General models for simulating population growth in insects grouped both by stages and age classes

1984 ◽  
Vol SMC-14 (2) ◽  
pp. 339-345 ◽  
Author(s):  
R. L. Tummala ◽  
Li Dianmo ◽  
D. L. Haynes
Keyword(s):  
Population Growth ◽  
Age Classes

Biology, Management, and Protection of North American Sturgeon

2002 ◽  
Keyword(s):  
Population Growth ◽  
Life Histories ◽  
Habitat Restoration ◽  
Negative Impact ◽  
Elasticity Analysis ◽  
Age Classes ◽  
Adult Age ◽  
Significant Negative Impact ◽  
Young Of The Year ◽  
Restoration Strategies

Abstract.— We use elasticity analyses for three sturgeon species, the shortnose sturgeon <em>Acipenser brevirostrum</em>, Atlantic sturgeon <em>A. oxyrinchus</em>, and white sturgeon <em>A. transmontanus</em>, to calculate the potential to increase population growth rate, λ, by improving survival and fecundity. Elasticity analysis is a means of assessing changes to λ resulting from conservation initiatives. The elasticity of λ to survival has a characteristic profile that includes a plateau of high elasticity values across the young of the year and the juvenile ages. However, survival elasticity falls at maturity and declines rapidly with increasing adult age. Changes to fecundity have relatively little impact; the total of the fecundity elasticities over all ages is equal to the single young-of-the-year survival elasticity. Even though the young-of-the-year survival elasticity is equal to that of any other juvenile age, the overall opportunity for affecting λ; is strongest in the young-of-the-year age-class because of its exceptional potential for increase to survival. The juvenile and adult stages have roughly equal total survival elasticities. These findings are particularly relevant in understanding the contributions of hatcheries, harvest regulations and habitat restoration as strategies for sturgeon conservation. Hatcheries are focused on the young of the year, the demographically most sensitive component of sturgeon life histories, and thus have the potential to make significant increases to λ if the genetic, evolutionary and ecological impacts of hatcheries can be controlled. Harvest, even at low levels, can have a significant negative impact on λ when it affects multiple age classes. Managers can use elasticity analysis to calculate the total impact of harvest and to mathematically evaluate the trade-off in exploiting young versus older individuals. Habitat restoration strategies, usually assessed in terms of survivals of the age classes impacted, would also benefit from using elasticity analysis to interpret their contributions to l. If restoration efforts target the survival of age classes with high elasticities, significant population growth may be achieved.

Trapping as a means of controlling tsetse, Glossina spp. (Diptera: Glossinidae): the relative merits of killing and of sterilization

1986 ◽  
Vol 76 (1) ◽  
pp. 89-95 ◽  
Author(s):  
P. A. Langley ◽  
D. Weidhaas
Keyword(s):  
Population Growth ◽  
Population Growth Rate ◽  
Population Decline ◽  
Cost Effective ◽  
Life Stages ◽  
Age Classes ◽  
Tsetse Control ◽  
Population Growth Rates ◽  
History Analysis ◽  
Population Numbers

AbstractA deterministic simulation model for Glossina spp. based upon a simple life-history analysis was used to test a variety of effects designed to cause a decline in population numbers. Average daily survival values for pupae were varied to make populations grow at different rates. All age classes were then updated for all life stages each day for a 12-month period. As expected, the population remained stable when Ro = 1·0, and the population doubled in 105 days when Ro = 2·0. Sub-routines were added to test the effects of trapping 0·5 to 2·5% of the population per day and killing both sexes, sterilizing and releasing both sexes or sterilizing and releasing males only, the females not being trapped. Results suggest that killing or sterilizing both sexes is always superior to sterilizing males only and leaving the females unharmed but that this superiority is diminished when either population growth rates are low (<1·0) or trapping rates are high (>2·0% per day). As population growth rate increases or trapping rates decline, there is a proportionately greater advantage to be gained by sterilizing both sexes than by adopting either of the other two strategies. A situation is illustrated where for a trapping rate of 1% per day within a population that is doubling at close to its optimal rate (Ro = 2·0) sterilization of both sexes is the only strategy which will cause a population decline. Results are discussed in terms of development of low technology, cost-effective methods of tsetse control which are non-polluting and therefore environmentally acceptable.

scholarly journals Closer to Carrying Capacity: Analysis of the Internal Demographic Structure Associated with the Management and Density Dependence of a Controlled Wolf Population in Latvia

2021 ◽  
Vol 13 (17) ◽  
pp. 9783
Author(s):  
Jurģis Šuba ◽  
Agrita Žunna ◽  
Guna Bagrade ◽  
Gundega Done ◽  
Mārtiņš Lūkins ◽  
...  
Keyword(s):  
Population Growth ◽  
Carrying Capacity ◽  
Dynamic Assessment ◽  
Wolf Population ◽  
Natural Ecosystems ◽  
Age Classes ◽  
Abundance Estimates ◽  
Essential Components ◽  
Demographic Processes ◽  
The Baltic

