Impact of harvest on survival of a heavily hunted game bird population

2010 ◽  
Vol 37 (5) ◽  
pp. 392 ◽  
Author(s):  
Virginie Rolland ◽  
Jeffrey A. Hostetler ◽  
Tommy C. Hines ◽  
H. Franklin Percival ◽  
Madan K. Oli
Keyword(s):  
Bird Species ◽  
Mortality Rates ◽  
Northern Bobwhite ◽  
South Florida ◽  
Extrinsic Factors ◽  
Hunting Pressure ◽  
Annual Survival ◽  
Northern Bobwhites ◽  
Game Bird ◽  
Specific Mortality

Context. Despite their economic importance and intensive management, many game bird species, including the northern bobwhite Colinus virginianus, are in decline. Declines may be explained, at least in part, by low survival due perhaps to poor habitat quality, high predation or excessive hunting pressure. Aims. This study sought to estimate and model annual/seasonal survival probabilities, to evaluate factors influencing them and to determine the cause-specific mortality rates for northern bobwhites subject to varying levels of harvest on the Babcock–Webb Wildlife Management Area (BW area), south Florida, USA. Methods. We applied Cox’s proportional hazard models to data collected from 2066 radio-tagged bobwhites during 2002–2008 to test for intrinsic and extrinsic factors affecting survival and the non-parametric cumulative incidence function estimator to estimate cause-specific mortality rates. Key results. Mean annual survival (0.091 ± 0.006) in the BW area was lower than most estimates reported for other bobwhite populations. Annual survival differed between adults (0.111 ± 0.008) and juveniles (0.052 ± 0.008), and varied among years. Survival in winter (October–March; 0.295 ± 0.014) was similar to that in summer (April–September; 0.307 ± 0.013). Density of food strips (i.e. long and narrow food plots) did not influence survival, but hunting effort (number of hunters per day per km2) had a substantial negative impact on survival. In the lightly hunted field trial zone, winter (October–March) survival was significantly higher (0.414 ± 0.035) than in the other more heavily hunted management zones (0.319 ± 0.016). Cause-specific mortality analyses revealed that bobwhite mortality during summer (April–September) was mainly due to raptor (39.7%) and mammalian predation (35.6%), whereas hunting was the primary cause of mortality during winter (47.1%). Conclusions. Our results highlight the potential role of harvest as an important cause of the northern bobwhite population declines in south Florida. High mortality during winter may reduce recruitment of juveniles to the reproductive segment of the population, and ultimately the population growth. Implications. Our results suggest that reduction in hunting pressure may be necessary to reverse the declining population trends in heavily hunted game species in public lands, such as the northern bobwhites in the BW area.

scholarly journals Monitoring progress with national and subnational health goals by integrating verbal autopsy and medically certified cause of death data

2021 ◽  
Vol 6 (5) ◽  
pp. e005387
Author(s):  
Tim Adair ◽  
Sonja Firth ◽  
Tint Pa Pa Phyo ◽  
Khin Sandar Bo ◽  
Alan D Lopez
Keyword(s):  
Cause Of Death ◽  
Verbal Autopsy ◽  
Integration Method ◽  
Mortality Rates ◽  
Vital Statistics ◽  
Death Registration ◽  
Chronic Respiratory Diseases ◽  
Health Goals ◽  
Specific Mortality ◽  
Four Causes

IntroductionThe measurement of progress towards many Sustainable Development Goals (SDG) and other health goals requires accurate and timely all-cause and cause of death (COD) data. However, existing guidance to countries to calculate these indicators is inadequate for populations with incomplete death registration and poor-quality COD data. We introduce a replicable method to estimate national and subnational cause-specific mortality rates (and hence many such indicators) where death registration is incomplete by integrating data from Medical Certificates of Cause of Death (MCCOD) for hospital deaths with routine verbal autopsy (VA) for community deaths.MethodsThe integration method calculates population-level cause-specific mortality fractions (CSMFs) from the CSMFs of MCCODs and VAs weighted by estimated deaths in hospitals and the community. Estimated deaths are calculated by applying the empirical completeness method to incomplete death registration/reporting. The resultant cause-specific mortality rates are used to estimate SDG Indicator 23: mortality between ages 30 and 70 years from cardiovascular diseases, cancers, chronic respiratory diseases and diabetes. We demonstrate the method using nationally representative data in Myanmar, comprising over 42 000 VAs and 7600 MCCODs.ResultsIn Myanmar in 2019, 89% of deaths were estimated to occur in the community. VAs comprised an estimated 70% of community deaths. Both the proportion of deaths in the community and CSMFs for the four causes increased with older age. We estimated that the probability of dying from any of the four causes between 30 and 70 years was 0.265 for men and 0.216 for women. This indicator is 50% higher if based on CSMFs from the integration of data sources than on MCCOD data from hospitals.ConclusionThis integration method facilitates country authorities to use their data to monitor progress with national and subnational health goals, rather than rely on estimates made by external organisations. The method is particularly relevant given the increasing application of routine VA in country Civil Registration and Vital Statistics systems.

