Proposal (592) to South American Classification Committee


For Thamnophilus atrinucha, undo the recently adopted English common name “Black-crowned Antshrike” and revert to “Western Slaty Antshrike


Background: With the passage of SACC Proposal 570 (Adopt a new English name for Thamnophilus atrinucha (2)), the English common name of Western Slaty Antshrike was changed to Black-crowned Antshrike. T. atrinucha was originally thought to be a subspecies of T. punctatus, until the work of Isler (1997) split atrinucha from punctatus based on vocal, morphological, and behavioral characters. Isler (1997) proposed a new name, “Western Slaty-Antshrike” for the species trans-Andean atrinucha. This English common name “Western Slaty Antshrike” was quickly adopted by field ornithologists (Roper & Goldstein 1997; common name without a hyphen) and subsequently accepted by the AOU (1998) as “Western Slaty-Antshrike” (with hyphen). Brumfield & Edwards (2007) provided evidence that atrinucha was no longer a sister taxon to the “Slaty-Antshrike” group (i.e. punctatus and stictocephalus). In 2012, Isler (SACC Proposal 556) therefore proposed to effectively eliminate “Slaty-” from the nomenclature of atrinucha by proposing the name “Western Antshrike,” stating that “The name seems appropriate for the species, because its distribution is the most western of the antshrikes, rivaled only by that of the Barred Antshrike, Thamnophilus doliatus.” Isler also wrote that “The name Western Antshrike is so perfect for this species that I would recommend its adoption despite the possible confusion resulting from the prior use of the name for Dysithamnus occidentalis.” This proposal was rejected by the Committee, arguing that “Western Antshrike” would still be confused with the usage in Hilty & Brown (1986). The Committee suggested an alternate name of “Black-naped Antshrike” which was altered to “Black-crowned Antshrike” in Proposal 570 (Isler).


The Committee writes “Proposals to modify English names...involve weighing competing factors to determine whether the changes proposed improve accuracy and clarity sufficiently to outweigh the cost of the instability they would cause.” (Auk 124(4):1472, 2007). The change of the English name from Western to Black-crowned fails to improve scientific accuracy and introduces instability to nascent research on this species. These effects are detrimental to ornithology and are counter to the nomenclature rules of to the academic credibility of the AOU for the following reasons:


[1] The new English common name provides no new scientific information for practicing ornithologists and obscures communication with the public: Unlike casual hobbyists, it is well-known that scientific ornithologists do not rely on English common names for their understanding of taxonomic relationships between birds. For example, Brumfield & Edwards (2007) avoids the name “Slaty-” altogether, restricting his use to “antshrike” and scientific binomials. English common names are, for all modern intents and purposes, scientific trivialities. Ornithologists are not--and likely never will be--confused about the now well-resolved phylogenetic relationships of the “Slaty Antshrike” species formerly thought to be conspecific (Brumfield & Edwards, 2007). Therefore, the elimination of the current “Slaty-” nomenclature has no impact to the AOU goals of “[advancing] the scientific understanding of birds...and [promoting] a rigorous scientific basis for the conservation of birds.” If anything, it respects the work of those past individuals working so tirelessly to resolve phylogenetic relationship without the use of genetics techniques. Retention of “Slaty-” can provide a window to the past for new researchers. Lastly, because the scientific value of English names is effectively trivial, changing these names whenever species are phylogenetically rearranged is an unnecessary approach that will make reference to English names a moving target for scientists communicating with the public.


