Influence of rodent abundance on nesting success of prairie waterfowl

2008 ◽  
Vol 86 (6) ◽  
pp. 497-506 ◽  
Author(s):  
Rodney W. Brook ◽  
Maria Pasitschniak-Arts ◽  
David W. Howerter ◽  
François Messier
Keyword(s):  
Prairie Pothole Region ◽  
Microtus Pennsylvanicus ◽  
Nesting Success ◽  
Curvilinear Relationship ◽  
Prairie Pothole ◽  
Predator Prey ◽  
Management Plans ◽  
Study Sites ◽  
The Relationship ◽  
Rodent Abundance

Most waterfowl nesting failure in the prairie biome is attributed to predation. However, the contribution of small mammal abundance to the prairie predator–prey cycle and how this affects waterfowl productivity is not known. We modelled seasonal variability of nesting success, including a number of habitat and nest-related variables, to quantify influence of rodent abundance for prairie nesting waterfowl for six study sites in the Prairie Pothole Region of Canada, 1996–1998. We estimated there is a curvilinear relationship between the abundance of meadow voles ( Microtus pennsylvanicus (Ord, 1815)) and the nesting success of ducks. The relationship has characteristics of the alternate prey hypothesis at low vole density and characteristics of the shared prey hypothesis at higher densities. At low vole densities, duck nests appear to be buffered from predation by voles but, at higher densities, nesting success was affected negatively. We recommend that predator–prey dynamics should be included as an integral part of management plans for nesting waterfowl and suggest further research using rigorous experiment design to elucidate mechanisms and pathways responsible for this observed relationship.

scholarly journals Effects of Water Conditions on Clutch Size, Egg Volume, and Hatchling Mass of Mallards and Gadwalls in the Prairie Pothole Region

The Condor ◽  
2000 ◽  
Vol 102 (4) ◽  
pp. 936-940 ◽  
Author(s):  
Pamela J. Pietz ◽  
Gary L. Krapu ◽  
Deborah A. Buhl ◽  
David A. Brandt
Keyword(s):  
North Dakota ◽  
Clutch Size ◽  
Prairie Pothole Region ◽  
Prairie Pothole ◽  
Egg Volume ◽  
Water Conditions ◽  
Breeding Grounds ◽  
Using Data ◽  
The Relationship ◽  
Basin Area

AbstractWe examined the relationship between local water conditions (measured as the percent of total area of basins covered by water) and clutch size, egg volume, and hatchling mass of Mallards (Anas platyrhynchos) and Gadwalls (A. strepera) on four study sites in the Prairie Pothole Region of North Dakota and Minnesota, 1988–1994. We also examined the relationship between pond density and clutch size of Mallards and Gadwalls, using data collected at another North Dakota site, 1966–1981. For Mallards, we found no relationships to be significant. For Gadwalls, clutch size increased with percent basin area wet and pond density; hatchling mass marginally increased with percent basin area wet. These species differences may reflect, in part, that Mallards acquire lipid reserves used to produce early clutches before they reach the breeding grounds, whereas Gadwalls acquire lipid reserves locally; thus Gadwall clutches are more likely to be influenced by local food resources.

scholarly journals Diet of the wild boar (Sus scrofa): implications for management in forest-agricultural and urban environments in South Korea

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7835 ◽  
Author(s):  
Seong-Min Lee ◽  
Eun-Jae Lee
Keyword(s):  
South Korea ◽  
Wild Boar ◽  
Urban Areas ◽  
Feeding Habits ◽  
Stomach Contents ◽  
Urban Environments ◽  
Natural Food ◽  
Management Plans ◽  
Study Sites ◽  
The Relationship

The wild boar is one of the most widely distributed in the world. In South Korea, the wild boar population has rapidly increased and their habitat use has expanded from forests to urban environments. This expansion has led to increased conflicts with humans, such as the severe damaging of crops and the attacking of people in urban areas. We assessed the stomach contents of wild boar killed by hunters in two different environments in Geochang and Seoul, South Korea, from 2012 to 2017. We compared the feeding habits between sites and between seasons and explored the relationship between the number of earthworms and the main diet. The diet of wild boars inhabiting the two environments were found to differ and vary seasonally. Wild boar in Geochang preferred crops, when available, to natural food resources. Although wild boar in Seoul also preferred crops, they had a higher composition of natural food in their diets because of a low availability of crops. The preference of crops and discarded food waste in urban areas is expected to have accelerated the appearance of wild boar in urban areas. The consumption of earthworms did not differ between the two study sites, but it did differ seasonally due to availability. The number of earthworms was significantly negatively correlated with crop availability in both sites. Effective management plans that involve targeted hunting by baiting with food in Seoul and direct hunting in the fall in Geochang should be implemented to resolve the human–wild boar conflicts in these areas.

Gender Ideology and Fertility: Evidence for a Curvilinear Hypothesis

2020 ◽  
Author(s):  
Serena Stefani ◽  
Gabriele Prati
Keyword(s):  
Gender Ideology ◽  
Two Dimensions ◽  
Curvilinear Relationship ◽  
World Population ◽  
Fertility Rates ◽  
The World ◽  
And Gender ◽  
Using Data ◽  
National Analysis ◽  
The Relationship

Research on the relationship between fertility and gender ideology revealed inconsistent results. In the present study, we argue that inconsistencies may be due to the fact that such relationship may be nonlinear. We hypothesize a U- shaped relationship between two dimensions of gender ideology (i.e. primacy of breadwinner role and acceptance of male privilege) and fertility rates. We conducted a cross-national analysis of 60 countries using data from the World Values Survey as well as the World Population Prospects 2019. Controlling for gross domestic product, we found support for a U-shaped relationship between gender ideology and fertility. Higher levels of fertility rates were found at lower and especially higher levels of traditional gender ideology, while a medium level of gender ideology was associated with the lowest fertility rate. This curvilinear relationship is in agreement with the phase of the gender revolution in which the country is located. Traditional beliefs are linked to a complementary division of private versus public sphere between sexes, while egalitarian attitudes are associated with a more equitable division. Both conditions strengthen fertility. Instead, as in the transition phase, intermediate levels of gender ideology’s support are associated with an overload and a difficult reconciliation of the roles that women have to embody (i.e. working and nurturing) so reducing fertility. The present study has contributed to the literature by addressing the inconsistencies of prior research by demonstrating that the relationship between gender ideology and fertility rates is curvilinear rather than linear.

