 Archaeological evidence from the measurement of bones (osteometry) demonstrates that sheep in southern Portugal increased in size during the Islamic period, while cattle increased when the area became Christian after its reconquest.The archaeologist Simon Davis assumes that the change in size signifies improvement by animal husbandry, while in his view the choice of sheep is readily explained by the Islamic liking for mutton.During the period, irrigated cultivation developed due to the growing use of animal power, water power and wind power.