Dietary Selection against Cottonseed Meal by Captive Northern Bobwhites

2018 ◽  
Vol 11 (3) ◽  
pp. 191-195 ◽  
Author(s):  
Amy L. Farthing ◽  
Thomas W. Schwertner ◽  
Heather A. Mathewson ◽  
Kimberly A. Guay
Keyword(s):  
Cottonseed Meal ◽  
Cultural Value ◽  
Feed Consumption ◽  
Published Data ◽  
Northern Bobwhites ◽  
Dietary Preference ◽  
Game Bird ◽  
Selection For ◽  
Whole Cottonseed ◽  
Preference Study

Gossypol, a secondary plant compound found in cotton (Gossypium spp.), is known to be toxic to a variety of animals, particularly monogastric mammals and birds. Because ruminants are resistant to gossypol, whole cottonseed and cottonseed meal have been used as a feed supplement for many decades. Concerns over gossypol toxicity arise because of its presence in cottonseed products, particularly livestock and wildlife feed. The concentration of cottonseed in the environment near livestock and wildlife feeding stations presents the possibility that it may be ingested in significant amounts by non-target wild animals, resulting in inadvertent gossypol dosing. A species of significant economic and cultural value is the Northern Bobwhite (Colinus virginianus). However, there are no published data regarding if Northern Bobwhites would consume cottonseed meal given the opportunity. We assessed selection for or against cottonseed meal by performing a dietary preference study. Birds (n =120) were given the choice between commercial game bird feed, scratch grains, and cottonseed meal containing 0.74% total gossypol. We measured feed consumption for five days. The birds’ diet consisted of 51.74% game bird feed, 37.72% scratch grains, and 10.54% cottonseed meal, and percentages varied significantly among all feed types (P≤0.001, n =360). We concluded that Northern Bobwhites selected against the cottonseed meal in favour of the game bird feed first and the scratch grains second. Our results suggest that given the choice, Northern Bobwhites will select against cottonseed meal if other feed choices are available.

Slowing of age-specific mortality rates in Drosophila melanogaster

1993 ◽  
Vol 28 (6) ◽  
pp. 585-599 ◽  
Author(s):  
H.Henry Fukui ◽  
Liang Xiu ◽  
James W. Curtsinger
Keyword(s):  
Drosophila Melanogaster ◽  
Mortality Rates ◽  
Specific Mortality

scholarly journals Drug Overdose Trends among Black Indiana Residents: 2013-2017

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Raven Helmick
Keyword(s):  
Mortality Rate ◽  
Drug Overdose ◽  
Rate Increase ◽  
Mortality Rates ◽  
Time Frame ◽  
Minority Population ◽  
Racial Inequalities ◽  
Specific Mortality ◽  
Overdose Mortality ◽  
Overdose Deaths

ObjectiveTo understand trends in race-specific mortality rates between blacks and whites to discover any racial inequalities that might exist for drug overdose deaths. To delve into the types of drugs that are prominently involved in black drug overdose deaths from 2013-2017 in the state of Indiana.IntroductionBlack Hoosiers, the largest minority population in Indiana, make up almost 10% of the state’s population, and accounted for 8% of the total resident drug overdose deaths from 2013-2017 compared to whites at 91%. However, a closer look at race-specific mortality rates might reveal racial inequalities. Therefore, the purpose of this project was to analyze drug overdose morality rates among white and black Hoosiers to discover possible racial inequalities and to discover trends in drug involvement in overdose deaths among blacks.MethodsDrug overdose deaths that occurred in Indiana between 2013 and 2017 were identified using the underlying and contributing cause of death ICD-10 codes and abstracted from the Indiana State Department of Health’s annual finalized mortality dataset. Race-specific drug overdose death rates were calculated and compared among racial groups. Drug overdose deaths in blacks were examined for trends over time and by the types of drugs involved.ResultsBetween 2013 and 2017, drug overdose mortality rates for whites increased from 17.05 to 27.28 per 100,000. Blacks saw a higher rate increase during this same time frame: from 10.74 to 30.62 per 100,000, surpassing the mortality rate of whites by the end of 2017. Drug overdose deaths in blacks increased 197% from 2013-2017 and drug specific mortality rate increases were seen across all drug category’s. Opioids, which were involved in 61% of the 2017 drug overdose deaths among blacks, had a rate increase from 3.05 to 18.62 per 100,000 between 2013 and 2017. Drug specific overdose mortality rate increases were also seen for overdoses involving cocaine (1.76 to 10.62 per 100,000), benzodiazepines (0.32 to 3.08 per 100,000), and psychostimulants other than cocaine (0.16 to 1.69 per 100,000) such as amphetamines.ConclusionsWhile white Hoosiers had higher drug overdose mortality rates between 2013 and 2016, black Hoosiers had a greater mortality rate increase and surpassed the mortality rate in whites in 2017. Opioids, the most frequently involved substance in overdose deaths among blacks from 2013-2017, showed increasing rates during this time period. However, increases in drug specific overdose mortality rates for cocaine, benzodiazepines, and psychostimulants other than cocaine also call for public health attention. These results promote the inclusion of minority health experts in drug overdose prevention efforts and issue a call for future prevention efforts to be targeted toward the state’s largest minority population. 

