Also, each strategy's effectiveness can be highly variable because females in a heat-stressed herd will be at different levels of reproductive competence.
(each strategy's effectiveness; can be; highly variable; because females in a heat-stressed herd will be at different levels of reproductive competence) (females in a heat-stressed herd; will be; at different levels of reproductive competence)
each strategy's effectiveness females in a heat-stressed herd
can be will be
highly variable because females in a heat-stressed herd will be at different levels of reproductive competence
at different levels of reproductive competence