High temperature demands associated with gestation and rearing young may limit the northern range for reproductive females.

Workers are produced throughout the year, as are reproductive females.

Approximately 130 western gray whales remain, of which only 30-35 are reproductive females.

Caviar harvesting further endangers the fish stocks, since it targets reproductive females.

In eusocial mammals this is mainly achieved by aggressive interactions between the potential reproductive females.

Territories tend to be controlled by reproductive females.

Male geladas seem to have different strategies for obtaining reproductive females depending on the state of the population.

It has been shown that colonies contain over 300 individuals, but only one reproductive female.

The queens (reproductive females) are morphologically similar to workers, though sometimes slightly larger or differently colored.

In some species, nests are founded by a small number of reproductive females, possibly a single one.