Also at Sprinkle Pill mouth this afternoon, I was alarmed and sad to see 1 dead and 1 sick Canada Goose. Although not confirmed as resulting from avian flu, the actions of the sick bird were similar to those I've seen in videos of geese reported to have HPAI. This prompted me to find out (with Bob's help) what the latest reporting procedures are for dead/ill birds. I share in case others find other cases - with the hope that we don't.
The official route is to phone a DEFRA helpline 03459 33 55 77. That said, two affected geese do not pass DEFRA's minimum reporting threshold for this route (there are different thresholds depending on the type of bird). Unofficially, BTO are also collecting data on all dead/sick birds through their latest update to the Birdtrack app. Reporting a dead/sick bird is one of 3 options on the 'homepage' to this app and the process to report by this route is pretty straightforward.