There seems to be a lot of wishful thinking in the research. The article mentions the Great Tits having 2 calls for alarm, which if made out of order have no effect, and calling that grammar. You could also call it a single call. Grammar to me means being able to construct new meaning from parts. While interesting and maybe useful, if this sort of research bears fruit I believe lots of people waxing lyrical over how amazing it will be to talk with the animals are going to be rather disappointed. Basic conversation requires a vocabulary in the hundreds, and so far it seems we are looking at word-equivalents maybe in the dozens, in the more capable species. And then you have all the concepts we take for granted except in infants, such as 'I' and 'you' and self awareness.
