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Ungulate reproductive success (calf production and survival) influences population performance. The moose (Alces alces) population in northeastern Minnesota, USA, has declined 65% from 2006 to 2018 but has begun to stabilize. Because causes of this decline were largely unknown, we investigated production, survival, and cause-specific mortality of calves of the global positioning system (GPS)-collared females in this population. In 2013 and 2014, we GPS-collared 74 neonates and monitored them for survival. In 2015 and 2016, we monitored 50 and 35 calving females for signs of neonatal mortality using changes in adult female velocities and assessed seasonal calf survival by aerial surveys. In 2013 and 2014 (pooled), survival to 9 months was 0.34 (95% CI = 0.23–0.52) for collared calves, and in 2015 and 2016 (pooled) survival was 0.35 (95% CI = 0.26–0.48) for uncollared calves. Mortality in all 4 years was high during the first 50 days of life. In 2013 and 2014 (pooled), calving sites were relatively safe for collared neonates; predator-kills occurred a median 17.0 days after departure and a median 1,142 m from calving sites. Predation was the leading cause of death of collared calves (84% of mortalities), with wolves (Canis lupus) accounting for 77% of these. Other forms of mortality for collared and uncollared calves included drowning, infection, vehicle collision, and natural abandonment. We documented higher wolf predation than other recent studies with similar predator communities. Identifying specific causes of calf mortality and understanding their relations to various landscape characteristics and other extrinsic factors should yield insight into mechanisms contributing to the declining moose population in northeastern Minnesota and serve as a basis for ecologically sound management responses.

The relationship between the rate of predation and prey abundance is an important component of predator–prey dynamics. However, functional responses are less straightforward when multiple predators compete for shared prey. Interactions among competing predators can reduce or enhance effects of predation on prey populations. Because many avian populations experience high rates of nest predation, understanding the role of specific predators on nest mortality will lead to more informed conservation and management strategies which attempt to increase productivity by removing certain predators or managing habitat to limit their impact. Our goal was to evaluate effects of specific predators and the influence of nest abundance on nest mortality. We monitored snowy plover Charadrius nivosus nests across 7 years at two study areas in Utah, USA, with remote cameras. We modelled predator‐specific hazard rates for nest mortality in a Bayesian framework to assess relationships between competing predators and the role of nest abundance on predator‐specific hazard rates. We found that hazard rates for nest mortality by gulls Larus spp. decreased with increasing nest abundance, whereas nest mortality by foxes Vulpes spp. and ravens Corvus corax initially increased, indicating that dietary switching may occur when nests become more abundant. Nest mortalities of specific predators were often not independent and ranged between compensatory (e.g. mammalian mesopredators) and superadditive (e.g. avian predators) across the breeding season. The non‐independence between nest mortalities suggests that reductions in some predators may not translate to additive increases in overall nest success. Analyses of cause‐specific mortality are rarely applied to avian nests, but examination of interacting impacts among competing predators on nest survival may provide insight into specific drivers of avian population dynamics. A free Plain Language Summary can be found within the Supporting Information of this article. A free Plain Language Summary can be found within the Supporting Information of this article.

