Above: Ben Black and Buster Brown, Milton Burro
male donkey (jack) + female horse (mare)= "mule"
female donkey(jenny) + male horse(stallion)= "hinney"
the rare fertile female mule= "molly"
there are no recorded cases of male mule fertility
Common colors are sorrel, bay, bay-brown, black, and grey. Less common are white, roans (both blue and red), palomino, dun, bright-bay, piebald, appaloosa and buckskin. Least common are paint mules or tobianos.
Geldings are male equestrian animals that have been castrated. It is important for mules to be gelded since they are extremely active sexually. Even after gelding, they remain sexually active, especially when not working.
Mules exhibit a higher cognitive intelligence than their parent species - horses and donkeys. This is believed to be the result of hybrid vigour, similar to how mules acquire greater height and endurance than either parents.
Mules are highly intelligent. They tend to be curious by nature. A mule generally will not let the rider put it in harm's way. However, the stereotype of the mule as being stubborn is somewhat unfair and inaccurate.
Mules come in a variety of shapes and sizes, from minis under 50 pounds to maxis over 1000 pounds.