The St. Croix is an American sheep breed that is part of the Caribbean Hair sheep family of breeds. Caribbean Hair sheep were developed from the hair sheep of West Africa and a few European wooled sheep that were brought to the Caribbean islands beginning in the 1600s. The sheep proliferated as subsistence livestock, and they were also valued for the manure critical to sugar cane production. Over time, Caribbean Hair sheep became well adapted to the heat and humidity of their environment. The hair coat, which eliminates the need for shearing, is part of this adaptation. Today, there are several landrace populations within this breed family in the Caribbean region. Two breeds, the Barbados and the St. Croix, are also found in mainland North America. The St. Croix is adapted to the heat and humidity of a tropical climate, and this adaptation has several manifestations. The breed has well-documented parasite resistance, far superior to that found in most other sheep breeds. It is small, with ewes averaging 120 pounds and rams 165 pounds. St. Croix sheep are known for their high fertility, and ewe lambs become fertile at about six months of age. Ewes often produce twins and have plenty of milk to raise them. Two lambings a year are not uncommon. The original St. Croix landrace is found throughout the Caribbean, particularly on St. Croix (U.S. Virgin Islands). Most of these sheep are white and polled (the so-called Virgin Islands White strain), though local variants can have different coloration or markings: black, black-bellied, or spotted. To the best of our knowledge, there are 2 strains of St. Croix sheep. One is being raised only on the North American mainland and has not yet been reintroduced to the Caribbean region. However, the original St. Croix landrace, a broader genetic population belonging to the same breed, continues to be raised on the islands. The Agricultural Experimental Station at University of the Virgin Islands has an active breeding program of St. Croix sheep. In 1975, Dr. Warren Foote of Utah State University imported 22 ewes and three rams from St. Croix in the U.S. Virgin Islands. Foote chose a relatively consistent group of polled, white sheep from a diverse landrace called St. Croix (or Virgin Islands White). Offspring of this imported group were further selected for consistency of conformation, and this process has resulted in the development of the mainland St. Croix strain, which is now recognized as a standardized breed in the United States. Genetically speaking, however, both the original island landrace and the standardized mainland strain are considered to be part the same breed.