scholarly journals FITTING OF AGE-SPECIFIC MORTALITY

2019 ◽  
Vol 7 (7) ◽  
pp. 405-415
Author(s):  
A.S. Talawar ◽  
Rajani P. Agadi
Keyword(s):  
Parameter Estimation ◽  
Life Table ◽  
Total Population ◽  
Mortality Rates ◽  
Demographic Characteristics ◽  
Parametric Models ◽  
Model Fit ◽  
Survival Functions ◽  
Mortality Pattern ◽  
Specific Mortality

The age-pattern of mortality can be represented by various parametric models. In the present paper we consider a mixture of Weibull, Inverse-Weibull, and Gompertz-Makeham (GoMa) survival functions and Heligman–Pollard model to fit U.S. life table 2014.  We use loss criterion for parameter estimation and demonstrate fitting of model. Both mixture and Heligman–Pollard model fit the mortality pattern reasonably well up to age 90.  We notice that the estimated mortality rates fit the actual pattern fairly well, although the fit at the earlier ages could be better. We have obtained the plots using our estimated values. The plots for mortality pattern of total population and other demographic characteristics (sex and race) are also considered.

Differences in trapping mortality rates of northern flying squirrels

1993 ◽  
Vol 71 (3) ◽  
pp. 660-663 ◽  
Author(s):  
Daniel K. Rosenberg ◽  
Robert G. Anthony
Keyword(s):  
Mortality Rates ◽  
Differential Mortality ◽  
Glaucomys Sabrinus ◽  
Adult Males ◽  
Extrinsic Factors ◽  
Age Cohorts ◽  
Flying Squirrels ◽  
Northern Flying Squirrel ◽  
Northern Flying Squirrels ◽  
Juvenile Males

We described trapping mortality rates of northern flying squirrel (Glaucomys sabrinus) populations in western Oregon, U.S.A., and evaluated the effects of sex, age, body mass, and number of times an individual was recaptured on these rates. Although the overall trapping mortality rates were relatively low (7%) during 16–21 day trapping sessions, we observed differential mortality rates among the sex and age cohorts. The order of mortality rates was: juvenile females (32.3%) > juvenile males (11.1%) > adult females (5.1%) = adult males (4.1%). Overall trapping mortality rates were not affected by the number of times an individual was captured. We hypothesize that the differences we found were due to extrinsic factors (weather-related) acting on differential behavioral responses to trapping and thresholds of stress an animal can tolerate.

THE STUDY OF RUSSIAN CIVILIAN AVIATION PILOTS’ MORTALITY

2021 ◽  
Author(s):  
I.V. Bukhtiyarov ◽  
◽  
E.V. Zibarev ◽  
K.V. Betts
Keyword(s):  
Working Conditions ◽  
Mortality Risk ◽  
Age Groups ◽  
Mortality Rates ◽  
Russian Population ◽  
Standardized Mortality Ratio ◽  
Long Term Effects ◽  
Specific Mortality ◽  
Aviation Pilots

Abstract. Introduction. The work of civilian aviation pilots is characterized by heavy psychological and emotional stress in combination with other occupational factors. Such complex of adverse working conditions appears to be a risk for functional and somatic disorders, which may subsequently be reflected in the causes and rates of mortality in the distant period. The aim of this work is to study the mortality of retired civilian aviation pilots. Methods. A prospective cohort epidemiological study of civilian aviation pilots’ mortality. The cohort included 4513 male civilian aviation pilots of Russia who completed their employment and received employment pension. The follow-up period was 10 years (01.01.2010-31.12.2019), with 22156.9 person-years obtained. The age-specific mortality rates were calculated for 5-year age groups, the mortality risk was assessed using standardized mortality ratio (SMR) with 95% confidence interval (95% CI). The comparison group was the male Russian population. Results. As of 31.12.2019, out of 4513 civilian aviation pilots, 150 people deceased (3.3%). The age-specific mortality rates in the retired pilots’ cohort were lower in all age groups compared to the male Russian population, except for the 35-39 age group. The all-cause mortality risk for civilian aviation pilots was significantly lower compared to the male Russian population, SMR=0.31 (95%CL 0.26-0.36). Conclusion. Further research is required to determine the long-term effects of working conditions on civilian aviation pilots’ health. The follow-up period for the pilots’ cohort should be increases to 20 years and more.

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