A relationship between winter weather and survival of northern ungulates has long been established, yet the possible roles of biological (e.g., nutritional status) and environmental (e.g., weather) conditions make it important to determine which potential limiting factors are most influential. Our objective was to examine the potential effects of individual (body mass and age) and extrinsic (winter severity and snowmelt conditions) factors on the magnitude and timing of mortality for adult (>2.5 years old) female white‐tailed deer (Odocoileus virginianus [Zimmerman, 1780]) during February–May in the Upper Peninsula of Michigan, USA. One hundred and fifty deer were captured and monitored during 2009–2015 in two areas with varying snowfall. February–May survival ranged from 0.24 to 0.89 (mean = 0.69) across years. Mortality risk increased 1.9% with each unit increase in cumulative winter severity index, decreased 8.2% with each cumulative snow‐free day, and decreased 4.3% with each kg increase in body mass. Age and weekly snow depth did not influence weekly deer survival. Predation, primarily from coyote (Canis latrans [Say, 1823]) and wolves (Canis lupus [L., 1758]), accounted for 78% of known‐cause mortalities. Our results suggest that cumulative winter severity, and possibly to a lesser degree deer condition entering winter, impacted deer winter survival. However, the timing of spring snowmelt appeared to be the most influential factor determining late‐winter mortality of deer in our study. This supports the hypothesis that nutrition and energetic demands from weather conditions are both important to northern ungulate winter ecology. Under this model, a delay of several weeks in the timing of spring snowmelt could exert a large influence on deer survival, resulting in a survival bottleneck. Northern ungulate population dynamics are correlated with winter weather patterns, and our goal was to evaluate when and why white‐tailed deer winter mortality occurs. We modeled weekly mortality risk of 150 adult female white‐tailed deer in Michigan in response to environmental and biological factors. The results suggested that body mass, severity of winter weather, and timing of spring snowmelt are influential on deer mortality, with the timing of snowmelt explaining the greatest amount of variation.

Background Glycemic control is crucial in peritoneal dialysis (PD) patients with diabetes. Although fasting blood glucose (FBG) is the most commonly used index to measure blood glucose levels, there is currently no evidence supporting the association between FBG level and mortality risk in PD patients. Methods A total of 3548 diabetic PD patients between 2002 and 2018 were enrolled from the National Health Insurance Service database of Korea. We investigated the association between FBG levels and the risk of all‐cause and cause‐specific mortality. Results Patients with FBG levels 80–99 mg/dL exhibited the highest survival rates, whereas those with FBG levels ≥180 mg/dL had the lowest survival rates. Compared with FBG levels 80–99 mg/dL, the adjusted hazard ratios and 95% confidence interval for all‐cause mortality significantly increased as follows: 1.02 (0.87–1.21), 1.41 (1.17–1.70), 1.44 (1.18–2.75), and 2.05 (1.73–2.42) for patients with FBG 100–124 mg/dL, FBG 125–149 mg/dL, FBG 150–179 mg/dL, and FBG ≥180 mg/dL, respectively. The risk for all‐cause mortality also showed an increasing pattern in patients with FBG levels <80 mg/L. The risk of cardiovascular death significantly increased as FBG levels exceeded 125 mg/dL. However, the risk of infection‐related and malignancy‐related deaths did not show a significant increase with increasing FBG levels. Conclusion There was an increase in the risk of all‐cause mortality as FBG levels exceeded 125 mg/dL in PD patients with diabetes, and the risk of cardiovascular death showed a strong correlation with FBG levels compared with other causes of death. Highlights A clear association was observed between FBG levels and the risk of all‐cause mortality in PD patients, indicating that FBG is a significant indicator for quantifying the risk of all‐cause mortality in these patients. Although a higher FBG level was significantly associated with an increased risk of cardiovascular‐related death, there was no notable increase in the risk of death from cancer or infections as the FBG levels increased.

Population growth can be sensitive to changes in survival rates for many avian species. Understanding sources of mortality, and how to mitigate negative effects on survival, can give managers insight into factors contributing to population change. Harvest trends of eastern wild turkeys (Meleagris gallopavo silvestris) in northeastern South Dakota suggest a decline in abundance. We investigated factors influencing survival of wild turkeys to identify potential factors contributing to the decline. We monitored 122 female wild turkeys using VHF radio transmitters from February 2017 to April 2019. Annual survival was 0.52 (95% CI = 0.33–0.64) for juvenile and 0.49 (95% CI = 0.23–0.63) for adult females, respectively. Daily survival probability was significantly lower during the spring (log-odds ratio [LOR] = −0.9; 95% CI = −1.5–−0.2) and while a juvenile female was incubating (LOR = −0.67; 95% CI = −1.23–−0.09) but not while an adult female was incubating (LOR = −0.35; 95% CI = −0.92–0.24). Mammalian predation was the leading cause of mortality, and female wild turkeys were most vulnerable to predation during the spring while engaging in nesting and rearing of young broods. Wild turkeys were at risk for additional sources of mortality while incubating nests that were not contributors to mortality during other periods of the year, as deaths caused by haying equipment—the second greatest cause of mortality—only occurred while a female was incubating. Reducing female mortality due to haying, by delaying cutting, installing flushing bars on haying equipment, or increasing availability of suitable nesting cover types to reduce the probability of nesting in hayfields, could improve female survival. Annual survival during our study was about 16–29% lower than survival estimates from northeastern South Dakota during the 1990s, suggesting that reduced female survival could be contributing to the apparent decline in wild turkey abundance.

