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opencc-zeroNov 2022View details →

Divergent response and adaptation of specific leaf area to environmental change at different spatio-temporal scales jointly improve plant survival

Specific leaf area (SLA) is one of the most important plant functional traits. It integrates multiple functions and reflects strategies of plants to obtain resources. How plants employ different strategies (e.g., through SLA) to respond to dynamic environmental conditions remains poorly understood.This study aimed to explore the spatial variation in SLA and divergent adaptation of plants by changing SLA through the lens of biogeographic patterns, evolutionary history, and short-term responses. SLA data for 5424 plant species from 76 natural communities in China were systematically measured and integrated with meta-analysis of field experiments (i.e., global warming, drought, and nitrogen addition). The mean value of SLA across all species was 21.8 m2 kg–1, ranging from 0.9 to 110.2 m2 kg–1. SLA differed among different ecosystems, temperature zones, vegetation types, and functional groups. Phylogeny had a weak effect on SLA, but plant species evolved toward higher SLA. Furthermore, plants responded nonlinearly to environmental change by changing SLA. Unexpectedly, radiation was one of the main factors determining the spatial variation in SLA on a large scale. Conversely, short-term manipulative experiments showed that SLA increased with increased resource availability and tended to stabilize with treatment duration. However, different species exhibited varying response patterns. Overall, long-term adaptation of plants to environmental gradients and its short-term response to resource pulses through variation in SLA jointly improve plant adaptability to a changing environment. Overall SLA-environment relationships should be emphasized as a multidimensional strategy for elucidating environmental change in future research.

opencc-zeroNov 2022View details →

Validation of Sepsis-3 using survival analysis and clinical evaluation of quick SOFA, SIRS, and burn-specific SIRS for sepsis in burn patients with suspected infection

Purpose: Sepsis-3 is a life-threatening organ dysfunction caused by dysregulated host responses to infection; and defined using the Sepsis-3 criteria, introduced in 2016, however, the criteria need to be validated in specific clinical fields. We investigated mortality prediction and compared the diagnostic performance of quick Sequential Organ Failure Assessment (qSOFA), systemic inflammatory response syndrome (SIRS), and burn-specific SIRS (bSIRS) in burn patients. Methods: This single-center retrospective cohort study examined burn patients in Seoul, Korea during January 2010–December 2020. Overall, 1,391 patients with suspected infection were divided into four sepsis groups using SOFA, qSOFA, SIRS, and burn-specific SIRS. Results: Hazard ratios (HRs) of all unadjusted models were statistically significant; however, the HR (0.726, p = 0.0080.001) in the SIRS ≥2 group is below 1. In the adjusted model, HRs of the SOFA ≥2 (2.426, p < 0.001), qSOFA ≥2 (7.198, p < 0.001), and SIRS ≥2 (0.575, p < 0.001) groups were significant. The diagnostic performance of dichotomized qSOFA, SIRS, and bSIRS for sepsis was defined by the Sepsis-3 criteria. The mean onset day was 4.13±2.97 according to Sepsis-3. The sensitivity of SIRS (0.989, 95% confidence interval [CI]: 0.982–0.994) was higher than that of qSOFA (0.841, 95% CI: 0.819–0.861) and bSIRS (0.803, 95% CI: 0.779–0.825). Specificities of qSOFA (0.929, 95% CI: 0.876–0.964) and bSIRS (0.922, 95% CI: 0.868–0.959) were higher than those of SIRS (0.461, 95% CI: 0.381–0.543). Conclusion: Sepsis-3 is a good alternative diagnostic tool because it reflects sepsis severity without delaying diagnosis. SIRS showed higher sensitivity than qSOFA and bSIRS and may therefore more adequately diagnose sepsis.

opencc-zeroDec 2022View details →

The role of reed management and habitat quality on brood parasitism and chick survival of the brood parasitic Common Cuckoo

