Proposal (419) to South American Classification Committee


Recognize the newly described Serpophaga griseicapilla


Effect on South American CL: This proposal would add a new species to our list, Serpophaga griseicapilla.


Background: This taxon has a long and convoluted history. Berlioz (1959) described a new species of Serpophaga from Cochabamba, Bolivia, and calls it griseiceps, based on the lack of a white coronal stripe, but presence of a variable gray coronal patch stripe. Traylor (1979) determined that in fact griseiceps is the juvenile of Serpophaga munda, and therefore is synonymized with munda. This decision is generally accepted, i.e. Remsen and Traylor (1989).  Then, Straneck (1993) decided that subcristata and munda should be united as his vocal data suggested that there is little difference between them; on the other hand he finds that there is a bird with a distinctly different voice in central Argentina. He decided that this different voice is a distinct taxon, and that it in fact is S. griseiceps. This is perhaps the decision that most muddied up the Argentine Serpophaga situation. Herzog and Mazar Barnett (2004) studied the Berlioz specimens and compared them to juvenile S. munda, and indeed the specimens of griseiceps matched those of juvenile munda, in coloration as well as measurements. On the other hand, specimens pertaining to the differing vocal type discovered by Straneck were consistently smaller than the Berlioz specimens of griseiceps. Furthermore, they differ in coloration, with Straneck’s specimens being yellowish on the belly, whereas Berlioz’s griseiceps were whitish, typical of munda. Herzog and Mazar Barnett (2004) also noted that presently the only Serpophaga found in the Cochabamba area of Bolivia is munda; there is no other vocal type there based on exhaustive field work in the area.

In conclusion, Herzog and Mazar Barnett (2004) concluded that the Berlioz type series of griseiceps are indeed juveniles of Serpophaga munda. They also concluded that Straneck’s bird from Argentina is indeed vocally distinct enough to warrant species status, but it is not griseiceps. They suggest this is an undescribed cryptic species in the genus Serpophaga.


New information: For well over a decade birders and researchers have been detecting this taxon with the differing vocalization and have given it the handle “griseiceps,” although it was clear that this creature needed a new name. Straneck discovered this new taxon, but he interpreted it incorrectly in my opinion. So it was superb to eventually discover that Straneck (2007) decided to formally describe this new species, albeit in an obscure journal particularly for ornithology.

There is clear annoyance in Straneck’s article, and I only mention this because he chose to give the new species a rather similar name – Serpophaga griseicapilla – to what he had called griseiceps for many years. It's unfortunate that the new name is not more distinctive and with less likelihood of being mistaken for the junior synonym of munda.  The type specimen is a male (M.A.C.N 61.633) from Misión Nueva Pompeya, Chaco, Argentina (August 16, 1990). At that early date it may in fact be a bird still in its wintering habitat? Sebastian Herzog (pers. comm.) notes that in Santa Cruz, Bolivia, the species is still in wintering sites in mid August; similarly Jaramillo (unpublished data) has observed the species in Paysandu, Uruguay, at a wintering site in late September. Straneck confirms that morphometrics of griseicapilla are consistently smaller than either subcristata or munda. In plumage griseicapilla is more similar to subcristata with yellowish belly and greenish toned back, as opposed to the grey and white munda.

         The vocal repertoire of griseicapilla versus subcristata/munda is quite different and Straneck (1993, 2007) describe and publish sonograms of the voice of griseicapilla. 


Below is the “chin-chu-riza” (pronounce in Spanish) vocalization of Serpophaga subcristata from Straneck (2007).



Below is the common vocalization (perhaps the territorial song?) of Serpophaga griseicapilla from Straneck (2007).



The distribution of griseicapilla is still being determined. It appears to breed in the Arid West of Argentina (Monte Desert) south to N Chubut, and N to Salta, and bordering to the Andean foothills in Mendoza for example. A summer record from Tarija, Bolivia, in Chaco habitat (Herzog pers. comm.) suggests it may breed farther north than currently recognized. It is migratory and in the non-breeding season it is common north to Santa Cruz, Bolivia (based on vocalizations and specimens – S. Herzog pers. comm.), and it also ventures eastward to Buenos Aires, Entre Rios, Misiones etc. In 2008 Jaramillo recorded it in westernmost Uruguay, which is a new country record for this taxon. It also reaches Paraguay during the non-breeding season, and it is unclear what the status is in southernmost Brazil.


English Names: The English name for Serpophaga griseiceps was Gray-crowned Tyrannulet. This is what griseicapilla translates to, but as it would cause too much confusion I feel that a new name is needed for this taxon. The handle that I have heard used most is Monte Tyrannulet to note the eco-region that encompasses a great portion of the breeding range of this species. While this is not its only breeding habitat, the name is distinctive and I don’t think misleading, perhaps incomplete for literalists, but not misleading I would say. If this proposal is accepted, and there are rumblings about the name than a short proposal to deal with the English name would be necessary. In the meantime, if there is public opinion on the English name it would be good to hear that.


Recommendation:  I recommend that we end a long period of confusion over this rather distinctive and certainly new species, and accept Serpophaga griseicapilla as a valid new taxon.


Literature Cited.


BERLIOZ, J. 1959. Description de deux éspeces nouvelles d’oiseaux de Bolivie. Bull.du Mus.Nat.D’Hist. Nat. 3: 218-219.

