Population characteristics-II

2.     Natality

In a given population the total number of new born offspring produced either by fission, germination or hatching per unit time defines Natality. It has been categorized into Ecological/Realized Natality and Physiological/Absolute/Crude Natality.

a.                 Ecological Natality

          Under actual environment conditions offspring produced and leads to enhancement in population size termed as Ecological Natality also known as Realized Natality. For a given population, realized Natality is over variable and depends on size, composition, age and physical surrounding condition.

b.                Crude or Physiological Natality

Under idealistic conditions the maximum number of offspring’s produced by the organisms in its physiological limits is termed as physiological Natality. It’s a constant component of population statistical characteristic and also known as Absolute Natality. Although in a wild population, it near to impossible to achieve Physiological Natality. But under favourable conditions with no limiting factor small population of bacterial culture in nutrient broth under all optimal conditions, maximum reproduction is achievable, thus, indicating maximum Natality. It is important as it’s used in calculating equations of increase in rate of population growth and also act as standard for realized natality comparison.

Natality can be expressed in terms of offspring’s produced per unit time per unit population,

i.e.  ΔNn/NΔt= Natlity/rate of birth.

or

Absolute or crude natality/rate of birth=Nn/Δt.