Despite efforts on ecosystem restoration and management, biodiversity loss remains one of the major environmental concerns of our time. Beyond the focus on threatened species, animals that indicate regional biodiversity hotspots and population trends, such as brood parasites, should also be targeted by conservation actions. We studied how reed habitat quality and management influence brood parasitism rate and offspring survival in Common Cuckoos Cuculus canorus parasitizing nests of Great Reed Warblers Acrocephalus arundinaceus. In six reed habitats in an intensive agricultural landscape. Data collected from 45 sites over 13 years showed that the brood parasitism rate was highest on large canals and was positively influenced by the availability of potential perches (Cuckoo vantage points) and the height where host nests were built. Cuckoo chick survival decreased with water depth and was not affected by other factors. Our results suggest that the habitat-dependent detectability of host nests was central in brood parasitism rate and that water level was central in Cuckoo chick survival. Our study shows that a maintenance of intermediate water levels is the most optimal for maintaining Cuckoo populations in intensive agricultural landscapes. Because brood parasites are excellent bioindicators as their presence predicts regional hotspots of taxonomic and functional diversity as well as population trends in bird communities, knowledge on their habitat requirements is relevant in management targeting diverse bird communities.

opencc-zeroDec 2022View details →

Dataset for: Breeding populations of Marbled Godwits and Willets have high annual survival and strong site fidelity to managed wetlands

The Prairie Pothole Region of central Canada supports a diverse community of breeding waterbirds but many species have declining populations and the demographic mechanisms driving the declines remain unknown. We conducted a 7-year field study during 1995–2001 to investigate the demographic performance of Marbled Godwits (Limosa fedoa) and Willets (Tringa semipalmata) breeding in managed wetlands near Brooks, Alberta. Mark-recapture analyses based on Cormack-Jolly-Seber models revealed that the annual rates of apparent survival for Marbled Godwits (phi-hat = 0.934 ± 0.015SE) and Willets (phi-hat = 0.849 ± 0.018SE) are among the highest rates of survivorship reported for any breeding or nonbreeding population of large-bodied shorebirds. Our estimates of life expectancy for males were comparable to longevity records in godwits (E-hat = 17.3 years ± 5.8SE vs. 25-29+ years) and Willets (E- hat = 7.7 ± 1.5SE vs. 10+ years). The two species both showed strong breeding site fidelity but differed in rates of mate fidelity. Pairs that reunited and males that switched mates usually nested <300 m from their previous nests whereas females that switched mates usually moved longer distances >1.1 to 1.5 km. Returning pairs usually reunited in godwits (85%) but not in Willets (28%), possibly because of species differences in adult survival or patterns of migration. Baseline estimates of annual survival for banded-only birds will be useful for evaluating the potential effects of new tracking tags or the environmental changes that have occurred during the past 20 years. Conservation strategies for large-bodied shorebirds should be focused on reduction of exposure to anthropogenic mortality because low rates of natural mortality suggest that losses to collisions at breeding sites or harvest at nonbreeding areas are likely to cause additive mortality.

opencc-zeroJan 2023View details →

Why do parents produce small broods of offspring that have lower body mass, survival, and lifetime reproductive success? A case study in a long-lived bird

Numerous studies have examined the correlation between offspring quantity and quality, and many have found that the most common brood size is often smaller than broods with the highest offspring quality or production. However, the reasons why these small broods with lower offspring quality are produced, are still poorly explained. Using data spanning 29 years, we investigated the effects of brood size on nestlings' body mass and the lifetime fitness for those offspring as adults (as proxies of offspring quality) in the Crested Ibis (Nipponia nippon). We also examined the temporal variation of brood size. We found that overall offspring quality increases with brood size and that individuals from broods of three had the highest quality, as quantified by larger body mass, higher adult survival, and lifetime reproductive success. Furthermore, brood size of an individual pair significantly varied across years, and the proportion of broods containing two offspring increased while broods of three decreased after 2000 when the population dispersed to low-quality habitat. These findings indicate that spatiotemporal variation in resources may impact variation in brood size and subsequent fitness consequences, and that small broods are more common in resource-poor years or low-quality habitats. In contrast, parents with access to high-quality resources produce larger broods of nestlings that achieve higher body mass and subsequently experience higher adult survival and lifetime fitness. This study highlights how variation in life history traits can be influenced by resource condition, and provides an insight into particular habitat that need conservation for Crested Ibis.

opencc-by-4.0Jan 2023View details →

Dietary Phytoimmunostimulant Enhanced Hematological Status and Survival Rate of Common Carp (Cyprinus carpio L.)