HERZOG, S. K. & J. MAZAR BARNETT. 2004. On the validity and confused identity of Serpophaga griseiceps Berlioz 1959 (Tyrannidae). Auk 121(2): 415-421.

REMSEN, J. V. Jr. & M. A. TRAYLOR Jr. 1989. An annotated list of birds of Bolivia, Buteo Book, Vermilion. S.D. pp 1-57.

STRANECK, R. J. 1993. Aportes para la unificación de Serpophaga subcristata y Serpophaga munda, y la revalidación de Serpophaga griseiceps (Aves: Tyrannidae) Revista del Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”. Zoología, 16: 51-63.

STRANECK, R. 2007. Una nueva especie de Serpophaga (Aves: Tyrannidae). Revista FAVE - Ciencias Veterinarias 6 (1-2):  31 - 42

TRAYLOR, M. A. Jr. 1979. Check-list of Birds of the World, 8. Mus. of Comparative Zool. Cambridge, Massachusetts.

Alvaro Jaramillo, February 2010


Addendum on English name: Given Alvaro’s proposal to recognize S. griseicapilla as a good species, and his suggestion for contributions on the common English name, a group of researchers from four different countries within its distribution deemed it appropriate to suggest an alternative common English name that was not included by him in the proposal: ‘Straneck’s Tyrannulet’. We submit that this is a better name than Monte Tyrannulet because: a) although most breeding habitat of this cryptic species is within the Monte desert (a habitat endemic to Argentina), this is not its only breeding habitat, b) during its winter migration, it uses several habitat types (Chaco, Pampas, Espinal, etc.) in Argentina, Paraguay, southern Brasil, Bolivia and Uruguay, c) Roberto Straneck deserves credit for his discovery, and he should be honored, not only for this discovery but also for his pioneering work in the usage of bioacoustics in taxonomic studies of Southern Cone birds (e.g., split of Strix rufipes and S. chacoensis, recognition of Anthus chacoensis as different from Anthus lutescens, and description of Otus hoyi), and d) this English name has been recently used in (Spanish) literature (Pagano & Mérida 2010).

We therefore recommend the application of Straneck’s Tyrannulet to Serpophaga griseicapilla.


Literature cited:

Pagano L. G. and Mérida, E. 2010. Aves del Parque Costero del Sur. In Athor J (ed.) Parque Costero del Sur – Naturaleza, conservación y patrimonio cultural. Fundación de Historia Natural “Félix de Azara”, Buenos Aires, Argentina.


Argentina-Nacho Areta, Alejandro Bodrati, Luis Pagano, Diego Monteleone, Ignacio Roesler, José Segovia. Bolivia-Quillén Vidóz. Brasil-Glayson Bencke, Márcio Repenning. Paraguay-Rob Clay, Hugo del Castillo, Andrés Colman, Nelson Pérez, Paul Smith, Myriam Velázquez - March 2010




Comments from Robbins: “YES.  Alvaro has done an excellent job of summarizing the very confusing history of this Serpophaga.  I vote yes for recognizing griseicapilla as a valid species. I’m also fine with his English name suggestion, but perhaps Areta et al.’s is better.”


Comments from Bret Whitney: “Yes.  The tyrannulet that Straneck identified as specifically distinct from other Argentinean members of the genus needed a name at the species level based on it distinctive morphology (especially small size) and vocalizations although I’m not convinced that Straneck compared homologous vocalizations as shown by Alvaro (the repertoires are so different that it’s “alright”).  Unfortunately, he erred in applying the name griseiceps but recovered (following the light of Herzog and Mazar Barnett) in time to give it the name griseicapilla.  I think Straneck’s Tyrannulet would be a good English name.  Whether S. munda is specifically distinct from S. subcristata is another matter, dealt with appropriately by Herzog (2001) for the present, but it certainly deserves detailed study.”


Comments from Stiles:  YES. The evidence from color, morphology and vocalizations all support species status for griseicapillus.  The differences seem comparable to those of other species in this difficult genus.  My impression from the proposal is that “Monte Tyrannulet” is an informal name and given the circumstances of its discovery, I would not be averse to “Straneck’s Tyrannulet” for this taxon.”


Comments from Nores: “YES.  Aunque como ha sido señalado por otros miembros, la revista en que fue publicada no es la más apropiada, las diferencias de coloración, medidas y canto parecen ser suficientes para validar la especie.  Lo que no estoy de acuerdo es ponerle ‘Straneck’s Tyrannulet’, no porque considere que Roberto no lo merezca, sino porque no corresponde poner el nombre de la persona que describió la especie (que va en la sigla) sino el de la persona a la cual fue dedicada la especie. Ejemplos: Darwin´s Tinamous (Nothura darwinii), Swainson’s Hawk (Buteo swainsoni), Des Murs´ Wiretail (Sylviorthorhynchus desmursii), Azara’s Spinetail (Synallaxis azarae), Spix’s Spinetail (S. spixi), Cabanis´ Spinetail (S. cabanisi), Goeldi’s Antbird (Myrmeciza goeldii), Swainson’s Flycatcher (Myiarchus swainsoni), Lawrence’s Thrush (Turdus lawrencii), Hauxwell’s Thrush (Turdus hauxwelli), etc.


Comments from Schulenberg: “YES to recognize griseicapilla as a species. It's nice to see this wrapped up, finally.”


Comments from Remsen: “YES.  All data are consistent with griseicapilla being treated as a species.”