of mule deer during migration is influenced by both anthropogenic disturbances and their ability to track high-quality forage. The availability of stopovers, however, modulates physiological responses to those stressors. Thus, our results support a recent call for the prioritization of stopover locations and connectivity between those locations in conservation planning for migratory large herbivores.

16.
Elife ; 72018 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-30277211

RESUMO

Developed areas are thought to have low species diversity, low animal abundance, few native predators, and thus low resilience and ecological function. Working with citizen scientist volunteers to survey mammals at 1427 sites across two development gradients (wild-rural-exurban-suburban-urban) and four plot types (large forests, small forest fragments, open areas and residential yards) in the eastern US, we show that developed areas actually had significantly higher or statistically similar mammalian occupancy, relative abundance, richness and diversity compared to wild areas. However, although some animals can thrive in suburbia, conservation of wild areas and preservation of green space within cities are needed to protect sensitive species and to give all species the chance to adapt and persist in the Anthropocene.


Assuntos
Biodiversidade , Conservação dos Recursos Naturais/métodos , Ecossistema , Mamíferos/crescimento & desenvolvimento , Animais , Cidades , Conservação dos Recursos Naturais/estatística & dados numéricos , Florestas , Humanos , Mamíferos/classificação , População Rural/estatística & dados numéricos , População Suburbana/estatística & dados numéricos , População Urbana/estatística & dados numéricos , Reforma Urbana/estatística & dados numéricos
17.
Ecol Evol ; 8(1): 790-800, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29321914

RESUMO

Analog forecasting is a mechanism-free nonlinear method that forecasts a system forward in time by examining how past states deemed similar to the current state moved forward. Previous applications of analog forecasting has been successful at producing robust forecasts for a variety of ecological and physical processes, but it has typically been presented in an empirical or heuristic procedure, rather than as a formal statistical model. The methodology presented here extends the model-based analog method of McDermott and Wikle (Environmetrics, 27, 2016, 70) by placing analog forecasting within a fully hierarchical statistical framework that can accommodate count observations. Using a Bayesian approach, the hierarchical analog model is able to quantify rigorously the uncertainty associated with forecasts. Forecasting waterfowl settling patterns in the northwestern United States and Canada is conducted by applying the hierarchical analog model to a breeding population survey dataset. Sea surface temperature (SST) in the Pacific Ocean is used to help identify potential analogs for the waterfowl settling patterns.

18.
J Wildl Dis ; 54(1): 95-100, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28820300

RESUMO

: Meningeal worm ( Parelaphostrongylus tenuis) is an important cause of mortality of elk ( Cervus canadensis) in populations in the eastern US and has been implicated in the failure of several restoration attempts. From 2011 to 2013, the Missouri Department of Conservation translocated 108 adult and yearling elk from Kentucky (US) to southern Missouri (US) to establish a free-ranging population. From release in spring 2011 through August 2015, we monitored 167 elk (adult, yearling, and calf) to determine causes of mortality. Of 78 mortalities, 26 (33%) were linked to meningeal worm based on necropsy results and/or observed behavior; this group included 19 elk with confirmed or suspected cases of meningeal worm infection that died of other proximate causes. Other important mortality sources included euthanasia ( n=11, 14%), emaciation ( n=7, 9%), and predation ( n=5, 6%). Eleven of the 26 (42%) meningeal worm-related mortalities were adults, and 22 (85%) were female. Meningeal worm was an important cause of mortality during the restoration of Missouri elk, potentially contributing to the loss of 16% of the monitored individuals. Greater mortality in adult female elk could reduce initial population growth by limiting reproductive output in the restored herd, especially given that females were disproportionately affected in Missouri. Because translocated Missouri elk undoubtedly were exposed to meningeal worm in Kentucky, our results could be explained by exposure to a different genetic strain of meningeal worm once in Missouri, loss of immune response due to translocation, increased dose of larval worms, or some unquantified factor.