As wildlife populations continue to decline worldwide, human‐caused mortality of terrestrial vertebrates is of increasing importance. However, there is a limited understanding of how direct anthropogenic mortality compares in magnitude to natural mortality. Here, we present CauseSpec, a database of global terrestrial vertebrate cause‐specific mortality. We compiled studies that used telemetry to monitor terrestrial vertebrates and determine cause of death. We distinguished between anthropogenic and natural mortality and also documented the specific mortality source where possible (e.g., harvest, vehicle collision, predation, and starvation). This database consists of 1,134 studies that collectively monitored the fates of 123,747 individual animals. From this, there are 43,998 deaths of known cause among 307 species. It is an updated version of the data set used in Hill et al. (2019) and will continue to be updated in the future. These data can be combined with data on species morphology and behavior to examine how species attributes influence susceptibility to various mortality sources. Our database also includes the geographic coordinates of the study site so that site attributes can be included in analyses. We also distinguish between adults and juveniles where possible, allowing for age‐specific mortality analyses. Study start and end dates are available as well so that analyses of temporal changes in mortality are possible. Last, users can select all cause‐specific mortality studies from a single species to perform a species‐level analysis. The data set will allow users to circumvent a literature search, facilitating more rapid publication of large‐scale vertebrate mortality studies and elucidating mortality patterns of terrestrial vertebrates around the world. There are no copyright or proprietary restrictions. We would like researchers to cite this paper if the associated database is used to find studies of interest for analysis.

Cause-specific mortality forecasting is often based on predicting cause-specific death rates independently. Only a few methods have been suggested that incorporate dependence between causes. An attractive alternative is to model and forecast cause-specific death distributions, rather than mortality rates, as dependence between the causes can be incorporated directly. We follow this idea and propose two new models which extend the current research on mortality forecasting using death distributions. We find that adding age, time and cause-specific weights and decomposing both joint and individual variation between different causes of death increased the forecast accuracy of cancer deaths by using data for French and Dutch populations.

The realized effect of multiple carnivores on juvenile ungulate recruitment may depend on the carnivore assemblage as well as compensation from forage and winter weather severity, which may mediate juvenile vulnerability to predation in ungulates. We used a time-to-event approach to test for the effects of risk factors on annual elk (Cervus canadensis) calf survival and to estimate cause-specific mortality rates for 2 elk populations in adjacent study areas in the southern Bitterroot Valley, Montana, USA, during 2011-2014. We captured and radio-tagged 286 elk calves: 226 neonates, and 60 6-month-old calves. Summer survival probability was less variable than winter (P=0.12) and averaged 0.55 (95% CI=0.47-0.63), whereas winter survival varied more than summer and significantly across study years (P=0.003) and averaged 0.73 (95% CI=0.64-0.81). During summer, elk calf survival increased with biomass of preferred forage biomass, and was slightly lower following winters with high precipitation; exposure to mountain lion (Puma concolor) predation risk was unimportant. In contrast, during winter, we found that exposure to mountain lion predation risk influenced survival, with a weak negative effect of winter precipitation. We found no evidence that forage availability or winter weather severity mediated vulnerability to mountain lion predation risk in summer or winter (e.g., an interaction), indicating that the effect of mountain lion predation was constant regardless of spatial variation in forage or weather. Mountain lions dominated known causes of elk calf mortality in summer and winter, with estimated cause-specific mortality rates of 0.14 (95% CI=0.09-0.20) and 0.12 (95% CI=0.07-0.18), respectively. The effect of carnivores on juvenile ungulate recruitment varies across ecological systems depending on relative carnivore densities. Mountain lions may be the most important carnivore for ungulates, especially where grizzly bears (Ursus arctos) and wolves (Canis lupus) are rare or recovering. Finally, managers may need to reduce adult female harvest of elk as carnivores recolonize to balance carnivore and ungulate management objectives, especially in less productive habitats for elk. © 2016 The Wildlife Society.