Glycogenolytic rates and cAMP in livers of rats running at different treadmill speeds

1983 ◽  
Vol 245 (3) ◽  
pp. R353-R356
Author(s):  
W. W. Winder ◽  
M. A. Beattie ◽  
E. O. Fuller
Keyword(s):  
Liver Glycogen ◽  
Work Rate ◽  
Curvilinear Relationship ◽  
Camp Concentration ◽  
Running Speed ◽  
Cyclic Monophosphate ◽  
High Degree ◽  
The Relationship ◽  
Camp Levels ◽  
Liver Glycogenolysis

The purposes of this study were to determine the effect of different work rates on the rate of liver glycogenolysis and to determine the relationship between liver adenosine 3',5'-cyclic monophosphate (cAMP) levels and the glycogenolytic rate. Rats were run at treadmill speeds ranging from 10 to 34 m/min up a 15% grade for either 30 or 60 min. Both the magnitude of the decrease in liver glycogen and the increase in hepatic cAMP were dependent on the running speed and the duration of running. At the highest work rate a disproportionate acceleration in the liver glycogenolytic rate was observed compared with that at lower work loads, thus resulting in a curvilinear relationship between work rate and liver glycogenolytic rate. A high degree of correlation was found between the liver glycogenolytic rate and hepatic cAMP concentration (r = 0.98). This observation is consistent with the idea that hepatic glycogenolytic rates are determined by cAMP-mediated mechanisms.

scholarly journals Evaluating the Relationship Between Initial Injury, Referral to A Pain Clinic, and Medical Retirement from the Army: A Retrospective Analysis

2021 ◽  
Vol 186 (Supplement_1) ◽  
pp. 502-505
Author(s):  
Justin J Stewart ◽  
Diane Flynn ◽  
Alana D Steffen ◽  
Dale Langford ◽  
Honor McQuinn ◽  
...  
Keyword(s):  
Chronic Pain ◽  
Retrospective Analysis ◽  
Extended Period ◽  
Pain Clinic ◽  
Outcome Variable ◽  
Future Research ◽  
Curvilinear Relationship ◽  
The Impact ◽  
Pain Care ◽  
The Relationship

ABSTRACT Introduction Soldiers are expected to deploy worldwide and must be medically ready in order to accomplish their mission. Soldiers unable to deploy for an extended period of time because of chronic pain or other conditions undergo an evaluation for medical retirement. A retrospective analysis of existing longitudinal data from an Interdisciplinary Pain Management Center (IPMC) was used to evaluate the temporal relationship between the time of initial duty restriction and referral for comprehensive pain care to being evaluated for medical retirement. Methods Patients were adults (>18 years old) and were cared for in an IPMC at least once between May 1, 2014 and February 28, 2018. A total of 1,764 patients were included in the final analysis. Logistic regression was used to evaluate the impact of duration between date of first duty restriction documentation and IPMC referral to the outcome variable of establishment of a permanent 3 (P3) profile. Results The duration between date of first duty restriction and IPMC referral showed a curvilinear relationship to probability of a P3 profile. According to our model, a longer duration before referral is associated with an increased probability of a subsequent P3 profile with the highest probability peaking at 19 months. The probability of P3 declines gradually for those who were referred later. Discussion This is the first time the relationship between time of initial duty restriction, referral to an IPMC, and subsequent P3 or higher profile has been tested. Future research is needed to examine medical conditions listed on the profile to see how they might contribute to the cause of referral to the IPMC. Conclusion A longer duration between initial duty restriction and referral to IPMC was associated with higher odds of subsequent P3 status for up to 19 months. Referral to an IPMC for comprehensive pain care early in the course of chronic pain conditions may reduce the likelihood of P3 profile and eventual medical retirement of soldiers.

The Impact of Organisational, Social Environmental and Job Content Stressors on the Work Related Strains of Probation Officers

2001 ◽  
Vol 34 (2) ◽  
pp. 193-203 ◽  
Author(s):  
Clare O'donnell ◽  
Christine Stephens
Keyword(s):  
New Zealand ◽  
Health And Safety ◽  
Workplace Stress ◽  
Probation Officers ◽  
Curvilinear Relationship ◽  
Work Stressors ◽  
Work Related ◽  
Job Content ◽  
The Impact ◽  
The Relationship

In recent years workplace stress has been seen as an important occupational health and safety problem and probation officers in New Zealand have been identified as suffering from increasing perceptions of stress. Accordingly, the present study was undertaken with a sample of 50 New Zealand Probation Officers in three offices to examine the relationship of individual, organisational and work stressors with work related strains. It was predicted that work stressors would be positively related to strains and that individual differences (e.g., age or gender) would have a moderating effect on the relationship between stressors and strains. The results showed that stressors caused by organisational problems, such as role boundary and overload, were related to strains, more strongly than job content problems, such as difficult clients. Secondly, age may have a curvilinear relationship to strains. Thirdly, the office, or place of work, moderates the stressor strain relationship.

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