Poecile said:
Ok, ok, I know this has been done to death on the other thread, but the information on there is patchy and conflicting. Both the BTO and RSPB seem to have been caught on the hop a little with this. Anyway, clear information and advice is now available. This was summed up well in today's Times, with useful links and advice:
http://www.timesonline.co.uk/article/0,,2-2355593,00.html
For those still in doubt about whether to keep feeding or not, the advice is now crystal clear: if you see sick birds (or are in an area where outbreaks are occurring) then stop feeding and watering for at least 2 weeks. The disease is a protozoan called Trichomonas, and it's killing birds in large numbers, with garden feeding stations being the major suspect for high transmission rates.
I believe this outbreak is the direct result of the 'feed all year' mania that seems to have taken hold in the last two years or so thanks to RSPB endorsement of the practice: (all quotes from the RSPB's website). Time will prove me right one way or the other.
http://www.rspb.org/advice/helpingbirds/feeding/when_to_feed.asp
"Although winter feeding benefits birds most, food shortages can occur at any time of the year. By feeding year round, we are giving birds a better chance to survive the periods of food shortage whenever they may occur."
"Only selected foods should be fed at this time and good hygiene is vital, or feeding may do more harm than good." ... so at least they admit that summer feeding is potentially problematic.
"During the summer months birds require high protein foods, especially while they are moulting."
"Black sunflower seeds, pinhead oatmeal, soaked sultanas, raisins and currants, mild grated cheese, mealworms, waxworms, mixes for insectivorous birds, good seed mixtures without loose peanuts, RSPB food bars :eek!: and summer seed mixture :eek!: (
corporate opportunity not left unexploited) can all be used."
"Temporary food shortage can occur at almost any time of the year, and if this happens during the breeding season, extra food on the bird table can make a big difference to the survival of young."
"Birds time their breeding period to exploit the availability of natural foods, in the case of blackbirds and song thrushes, earthworms; in the case of tits and chaffinches, caterpillars. It is now known that if the weather turns cold or wet during the spring or summer months, severe shortage of insect food can occur, and if the weather is exceptionally dry, earthworms will be unavailable to the ground feeders because of the hard soil."
Even winter feeding (which gives everyone a lot of pleasure) might be distorting populations. High overwinter survival of resident species (tits, dunnocks, robins, finches) thanks to feeding may reduce the niches available to trans-Saharan migrants on their return. The uplands of Scotland and Wales as well as the Alps and eastern Europe are dominated by long-distance migrant bird communities because winter temperatures are so low. Feeding birds allows species to overwinter and reduces migrant birds' opportunities.
In short.... summer feeding is nuts.