Large carnivores are essential components of natural ecosystems. In populated areas, their conservation depends on preserving a favorable status in coexistence with humans, which may require the elimination of excess carnivores to minimize public concerns. As the Baltic region currently hosts a thriving wolf population, locally sustainable management of wolves is important for preserving biodiversity at a European scale. In this paper, we provide a dynamic assessment of the Latvian wolf subpopulation from 1998 until 2020. This study is based on age composition and fecundity data from teeth, uteri, and ovaria inspections obtained from samples of legally culled or accidentally killed individuals. The abundance estimates indicated population growth that exceeded the previously predicted carrying capacity. The proportion of juveniles among the culled individuals increased in recent years, but the mean age of culled adults exhibited a stable trend. In presumably nonselective hunting, the juveniles and individuals older than 3 years had greater culling mortality estimates in comparison with other age classes, and the culling rates for adult females of particular age classes were higher than for males of the same age. While creating significant hunting pressure, wolf management in Latvia may have contributed to the population growth by affecting its demographic processes.

scholarly journals Density but not climate affects the population growth rate of guanacos (Lama guanicoe) (Artiodactyla, Camelidae)

F1000Research ◽  
2013 ◽  
Vol 2 ◽  
pp. 210
Author(s):  
María Zubillaga ◽  
Oscar Skewes ◽  
Nicolás Soto ◽  
Jorge E Rabinovich
Keyword(s):  
Growth Rate ◽  
Population Growth ◽  
Population Growth Rate ◽  
Tierra Del Fuego ◽  
Climatic Variables ◽  
Time Lags ◽  
Age Classes ◽  
Lama Guanicoe ◽  
Population Sampling ◽  
The Matrix

We analyzed the effects of population density and climatic variables on the rate of population growth in the guanaco (Lama guanicoe), a wild camelid species in South America. We used a time series of 36 years (1977-2012) of population sampling in Tierra del Fuego, Chile. Individuals were grouped in three age-classes: newborns, juveniles, and adults; for each year a population transition matrix was constructed, and the population growth rate (λ) was estimated for each year as the matrix highest positive eigenvalue. We applied a stepwise regression analysis with population growth rate (λ) as dependent variable, and total guanaco population (in natural logs), annual mean precipitation, and winter mean temperature as independent variables, with and without time lags. The effect of population size was statistically significant, but the effect of the climatic variables on guanaco population growth rate was not significant.

İstanbul İlçelerinin Nüfus Değişimi ve Kütük Bilgilerinin Analizi

2019 ◽  
Vol 6 (1) ◽  
pp. 37-72
Author(s):  
Ulaş Sunata ◽  
Dila Ergül
Keyword(s):  
Population Growth ◽  
Population Growth Rate ◽  
Population Change ◽  
Urban Migration ◽  
Specific Population ◽  
Related Factors ◽  
Internal Migrant ◽  
Level Analysis ◽  
Study District ◽  
Demographic Features

39 ilçesiyle Türkiye’nin en büyük nüfusuna sahip ili İstanbul aynı zamanda Türkiye’nin en çok iç göç alan şehridir. Özellikle kırdan kente göç bağlamında sosyo-ekonomik ve demografik özellikleriyle birçok araştırmaya konu olmuştur. Fakat İstanbul yerleşik nüfusunun Türkiye’nin diğer şehirlerine kayıtlı olma yoğunluğu da önemlidir. Bu çalışmanın amacı 2012 ve 2017 yıllarındaki nüfus değişimini göz önünde bulundurarak İstanbul ilçelerinin ayrıntılı nüfus yoğunluğu ve büyüme analizini yapmak, ilgili faktörleri değerlendirmek, hemşehri ağlarını okumak adına yerleşik nüfus kütük bilgileri bakımından inceleyerek elde edilen örüntüler doğrultusunda ilçe tipolojileri oluşturmaktır. Çalışmanın birinci bölümünde ilgili beş yıllık nüfus değişimlerine göre İstanbul ilçe nüfusları analiz edilmiştir. Ardından her bir ilçe için nüfusa kayıtlı olunan kente göre nüfus büyüme hızlarına bakılarak ilçelerin ağırlıklı olarak barındırdığı hemşehri ağları belirlenmiştir. İkinci bölümde ise ilçeler nüfus değişim özelliklerine göre belirli kategorilere ayrılmış ve bu kategoriler doğrultusunda ilçe tipolojileri oluşturulmuştur..ABSTRACT IN ENGLISHA District Level Analysis of Istanbul’s Population Change (2012-2017)Istanbul having the largest population of Turkey with its 39 districts is the most internal-migrant-receiving city in Turkey. Particularly in the context of rural-to-urban migration, Istanbul has been became a subject of various researches with its socio-economic and demographic features. However, the density of Istanbul’s settled population who registered other cities of Turkey is important. The main aim of this study is to analyse population growth of all districts considering the population change between 2012 and 2017, to evaluate the related factors and to develop a district typology by using the data of settled population according to their family registration in the name of reading the current countryman networks. In the first section of the study, district populations of Istanbul are examined regarding the related five-year change. Afterwards, most repeated countryman networks of all Istanbul’s districts are specified regarding the population growth rate of the registered cities. In the latter section of the study, districts were divided into categories regarding the specific population change features which help to create district typology.

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