scholarly journals THE EFFECTS OF WEATHER AND REED MANAGEMENT ON NESTING PARAMETERS OF THE GREAT REED WARBLER, ACROCEPHALUS ARUNDINACEUS (AVES: SYLVIIDAE)

2016 ◽  
Vol 7 ◽  
pp. 305-312
Author(s):  
Thomas Oliver Mérő ◽  
Antun Žuljević
Keyword(s):  
Clutch Size ◽  
Water Depth ◽  
Abiotic Factors ◽  
Negative Relationship ◽  
Nesting Success ◽  
Great Reed Warbler ◽  
Nest Density ◽  
Hatching Rate ◽  
Reed Warbler ◽  
The Impact

Nesting parameters such as clutch size, hatching rate or nesting success have been extensively studied in birds in relation to biotic and abiotic factors. In this study we aimed to investigate the effects of air temperature, amount of precipitation, reed burning, and water depth (independent variables) on nest density, clutch size, hatching rate, and nesting success (dependent variables) of the Great Reed Warbler during a nine-year period. We found that neither the clutch size nor the hatching rate was influenced by any of the predictor variables. Nest density was positively influenced by the water depth, while the nesting success was negatively related to the amount of precipitation. Reed burning had no effect on any of the nesting parameters. Similarly, to our results, short-term studies reported a positive relationship between nest density and water depth, and a negative relationship between the nesting success and amount of precipitation, indicating that these two environmental variables generally influence the two nesting parameters. However, the impact of various reed management practices, such as harvesting or removal, on the nesting variables of the Great Reed Warbler needs further clarification.

The impact of geographic range, sampling, ecology, and time on extinction risk in the volatile clade Graptoloida

Paleobiology ◽  
2016 ◽  
Vol 43 (1) ◽  
pp. 85-113 ◽  
Author(s):  
James Boyle ◽  
H. David Sheets ◽  
Shuang-Ye Wu ◽  
Daniel Goldman ◽  
Michael J. Melchin ◽  
...  
Keyword(s):  
Ecological Niche ◽  
Extinction Risk ◽  
Biological Effects ◽  
Abiotic Factors ◽  
Explanatory Power ◽  
Negative Relationship ◽  
Geographic Range ◽  
Range Size ◽  
Age Cohorts ◽  
The Impact

AbstractAlthough extinction risk has been found to have a consistent negative relationship with geographic range across wide temporal and taxonomic scales, the effect has been difficult to disentangle from factors such as sampling, ecological niche, or clade. In addition, studies of extinction risk have focused on benthic invertebrates with less work on planktic taxa. We employed a global set of 1114 planktic graptolite species from the Ordovician to lower Devonian to analyze the predictive power of species’ traits and abiotic factors on extinction risk, combining general linear models (GLMs), partial least-squares regression (PLSR), and permutation tests. Factors included measures of geographic range, sampling, and graptolite-specific factors such as clade, biofacies affiliation, shallow water tolerance, and age cohorts split at the base of the Katian and Rhuddanian stages.The percent variance in durations explained varied substantially between taxon subsets from 12% to 45%. Overall commonness, the correlated effects of geographic range and sampling, was the strongest, most consistent factor (12–30% variance explained), with clade and age cohort adding up to 18% and other factors <10%. Surprisingly, geographic range alone contributed little explanatory power (<5%). It is likely that this is a consequence of a nonlinear relationship between geographic range and extinction risk, wherein the largest reductions in extinction risk are gained from moderate expansion of small geographic ranges. Thus, even large differences in range size between graptolite species did not lead to a proportionate difference in extinction risk because of the large average ranges of these species. Finally, we emphasize that the common practice of determining the geographic range of taxa from the union of all occurrences over their duration poses a substantial risk of overestimating the geographic scope of the realized ecological niche and, thus, of further conflating sampling effects on observed duration with the biological effects of range size on extinction risk.

Where in Europe should we look for sources of the cutaneous trematode Collyriclum faba infections in migrating birds?

