Tree Sparrow decline reasons

I have been reading recent reports on Tree Sparrow Passer montanus decline in Nottinghamshire and the UK and these are pointing fingers mostly at habitat destruction and modern hedgerow management practices leading to a lack of winter food and shelter but I wonder if this is the complete picture? Tree Sparrow populations seem to be doing fairly well on a lot of our Wetland Nature Reserves in the country and I wonder if this is down not just to very good feeding regimes in place on these sites but also because these sites are very rich in insect life during the breeding period and when the chicks hatch, which sadly a lot of our agricultural land no longer is.

Both Tree Sparrow and House Sparrow feed their young on a diet of insects and the decline in a lot of insect populations in the UK seems to mirror the decline of these bird populations. At one time within living memory if you took a rural car journey in late spring to mid summer your car windscreen would be black with insect bodies at the end of it but this in most areas seems to be a thing of the past. I wonder if the Tree Sparrow and a lot of our farmland bird species declines are through a combination of habitat destruction, land management and a continuous reliance upon pesticides and herbicides which also greatly affect insect populations.
Source: Wild About Britain, unknown contributor, posted in January 2010
http://www.wildaboutbritain.co.uk/forums/british-birds/81098-tree-sparr…