I was removing one of the terriers from another woodpile when this little patch of bright yellow caught my eye. To touch it's quite spongy and bouncy but hunting around the heap I couldn't find any more clumps, just this one small area growing on the end grain of a log.
Subsequent research revealed that it could well be an Orange Jelly Fungus which seems to start yellow and darken to orange, inevitably it's poisonous having a skull and crossbones next to the description. Not one for a sandwich then.
The white fungi I haven't been able to identify yet, no doubt the colour changes from white as it matures so I'll just have to keep an eye on the maturing process.