2006 ◽  
Vol 80 (4) ◽  
pp. 349-355 ◽  
Author(s):  
J. Sitko ◽  
J. Sitko
Keyword(s):  
Western Europe ◽  
Great Reed Warbler ◽  
Reed Warbler ◽  
Garden Warbler ◽  
Song Thrush ◽  
Breeding Migration ◽  
Sylvia Borin ◽  
Migrating Birds ◽  
The Impact ◽  
Eurasian Treecreeper

AbstractCutaneous cysts with trematodes of Collyriclum faba have been found in birds during their spring and post-breeding migrations in the Czech Republic. During spring migrations, C. faba was found in one dunnock Prunella modularis, two European robins Erithacus rubecula, three common nightingales Luscinia megarhynchos, one song thrush Turdus philomelos and one great reed warbler Acrocephalus arundinaceus. During post-breeding migration, the same parasite was found in one garden warbler Sylvia borin, one whitehroat S. communis, three goldcrests Regulus regulus and one Eurasian treecreeper Certhia familiaris. The newly identified hosts of C. faba are dunnock, common nightingale, song thrush, great reed warbler and Eurasian treecreeper. Geographical areas of the birds' infection were identified from an analysis of reports on ringed birds of the same species, the time necessary for the development of cutaneous cysts with C. faba and the time of their survival, and hitherto known geographical areas of endemic occurrence of C. faba. It is presumed that birds trapped during spring migrations were infected in some montane and submontane regions in south-western Europe (the Alps, the Apennines). Birds infected during autumn migration or post-breeding vagrancy could have been infected in the Central European Carpathians, the region of C. faba endemic occurrence. For migrating birds, the impact of C. faba infections has not been hitherto assessed.

scholarly journals Reproductive trade-offs of the estuarine copepod Eurytemora affinis under different thermal and haline regimes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anissa Souissi ◽  
Jiang-Shiou Hwang ◽  
Sami Souissi
Keyword(s):  
Clutch Size ◽  
Egg Size ◽  
Abiotic Factors ◽  
Negative Relationship ◽  
Cold Temperature ◽  
Female Size ◽  
Eurytemora Affinis ◽  
Trade Off ◽  
Trade Offs ◽  
Higher Temperature

AbstractCopepod females invest a quantity of resources in their reproduction. Depending on several biotic and abiotic factors and their evolutionary history a trade-off can be commonly observed between producing a large number of smaller offspring or a small number of larger offspring. In this study, a multi-generational approach was applied to determine whether a trade-off between clutch size and egg size existed in the copepod Eurytemora affinis under different controlled conditions of temperature and salinity. This protocol was based on the follow-up of reproductive (Clutch Size ‘CS’, Egg Diameter ‘ED’) and morphological (Prosome Length ‘PL’) traits during several generations. Copepods were acclimated to cold (7 °C) and warm (20 °C) temperatures, and then their reproductive output was tested at the higher temperature of 24 °C. CS and ED were positively correlated to PL, so as a first step linear regressions between each reproductive trait and female PL were performed. The residuals from the regression lines of CS and ED with PL were calculated to remove the effect of female size. When the normalized data (residuals) of CS and ED plotted together a negative relationship between egg size and egg number revealed the existence of a trade-off. Copepod populations initially acclimated to cold temperature are commonly characterized by relatively smaller CS and larger ED. Conversely, warm temperature adapted females produced relatively larger CS and smaller ED. After transfer to a temperature of 24 °C, the ED did not change but the CS showed high variability indicating stressful conditions and no trade-off was observed. These observations suggest that E. affinis is able to modulate its reproduction depending on the encountered temperature. It seems that this copepod species can shift between a K- and an r-strategy in response to colder or warmer conditions. In a late winter-early spring like cold temperature, copepod females seem to invest more on offspring quality by producing relatively larger eggs. This ecological strategy ensures a high recruitment of the spring generation that is responsible for the strength of the maximum population size usually observed in late spring-early summer (May–June). To the contrary, at summer-like temperature, where the population density decreases significantly in the Seine estuary, copepod females seem to switch from K to r strategy by favoring offspring number compared to offspring size. Finally, the use of a higher temperature of 24 °C seems to disrupt the observed reproductive trade-off even after several generations. These results suggest that a switching between K- or r-strategy of E. affinis depends highly on temperature effects. The effect of salinity increase during a summer-like temperature of 20 °C as well as after transfer to 24 °C decreased PL and CS but the ED did not change significantly.