[2] The new English common name is not sex neutral and is likewise as inaccurate as a descriptor as the original “Slaty Antshrike” or “Western Slaty Antshrike”: In SACC Proposal 556, Clapham suggested the name “Black-naped Antshrike” (atrinucha= “black or slaty-naped”). In Proposal 570, Isler’s recommendation of a name change was based on a preference for the name Black-crowned Antshrike as it provided “a more accurate description of the appearance of this species...” This is true for half of the species, as only males exhibit black crowns. Neither “Western Slaty Antshrike” nor the new name “Black-crowned Antshrike” is sex neutral. The binomen Thamnophilus atrinucha unfortunately also has such a sex bias, as it roughly describes the plumage characteristics (black or slaty-naped) of the male, but this is now the common historical binomen. If improving accuracy of the nomenclature in a consistent manner is the intended goal of the AOU, the scientific binomen should also be changed to reflect traits that are common to both sexes. The proposal and subsequent adoption of the name Black-crowned Antshrike compounds the sex bias unnecessarily, especially given the increasing number of studies on cryptic sexual dichromatism in birds (including Thamnophilidae). Precedence exists for adopting English common names that are sex-neutral. For instance, Donegan (SACC Proposal 583) based his renaming of Myrmeciza immaculata to “Blue-lored Antbird” on a “feature for this species uniting both sexes.” In sum, the new English name “Black-crowned Antshrike” does not improve accuracy of the English name, is not sex neutral, and therefore should not be retained.


[3] The changing of this English common name directly impacts current, active research on Thamnophilus atrinucha: Thamnophilus atrinucha is the most well-studied Thamnophilus species. Research on this species has been published by A. Skutch (1930s), Y. Oniki (1970s), J. Roper (1990s, 2000s), W.D. Robinson and J.D. Brawn (2000s, 2010s), C.E. Tarwater (2000s, 2010s), and J.P. Kelley (2000s, 2010s). In the last five years, papers by C.E. Tarwater on atrinucha have appeared in The Auk (x2), Behavioral Ecology and Sociobiology, Behavioral Ecology, Journal of Avian Biology, Wilson Journal of Ornithology, Animal Behaviour (x2), and Ecology. In 2013, the AOU awarded the Ned K. Johnson Young Investigatot Award to C.E. Tarwater for her body of work on the “Western Slaty Antshrike.” And additional papers in high-impact journals are forthcoming by authors J.P. Kelley and C.E. Tarwater. All of the aforementioned work used the English common name “Slaty Antshrike” or “Western Slaty Antshrike.” As a species, Thamnophilus atrinucha is therefore of particular scientific value, and its English name “Western Slaty Antshrike” has considerable precedence in the scientific literature. Given this, it will be necessary for currently active researchers of Thamnophilus atrinucha to retain “Western Slaty Antshrike” as the preferred English name and encourage its continued use (thereby ignoring this AOU recommendation).


The cavalier changing of the English common name--without regard to current and active research programs--directly harms young researchers’ abilities to communicate their research widely by effectively creating a dual English nomenclature (e.g. Some website have the old English name while others have the new one). Current grant proposals, outreach websites, collection and animal care and use proposals, and libraries of presentation slides will all need to be altered. Researchers and hobbyists seeking to read scientific literature on the subject often only search by English common names. This would result in them finding a dearth of information on the study species. Given that scientific names have been changing frequently owing to new findings based on genetic data, many researchers and hobbyists more frequently search by English common names under the assumption that these are less subject to change. This was be troublesome and misleading in the case of T. atrinucha.


The willingness to change the English common name is likely due to the Committee’s “[unanimous rejection of] the proposal to adopt the IOC guidelines and spelling rules for English names of North American birds” (The Auk 124(4):1472, 2007). The IOC guideline relevant to this proposal is that “Established names should prevail.”


Specifically, the IOC World Bird List (v3.5) states:


“A long-established name would not be changed just to correct a perceived inaccuracy or misdescription... Names utilizing widespread words like Warbler and Robin for many groups of unrelated species generally would not be changed. Names with faulty descriptions of taxa were subject to change if the taxa had had several names, or if the name or the taxon was not widely known (as is notably the case for a number of tropical taxa).”


Adoption of these guidelines could have prevented the present issue while simultaneously respecting the kind of academic tradition on which the reputation of the AOU rests.


