scholarly journals Long-term study of population dynamics and habitat selection of rodents in the Negev Desert

2010 ◽  
Vol 91 (4) ◽  
pp. 776-786 ◽  
Author(s):  
Georgy Shenbrot ◽  
Boris Krasnov ◽  
Sergei Burdelov
Keyword(s):  
Population Dynamics ◽  
Habitat Selection ◽  
Negev Desert ◽  
Term Study ◽  
Long Term Study ◽  
Selection Of

Spatial structure of harbour seal populations and the implications thereof

2001 ◽  
Vol 79 (12) ◽  
pp. 2115-2127 ◽  
Author(s):  
T Härkönen ◽  
K C Harding
Keyword(s):  
Population Dynamics ◽  
Site Fidelity ◽  
Phoca Vitulina ◽  
Population Increase ◽  
Dynamic Processes ◽  
Term Study ◽  
Long Term Study ◽  
Harbour Seals ◽  
Age And Sex

A long-term study of freeze-branded harbour seals (Phoca vitulina) revealed explicit site fidelity. Individuals were followed up to 14 years of age and none of the 163 branded animals were observed to haul out beyond a 32-km distance from the site where they were branded as pups. Within this range, striking spatial segregation by age and sex prevailed. While females' site fidelity increased with age, males spent less time at their natal site with increasing age. These findings have consequences for understanding the population dynamics of harbour seals, since single "colonies" will act as partly isolated "subpopulations" in some contexts but not in others. The differing migration tendencies of the population segments lead to spatially segregated sex and age ratios of subpopulations and create a complex pattern of connectivity among these subpopulations. Ignoring the spatial scale will lead to severe misinterpretations of analyses of basic population-dynamic processes, especially rates of population increase, rates of gene flow, and the dynamics of the spread of diseases. We suggest that when studies have different aims, these should be addressed by encompassing different numbers of subpopulations.

scholarly journals Climatic Factors, Reproductive Success and Population Dynamics in the Montane Vole, Microtus montanus

1991 ◽  
Vol 15 ◽  
pp. 162-164
Author(s):  
Aelita Pinter
Keyword(s):  
Population Dynamics ◽  
Reproductive Success ◽  
Population Density ◽  
Environmental Variables ◽  
Climatic Factors ◽  
Small Rodents ◽  
Term Study ◽  
Microtus Montanus ◽  
Long Term Study

Multiannual fluctuations in population density ("cycles") of small rodents have been known since antiquity (Elton 1942). Numerous hypotheses have been proposed to explain this phenomenon (for reviews see Finerty 1980, Taitt and Krebs 1985). However, none of these hypotheses, alone or in combination, have been able to explain the causality of cycles. The objectives of this long-term study are to determine whether environmental variables, possibly acting through reproductive responses, contribute to the multiannual fluctuations of the montane vole, Microtus montanus.

scholarly journals Climatic Factors, Reproductive Success and Population Dynamics in the Montane Vole, Microtus montanus

1987 ◽  
Vol 11 ◽  
pp. 103-105
Author(s):  
Aelita Pinter
Keyword(s):  
Population Dynamics ◽  
Reproductive Success ◽  
Population Density ◽  
Environmental Variables ◽  
Climatic Factors ◽  
Small Rodents ◽  
Term Study ◽  
Microtus Montanus ◽  
Long Term Study

Multiannual fluctuations in population density of small rodents have been known since antiquity. However, factors responsible for this phenomenon remain unknown (Krebs and Myers 1974, Finerty 1980, Taitt and Krebs 1985). The objectives of this long-term study are to determine whether environmental variables, possibly acting through reproductive responses, contribute to the multiannual fluctuations of the montane vole, Microtus montanus.

scholarly journals Attempts to control clothes-borne infection in a burn unit, 2. Clothing routines in clinical use and the epidemiology of cross-colonization

1979 ◽  
Vol 82 (3) ◽  
pp. 369-384 ◽  
Author(s):  
Ulrika Ransjö
Keyword(s):  
Staphylococcus Aureus ◽  
Close Contact ◽  
Clinical Use ◽  
Cross Contamination ◽  
Term Study ◽  
Long Term Study ◽  
Burn Unit ◽  
Colonization Rates ◽  
Selection Of

SUMMARYPrevious investigations have shown that cross-contamination in a burn unit is mainly clothes-borne. New barrier garments have been designed and tried experimentally. The aim of the present study was to investigate the effects of different clothing routines on cross-contamination. In a long-term study, the rates and routes of colonizations withStaphylococcus aureus, Streptococcusgroups A, B, C, F, and G andPseudomonas aeruginosawere examined. The exogenous colonization rates were, withS. aureus77%, withStreptococcusspecies 52% and withPs. aeruginosa32%. The colonization rate withPs. aeruginosawas higher in patients with larger burns. Patients dispersedStreptococcusandPs. aeruginosaas well asS. aureusinto the air of their rooms in considerable amounts, but dispersers were not more important as sources of cross-colonization than non-dispersers. In comparison of clothing routines, there was no difference in overall colonization rates. The newly designed barrier garment that was made from apparently particle-tight material did not reduce the transfer of bacteria from patient to patient. A less rigid routine than that previously used did not increase the risk of cross-contamination. A thorough change of barrier dress after close contact nursing delayed the first exogenousS. aureuscolonization from day 6 to day 14 after admission. This routine might be recommended for clinical use. Otherwise, methods must be developed for adequate selection of materials intended for barrier garments.

scholarly journals Climatic Factors, Reproductive Success and Population Dynamics in the Montane Vole, Microtus montanus

1988 ◽  
Vol 12 ◽  
pp. 121-124
Author(s):  
Aelita Pinter
Keyword(s):  
Population Dynamics ◽  
Reproductive Success ◽  
Population Density ◽  
Environmental Variables ◽  
Climatic Factors ◽  
Small Rodents ◽  
Term Study ◽  
Microtus Montanus ◽  
Long Term Study

Multiannual fluctuations in population density ("cycles") of small rodents have been known since antiquity (Elton 1942). Numerous hypotheses have been proposed to explain this phenomenon (for reviews see Krebs and Myers 1974, Finery 1980, Taitt and Krebs 1985). However, none of these hypotheses, alone or in combination, can explain the causality of cycles. The objectives of this long-term study are to determine whether environmental variables, possibly acting through reproductive responses, contribute to the multiannual fluctuations of the montane vole, Microtus montanus.

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