Oscine/suboscine vocalisations (1 Viewer)

After a lengthy and at time heated debate down the pub last night I wonder if BF members can tell me if any of these statements are true.

1) Oscine passerines calls are innate but their songs are, at least in part, learnt. The complexity of their songs is due to a highly developed syrinx. As a result oscine passerine songs are of limited value in taxonomic evaluations.

2)Suboscine passerines calls and songs are innate and their songs are not learnt. The relative simplicity of their songs is due to a less developed syrinx. As a result suboscine passerine songs are of considerable value in taxonomic evaluations.

3) The same situation as in 2) applies to most, if not all non-passerines.

Thanks

Ian

Ask Mark Constantine of the Sound Approach, he lectured about this subject at 1 February on the annual Dutch Birding day.

JustinJansen said:

Ask Mark Constantine of the Sound Approach, he lectured about this subject at 1 February on the annual Dutch Birding day.

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That is whom I was having the 'lengthy and at time heated debate' with:-O

Ian

That is my understanding. At the very least SACC seem to have far less trouble splitting suboscines on vocals alone compared to other taxa

I am not an expert, but this is the broad generalization. However, generalizations are usually full of exceptions.
I am sure any good birder can give some examples of oscines with as simple songs as sub-oscines. Can a bird have simpler song than a Zitting Cisticola? It is also well known that some calls of oscines are learnt - for example contact calls of crossbills, or some calls of social corvids. It is also known that some non-passeriformes are vocal learners, at least parrots and hummingbirds.

Also, very few bird species, especially sub-oscines, were actually researched for whether they learn songs or not. So I wouldn't be surprised is somebody reported a sub-oscine bird which learns its song.

About the use of songs in taxonomy I would not comment. Taxonomy is only half science and half bureaucracy.

jurek said:

Can a bird have simpler song than a Zitting Cisticola?

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Are you talking about western birds, or eastern (Oriental) birds, which have a distinct song, suggesting they probably ought to be treated as different species?

On (2), largely true, BUT, (a) male Procnias bellbirds unquestionably learn to sing (just listen to a green-plumaged male and you'll hear what I mean), and remember that (b) clinal variation in songs is known, e.g., for Thamnophilus caerulescens, Conopophaga lineata, so care is needed, as always, in reaching robust taxonomies.

Among non-passerines, hummingbirds are well known for learned songs.

Andy

Thank you everyone, I didn't know that hummingbirds could learn songs but your replies pretty much back up what I previously believed to be true.

Ian

I wonder to what extent the last sentence in #1 is correct? I can think of several examples where the existence of cryptic oscine species has been revealed purely on the basis of different vocalisations, and there are plenty of examples of closely-related species having dramatically different songs.

Although oscine songs may not be innate, in most species they are clearly "passed on" through the generations, albeit through learning rather than genetics, and play a significant role in assortative mating.

This is the classic study demonstrating (at least one) suboscine to have innate vocalisations. With Empidonax, a tyrant flycatcher (Tyrannidae) You steal an egg, raise the chick, and play the song of a related species at it repeatedly. Outcome: it sings like its parents did, despite never having heard them:

https://academic.oup.com/auk/article-abstract/101/1/13/5191285?redirectedFrom=fulltext

The same holds true for some antbirds (Thamnophilidae):
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0095746

The same does not work so well for Bellbirds, another suboscine (Cotingidae). I suspect this may be an exceptional instance among suboscines, given how unusual bellbird calls are for the group, but probably there are others like this remaining to be found.
https://www.researchgate.net/public...e_Suboscine_Bellbirds_Procnias_spp_Cotingidae

For oscines (and any other cases of suboscines that learn), the thinking is that voices can be learned. However, there is strong geographical variation in voice. And some traits - e.g. the ability to trill very quickly, the highest and lowest notes that a bird can attain, the quality of timbre of sound - MUST be defined physiologically to some extent. I don't think you could teach a warbler to make a sound like an owl.
https://www.researchgate.net/public...hree-striped_Warbler_Basileuterus_tristriatus

I don't know if things have moved on since 2014, but this summarises where they were then in the context of this particular study, for oscines.