The guidelines for submitting proposals to the NACC or SACC state that “Proposals for changes must be based on previously published data, information, or analyses.” As this guideline does not require that literature be taxonomic in nature, a list of recent publications on Thamnophilus atrinucha as the Western Slaty Antshrike is presented as evidence for the destabilizing effect that this name change will have for current and active research by two researchers (Tarwater and Kelley).




Author, title, journal


Tarwater, C.E., J.D. Brawn, and J.D. Maddox. Low extra-pair paternity in a tropical bird despite ample opportunities for extra-pair mating. In press, The Auk.


Kelley, J.P. Predator-driven selection shapes behaviors and life-history of a Neotropical rainforest bird. Proquest dissertation. (Four chapters to be submitted by Jan. 2014)


Tarwater, C.E. 2012. The influence of phenotypic and social traits on dispersal in a family living, tropical bird. Behavioral Ecology 23: 1242-1249.


Tarwater, C. E., R.E. Ricklefs, J.D. Maddox, and J.D. Brawn. Pre-reproductive survival in a tropical bird and its implications for avian life histories. Ecology 92:1271-1281.


Brawn J.D., G. Angehr, N. Davros, W.D. Robinson, J. Styrsky, and C.E. Tarwater. Sources of variation in the nesting success of understory tropical birds. Journal of Avian Biology 42: 61-68.


Tarwater C.E., and J.D. Brawn. The post-fledging period in a tropical bird: patterns of parental care and survival. Journal of Avian Biology 41:479-487.


Tarwater C.E., and J.D. Brawn. Family living in a Neotropical bird: variation in timing of dispersal and higher survival for delayed dispersers. Animal Behaviour 80:535-542.


Tarwater, C.E., and J.P. Kelley. Western Slaty-Antshrike (Thamnophilus atrinucha), Neotropical Birds Online (T.S. Schulenberg, Editor). Ithaca: Cornell Lab of Ornithology; retrieved from Neotropical Birds Online: overview? p_p_spp =369186


W.D. Robinson, M. Hau, K.C. Klasing, M. Wikelski, J.D. Brawn, S.H. Austin, C.E. Tarwater, and R. E. Ricklefs. Diversification of life histories in New World birds. Auk 127:253-262.


Tarwater C.E., J.P. Kelley, and J.D. Brawn. Parental response to elevated begging in a high predation, tropical environment. Animal Behaviour 78:1239-1245.


Tarwater C.E., and J.D. Brawn. Patterns of brood division and an absence of behavioral plasticity in a Neotropical passerine. Behavioral Ecology and Sociobiology 62:1441-1452.


Tarwater C.E. Predators at nests of the Western Slaty Antshrike.  Wilson Journal of Ornithology 120:620-624.


Recommendation: Undo the recently adopted English common name “Black-crowned Antshrike” and revert to “Western Slaty Antshrike”. Reversal of nomenclature changes has precedent in cases where substantial research has been done on the species, as shown by the past name change from “Mexican Jay” to “Grey-breasted Jay” and back again (AOU supplement number unknown). The adoption of Black-crowned Antshrike by the SACC (Proposal 570) (i) presents a name that provides no new scientific information or value for practicing ornithologists, (ii) substitutes an equally inaccurate English name for another, (iii) ignores a long-established English common name (used by Skutch, Chapman, and others), and (iv) directly impacts current and active research on this species. We call for this proposal to be passed immediately before the submission of new manuscripts for publication.



Committee on Classification and Nomenclature of Birds (North and Middle America) Policy on English Common Names of Birds. 2007. The Auk 124(4):1472.


Brumfield, R. T., and S. V. Edwards. 2007. Evolution into and out of the Andes: a Bayesian analysis of historical diversification in Thamnophilus antshrikes. Evolution 61:346–367.


Hilty, S.L., and W.L. Brown. 1986. A guide to the birds of Colombia. Princeton University Press, Princeton, New Jersey.


