What are these?

[goosey]

I was cycling along when I saw these at the base of a tree. Seeing as they were so small they stood out a mile!
I jumped off my bike to have a better look, I thought they were fungi. There were 10 of them, the largest being about 5mm across, some were bright red but a couple were much paler almost pink, and were 6cm above the ground on the trunk of an oak tree.
I think they are more plant than fungal, I don't think slime mould either, but don't really know.
Do you think they could be new shoots or something?
What do you think?

[The Woodman]

If the tree was an oak and you say it is - then consider oak apple galls.

I've lifted this text from UK Safari

These are seen between May and June. They are home to the larvae of the oak apple gall wasp (Biorhiza pallida). The female lays her eggs in the leaf bud causing the oak tree to produce this apple-like growth.

The gall itself is about 4cms in diameter, and inside there are around thirty chambers each containing one wasp larvae. If you cut an old one in half you can see the tunnels where the larvae chewed their way out.

The 29th of May is traditionally 'Oak Apple Day' in Britain, which celebrates Charles II's return to England in May 1660.

[goosey]

Thanks Woodman.
I thought the oak (it was definitely oak) galls were only on the acorn/cup or leaf, I didn't know they could grow on the bark as well.
These are very small at the moment but I will keep an eye on them, I should be in the area once a week at least.