Why does my willow tree no longer have catkins in the spring?

It's possible that the birds have been eating them in the winter. (bullfinches).

Good evening Bob I wondered why one of my dwarf willow trees has no catkins ,one does and the other does not.

Thanks Doctor bob for replying. We do have bullfinches in the garden but if they had been eating the catkins in winter we would have seen them doing it , the tree is right near a back window and to eat them all they would have to spend alot of time on the tree , they are usually seen further away from the house. So I don't think this is the reason. Although we do have alot of blue tits which congregate in the tree as they queue up to use the bird feeder. Would they eat the catkins do you think?

Yes Jane,
Any birds but mainly bullfinches, they have had a long winter this year.

Turns out it is probably short of water which stops the catkins forming as the trees energy is put into the leaves etc , seems more likely to me then bullfinches eating all the catkin buds , as we would see them doing it and there should be one or two left , but there are never any on the tree anywhere anymore. Another theory was that I had pruned out all the branches that were going to produce catkins , but as I have never pruned it that can't be right either! Someone somewhere must know the answer to this!

All willows like wet conditions, but not waterlogged, winter and summer.