This study determined the effectiveness of mango leaves (Mangifera indica), guava leaves (Psidium guajava), and noni leaves (Morinda citrifolia), in increasing the immune parameters of common carp (Cyprinus carpio L.). This research was conducted using a one-factor completely randomized design, consisting of experimental controls (commercial feed without phytoimmunostimulants = T0), and commercial feed which was supplemented with mango leaves (T1), guava leaves (T2), and noni leaves (T3). These were used in 3 replicate experiment in common carp that had been reared in floating net cages in the Koto Panjang PLTA Reservoir. Fish in groups of 100 were fed at 5% of body weight per day for 60 days with feed supplemented with 1.5 g of plant material/100g of diet. The parameters observed were erythrocyte and leukocyte profile and survival rate. The results showed that the addition of plant leaves to the feed significantly increased the profile of erythrocytes of common carp (P<0.05) with the best result resulting from supplementation with guava leaves. Here, the hematological profiles were erythrocytes (1.82-1.97 x106 cells/mm3), hemoglobin (8.53-9.2 g/dL), hematocrit (35.67-39.67%,) total leukocytes )3.21-3.87 x104 cells/mm3), phagocytic index (21.33-27.00%), lymphocytes (83.33-84.33 %), monocytes (8.00-9.33%), neutrophils (7.33-7.67%), blood glucose (1.67-104 mg/dL) and survival rate (95.67%).

opencc-zeroJan 2023View details →

Data from: Phylogenetic structure of the extinction and biotic factors explaining differential survival of terrestrial notosuchians at the Cretaceous-Palaeogene crisis

Although the clade Crocodylomorpha is represented by few extant species (Crocodylia), it has a rich fossil record. Hundreds of species adapted to terrestrial, semi-aquatic and marine environments, have existed over more than 200 million years. Numerous studies have attempted to characterize the factors driving the diversification and extinction events of Crocodylomorpha, resulting in ambiguous and even contradictory conclusions, which points to the need for phylogenetically and temporally smaller-scaled studies. Here, we focus on differential survival at the Cretaceous-Palaeogene crisis of Notosuchia, a diverse clade of mostly terrestrial Crocodylomorpha that achieved great diversity during the Cretaceous. More precisely, we tested the effect of body size and palaeotemperatures on notosuchian survival probability during the K-Pg crisis as well as the effect of diet on the evolution of their body size. We find that Notosuchia showed an evolutionary trend towards larger body sizes through time, associated with a shift from an omnivorous to a carnivorous diet. This may explain why sebecids were the only notosuchians to survive the K-Pg crisis. We also corroborate conclusions of previous studies that detected a Lagerstätten effect occurring in the Adamantina Formation (Upper Cretaceous, Brazil, Bauru Group). This work confirms the value of more finely-scaled macroevolutionary studies for understanding the history of a rich and complex group such as Crocodylomorpha.

Wolbachia-infected pharaoh ant colonies have higher egg production, metabolic rate, and worker survival

Wolbachia is a widespread endosymbiotic bacteria with diverse phenotypic effects on its insect hosts, ranging from parasitic to mutualistic. Wolbachia also commonly infects social insects, where it faces unique challenges associated with its hosts' caste-based reproductive division of labor and colony living. Here we dissect the benefits and costs of Wolbachia infection on life-history traits of the invasive pharaoh ant, Monomorium pharaonis. Pharaoh ants are relatively short-lived and show natural variation in Wolbachia infection between colonies, thereby making them an ideal model system for this study. We quantified effects on the lifespan of queen and worker castes, the egg-laying rate of queens across queen lifespan, and the metabolic rates of whole colonies and colony members. Newly-infected queens laid more eggs than uninfected queens but had similar metabolic rates and lifespans. Surprisingly, infected workers outlived uninfected workers. At the colony level, infected colonies were more productive due to increased queen egg-laying rates and worker longevity, and infected colonies had higher metabolic rates during peak colony productivity. While some effects of infection, such as elevated colony-level metabolic rates may be detrimental in more stressful natural conditions, we did not find any costs of infection under relatively benign laboratory conditions. Overall, our study emphasizes the beneficial effects of Wolbachia on colony-level growth and metabolism in this species.

