Donkey
Donkeys can interbreed with other members of the family Equidae, and are commonly interbred with horses. The hybrid between a jack and a mare is a mule, valued as a working and riding animal in many countries. Some large donkey breeds such as the Asino di Martina Franca, the Baudet de Poitou and the Mammoth Jack are raised only for mule production. The hybrid between a stallion and a jenny is a hinny, and is less common. Like other inter-species hybrids, mules and hinnies are usually sterile. Donkeys can also breed with zebras in which the offspring is called a zonkey (among other names).
Empidoidea
Several species within Empidoidea are of particular interest to ethologists and ecologists, due to elaborate mating rituals and life histories involving freshwater.
The most familiar families in the group are the Empididae and Dolichopodidae, both of which occur worldwide and contain thousands of species. The smaller families were formerly included in the Empididae, but have since been accorded family status. The monophyly of most of these groups have since been confirmed by subsequent studies. The Brachystomatinae and Microphorinae are sometimes elevated to full family status, too, but this would apparently make the Empididae and Dolichopodidae paraphyletic and thus they are retained as subfamilies here. Atelestidae forming the sister group to the rest of Empidoidea is a unanimous result in all studies that have utilized molecular data.