2 resultados para immigration mean

em DigitalCommons@University of Nebraska - Lincoln


Relevância:

20.00% 20.00%

Publicador:

Resumo:

English abstract: We hypothesized that the arctic fox, Alopex lagopus (Linnaeus), population on St. Lawrence Island was cyclic and that its fluctuations in size. structure, and productivity were correlated with the relative size of the population of northern voles, Microtus oeconomus Pallas, the primary prey. Based on a nine-year study, we determined that the variations in size of the fox and vole populations were similar, but they both were of low amplitude and not closely correlated. The high pregnancy rate (mean, 86%/yr) and numbers of young conceived (mean, 11.5/pregnancy) did not vary significantly among years, probably because of the consistently abundant and diverse food supply available to the foxes. The age composition of the trappers' catch of foxes each winter also was comparatively stable, but it was closely correlated with the size of the vole population in the previous summer. The survival of the young foxes during the summer probably was dependent on the availability of the voles, The composition of the catch also appeared to be influenced by immigration of faxes from the adjacent continents via the pack ice. French abstract: Nous avons émis I'hypothèse que la population du renard arctique, Alopex lagopus (Linnaeus), sur I'île Saint Lawrence était cyclique el que les fluctuations concernant sa tailIe, sa structure et sa productivité étaient corrélées à la taille relative de la population du campagnol nordique. Microtus oeconomus Pallas, sa principale proie. En nous appuyant sur une étude menée sur neuf ans, nous avons déterminé que les variations dans la taille des populations du renard et du campagnol étaient semblables. mais que toutes deux avaient une faible amplitude et n'étaient pas corrélées de façon étroite. Le taux de grossesse élevé (moyenne 86 p. cent/an) et Ie nombre dc petits conçus (moyenne 11,5/grossesse) ne variaient pas de façon significative au cours des ans, probablement à cause de I'abondance et de la variété de sources de nourriture pour les renards. La composition d'âge des prises des trappeurs était également stable d'un hiver à I'autre, mais elle était corrélée de façon étroite avec la taille de la population dc campagnols au cours de I'été précédent. La survie des renardeaux au cours de I'été dépendait probablement de la disponibilité des campagnols. La composition des prises semblait aussi être influencée par I'immigration des renards venant des terres continentales adjacentes par la voie de la banquise.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The North American West is a culturally and geographically diverse region that has long been a beacon for successive waves of human immigration and migration. A case in point, the population of Lincoln, Nebraska -- a capital city on the eastern cusp of the Great Plains -- was augmented during the twentieth century by significant influxes of Germans from Russia, Omaha Indians, and Vietnamese. Arriving in clusters beginning in 1876, 1941, and 1975 respectively, these newcomers were generally set in motion by dismal economic, social, or political situations in their sending nations. Seeking better lives, they entered a mainstream milieu dominated by native-born Americans -- most part of a lateral migration from Iowa, Illinois, and Pennsylvania -- who only established their local community in 1867. While this mainstream welcomed their labor, it often eschewed the behaviors and cultural practices ethnic peoples brought with them. Aware but not overly concerned about these prejudices, all three groups constructed or organized distinct urban villages. The physical forms of these enclaves ranged from homogeneous neighborhoods to tight assemblies of relatives, but each suited a shared preference for living among kinspeople. These urban villages also served as stable anchors for unique peoples who were intent on maintaining aspects of their imported cultural identities. Never willing to assimilate to mainstream norms, urban villagers began adapting to their new milieus. While ethnic identity constructions in Lincoln proved remarkably enduring, they were also amazingly flexible. In fact, each subject group constantly negotiated their identities in response to interactions among particular, cosmopolitan, and transnational forces. Particularism refers largely to the beliefs, behaviors, and organizational patterns urban villagers imported from their old milieus. Cosmopolitan influences emanated from outside the ethnic groups and were dictated largely but not exclusively by the mainstream. Transnationalism is best defined as persistent, intense contact across international boundaries. These influences were important as the particularism of dispersed peoples was often reinforced by contact with sending cultures. Adviser: John. R. Wunder