Effects of environmental factors on the ecology and survival of a widespread, endemic Cerrado frog

Understanding the mechanisms that affect habitat use by vertebrates is critical for understanding how species are distributed across landscapes and how they cope with habitat change. The Brazilian Savanna (the Cerrado) has vegetation ranging from grassland to woodland savannas and harbors a rich and diverse amphibian fauna impacted by accelerated habitat loss. Here, we test the influence of vegetation type (from grassy scrubland to woodland) and distance from breeding sites (ephemeral water bodies) on body size, abundance, and survival of the frog Physalaemus nattereri in a natural metapopulation system of south-central Brazil. We also test whether body size is a significant predictor of population abundance. We found that the abundance of P. nattereri varies according to the mean snout-vent length of each metapopulation (sampling unit), as well as a higher estimated mortality rate in woodlands compared to typical Cerrado. Furthermore, we found no difference in estimated mortality among sampling units located far or close to ephemeral water bodies. Thus, our results highlight variable responses of P. nattereri metapopulations to environmental factors, despite the observed high heterogeneity among sampled habitats and the importance of ephemeral water bodies for reproduction. These findings highlight that land cover and availability of breeding sites might not always interact to explain population persistence of Cerrado frogs.

opencc-by-4.0Dec 2022View details →

"STILL AROUND": Experiences and Survival Strategies of Veteran Women Software Developers (Supplementary Material)

The intersection of ageism and sexism can create a hostile environment for veteran software developers belonging to marginalized genders. In this study, we conducted 14 interviews to examine the experiences of people at this intersection, primarily women, in order to discover the strategies they employed in order to successfully remain in the field. We identified 283 codes, which fell into three main categories: Strategies, Experiences, and Perception. Several strategies we identified, such as (Deliberately) Not Trying to Look Younger, were not previously described in the software engineering literature. We found that, in some companies, older women developers are recognized as having particular value, further strengthening the known benefits of diversity in the workforce. Based on the experiences and strategies, we suggest organizations employing software developers to consider the benefits of hiring veteran women software developers. For example, companies can draw upon the life experiences of older women developers in order to better understand the needs of customers from a similar demographic. While we recognize that many of the strategies employed by our study participants are a response to systemic issues, we still consider that, in the short-term, there is benefit in describing these strategies for developers who are experiencing such issues today.

Low Kirtland's Warbler fledgling survival in Wisconsin plantations relative to Michigan plantations

The Kirtland's Warbler (Setophaga kirtlandii) is a formerly endangered habitat specialist that breeds mainly in young jack pine (Pinus banksiana) forests in northern Lower Michigan, USA. The species is conservation-reliant and depends on habitat management. Management actions have primarily focused on creating jack pine plantations, but the species also breeds in red pine (Pinus resinosa) plantations in central Wisconsin, USA. However, the plantations were not intended as breeding habitat and have suboptimal pine densities. While nesting success is similar between low-density red pine plantations and optimal jack pine habitat, it is not clear if low-density red pine plantations support high fledging survival. If high-quality nesting and post-fledging habitat are not synonymous, fledgling survival and breeding population recruitment may be low. We characterized survival, habitat use, and movement patterns of dependent Kirtland's Warbler fledglings in Wisconsin red pine plantations and compared fledgling survival between Wisconsin and Michigan. Mayfield cumulative survival estimates at 30 days post-fledging were 0.20 for Wisconsin fledglings and 0.43 to 0.78 for Michigan fledglings. Logistic exposure cumulative survival estimates for Wisconsin fledglings were 0.23 to 0.34 at 30 days post-fledging. Fledglings in Wisconsin used areas where vegetation cover and density of red and jack pine were high relative to available areas but not at greater proportions than what was available. Our findings demonstrate that red pine plantations with low pine densities were not equally suitable as nesting and post-fledging habitat, as fledgling survival rates were low. We hypothesize that habitat structure, and not particular pine species, likely contributed to reduced fledgling survival in Wisconsin. Thus, we recommend including red pine as a component in managed Kirtland's Warbler habitat only if tree densities approach optimal levels.

opencc-by-4.0Feb 2023View details →

Raw Data for the article: Atrial fibrillation ablation improves late survival after concomitant cardiac surgery

