Mule Mule A mule is the offspring of a male donkey (jack) and a female horse (mare). Horses and donkeys are different species, with different numbers of chromosomes. Of the two F1 hybrids (first generation hybrids) between these two species, a mule is easier to obtain than a hinny, which is the offspring of a female donkey (jenny) and a male horse (stallion). The size of a mule and work to which it is put depend largely on the breeding of the mule's female parent (dam). Mules can be lightweight, medium weight or when produced from draft horse mares, of moderately
Cryptic female choice in which a male's interaction with a female is of detriment to her personal well-being and that of her offspring, one such situation occurs when a male harasses a female prior to copulation. In such circumstances where the female's lifespan and fertility are compromised, it benefits females to develop evasive mechanisms. In addition, in some species where multiple males inseminate a female, a female is able to select the most desirable sperm for her offspring by rejecting that which she desires less. In both of the aforementioned situations it is a female's reproductive actions that affect male reproductive success following