That is, the effect an individual's behaviors have on: being personally better-suited to reproduce offspring, and aiding descendent and non-descendent relatives in their reproductive efforts.
Hispid cotton rat populations are largely sedentary; population density depends mainly on current reproductive effort and not as strongly on immigration.
It is to invoke that store of energy normally reserved for the reproductive effort.
If this hypothesis were true however, age at menopause should be negatively correlated with reproductive effort and the available data does not support this.
Females are solely responsible for the rest of the reproductive effort.
It appears that kangaroo rats can assess their local conditions and adjust their reproductive efforts accordingly.
Or, perhaps, the hawks' reproductive effort will fail, as it did last year.
This evolutionary driving force was dubbed 'kin selection', to distinguish it from the additional (and inevitable) shaping of an individual's own reproductive efforts by natural selection.
Agricultural runoff and gravel dredging are significantly hurting the reproductive effort of the fish.
The relationship between available energy and reproductive efforts can be explained with the life history theory in the trade-off between fecundity and growth/survival.