Objective: Preoperative atrial fibrillation (AF) increases risk of stroke, heart failure, and all-cause mortality after cardiac surgery. Despite encouraging results and guideline recommendations, surgical ablation (SA) for AF concomitant with other heart surgery remains low. In the current study we aimed to address the long-term mortality after SA concomitant with cardiac surgery. Methods: This report pertains to the HEart surgery In atrial fibrillation and Supraventricular Tachycardia (HEIST) registry. We identified 20,765 adult patients (62% male) with preoperative AF who underwent conventional sternotomy heart surgery between 2010 and 2021 in 8 tertiary centers in Poland, Netherlands, and Italy. We used Cox proportional hazards models for computations and propensity score matching to minimize differences in baseline characteristics. Results: Of included patients, 2755 (13.4%) underwent SA for AF. The highest rates of SA were observed for mitral interventions (mitral valve repair or replacement and tricuspid intervention, 25.2%), lowest for isolated coronary artery bypass grafting (6.2%). Patients in the SA group were younger (mean age 64.5 ± 9.0 years vs 68.7 ± 16.0 years; P < .001) and lower risk (mean European System for Cardiac Operative Risk Evaluation [EuroSCORE] II, 4.1 vs 5.7; P < .001). During the 11-year study period, there was a mortality reduction associated with SA (hazard ratio, 0.57; 95% CI, 0.52-0.62; P < .001). After propensity matching, 2750 pairs with similar baseline characteristics were identified. SA was associated with 16% mortality decline (hazard ratio, 0.84; 95% CI, 0.75-0.94; P = .003). Conclusions: In this multicenter, retrospective, propensity matched study, SA concomitant with other cardiac surgery was associated with improved long-term survival regardless of baseline surgical risk.

opencc-by-4.0Feb 2023View details →

Raw Data for the article: Continuous Renal Replacement Therapy after Liver Transplantation: Peri-Operative Associated Factors and Impact on Survival

Continuous renal replacement therapy (CRRT) following orthotopic liver transplantation (OLT) is usually started for multifactorial reasons, with variable incidence among series. This paper presents a single-center retrospective observational study on the early use (within one week) of CRRT after consecutive cadaveric OLT from January 2008 to December 2016. Preoperative patient characteristics and intraoperative data were collected, and patients were divided into two groups (CRRT and no CRRT) to explore the factors associated with the use of CRRT. Repeated measurements of postoperative creatinine were analyzed with generalized estimating equation (GEE) models. Among 528 OLT patients, 75 (14.2%) were treated with CRRT at least once in the first week. Patients treated with CRRT showed lower survival in a Kaplan-Meier curve (log-rank p value &lt; 0.01). Patients treated with CRRT had a more severe preoperative profile, with a significantly higher age, MELD, BUN, creatinine, and total bilirubin, as well as a longer surgery time and a higher number of transfusions of red blood cells, plasma, and platelets (all p values &lt; 0.05). In a stepwise multiple analysis, the following characteristics remained independently associated with the use of CRRT: the MELD score OR 1.12 (95% CL: 1.07-1.16), p value &lt; 0.001, and the preoperative value for blood urea nitrogen OR 1.016 (95% CL: 1.010-1.023), p value &lt; 0.001. The early use of CRRT after OLT occurred at a low rate in this large cohort; however, it was associated with worse outcomes. Apart from the preoperative severity, repeated intraoperative hypotension episodes, which were likely modifiable or preventable, were associated with the increased use of CRRT and higher postoperative creatinine.

Consistent apparent adult survival and nest-site fidelity of Whimbrel (Numenius phaeopus) near Churchill, Manitoba, Canada over a 40-year period

