Top hunting for birds
Top hunting or top bird hunting is usually conducted at the time of year when there is so much snow on the ground that the forest bird needs to search the trees to find food. However, it can not be said that it can not be conducted earlier in the year. Both capercaillie and grouse are sometimes at the top of the tree even if there is no snow on the ground. In some cases, the birds eat shoots on the trees and sometimes they sit on top because they have been frightened.
In top hunting, a lot is about scouting trees at a leisurely pace in front of them. The trick is to spot the birds before they spot you. A good pair of binoculars is a tool that will definitely increase your chances of success. When it comes to optics, it is unfortunately the case that quality costs, but the difference is noticeable. I usually start by looking in my way for the treetops to see if something suspicious catches the eye, usually you perceive an unnatural round shape in the tree. If I do not see anything there, I usually make a sweep in the middle of the tree line as not all birds are at the top, but a little more in the middle of the tree. With no protrusion, I continue my way forward. Not being in a hurry is of utmost importance.
A good trick for top hunting
Even though no birds are now visible in the trees, they are usually found somewhere nearby. In some cases, they lie embedded in the snow-insulating blanket, or sometimes they eat berries on the ground. There are 2 options for getting the birds to the top, one is to get them up. That is, you scare them off the ground so they sit on the top of the tree. The second is that you have a dog with you. At best a bird dog of some kind but really any dog that runs around and ravages the ground works. That's why I like to have our fin tip with me even on top bird hunts.
As for ammunition for top hunting, there is an article about choosing bullet ammunition on bearskin.se and thoughts about it.
There are 2 ways to go regarding shots at birds in my opinion. Either you decide what a normal direction is approximately and then you try to stay close to that distance, say 120-150 m. When the direction is longer, you simply try to sneak closer.
Or you search for the target on the binocular sight (which I use), that method requires more preparation in terms of verification of bullet trajectories and a rangefinder and target funnels on your binocular sight to work smoothly, but also gives you an opportunity to shoot birds at significantly longer distances with maintained probability of hit. Good support is always important, otherwise it is better to give up.
I hope these lines helped you on your way to a slightly more successful top bird hunt!