A Grey Little Bird

Greetings friends.
The winter bird feeding season is over. The birds stopped coming to my tree for a photoshoot. Now I try to find them among the bushes while walking towards the river. Sometimes it can be quite difficult. Birds skillfully disguise themselves among the branches and leaves of the tree.
What is the name of this bird? I asked the internet about it and it told me that it was a Common Whitethroat.
It turns out that I don't know much about the birds of our forest.

This small bird is almost invisible against the background of the tree. A small colorless bird. It is easier for such a bird to survive in the wild.
I even remembered Saltykov-Shchedrin's fairy tale about the wise minnow, who was afraid to show himself in the open during the day and lived his whole life hiding in a hole.