There are features in the frequency ranges of bird calls that suggest this. Alarm calls are usually on frequencies that have better propagation (this also depends on the habitat that birds occupy - ground living birds have much lower frequency calls because the sound spreads better close to the ground. Calls that go to chicks tend to be on higher, less propagating frequencies. On the other side, the calls that hunting birds make tend to look like an all frequency sweep - possibly they are trying to get a response from other species to locate them.

This is the case even though English isn't even considered a tonal language. Mandarin is a highly tonal language with four distinct formalized tones. Not only that, but the brain has to adapt to pick out those tones clearly. As a result, "perfect pitch" is much more common for Mandarin speakers than speakers of non-tonal languages.

Tonal here is very different. The tone in Chinese is a completely different word. Multiple words have the same tone and thus pronunciation with different meaning (and character). Tone usage on one word would not change the interpretation.

There are cases where this is kind of like English, in the case of buy/sell 买/卖, but still quite different

Yes, that's why I referred to Mandarin as a "tonal language". It is a formal linguistic categorization. Speakers of all languages may use tone, but an actual tonal language is quite different, taking the concept of tone to a another level in terms of grammatic and lexical importance.

> "Predator!" vs "Predator?"

Should have gone with "Friendship!" VS "Friendship?"

There really are birds that have predator warning calls. Other animals even listen for them and hide when they hear them.

We can always tell when our neighbor's cat is outside when the birds in our yards start to get agitated.

I've noticed the warning call differs at times, I hear two chirps for land based predator and three for air. Small sample size, city finches.