The resinous compound which gives the buds their sticky nature presumably affords a measure of protection from insect attack, and maybe birds too, perhaps not in Britain but probably in the tree's native home in the Balkans.
The sticky buds of Horse Chestnut, Norton Road, Daventry.
28 February, 2017
I have avoided hesitation or repetition although perhaps I could be now accused of deviation from the subject of sticky buds, but I will return later in the spring to Horse Chestnut trees. You have been warned!