Reliable estimates of adult survival for many shorebird species are lacking. We used Cormack-Jolly-Seber (CJS) methods to provide an estimate of apparent, or local, survival (φ) of a population of Whimbrels, Numenius phaeopus, breeding in the subarctic Churchill, Manitoba region. We used data collected in two time periods: 1973–1976 and 2010–2014. We also quantified nest-site fidelity in 2010–2014 to provide context to our apparent survival estimates because mark-recapture analyses cannot distinguish between mortality and permanent emigration. The most parsimonious CJS model did not include effects of sex or time on apparent adult survival in either period (φ = 0.76 ± 0.13 SE; φ = 0.75 ± 0.04 SE, 1973 – 1976 and 2010 – 2014, respectively). Additionally, observations of marked Whimbrels between 2010 and 2019 (n = 124) showed that 61 of the 105 marked individuals (58.1%) were resighted. These estimates of return rates are, as expected, much lower than estimates of apparent survival. The median year-to-year distance between nests (n = 139) from 2010 to 2014 was 198 ± 88 m SE and did not differ significantly (p = 0.84) between females (x ̅ = 721.9 ± 119.8 m SE) and males (x ̅ = 720.3 ± 83.1 m SE). If our apparent survival estimate is indicative of true survivorship, then adult mortality during the nonbreeding season has remained constant over the last five decades, implying that the recent decline in Whimbrel populations may stem largely from reduced fecundity, including egg or juvenile survival, rather than primarily from reduced adult survival.

Survival data and code: Camouflage using 3D surface disruption

Disruptive markings are common in animal patterns and can provide camouflage benefits by concealing the body's true edges and/or by breaking the surface of the body into multiple depth planes. Disruptive patterns that are accentuated by high contrast borders are most likely to provide false depth cues to enhance camouflage, but studies to date have used visual detection models or humans as predators. We presented 3D-printed moth-like targets to wild bird predators to determine whether: (1) 3D prey with disrupted body surfaces have higher survival than 3D prey with continuous surfaces, (2) 2D prey with disruptive patterns or enhanced edge markings have higher survival than non-patterned 2D prey. We found a survival benefit for 3D prey with disrupted surfaces, even after accounting for luminance differences among the treatments. There was no evidence that false depth cues provided the same protective benefits as physical surface disruption in 3D prey, perhaps because our treatments did not mimic the complexity of patterns found in natural animal markings. Our findings indicate that disruption of surface continuity is an important strategy for concealing a 3D body shape.

Location Location Location: Survival of Antarctic biota requires the best real-estate

The origin of terrestrial biota in Antarctica has been debated since the discovery of springtails on the first historic voyages to the southern continent more than 120 years ago. A plausible explanation for the long-term persistence of life requiring ice-free land on continental Antarctica has, however, remained elusive. The default glacial eradication scenario has dominated because hypotheses to date have failed to provide a mechanism for their widespread survival on the continent, particularly through the Last Glacial Maximum when geological evidence demonstrates that the ice sheet was more extensive than present. Here, we provide support for the alternative nunatak refuge hypothesis – that ice-free terrain with sufficient relief above the ice sheet provided refuges and was a source for terrestrial biota found today. This hypothesis is supported here by an increased understanding from the combination of biological and geological evidence, and we outline a mechanism for these refuges during successive glacial maxima that also provides a source for coastal species. Our cross-disciplinary approach provides future directions to further test this hypothesis that will lead to new insights into the evolution of Antarctic landscapes and how they have shaped the biota through a changing climate.

opencc-by-4.0Mar 2023View details →

Survival analysis after vertebral compression fractures in population over 65 years old

Background: Mortality in vertebral compression fractures (VCF) is rarely directly associated with the fracture. Lower mortality has been demonstrated when fractures are treated surgically (vertebral augmentation) versus conservatively. However, the exact mechanism that justifies this increased survival is unknown. This study aims to analyze overall survival in elderly patients who have suffered a non-pathological VCF, its causes, and the relationship with different factors. Methods: All patients over 65 years old diagnosed with acute, non-pathologic thoracic or lumbar VCF, treated consecutively in our center from January 2017 to December 2020, were retrospectively selected for analysis. Those patients with follow-ups under two years or who required arthrodesis due to poor fracture evolution were excluded. Only the first process was considered for patients who presented a second VCF in the first three months. Results: A total of 509 consecutive fractures were registered. Seventeen were excluded, leaving 492 cases for final analysis. The mean age was 78.9 years old. Overall mortality was 36.2%. Survival rate at 1-, 12-, 24-, 48-, and 60-month follow-up was 97.4%, 86.6%, 78.0%, 64.4%, and 59.4%, respectively. The independent factors associated with a higher mortality risk were age, male, oncologic history, non-traumatic mechanism, and co-morbidity during hospitalization. No statistical differences were found when comparing the two survival curves by treatment (vertebral augmentation vs. conservative management) over time. No benefit was observed in those patients with comprehensive outpatient geriatric care.  Conclusion: Age, male sex, history of oncological disease, non-traumatic mechanism of the fracture, and any comorbidity during hospitalization were identified as variables independently associated with a higher risk of mortality following a VCF in the elderly. Vertebral augmentation and comprehensive outpatient geriatric care showed no benefit in overall survival.

