sentences:  Before the advent of widespread agriculture, they may not have been widely present in what is now the United States evidenced by a lack of fossil remains and absence from the journals of early European explorers.Their presence in California is likely recent, as a result of the manmade filling of the Salton Sea at the turn of the 20th century.The historical range of the dove closely mirrors that of the saguaro cactus, which it relies on heavily for nectar and fruit where it is found.