Relative Roles of Food Abundance and Cover in Determining the Habitat Distribution of Stream-Dwelling Cutthroat Trout (Salmo clarki)

1985 ◽  
Vol 42 (10) ◽  
pp. 1668-1672 ◽  
Author(s):  
Margaret A. Wilzbach
Keyword(s):  
Cutthroat Trout ◽  
Food Abundance ◽  
High Food ◽  
Habitat Distribution ◽  
Emigration Rate ◽  
Microhabitat Distribution ◽  
Summer Temperatures ◽  
Salmo Clarki

Emigration of wild cutthroat trout (Salmo clarki) from laboratory channels over 1-wk trial periods was greater under conditions of low than high food abundance (5 vs. 15% of total trout biomass daily), irrespective of the amount of cover (simulated cover structures added vs. removed). When food abundance was high, emigration of trout was slightly greater under conditions of low than high cover. Cover had no effect on emigration rate when food abundance was low. Trout occurred in association with cover structures when food abundance was high, but not when food abundance was low. These experiments suggest that at summer temperatures, food abundance overrides cover in determining the abundance and microhabitat distribution of adult cutthroat trout within a stream.

scholarly journals Migration, tourism, and the development of the home countries: Evidence from Morocco

2020 ◽  
Vol 10 (1) ◽  
pp. 44-57
Author(s):  
Mohamed Hadj Ahmed ◽  
Samir Djelti ◽  
Mohammed Seghir Guellil
Keyword(s):  
Key Words ◽  
Gravity Model ◽  
Life Style ◽  
Global Effect ◽  
Emigration Rate ◽  
Global Migration ◽  
Migration Networks ◽  
Real Value ◽  
Tourism Flows ◽  
Migration And Development

  The aim of this paper is to study, both theoretically and empirically, tourism as a channel of Migration and Development. Relaying on migration networks and trade literature, the study suppose that migration networks affect positively tourism flows to the origin countries. Theoretically, global migration networks effect on tourism is composed of migrant generations, transactions, preferences and emigrants’ life style effects. Such effects could adapt, promote and advertise tourism flows to origin countries. Empirically, the gravity model has been used to estimate the global effect of networks on Moroccan tourism inflows from the eight principal immigration countries during the periods (2000, 2010, 2011, 2012, 2013 and 2014). Our study reveals that a ten-percent rise in the emigration rate from Morocco increases the real value of Moroccan tourism inflows by 1.3 %.   Key words: Migration, Networks, Tourism, Development.

Welfare State and Labor Mobility: The Impact of Bismarck's Social Legislation on German Emigration before World War I

2008 ◽  
Vol 68 (1) ◽  
pp. 211-243 ◽  
Author(s):  
DAVID KHOUDOUR-CASTÉRAS
Keyword(s):  
World War I ◽  
The United States ◽  
Social Benefits ◽  
Rapid Decline ◽  
World War ◽  
Emigration Rate ◽  
Labor Earnings ◽  
Wage Rates ◽  
The Social ◽  
The Impact

The rapid decline of German emigration before World War I constitutes a puzzle that traditional explanations have difficulty in solving. The article shows that the social legislation implemented by Bismarck during the 1880s—the most developed at the time—played a key role in this process. Indeed, candidates for migration considered not only the gap between “direct wages” (labor earnings) in the United States and Germany, but also the differential in “indirect wages,” that is, social benefits. In that way, Bismarck's insurance system partly offset low wage rates in Germany and furthered the fall of the emigration rate.O sprecht! warum zogt ihr von dannen?Das Neckartal hat Wein und Korn;Der Schwarzwald steht voll finstrer Tannen,Im Spessart klingt des Ålplers Horn.Wie wird es in den fremden WäldernEuch nach der Heimatberge Grün,Nach Deutschlands gelben Weizenfeldern,Nach seinen Rebenhügeln ziehn!Ferdinand Freiligrath1

scholarly journals Weather explains high annual variation in butterfly dispersal

2016 ◽  
Vol 283 (1835) ◽  
pp. 20160413 ◽  
Author(s):  
Mikko Kuussaari ◽  
Susu Rytteri ◽  
Risto K. Heikkinen ◽  
Janne Heliölä ◽  
Peter von Bagh
Keyword(s):  
Annual Variation ◽  
Important Determinant ◽  
Average Distance ◽  
Empirical Studies ◽  
Weather Conditions ◽  
Dispersal Rate ◽  
Weather Variables ◽  
Emigration Rate ◽  
Mark Release Recapture ◽  
Increasing Temperature

