Sentence examples for declining natality from inspiring English sources
It is not known how much temporary immigration might have affected estimates of declining natality in the 2000s but some effect is probable.
Furthermore, a shifting ocean climate [15], [16] may have caused systematic changes in sightability of these animals over time that led to an illusion of declining natality.
The authors of the population dynamic model [13] assumed female sightability was constant over time and suggested that an increase of about 40% in the number of females observed would be necessary to counter the estimated decline in natality.
Shorter foraging periods would effectively cause an apparent decline in natality rates when simply counting ratios of adults to pups because more adults would be counted in relation to the number of pups in later years.
In our country, there is a steady decline in natality and mortality in the past 30 years, showing an irreversible and accelerated aging population process.
However, all recent estimates of natality in Steller sea lions are compared to natality in the presumed healthy population during the 1970s and declining population in the 1980s.
Notwithstanding variation in survival, natality rates of 60% to 75% have been generally associated with stable or increasing populations of pinnipeds [20] [22], whereas rates of 55% or lower have been associated with declining populations and related to the adverse effects of density dependant factors or food stress [8], [23].