scholarly journals Habitat use and nesting success of the Great Reed Warbler (Acrocephalus arundinaceus) in different reed habitats in Serbia

2015 ◽  
Vol 127 (3) ◽  
pp. 477-485 ◽  
Author(s):  
Thomas Oliver Mérő ◽  
Antun Žuljević ◽  
Katalin Varga ◽  
Szabolcs Lengyel
Keyword(s):  
Habitat Use ◽  
Nesting Success ◽  
Great Reed Warbler ◽  
Acrocephalus Arundinaceus ◽  
Reed Warbler

Dampak Kebijakan Moneter Pada Output Di Negara-Negara ASEAN Tahun 1980-2014

2017 ◽  
Vol 4 (1) ◽  
pp. 58-70
Author(s):  
Nur Widiastuti
Keyword(s):  
Monetary Policy ◽  
Interest Rate ◽  
Fixed Effects ◽  
Empirical Studies ◽  
Negative Relationship ◽  
Least Square ◽  
Fixed Effects Model ◽  
State Data ◽  
Ordinary Least Square ◽  
The Impact

The Impact of monetary Policy on Ouput is an ambiguous. The results of previous empirical studies indicate that the impact can be a positive or negative relationship. The purpose of this study is to investigate the impact of monetary policy on Output more detail. The variables to estimatate monetery poicy are used state and board interest rate andrate. This research is conducted by Ordinary Least Square or Instrumental Variabel, method for 5 countries ASEAN. The state data are estimated for the period of 1980 – 2014. Based on the results, it can be concluded that the impact of monetary policy on Output shown are varied.Keyword: Monetary Policy, Output, Panel Data, Fixed Effects Model

Risk Attitude and Corporate Investment under Output Market Uncertainty: Evidence from The Mekong River Delta, Vietnam

2016 ◽  
pp. 59-70
Author(s):  
Ninh Le Khuong ◽  
Nghiem Le Tan ◽  
Tho Huynh Huu
Keyword(s):  
Negative Relationship ◽  
Risk Attitude ◽  
Business Strategies ◽  
Risk Averse ◽  
Market Uncertainty ◽  
Firm Investment ◽  
Output Market ◽  
The Impact ◽  
The Relationship

This paper aims to detect the impact of firm managers’ risk attitude on the relationship between the degree of output market uncertainty and firm investment. The findings show that there is a negative relationship between these two aspects for risk-averse managers while there is a positive relationship for risk-loving ones, since they have different utility functions. Based on the findings, this paper proposes recommendations for firm managers to take into account when making investment decisions and long-term business strategies as well.

Characterizing the impact of recovering sea otters on commercially important crabs in California estuaries

2020 ◽  
Vol 655 ◽  
pp. 123-137
Author(s):  
TM Grimes ◽  
MT Tinker ◽  
BB Hughes ◽  
KE Boyer ◽  
L Needles ◽  
...  
Keyword(s):  
Abiotic Factors ◽  
Sea Otter ◽  
Dungeness Crab ◽  
Sea Otters ◽  
Elkhorn Slough ◽  
Enhydra Lutris Nereis ◽  
Crab Abundance ◽  
Population Sizes ◽  
Commercially Important ◽  
The Impact

Protective legislation and management have led to an increase in California’s sea otter Enhydra lutris nereis population. While sea otter recovery has been linked to ecosystem benefits, sea otter predation may negatively affect commercially valuable species. Understanding the potential influence of sea otters is of particular importance as their range expands into estuaries that function as nurseries for commercially valuable species like Dungeness crab Metacarcinus magister. We consider how sea otter predation has affected the abundance and size of juvenile Dungeness crab in Elkhorn Slough, California, USA, and analyzed cancrid crab abundance and size across 4 California estuaries with and without sea otters to understand how biotic and abiotic factors contribute to observed variation in crab size and abundance. We compared trends in southern sea otters relative to Dungeness crab landings in California to assess whether increasing sea otter abundance have negatively impacted landings. In Elkhorn Slough, juvenile Dungeness crab abundance and size have declined since 2012, coinciding with sea otter population growth. However, the impact of sea otters on juvenile Dungeness crab size was habitat-specific and only significant in unvegetated habitat. Across estuaries, we found that cancrid crab abundance and size were negatively associated with sea otter presence. While abiotic factors varied among estuaries, these factors explained little of the observed variation in crab abundance or size. Although we found evidence that sea otters can have localized effects on cancrid crab populations within estuaries, we found no evidence that southern sea otters, at recent population sizes, have negatively impacted Dungeness crab landings in California from 2000-2014.

