Proposal (393) to South American Classification Committee


Treat Upucerthia saturatior as a separate species from Upucerthia dumetaria



Almost all classifications treat U. dumetaria as a single, polytypic species.  Here is what our current Note says:


“4b. Esteban (1951) provided rationale for considering the subspecies saturatior a separate species from Upucerthia dumetaria, but this has not been followed by subsequent authors.  Areta and Pearman (2009), however, provided evidence of parapatry without intergradation as well as documented differences in song, bare parts colors, morphology, plumage, habitat, and migratory patterns that validate Esteban’s (1951) original assessment.  SACC proposal badly needed.”


Here is the Abstract from Areta and Pearman’s paper:


Abstract The Patagonian Forest Earthcreeper (Upucerthia saturatior) is a distinctive furnariid that inhabits the Patagonian forests of central-western Argentina and adjacent Chile within the Nothofagus Center of Endemism. After its description as a species in 1900, U. saturatior was quickly subsumed, without comment or study, as a subspecies of the Scale-throated Earthcreeper (U. dumetaria), a treatment followed by most subsequent authors. On the basis of an apparent geographical cline within U. dumetaria and a reanalysis of the morphology and plumage of reported intergrades between U. dumetaria and U. saturatior, there is no evidence of intergradation between these taxa. Upucerthia saturatior differs from U. dumetaria by its song (“p-p-tirik-tirik-tirik-tirik-tirik-tiruk” vs. “pli-pli-pli-pli-pli . . .”), which is also three times faster in dumetaria, call (“pep” vs. “keep”), morphology (smaller and darker with a short black bill vs. larger and paler with a long brown bill), distinctive tail pattern, breeding habitat (forest borders vs. shrubby steppe and open highland habitats), and migration patterns (trans-Andean vs. north–south). These differences exceed those between U. jelskii and U. albigula and are far greater than those between U. jelskii and U. validirostris; they overwhelmingly support ranking U. saturatior as a full species. The existence of a forest-dwelling species of Upucerthia parapatric to an open-country Upucerthia provides an opportunity for testing the role of habitat shift between dry exposed habitats and forest habitats (and vice versa) during speciation.


Because you should all have a pdf (if not, let me know), I won’t go over all the evidence in detail.  Rather, all I will do here is emphasize that they refuted previous reports of intergradation, showed that the two are nearly parapatric (at least as close as 25 km, but likely closer) without any sign of gene flow, showed that they are restricted to different habitats in the area of near-parapatry, and showed that “U. d. dumetaria/hypoleuca responded strongly to voices of widely distant populations of the same species while ignoring the voices of closer populations of saturatior.”


Analysis and Recommendation:  As the authors indicated, there is no evidence that would support treating these two taxa as conspecific.  Further, as the authors correctly noted, the differences between these two are of the same degree as those between U. albigula and U. jelskii and actually below the level between the latter and U. validirostris.  Therefore, I strongly support a YES vote on this one.



English name:  Here’s what Areta and Pearman wrote:

In the absence of an adequate English vernacular name for U. saturatior, we propose “Patagonian Forest Earthcreeper,” to highlight one of its most distinctive ecological features that instantly distinguishes it from the parapatric U. dumetaria.”


I personally find this name a little cumbersome, but we can start with it, and if anyone has a better name, do a proposal.



Lit Cit

ARETA, J. I., AND M. PEARMAN.  2009. Natural history, morphology, evolution, and taxonomic status of the earthcreeper Upucerthia saturatior (Furnariidae) from the Patagonian forests of South America. Condor 111: 135-149.


Van Remsen, March 2009



Comments from Cadena: “YES. Wish we had similarly solid data sets for other decisions on species.”


Comments from Nores: “YES, especialmente (o sólo) por las vocalizaciones. Lo que no estoy de acuerdo es llamarla “Patagonian Forest Earthcreeper” porque ante todo Upucerthia saturatior  no es una especie del bosque sino que habita  la zona de transición entre la estepa patagónica y el bosque en Argentina y en el matorral, donde no hay árboles, en Chile central. Aunque en el norte de su distribución en Chile es aparentemente migratoria, en la parte sur sería residente de acuerdo a lo expresado por Goodall et al. (1957). Además, los bosques que se encuentran en el sur de Chile y Argentina no son patagónicos sino que pertenecen biogeográficamente a  la Provincia Subantártica (Cabrera y Willink 1973) por lo que el nombre correcto sería “Subantarctic Forest ” o en todo caso “Nothofagus forest”.”


Comments from Zimmer: “YES.  Multiple data sets (vocal, morphological, habitat, migration patterns) all support this move.”


Comments from Jaramillo: “YES – The data are solid, using different datasets and unambiguous. The only problem I have with the proposal is the English name for this beast. Patagonian Forest Earthcreeper is just too much information --  it is not quite a Saltmarsh Sharp-tailed Sparrow, but nearly there. Why not just call it Forest Earthcreeper and leave it at that? The fact that it uses forested habitats is unique in Upucerthia is it not? Patagonian Forestcreeper would be even better, but I am clever enough to know that that one has no chance at all…tongue in cheek…but only slightly.”


Comments from Schulenberg: “YES.  "Patagonian Forest Earthcreeper" is not a helpful name, however. Either "Patagonian Earthcreeper" or "Forest Earthcreeper" would be fine (and shorter). "Forestcreeper" is kind of cute (and doesn't need the "Patagonian," until there is a second species of forestcreeper) but to me in conjures up images of something like a Premnornis or Premnoplex, rather than of an Upucerthia.”


Comments from Stiles: “YES. A solid, multidimensional dataset, duly published. No problem. Under the circumstances, “Forest “ (Woodland?) Earthcreeper would seem a reasonable and digestible English name.”


Comments from Pacheco: “YES.  Os múltiplos dados publicados corroboram, com sobras, a proposta.