Weather conditions fundamentally affect the activity of short-lived insects. Annual variation in weather is therefore likely to be an important determinant of their between-year variation in dispersal, but conclusive empirical studies are lacking. We studied whether the annual variation of dispersal can be explained by the flight season's weather conditions in a Clouded Apollo ( Parnassius mnemosyne ) metapopulation. This metapopulation was monitored using the mark–release–recapture method for 12 years. Dispersal was quantified for each monitoring year using three complementary measures: emigration rate (fraction of individuals moving between habitat patches), average residence time in the natal patch, and average distance moved. There was much variation both in dispersal and average weather conditions among the years. Weather variables significantly affected the three measures of dispersal and together with adjusting variables explained 79–91% of the variation observed in dispersal. Different weather variables became selected in the models explaining variation in three dispersal measures apparently because of the notable intercorrelations. In general, dispersal rate increased with increasing temperature, solar radiation, proportion of especially warm days, and butterfly density, and decreased with increasing cloudiness, rainfall, and wind speed. These results help to understand and model annually varying dispersal dynamics of species affected by global warming.

scholarly journals Methods and techniques to measure migration movements: Brazilian state of Goiás and the Federal District, 1975-1979 and 1986-1990

2018 ◽  
Author(s):  
Ernesto F. L. Amaral ◽  
Roberto do Nascimento Rodrigues ◽  
Moema Gonçalves Bueno Fígoli
Keyword(s):  
Federal District ◽  
Estimating Functions ◽  
Emigration Rate ◽  
Brazilian State ◽  
Methods And Techniques ◽  
Distrito Federal ◽  
Methodological Procedures ◽  
Last Stage ◽  
Using Data ◽  
Migratory Movements

Title in Portuguese: Métodos e técnicas de mensuração de movimentos migratórios: Goiás e Distrito Federal, 1975-1979 e 1986-1990Abstract: This article discusses methodological procedures used to obtain indicators of standards and levels of migratory movements. The objective is to understand processes for estimating functions of migration based on the Demographic Censuses of 1980 and 1991, and studies that propose methods for estimating migration were analyzed. The proposal by Machado (1993) for calculating specific rates of emigration (TEEx) from data on the last stage of residence is very efficient for estimating migration functions. But adjustments in the calculation of the TEEx are made to obtain more consistent patterns of migratory functions. In the case of the 1991 Brazilian Census, rates were also estimated using data from fixed dates. This article also proposes an analysis of the level of migration using the Total Emigration Rate (TET). These techniques were applied to migration to Goiás and the Federal District, with analysis of the pattern and level of the demographic flows.Resumo: O artigo discute os procedimentos metodológicos utilizados para obtenção de indicadores de padrão e nível de movimentos migratórios. O objetivo é compreender os processos de estimação de funções de migração com os dados dos Censos Demográficos de 1980 e 1991. Foram analisados estudos que propuseram metodologias de estimação da migração. A proposta de Machado (1993), de calcular Taxas Específicas de Emigração (TEEx) com dados de última etapa de residência, é muito eficiente para estimar funções de migração. Porém, são realizados ajustes no cálculo das TEEx para se obter padrões das funções de migração mais consistentes. No caso do Censo de 1991, também foram estimadas taxas com dados de data fixa. Além disso, o artigo propõe a análise do nível da migração com o uso da Taxa de Emigração Total (TET). Essas técnicas foram aplicadas à migração para Goiás e Distrito Federal, com análise do padrão e nível dos fluxos populacionais.

scholarly journals Dissatisfied, feeling unequal and inclined to emigrate: Perceptions from Macedonia in a MIMIC model

