• Welcome to BirdForum, the internet's largest birding community with thousands of members from all over the world. The forums are dedicated to wild birds, birding, binoculars and equipment and all that goes with it.

    Please register for an account to take part in the discussions in the forum, post your pictures in the gallery and more.
ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

Turdidae (13 Viewers)

Interesting that the recommendation is "no" because of lack of published data

Niels
I dunno, seems like a really messy situation, with different folks placing it in different species and treating it as a unique species. Not surprising a no vote, in contrast to some other proposals. Although I say that with having zero experience with Dagua Thrush
 
Interesting....I wasn't sure what was going to happen on the NACC/SACC end. If either committee rejects a proposal, does that mean it's sunk for inclusion in the new checklist? Or will discrepancies continue to exist?
Historically, both Clements/eBird and IOC have made decisions which differ from NACC's decisions (and maybe SACC's too but I can't recall any off the top of my head). So it wouldn't surprise me if the new committee does that too.
 
ebird/Clements have made only a very small number of decisions different from NACC, mostly concerning taxa that are largely old world.

But yes...IOC generally has more differences, including recognizing splits for several fairly well known North America birds. Although in recent years they have stuck to NACC/SACC more closely.
 
Interesting that the recommendation is "no" because of lack of published data

Niels
Proposal (922) to SACC

Treat Turdus daguae as a separate species from Turdus assimilis

I have to say this is one of the more depressing proposals there has been for some time - SACC's inclination to promote historical taxonomies where possible (even if they do not make much sense), and BirdLife's reluctance to consider molecular data, conspire to strike down what must be a clearly good split (or two). There is of course a conflict between some of the vocal and molecular data, and the Amazonian population could do with more sampling - but I am not convinced that lumping everything is the best solution here.

Paul Coopmans first noted this split, which was picked up in Birds of Ecuador; he drew it to my attention in when we met around 1999/2000 or so, to plot fieldwork for the basis to describe Henicorhina negreti. Twenty years later, Dagua Thrush still not recognised, and the wait looks set to continue for some time!
 
These are the current entries/definitions for Lamprophonus and Turdela from The Key (which is free to view on-line on the BOW site):

Lamprophonus
(Turdidae; syn. Turdus Mistle Thrush T. viscivorus) Gr. λαμπροφωνος lamprophōnos clear-voiced < λαμπρος lampros clear; φωνη phōnē voice, cry < φωνεω phōneō to speak (cf. φωνος phōnos loud-voiced); "Lamprophonus musicus, Throstle. Lamprophonus variegatus, White's Thrush. Lamprophonus viscivorus, Shrite. Lamprophonus pilaris, Fieldfare. Lamprophonus turdus, Redwing." (F. Morris 1837) (OD per Björn Bergenholtz); "Lamprophonus F. O. Morris, 1837, The Naturalist (ed. N. Wood), II (9), p. 125. New name for Turdus Linnaeus, 1758." (JAJ 2021) (see Seiren).



Turdela
(Turdidae; syn. Turdus Song Thrush T. philomelos) L. turdela little thrush < dim. turdus thrush; "§ 1º GRIVE. (TURDELA.) TOURDRE-GRIVE. - TURDUS MUSICUS. Linn. ... TOURDRE-MAUVIS. - TURDUS ILIACUS. Linn." (Webb et al. 1836); "Turdela Webb, Berthelot and Moquin-Tandon, 1836, Hist. Nat. Iles Canaries, II (2), Zoologie, Ornithologie Canarienne, p. 11. For the purposes of The Key only, type here fixed by subsequent designation, Turdus musicus Linnaeus, 1766 (not of Linnaeus, 1758) = Turdus philomelos Brehm,1831" (JAJ 2021).
Var. Turdula.
 
Last edited:
We can therefore suggest that musicus is the type species since it is cited first. A later work would have had to explicitly give musicus as a type species
Being cited 'first' does not give a species more 'right' to become the type.

(musicus was cited by Webb & Berthelot from Linnaeus 1766 [the page number they cited matches this edition of Syst. nat.], but not as a deliberate adoption of a misidentification of the name: the type of the genus-group name could only be Turdus musicus as defined where its name was made available, i.e., in 1758.
This name is a bit problematic, as it was originally published with a diagnosis of Redwing (Linnaeus apparently interchanged the diagnoses of the Song Thrush and Redwing, quite possibly by mistake -- most of the refs he cited under musicus concerned the Song Thrush, and most of those he cited under iliacus concerned the Redwing; he corrected this in his subsequent writings -- first in the 1761 ed. of Faun. svec., then in the 1766 ed. of Syst. nat.). musicus was moved onto the Redwing by Hartert in 1909 because of the 1758 Redwing diagnosis: this move is at the origin of our use of philomelos Brehm 1831 for the Song Thrush; the name was finally suppressed by the Commission in 1959, to preserve the use of philomelos and iliacus for the two species.)