Integrating host movement and pathogen data is a central issue in wildlife disease ecology that will allow for a better understanding of disease transmission. We examined how adult female mule deer (Odocoileus hemionus) responded behaviorally to infection with chronic wasting disease (CWD). We compared movement and habitat use of CWD‐infected deer (n = 18) to those that succumbed to starvation (and were CWD‐negative by ELISA and IHC; n = 8) and others in which CWD was not detected (n = 111, including animals that survived the duration of the study) using GPS collar data from two distinct populations collared in central Wyoming, USA during 2018–2022. CWD and predation were the leading causes of mortality during our study (32/91 deaths attributed to CWD and 27/91 deaths attributed to predation). Deer infected with CWD moved slower and used lower elevation areas closer to rivers in the months preceding death compared with uninfected deer that did not succumb to starvation. Although CWD‐infected deer and those that died of starvation moved at similar speeds during the final months of life, CWD‐infected deer used areas closer to streams with less herbaceous biomass than starved deer. These behavioral differences may allow for the development of predictive models of disease status from movement data, which will be useful to supplement field and laboratory diagnostics or when mortalities cannot be quickly retrieved to assess cause‐specific mortality. Furthermore, identifying individuals who are sick before predation events could help to assess the extent to which disease mortality is compensatory with predation. Finally, infected animals began to slow down around 4 months prior to death from CWD. Our approach for detecting the timing of infection‐induced shifts in movement behavior may be useful in application to other disease systems to better understand the response of wildlife to infectious disease. Our manuscript characterizes how infection with chronic wasting disease (CWD) alters the movement and habitat use of free‐ranging mule deer. We demonstrate that movement data (i.e., locations from GPS collars) are predictive of disease status as early as 4–6 months prior to death from CWD. We further demonstrate that behavioral changes (e.g., decreased movement speed, increased use of riparian habitat) in CWD‐infected deer can be distinguished from similar behavioral shifts in other pathologic states such as malnutrition and starvation.

Understanding the types and magnitude of human‐caused mortality is essential for maintaining viable large carnivore populations. We used a database of cause‐specific mortality to examine how hunting regulations and landscape configurations influenced human‐caused mortality of North American gray wolves (Canis lupus). Our dataset included 21 studies that monitored the fates of 3564 wolves and reported 1442 mortalities. Human‐caused mortality accounted for 61% of mortality overall, with 23% due to illegal harvest, 16% due to legal harvest, and 12% the result of management removal. The overall proportion of anthropogenic wolf mortality was lowest in areas with an open hunting season compared to areas with a closed hunting season or mixed hunting regulations, suggesting that harvest mortality was neither fully additive nor compensatory. Proportion of mortality from management removal was reduced in areas with an open hunting season, suggesting that legal harvest may reduce human‐wolf conflicts or alternatively that areas with legal harvest have less potential for management removals (e.g., less livestock depredation). Proportion of natural habitat was negatively correlated with the proportion of anthropogenic and illegal harvest mortality. Additionally, the proportion of mortality due to illegal harvest increased with greater natural habitat fragmentation. The observed association between large patches of natural habitat and reductions in several sources of anthropogenic wolf mortality reiterate the importance of habitat preservation to maintain wolf populations. Furthermore, effective management of wolf populations via implementation of harvest may reduce conflict with humans. Effective wolf conservation will depend on holistic strategies that integrate ecological and socioeconomic factors to facilitate their long‐term coexistence with humans. Wolf mortality from management removal was reduced when harvest was legal, suggesting that legal harvest may reduce human–wolf conflicts. Anthropogenic mortality of wolves was greatest in landscapes with less natural habitat.