Two kestrel fighting in a nest box
According to the info on the site hosting the nest cam, these are two female kestrels (German: Turmfalke) fighting over a nest with 6 eggs (now 7) inside of a nest box. More info (all in German though) is here:
Turmfalken-Cam. Apparently, there are additional encounters between the two female kestrels. And the blog suggests that the intruder displaced the initially breeding female. Crazy! The author speculates that both female laid eggs in the nest... And then there were 8 eggs.
Thought you might enjoy. Best, Jörg