"Voice has been widely used to delimit species in suboscine passerines (in which vocalisations are considered innate: Kroodsma 1984, Isler et al. 1998), but is relatively little used for Neotropical oscines. Vocal differences are nonetheless evident between allopatric oscine populations (e.g.
Cadena et al. 2007, Donegan & Avendaño 2010). Gape muscle strength and bill mass must influence the vocal repertoire of oscines, e.g. their ability to trill at given speeds or deliver notes of certain lengths or frequencies (e.g. Podos et al. 2004), and vocal differentiation is considered relevant to species limits in all birds (e.g. Helbig et al. 2002, Tobias et al. 2010).

It is unclear whether all vocal variables found here to be differentiated reflect
physiological or innate differences between populations. For example, from this study it appears that most B. tristriatus populations avoid acoustic frequencies used by crickets, cicadas or other insects, by singing at a higher pitch. It is perhaps no coincidence that the ‘highest frequency’ population (in San Lucas) has some of the highest frequency insects (max. 4.9–6.1 kHz vs. 4.2–4.6 kHz for Central Andes populations in a sample of slow songs)
or that the lowest frequency songs (in Bolivia) rarely have insect calls vocalising together (and when insect calls are present, the rising song ‘crosses the insect line’: ML132723). It is unclear whether differences in usage of low frequencies are learned / behavioural or innate.
Other differences, in repertoire, song structure, song speed and max. frequencies (which are unconstrained by insects) are probably reflective of physiological or innate differences."

As a "former amateur ornithologist", I've not been following this one recently though, maybe there are some novel developments since.

jurek said:

Taxonomy is only half science and half bureaucracy.

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It does not have to be such. I think the Tobias/Collar model was a first major attempt to put rationality first and get away from committee-based bureaucracy in the discipline. That committees did not like it is predictable. I believe it is entirely possible to come up with a rational measurement-based system for dealing with the main "problem" (the allopatric species "problem") as proposed here:

https://www.researchgate.net/public...pEgJtjBMwC0rDJKHYJeUHsnSKcDOhy38oUdF4ePlTuqeQ

And as widely proposed by molecular biologists using various techniques to identify monophyletic groups or distance-based groups.

I'd say shy of having to raise young of hundreds of species to see if they can learn songs or if their species-specific songs are innate, one can use the proxy of dialect forming. We know from our own species that we learn our vocalizations ("language," as it's widely known). An inherent part of this learning is copy error, those small errors in learning that build up over time to become new pronunciations, then dialects, and eventually languages. This is an inherent property of auditory/vocal learning. Thus, species that show geographic dialects are almost certainly learning their vocalizations. We know, from a few select studies, that all species that learn their vocabularies have genetically-programed templates so that they are likely to recognize and focus on their own species' vocalizations in their period of learning (consider: we can recognize human speech as such, even it if is unintelligible). Thus, vocalization learning is not a complete free-for-all, with the young of species X learning the song of species Y simply because they heard it most during their learning phase. Rather, young species X are able to recognize the song of their own species and use that as their basis for learning their species-specific songs. In the process, however, they make small copy errors that, compounded over time, result in shifting dialects.

In those species that have innate vocalizations, dialects do not seem to form. There is geographic variation in voice in many taxonomic complexes within this group of birds, but this variation is not exhibited as broad geographic clines of change. Rather, it shifts abruptly and it seems to track closely to genetic lineages (for example, the distinctive voices of Zimmerius chrysops and viridiflavus in Peru match genetic clusters, despite the populations being nearly identical in plumage where they come closest together; see Rheindt et al. 2014). This has been borne out again and again with Neotropic suboscine groups such as tyrannids, furnariids, and thamnophilids for which there is a molecular and voice dataset to compare. There is at least the case of Procnias that suggests that not all suboscines have innate voices, but so far, this appears to be the outlier among Neotropical suboscines. So, although we do not have extensive experimentation to demonstrate that *all* members of these families (Tyrannidae, Furnariidae, Thamnophilidae, etc.) probably have innate vocalizations, we can use this proxy (lack of dialect forming) to be fairly certain that this is true. It is not much of a stretch to then extend this dialect proxy to non-passerines such as owls, piciformes, etc. As has been stated by others above, parrots and hummingbirds *do* seem to form dialects, and clearly parrots can learn vocalizations, so it seems likely that hummingbirds can too.

