The Web of Life (121-1-2) Mating Choice

 Mating Choice

There has been much to debate about how animals choose a mate, most notably the degree to which mating is instinctual or a conscious decision. Biological bias plays a strong hand in selection, including in humans.

Across the animal kingdom, familiarity between individuals affects mating preferences. Familiarity can breed contentment with a partner.

Or not. Guppy females prefer novel males over ones familiar to them, thereby promoting genetic diversity. A single brood of guppies may be sired by up to 12 fathers.

Conversely, a female Japanese rice fish prefers a mate she knows. So too with many rodents.

Prairie voles mate for life. A vole lady prefers a male she knows, in the hope that he may be steady on.

Courtship behaviors are among Nature’s greatest dramas. Sandhill cranes perform an elaborate ballet. Bald eagles display stupendous flying cartwheels.

Where choice is abundant, conventional thinking is that a female chooses a mate based on attributes that the next generation of females will find favorable. Peahens presumably choose peacocks with colorful plumage in their long tails or pay the price that their offspring will not attract the females that ensure a succeeding generation in the family line.

Whatever signals convey fitness in a species are commonly compelling to females with a choice. Surprisingly, in numerous species females don’t always make the obvious choice.

Further, in many species, females have little or no choice. Males competitively determine relative fitness, and thereby earn the right to breed with as many mates as can be guarded. Females submit.

In some species, female submission to the dominant male comes with the caveat of extra-pair mating if the opportunity arises. All told, mating selection is seldom simple.