It looks like the sonograms are full of harmonics. The conventional musical notation for a note with rich harmonic content, such as a single pluck of a guitar string, is not a vertical line on the staff with notes at every harmonic; instead, you just indicate the pitch of the fundamental. (Even if the fundamental itself is mostly missing, like in the low notes on an upright piano, that's where you put the note.) Then, notes with different harmonic content (because they are played on different instruments) are plotted on different staffs, although this might be counterproductive for visualizing whale songs. Colors are probably better for that.
It would be interesting to see if a second-order Markov model of the whale song unit sequence finds information that is not captured in a first-order model. More interesting still would be if a stochastic context-free or pushdown model were able to predict whale songs better than a similarly-complex Markov model, as it would indicate that the whale song has a recursive structure, like human language.
It makes some sense that you would use a long, highly-redundant transmission of a sequence of discrete symbols, which then you would repeat after hearing, to distribute information of general interest around the ocean, where travel is slow and the latency-bandwidth product is high. The researchers speculate (largely on the basis of sexual dimorphism) that the information communicated is merely fashion — but surely there is some generally-useful, temporally-changing information of interest to humpback whale survival and fecundity.
It would be interesting to see if a second-order Markov model of the whale song unit sequence finds information that is not captured in a first-order model. More interesting still would be if a stochastic context-free or pushdown model were able to predict whale songs better than a similarly-complex Markov model, as it would indicate that the whale song has a recursive structure, like human language.
It makes some sense that you would use a long, highly-redundant transmission of a sequence of discrete symbols, which then you would repeat after hearing, to distribute information of general interest around the ocean, where travel is slow and the latency-bandwidth product is high. The researchers speculate (largely on the basis of sexual dimorphism) that the information communicated is merely fashion — but surely there is some generally-useful, temporally-changing information of interest to humpback whale survival and fecundity.