Habitat: Domestic sheep are extremely versatile and exist in a wide variety of habitats worldwide ranging from temperate mountain forests to desert conditions.

Diet: Domestic sheep are extremely hardy animals and can survive on a diet consisting of only cellulose, starch or sugars as an energy source and a nitrogen source which need not be protein. In general, sheep feed mainly on grasses while in pastures and can be fed a wide variety of hays and oats. Grazing sheep ingest a large amount of food in a short time, then retire to rest and rechew the ingested matter. Sheep spend their day alternating between these periods of grazing and ruminating. Ovis aries has a large and complex stomach which is able to digest highly fibrous foods that can not be digested by many other animals. Its modest nutritional requirements contribute to its economic significance.

Reproduction: Ovis aries breeds on a seasonal basis, determined by day length, with females (ewes) first becoming fertile in the early fall and remaining fertile through midwinter. Estrus cycles range between 14 and 20 days with 17 as the average. Females are in heat on average for 30 hours. Males (rams) are fertile year round and most domestic sheep breeders use 1 ram to 25 to 35 ewes. Gestation averages 148 days with most lambs born in mid spring. One or two lambs, which are able to stand and suckle within a few minutes of birth, are born to each ewe. Both male and female lambs reach sexual maturity within one year.

Physical Description: The physical details of domestic sheep vary greatly among breeds. Head and body length is 1,200-1,800 mm and shoulder height is 650-1,270 mm. Female sheep tend to be three quarters to two thirds the size of males. Wild sheep have tails between 70-150 mm but in domestic sheep tails may be larger and used as a fat reserve, although these long tails are removed on most commercial farms. Sheep have a vertical cleft and narrow snout completely covered with short hair except on the margins of the nostrils and lips. The genus Ovis is characterized by the presence of glands situated in a shallow depression in the lacrimal bone, the groin area, and between the two main toes of the foot. Selection for economically important traits has produced domestic sheep with or without wool, horns, and external ears. Coloration ranges from milky white to dark brown and black. There is considerable diversity among the over 200 distinct breeds of sheep.

Behavior: Ovis aries has a highly developed flocking or herding instinct. Large groups of sheep (up to 1000 or more) move over an area in groups, rather than as individuals. No "leaders" in the flock initiating grazing or other forms of behavior, including flight. This flocking instinct contributes to their economic significance as a single shepherd can control a large flock of animals. Sheep become considerably stressed when separated from others, often calling and pawing at the ground.

Conservation Status: Common

Fun Facts:

• There is considerable controversy over when and from what wild species the first domestic sheep descended. Current chromosomal and archeological evidence indicates that the divergence occurred about 9000-11000 years ago and that the first sheep domesticated were from the mounflon flocks from Sardinia and Corsica.
• They have been a source of meat, milk, wool and hides in nearly every country.
• Sheep have become important as a tool for scientific research. Because of their large size and low maintenance costs they make an ideal model for a great deal of scientific research.