OD 1 - 2 (1837-38) - Naturalist (Maund, Hall & Wood.) - Biodiversity Heritage Library

Morris' work was an attempt to compile a list of British birds under strongly idiosyncratic rules, which i.a. stipulated that all generic names should be 'classical' Greek and all specific names 'classical' Latin. Although, from a taxonomic viewpoint, the author's intents were generally made clear by the English names he associated to his scientific names (he did not describe the birds or give an authority for any name in his list), I do not believe that his names can be deemed available as nomina nova, because he nowhere presented any individual name as being rejected and replaced with the names he was using. In a number of cases, which name would have been intended is not actually clear. Why is Nyctimene a new name for Flammea Fournel 1836, not for Aluco Flemming 1822? Why is Philomela a new name for Sibilatrix Kaup 1829, not for Ficedula Koch 1816? Why is Aedonis a new name for Luscinia Forster 1817, not for Sylvia Scopoli 1769? I think this type of interpretations is simply too subjective to be tenable. The truth is that Morris did not indicate what, if anything, he was replacing, and that his names should stand based on what he actually told us in his work -- things that we don't need to guess. In my reading, the only way that some of Morris' names can be available is under ICZN 12.2.5, for those among them that were (explicitly) combined with one or more recognizable available species-group names ; I view those that were combined only with specific epithets which Morris had also changed (and were thus not pre-available species-group names; e.g. "Epops upupa" instead of Upupa epops, for the "Hoopoo" -- upupa had never been used as a specific name for this species before) as pure nomina nuda.

The originally included nominal species of Lamprophonus were Lamprophonus musicus (= Turdus musicus Linnaeus 1758), L. variegatus (a corruption of Turdus varius Horsfield 1821), L. viscivorus (= Turdus viscivorus Linnaeus 1758), and L. pilaris (= Turdus pilaris Linnaeus 1758), plus "L. turdus" (for Redwing, a nomen nudum, hence not eligible to be the type); we would need a type designation, but I'm not aware that one was ever published in a Code-compliant way.

Although Lamprophonus Morris 1837 is not in use, deeming it unavailable (due to the lack of authorities or descriptions associated to the species) seems undesirable, because it would be destabilizing to entomology (its availability is the reason of the use of the nomen novum Lampetes Andrewes 1940, instead of Lamprophonus Bates 1889, in Coleoptera).
 
Last edited:
Termignoni-Garcia, F., J.J. Kirchman, J. Clark, and S.V. Edwards (2021)
Comparative population genomics of cryptic speciation and adaptive divergence in Bicknell’s and Gray-Cheeked Thrushes (Aves: Catharus bicknelli and C. minimus)
Genome Biology and Evolution (advance online publication)
doi: 10.1093/gbe/evab255

Cryptic speciation may occur when reproductive isolation is recent or the accumulation of morphological differences between sister lineages is slowed by stabilizing selection preventing phenotypic differentiation. In North America, Bicknell’s Thrush (Catharus bicknelli) and its sister species, the Gray-cheeked Thrush (Catharus minimus), are parapatrically breeding migratory songbirds, distinguishable in nature only by subtle differences in song and coloration, and were recognized as distinct species only in the 1990s. Previous molecular studies have estimated that the species diverged ∼120 - 420 thousand YBP and found very low levels of introgression despite their similarity and sympatry in the spring (prebreeding) migration. To further clarify the history, genetic divergence, genomic structure and adaptive processes in C. bicknelli and C. minimus, we sequenced and assembled high-coverage reference genomes of both species and re-sequenced genomes from population samples of C. bicknelli, C. minimus, and two individuals of the Swainson’s Thrush (C. ustulatus). The genome of C. bicknelli exhibits markedly higher abundances of transposable elements compared to other Catharus and chicken. Demographic and admixture analyses confirm moderate genome-wide differentiation (Fst ≈ 0.10) and limited gene flow between C. bicknelli and C. minimus, but suggest a more recent divergence than estimates based on mtDNA. We find evidence of rapid evolution of the Z-chromosome and elevated divergence consistent with natural selection on genomic regions near genes involved with neuronal processes in C. bicknelli. These genomes are a useful resource for future investigations of speciation, migration, and adaptation in Catharus thrushes.
 

Pressure for rapid and accurate mate recognition promotes avian-perceived plumage sexual dichromatism in true thrushes (genus: Turdus)​

Alec B. Luro,Mark E. Hauber
First published: 05 October 2022
https://doi.org/10.1111/jeb.14089

Abstract

Ecological conditions limiting the time to find a compatible mate or increasing the difficulty in doing so likely promote the evolution of traits used for species and mate recognition. In addition to interspecific character displacement signalling species identity, intraspecific traits that signal an individual's sex and breeding status reduce the challenge of identifying a compatible conspecific mate and should be more common in migratory rather than sedentary species, species with shorter breeding seasons and species breeding under high sympatry with many closely related heterospecifics. Here, we tested this recognition hypothesis for promoting plumage sexual dichromatism in the true thrushes (Turdus spp.), a large and diverse genus of passerine birds. We used receptor-noise limited models of avian vision to quantify avian-perceived chromatic and achromatic visual contrasts between male and female plumage patches and tested the influence of breeding season length, spatial distribution and sympatry with other Turdus species on plumage dichromatism. As predicted, we found that (1) true thrush species with migratory behaviour have greater plumage sexual dichromatism than non-migratory species, (2) species with longer breeding seasons have less plumage sexual dichromatism, and (3) greater numbers of Turdus thrush species breeding in sympatry is associated with more plumage sexual dichromatism. These results suggest that social recognition systems, including species and mate recognition, play a prominent role in the evolution of plumage sexual dichromatism in true thrushes.
 

Users who are viewing this thread

Back
Top