>It's not even clear to me that birds are a primary food source for domesticated outdoor cats. They might be hunting them just for sport.

This seems like a condemnation of hunting for sport to me.

We must be coming from different places.

I still don't see a condemnation at all. Other than the implication that sport is not constrained by hunger and therefor can have unbounded externalities, which again is not moral, it's a practical observation and concern for bird populations.

Maybe you could pinpoint further which part of the sentence you quoted brings in morality.