<Li> P. d. hufufae Ticehurst and Cheeseman, 1924, described from Hofuf in Saudi Arabia, is found in north - eastern Arabia . </Li> <Li> P. d. rufidorsalis C.L. Brehm, 1855, described from Khartoum, Sudan, is found in the Nile valley from Wadi Halfa south to Renk in northern South Sudan, and in eastern Sudan, northern Ethiopia to the Red Sea coast in Eritrea . It has also been introduced to Mohéli in the Comoros . </Li> <P> The house sparrow originated in the Middle East and spread, along with agriculture, to most of Eurasia and parts of North Africa . Since the mid-19th century, it has reached most of the world, chiefly due to deliberate introductions, but also through natural and shipborne dispersal . Its introduced range encompasses most of North America, Central America, southern South America, southern Africa, part of West Africa, Australia, New Zealand, and islands throughout the world . It has greatly extended its range in northern Eurasia since the 1850s, and continues to do so, as was shown by the colonisations around 1990 of Iceland and Rishiri Island, Japan . The extent of its range makes it the most widely distributed wild bird on the planet . </P> <P> The house sparrow has become highly successful in most parts of the world where it has been introduced . This is mostly due to its early adaptation to living with humans, and its adaptability to a wide range of conditions . Other factors may include its robust immune response, compared to the Eurasian tree sparrow . Where introduced, it can extend its range quickly, sometimes at a rate over 230 km (140 mi) per year . In many parts of the world, it has been characterised as a pest, and poses a threat to native birds . A few introductions have died out or been of limited success, such as those to Greenland and Cape Verde . </P>

When were house sparrows introduced to north america