Comparing the Impact of Religious Discourse on HIV/AIDS in Islam and Christianity in Africa

2012 ◽  
Vol 8 ◽  
Author(s):  
Sloane Speakman
Keyword(s):  
Social Factors ◽  
Negative Relationship ◽  
Hiv Prevalence ◽  
Religious Discourse ◽  
Prevalence Rates ◽  
The Social ◽  
High Prevalence ◽  
Islam And Christianity ◽  
Sub Saharan ◽  
The Impact

In examining the strikingly high prevalence rates of HIV in many parts of Africa, reaching as high as 5% in some areas, how does the discourse promoted by the predominant religions across the continent, Islam and Christianity, affect the outlook of their followers on the epidemic? This question becomes even more intriguing after discovering the dramatic difference in rate of HIV prevalence between Muslims and Christians in Africa, confirmed by studies that have found a negative relationship to exist between HIV prevalence and being Muslim in Africa, even in Sub-Saharan African nations. Why does this gap in prevalence rates exist? Does Islam advocate participating in less risky behavior more so than Christianity? By comparing the social construction, epidemiological understanding and public responses among Muslim populations in Africa with Christian ones, it becomes apparent that many similarities exist between the two regarding discourse and that, rather than religious discourse itself, other social factors, such as circumcision practices, contribute more to the disparity in HIV prevalence than originally thought.

Globalization, Poverty, Environmental Degradation and Economic Growth Nexus: Empirical Analysis of SAARC Regions

2020 ◽  
Vol 39 (1) ◽  
Author(s):  
Adiqa Kiani ◽  
Ejaz Ullah ◽  
Khair Muhammad
Keyword(s):  
Economic Growth ◽  
Sri Lanka ◽  
Empirical Analysis ◽  
Environmental Degradation ◽  
Negative Relationship ◽  
Policy Makers ◽  
Significant Negative Relationship ◽  
The Impact

The main objective of this study is to investigate the impact of poverty, globalization, and environmental degradation on economic growth in the selected SAARC countries. This study is employed panel Autoregressive Distributive Lag (ARDL) technique for empirical analysis using selected SAARC regions including India, Pakistan, Bangladesh, Nepal and Sri Lanka over the period of 1980 to 2018. Globalization impacts economic growth positively and significantly.  In addition to this the significant negative relationship is found between population and economic growth. The results show that poverty is positively related with environmental degradation. Furthermore, the results indicate that globalization is positively and significantly associated with environmental degradation in the SAARC region. Finally, the results show that urbanization is positive and significantly associated with environmental degradation, which could be the serious concerns for the policy makers to control.

Measuring Effectiveness Of Economic Growth On Reducing Infant Mortality Rate In Tamilnadu

2019 ◽  
Vol 118 (4) ◽  
pp. 129-141
Author(s):  
Mr. Y. EBENEZER
Keyword(s):  
Economic Growth ◽  
Mortality Rate ◽  
Infant Mortality ◽  
Negative Relationship ◽  
Infant Mortality Rate ◽  
Domestic Product ◽  
Per Capita ◽  
The Impact ◽  
Adf Test ◽  
Bound Test

                   This paper deals with economic growth and infant mortality rate in Tamilnadu. The objects of this paper are to test the relationship between Per capita Net State Domestic Product and infant mortality rate and also to measure the impact of Per capita Net State Domestic Product on infant mortality rate in Tamil Nadu. This analysis has employed the ADF test and ARDL approach. The result of the study shows that IMR got reduced and Per capita Net State Domestic Product increased during the study period. This analysis also revealed that there is a negative relationship between IMR and the economic growth of Tamilnadu. In addition, ARDL bound test result has concluded that per capita Net State Domestic Product of Tamilnadu has long run association with IMR.

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