A mule is the offspring of a male donkey and a female horse. Because horses and donkeys are different species with a different number of chromosomes, a mule is a hybrid and very rarely able to reproduce. Mules can be either male or female and size generally is determined by the genes of the mare. A male donkey is referred to as a “jack” and a female donkey is a “jenny.“ On the rare occasion that a male horse and female donkey reproduce, the offspring is called a “hinny”. Typically, mules are stronger than a like-size horse with more endurance and requiring less food for survival and work. We’ve all heard, and perhaps been referred to as “stubborn as a mule.” This label is the result of a mule’s sense of independence, common sense and drive for self-preservation. Mules rarely rely on a herd or leader for direction and a sense of safety in their lives but are known to be very dedicated to their owner.
A jack can be black, brown, sorrel, dappled or spotted and can be bred to a mare of any breed and color. The size of the resulting offspring will be mostly dictated by the mare but color of any variety can be achieved based on the gene pool of both parents. That one distinctive feature, those large and sometimes floppy ears, are what set them apart from other equines and is a huge part of their charm!
The proliferation of mules in the United States can be traced back to George Washington, who saw the true value of mules for agriculture in America. Thanks to a gift of a “jack” from the King of Spain in 1785, an American dynasty was born. Additional purchases of jacks and jennies of the finest European breeds in the late 1700’s and early 1800’s allowed the development of strong work mules which were in great demand as settlers moved west to homestead. By the early 1900’s, the mule population in America was estimated at 6 million.
Like the large draft horse breeds, the number of mules and demand for them diminished with the invention of the combustion engine and ultimate shift to machine powered equipment for agriculture. However, a resurgence in demand has occurred over the last few decades as more and more people are re-discovering their value for riding, equine sports and driving. And their quirky personalities are charming their way into many hearts! Just ask anyone who owns a mule.