2015 ◽  
Vol 12 (3) ◽  
pp. 300-314 ◽  
Author(s):  
Marjan Petreski ◽  
Blagica Petreski
Keyword(s):  
Financial Constraints ◽  
Economic Environment ◽  
Continuous Variables ◽  
Ethnic Inequality ◽  
Emigration Rate ◽  
Mimic Model ◽  
Ethnic Inequalities ◽  
Multiple Indicator

Macedonia has a large diaspora, a high emigration rate and receives larger volume of remittances. This paper aims to describe the current inclination to emigrate from Macedonia, in the light of the dissatisfaction with the domestic political and economic environment and the potential feeling of gender and ethnic inequalities. Particular reference is made to the role of remittances. We use the Remittances Survey 2008 and treat dissatisfaction, feeling of inequality and inclination to emigrate as latent continuous variables in a MIMIC (Multiple-Indicator Multiple-Cause) model, observed only imperfectly in terms of respondents’ perceptions and opinions. Results suggest that dissatisfaction with the societal conditions in Macedonia grows among those who are at their 20s and early 30s, which is more prevalent among ethnic Albanians. Compared to others, Albanians also demonstrate stronger feeling of gender and ethnic inequality. Dissatisfaction, but not the feeling of inequality, then feeds inclination to emigrate. Further to this, however, males and less educated persons are more inclined to emigrate, irrespective of their level of dissatisfaction. We find remittances to play a strong role for the inclination to emigrate: the inclination is larger in households receiving remittances and increases with the amount received, as it is likely that remittances alleviate financial constraints for other persons of the household to emigrate.

Israel

2019 ◽  
pp. 97-125
Author(s):  
Yossi Harpaz
Keyword(s):  
Jewish History ◽  
Income Level ◽  
High Income ◽  
Insurance Policy ◽  
Emigration Rate ◽  
European Origin ◽  
Dual Citizenship

This chapter analyzes EU citizenship in Israel. Israel's high income level and low emigration rate set it apart from Serbia and Mexico and make dual citizenship less obviously useful. EU–Israeli dual citizens rarely refer to themselves as dual citizens, but instead see themselves as “Israelis with a European passport.” The chapter then demonstrates that citizenship applicants are mainly driven by two motivations that were conditioned by Jewish history. The first is the wish to hold an insurance policy against the possibility of Israel being destroyed. The second is the desire for a status symbol that signifies their elitist position in Israel as European-origin Jews. Ironically, the grandchildren of Jews who had left Europe for Israel now look to German or Hungarian passports for security.

scholarly journals Extinction debt in local habitats: quantifying the roles of random drift, immigration and emigration

2020 ◽  
Vol 7 (1) ◽  
pp. 191039
Author(s):  
Yongbin Wu ◽  
Youhua Chen ◽  
Shui-Ching Chang ◽  
You-Fang Chen ◽  
Tsung-Jen Shen
Keyword(s):  
Extinction Risk ◽  
Species Abundance ◽  
Biodiversity Loss ◽  
Local Area ◽  
Habitat Destruction ◽  
Target Area ◽  
Emigration Rate ◽  
Random Drift ◽  
Ecological Disturbance ◽  
Biodiversity Change

We developed a time-dependent stochastic neutral model for predicting diverse temporal trajectories of biodiversity change in response to ecological disturbance (i.e. habitat destruction) and dispersal dynamic (i.e. emigration and immigration). The model is general and predicts how transition behaviours of extinction may accumulate according to a different combination of random drift, immigration rate, emigration rate and the degree of habitat destruction. We show that immigration, emigration, the areal size of the destroyed habitat and initial species abundance distribution (SAD) can impact the total biodiversity loss in an intact local area. Among these, the SAD plays the most deterministic role, as it directly determines the initial species richness in the local target area. By contrast, immigration was found to slow down total biodiversity loss and can drive the emergence of species credits (i.e. a gain of species) over time. However, the emigration process would increase the extinction risk of species and accelerate biodiversity loss. Finally but notably, we found that a shift in the emigration rate after a habitat destruction event may be a new mechanism to generate species credits.

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