[Tweeters] House Sparrows

David Hutchinson flora.fauna at live.com
Wed Mar 24 15:19:31 PDT 2010



It is interesting to hear Dennis's concern re: a potential decline in HOSP and if true,a consideration of the variable explanations. In the U.K. and certainly in some major European cities, the species has been in a sharp decline for some decades, by over 50% in the last 40-50 years in the UK, and by 65% between 1997-2000. A recent study confirms this but cannot pin down the variable solutions - decline in invertebrate prey is in association with the decline, and loss of deciduous trees, shrubs and grassland in suburban areas is another factor. HOSP chicks showed starvation during the first 6 days in the nest. Whether competetition with other species that use invertebrates to feed the young within urban areas is a factor is not clear, but there are strong declines in rural areas too. In Greater Seattle we have seen Rufous Hummingbird and Purple Finch replaced by Anna's Hummingbird and House Finch without quite understanding why. But first whether there is a real decline in the House Sparrow must be established.

--
David Hutchinson, Owner
Flora & Fauna: Nature Books
Discovery Gardens: Native Plants
3212 W.Government Way
Seattle,WA.98199
http://www.ffbooks.net/
206-623-4727



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