I do not know how to tell you this but I think that birds are a bit special you see it's you and your luck. You can easily kill a bird but you can also lose it depends on their dodge and your hit. Of course i'm talking as a pally.
But honestly I could handle it against birds. I aim especially bears and other pally. No pally has arrived to kill me and I did not manage to kill them either so it makes us all the time equal. For bears it also depends if the bear has a ring 3pc there it is not impossible to kill but it's still hard as well. I find no difficulty against the 2pc bears.
I come back to the birds. My old build was 9 frostbite and 9 heal so I could easily kill any bird.
But then I reduced my heal to 7 points and my frostbite 2 points.
The hard part is that I have 2 debuffs and I do not know when to use the two skills. When I try to use them both at the same time I'm already dead. But when I try to nightmare for example it can easily dodge and the bird kills me before I do.
And it is the same for Weakness if I miss it or dodge it's dead.
I just want some advise when to use each debuff against enemies.