Ian's 'heated debate' and Marc Constantine's recent lecture for Dutch Birding make me wonder whether anything new or divergent was brought forward by him ?
Anyone who can elaborate ?

Some additional notes to the several quality contributions already made. The distinction between calls and song is of course a simplification, but as a general rule - yes: the calls of oscines are much less variable geographically than songs. European thrushes are good examples, and the species with simplest song, Redwing, is the easiest to study. The song varies a lot geographically, but one individual uses only one song type at a time, more rarely switching between two. Song dialects change abruptly and their areas are small, but flight call and alarm calls are the same everywhere. I think that it is more appropriate to call the phenomenon song matching than song learning. A male Redwing changes its song often (but not always) to resemble that of its neighbour. It may even be so, that the first individual to reach breeding areas from migration "decides" how a decent bird should sing in that area, but the dialects and their borders are surprisingly constant from year to year, for longer time than life span of any individual.
On the other hand, several oscine calls are also quite flexible. Crossbill call matching was already mentioned. There are probably many other cases, but this seems to be an incompletely studied area. I think that the phenomenon of 'sweeoo' calls of Chiffchaff has also lot to do with call matching.

Some fascinating comments here. To what extent (if any) could a novel variation in song be compared with a genetic mutation? Let's suppose females select males on the basis of song, would you expect the novel variation to either fail (fewer offspring to learn the song from the father) and disappear from the population, or be successful (more offspring to learn the song) and eventually dominate across the species's range, assuming "song flow" occurs?

jalid said:

I think that the phenomenon of 'sweeoo' calls of Chiffchaff has also lot to do with call matching.

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That's an interesting hypothesis. It would be quite impressive however that call matching on such a large scale (most of Western Europe) is possible. Based on the early overall occurrence in the last 'sweeoo year', it would at least require several simultaneous 'nuclei' I would think. This could e.g. be the increasing overwintering of first year birds which retained their juvenile call, combined with early arrivals of adult birds which then start call matching. It still doesn't seem to explain why it occurs only once every so many years? Or it would be that only occasionally there is an overlap between 'the end of juvenile call retention' and 'first arrival of adults'. Something to investigate!

If such a hypothesis would hold, then of course the taxonomic significance of call differences in other Phylloscopus warblers (think e.g. Bonelli's) would be somewhat reduced…

By the way, an excellent reference for many of the issues raised in this forum topic is:
Marler, P. and Slabbekoorn, H. (2004) Nature's Music. The Science of Birdsong. Elsevier Academic Press. (513pp)

DMW said:

Some fascinating comments here. To what extent (if any) could a novel variation in song be compared with a genetic mutation? Let's suppose females select males on the basis of song, would you expect the novel variation to either fail (fewer offspring to learn the song from the father) and disappear from the population, or be successful (more offspring to learn the song) and eventually dominate across the species's range, assuming "song flow" occurs?

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Actually, for a geneticist it is very difficult to impossible to imagine 'coding' in genes such a complex system as recognizing a complex bird song in the brain of a bird. I think this problem was never approached experimentally. It could be that the bird innately reacts to just 1-2 variables of a song. Most likely, however, the birds have a system where a weak instinctive preference is refined by learning, for example young females watch their fathers or watch and copy older females.

The biggest problem in discussions about bird vocalizations is, however, a false extension. Bird communication is not a system conserved between species. So it is unscientific to claim e.g. because several species behave a certain way, this can be extended to other related species (or even all birds or into some 'common theory' of all animal sounds). Such an extension works for e.g. bird anatomy, but not for traits like bird coloration or bird vocalizations.

Peter Boesman said:

Ian's 'heated debate' and Marc Constantine's recent lecture for Dutch Birding make me wonder whether anything new or divergent was brought forward by him ?
Anyone who can elaborate ?

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Not really, as far as I can tell most things we discussed are covered in this thread, although Mark talked about learned vocalisations in Common Quail.

Ian

Related to this subject: "The vocal organ of hummingbirds shows convergence with songbirds"

https://www.nature.com/articles/s41...QlRc2vHFiELBoN-Awfu0g7BXJ0FbQx4oe-4_gfCYX8teg