Are breeding activities risky for northern bobwhites? An assessment of survival costs of reproduction

Behaviors associated with breeding can increase mortality risk. This increased risk can be thought of as a cost of reproduction. Increased movements prior to breeding are common as individuals search for food and breeding sites. These increased movements are thought to entail greater predation risks as individuals travel through unfamiliar areas but few studies have looked at how these prebreeding movements affect survival, especially at a fine temporal resolution. Costs of reproduction may also occur during reproduction. For birds, incubation and brood-rearing can increase predation risk because individuals spend most of their time at nest sites or with broods, which may make them more easily detected and captured by predators. Using time- and individual-specific predictors of survival, I examined the relationship between survival, movements, habitat use, and breeding status of northern bobwhites Colinus virginianus in Colorado, USA. I found that prebreeding ranges were larger for breeders (29 ha) than non-breeders (18.7 ha) but daily movement distance was not different (163 m). Range size did not affect survival; however, longer recent daily movement distances (within 10 days) resulted in higher survival. Breeding status also affected survival; laying individuals experienced the highest daily survival rates followed by incubating, non-breeding and brood-rearing individuals. Overall, there appears to be a survival cost of reproduction for individuals during brood-rearing, but I found no evidence that increased movements results in decreased survival.

Open-population SCR model to estimate spatiotemporal variation in individual birth locations, detection rates, and survival

This is an open population SCR model developed by R. Chandler and K. Engebretsen. The full model incorporates 4 spatial covariates in birth location density submodel, 3 location-specific, temporal covariates in the detection submodel, and 4 spatial covariates in the survival submodel. Formatted data is provided for the 2015 and 2016 fawning season in south Florida and the model can be fit using the script fitFawnModel.R.

Identifying temporal dynamics in post-release survival of a restored large ungulate

Wildlife translocation is an important conservation tool for restoring species and reducing global biodiversity decline; however, this practice is challenging for wildlife, and translocated individuals must adjust to their release landscapes for restoration success. The period following release is a vulnerable time for wildlife and determining when animals acclimate following translocation improves long-term estimates of population dynamics and allows researchers to efficiently tailor translocation design and post-release management to each population's needs. We evaluated demographic acclimation and investigated changes in post-release survival of a population of 106 elk (Cervus canadensis) translocated to Missouri, U.S.A., from 2011 to 2013 using generalized survival modeling. We defined the acclimation period as the duration of time prior to stabilization in mortality risk relative to time from release, and we evaluated acclimation duration from flexible plots of estimated mortality hazards across time. We simultaneously investigated factors contributing to post-release survival and compared survival rates and mortality sources observed during acclimation and post-acclimation periods. Elevated mortality risk for translocated elk spanned a 5-month acclimation period following release, with an additional one-year period reflecting reduced, but still elevated, mortality hazards. Baseline hazards during the initial 5-month acclimation period were approximately four times higher than the subsequent 4.4 years following release. Release cohort, but not age class or sex, was associated with post-release mortality risk, and mortality sources within the acclimation period tended to be undetermined with greater frequency relative to mortalities occurring after the acclimation period. Synthesis and applications. Our results highlight the utility of flexible modeling approaches to evaluate dynamic post-release responses of translocated populations. Translocated elk demonstrated a pronounced demographic acclimation period that spanned five months following release. Changes in mortality sources and the timing of stabilization in mortality hazards suggest that demographic acclimation in translocated elk was associated with adjustments in physiological stress and movement rates that stabilize over a similar post-release duration. Improving post-release monitoring and assessment of restored populations by evaluating temporal dynamics of manifold biological and ecological responses of translocated animals.