I have a feeling the answer is “no”, but can anyone comment on whether or not this could be used to decode the utterances of other animals, such as whales?
This method works because both languages corpuses talk about the same things. Life, death, love, war... they happen to people speaking all languages.
To translate whale song, you need data that corresponds to what the whales are singing about.
You would need a bilingual dictionary as the first step of the process, so I'm afraid that this will not be possible.
Without commenting on whether this method could be applied to whales, the method described here does not require a bilingual dictionary. They learned their "dictionary" unsupervised by aligning monolingual word embeddings.