Assuntos
Cervos/parasitologia , Metastrongyloidea , Infecções por Strongylida/veterinária , Animais , Conservação dos Recursos Naturais , Feminino , Masculino , Missouri/epidemiologia , Infecções por Strongylida/epidemiologia , Infecções por Strongylida/mortalidade
19.
Cancer Nurs ; 41(2): 166-175, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-28151830

RESUMO

BACKGROUND: Psychoneuroimmunological theory suggests a physiological relationship exists between stress, psychosocial-behavioral factors, and neuroendocrine-immune outcomes; however, evidence has been limited. OBJECTIVE: The primary aim of this pilot study was to determine feasibility and acceptability of a salivary cortisol self-collection protocol with a mail-back option for breast cancer survivors. A secondary aim was to examine relationships between religiousness/spirituality (R/S), perceptions of health, and diurnal salivary cortisol (DSC) as a proxy measure for neuroendocrine activity. METHODS: This was an observational, cross-sectional study. Participants completed measures of R/S, perceptions of health, demographics, and DSC. RESULTS: The sample was composed of female breast cancer survivors (n = 41). Self-collection of DSC using a mail-back option was feasible; validity of mailed salivary cortisol biospecimens was established. Positive spiritual beliefs were the only R/S variable associated with the peak cortisol awakening response (rs = 0.34, P = .03). Poorer physical health was inversely associated with positive spiritual experiences and private religious practices. Poorer mental health was inversely associated with spiritual coping and negative spiritual experiences. CONCLUSIONS: Feasibility, validity, and acceptability of self-collected SDC biospecimens with an optional mail-back protocol (at moderate temperatures) were demonstrated. Positive spiritual beliefs were associated with neuroendocrine-mediated peak cortisol awakening response activity; however, additional research is recommended. IMPLICATIONS FOR PRACTICE: Objective measures of DSC sampling that include enough collection time points to assess DSC parameters would increase the rigor of future DSC measurement. Breast cancer survivors may benefit from nursing care that includes spiritual assessment and therapeutic conversations that support positive spiritual beliefs.


Assuntos
Adaptação Psicológica , Neoplasias da Mama/fisiopatologia , Neoplasias da Mama/psicologia , Sobreviventes de Câncer/psicologia , Hidrocortisona/análise , Religião , Espiritualidade , Adulto , Idoso , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Terapias Mente-Corpo , Projetos Piloto , Sobrevivência
20.
J Anim Ecol ; 86(4): 749-765, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28390066

RESUMO

Predators affect prey by killing them directly (lethal effects) and by inducing costly antipredator behaviours in living prey (risk effects). Risk effects can strongly influence prey populations and cascade through trophic systems. A prerequisite for assessing risk effects is characterizing the spatiotemporal variation in predation risk. Risk effects research has experienced rapid growth in the last several decades. However, preliminary assessments of the resultant literature suggest that researchers characterize predation risk using a variety of techniques. The implications of this methodological variation for inference and comparability among studies have not been well recognized or formally synthesized. We couple a literature survey with a hierarchical framework, developed from established theory, to quantify the methodological variation in characterizing risk using carnivore-ungulate systems as a case study. Via this process, we documented 244 metrics of risk from 141 studies falling into at least 13 distinct subcategories within three broader categories. Both empirical and theoretical work suggest risk and its effects on prey constitute a complex, multi-dimensional process with expressions varying by spatiotemporal scale. Our survey suggests this multi-scale complexity is reflected in the literature as a whole but often underappreciated in any given study, which complicates comparability among studies and leads to an overemphasis on documenting the presence of risk effects rather than their mechanisms or scale of influence. We suggest risk metrics be placed in a more concrete conceptual framework to clarify inference surrounding risk effects and their cascading effects throughout ecosystems. We recommend studies (i) take a multi-scale approach to characterizing risk; (ii) explicitly consider 'true' predation risk (probability of predation per unit time); and (iii) use risk metrics that facilitate comparison among studies and the evaluation of multiple competing hypotheses. Addressing the pressing questions in risk effects research, including how, to what extent and on what scale they occur, requires leveraging the advantages of the many methods available to characterize risk while minimizing the confusion caused by variability in their application.


Assuntos
Modelos Teóricos , Comportamento Predatório , Risco , Animais , Carnívoros , Ecossistema , Medo , Ruminantes
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...