The aim of this study is to estimate the contributions of changes in population distribution by marital status to the changes in adult mortality in six developed countries. The change in total mortality was decomposed into the contributions of: (i) mortality changes within each marital status category; and (ii) changes in population composition by marital status. The study provides evidence tha...

despite its largest range of distribution in comparison to other large carnivores in iran, the grey wolf has been the least-studied carnivore in the country with limited available data on its ecology. its social life and population composition have been investigated across its global range in europe and north america; however, it has been less explored in arid environments of asia. accordingly,...

In a classic statement, Hauser and Duncan (1959) defined demography as “the study of the size, territorial distribution, and composition of population, changes therein, and the components of such changes” (p. 2). It was fortunate that Hauser and Duncan explicitly included “composition of population” and “changes therein” in their definition, for their inclusion has broadened demography to encom...

Fish reproducing in group-spawning aggregations face intense fisheries during spawning events due to increased ease of capture. Other traits often associated with group spawning, such as late sexual maturation and sequential hermaphroditism, cause group-spawning species to be especially vulnerable to population declines, either because fishermen target large, reproductively mature specimens or ...

Many animal groups are heterogeneous and may even consist of individuals of different species, called mixed-species flocks. Mathematical and computational models of collective animal movement behaviour, however, typically assume that groups and populations consist of identical individuals. In this paper, we develop and analyse a model of merge and split group dynamics, also called fission-fusio...

Wildlife managers routinely survey age and gender compositions of elk (Cervus elaphus) during winter to assess population demographics and to prescribe and evaluate harvest strategies. We measured precision of replicated field classifications of antlerless elk conducted during 1996-1999 on the National Elk Refuge, Wyoming. We found classification discrepancies of 14% for elk calves. Next we exa...

the aim of the present study was to evaluate the effect of purslane on immune responses and cecal microflora composition of broiler chickens. one hundred forty four day old broiler chicks (ross 308) were allocated randomly in 3 groups and 4 replicates to receive diets supplemented with 0 (control), 1 and 2 % of dried purslane. at 21 and 35 days of age 1 ml of sheep red blood cell (srbc) injecte...

Obesity is a global problem that is reaching epidemic proportions. Body composition is an important parameter for humans because previous studies indicate high values of body fat as a predictor of mortality. The aim of the study was to assess gender differences in body composition and physical fitness in Saudi adult population. This epidemiological cross-sectional study included 411 healthy adu...