J. Patrick Kelley & Corey E. Tarwater, 7 October 2013




Comments from Remsen:  “NO.  The authors of the proposal are obviously quite upset that the English name of the species that they have studied and published on extensively has been changed.  However, by that criterion, no English name of any species would be subject to change once a body of literature exists using it.  With only a few minor exceptions, SACC has sought to conserve existing English names for stability unless taxonomic changes force such changes.  In this case, changes in species limits require a change in English name.  In this case, the name Slaty Antshrike, used for many decades by Skutch and other authors, had to be changed.  This was not a “cavalier” change (the accusation by Kelley and Tarwater) but the type of change undertaken by NACC, SACC, the IOC, and any other body in charge of standardizing English names in response to changes in species limits. The authors do not seem to realize that the IOC and AOU guidelines they quote do not apply to cases in which splits at the species level force the creation of two or more names from within an entity previously known by a single name.  In fact, both groups typically favor new names for all the newly recognized daughter species to avoid confusion between a formerly broadly defined species and one of the spinoff daughters.

            “For perspective and a quick summary, up until the work of Brumfield and Edwards, the Middle American taxon atrinucha was erroneously considered to be part of the South American T. punctatus group, all known as “the” Slaty Antshrike.  The name “Slaty” is retained by nominate punctatus and the members of that superspecies, so any retained association of “Slaty” with unrelated atrinucha is highly misleading, not only from the phylogenetic perspective but also from the standpoint of common sense.  Clearly, atrinucha needed a new name, no matter how much research had been done on the taxon using the older, antiquated, and now highly misleading name.  Any retention of “Slaty” with atrinucha would imply a confusing and misleading relationship to the T. punctatus superspecies.  Note also that “Western Slaty-Antshrike” was in use for barely a decade, so the “instability” caused by the change is minimal (compared to, say, “Sparrow Hawk”, which was in use for a century in North America, thus used in probably hundreds of publications).  Use of “Western Antshrike” was problematic as outlined in previous proposals (in addition to being regarded as insipid by many).  The name “Black-crowned Antshrike” is accurate, associates nicely with the scientific name, and clearly removes any misleading association with the true Slaty Antshrike group, something that the proposal authors should value.  If it were me, I would be happy that “my” species gets a clean break from the “Slaty Antshrike” group with which it had previously been mistakenly grouped – wipe the “slate” clean, so to speak (see what I did there?).  Contrary to statements in the proposal, the name does improve scientific accuracy in terms of relationships to other Thamnophilus, which may have also repercussions in terms of comparative reproductive ecology of antshrikes. As for gender neutrality, for better or worse, the vast majority of plumage-based names in the Thamnophilidae refer to male plumage features, and so the new name maintains the historical, comparative approach.”


Comments from Stiles: “NO.  The proponents apparently fail to recognize that English names should reflect increases in taxonomic knowledge insofar as possible, and that when new information changes our knowledge of phylogeny, English names that imply relationships found to be incorrect must be changed.”


Comments from Zimmer: “NO.  Where to begin?  There is much not to like about this proposal, not the least of which is the imperious tone of outrage in the call to “pass this proposal immediately.”  But I’ll set that aside and concentrate on the other holes in the authors’ arguments.  The authors first argue that English names are “scientific trivialities” and “the scientific value of English names is effectively trivial” (thereby begging the obvious question of, “If it’s so trivial, why do they obviously care so much?”), and then, go on to say that changing English names “directly harms young researchers’ abilities to communicate their research widely” and that “Researchers and hobbyists seeking to read scientific literature [italic emphasis mine] on the subject often only search by English common names.”  If English names are scientifically trivial, then changing one can’t, by definition, unleash scientific Armageddon.  They can’t have it both ways.  Also, I would suggest that a “researcher” who does a literature search using only the English name of a species, is failing to put the “search” in “research”.


“Then, there is the nonsense that anything other than gender-neutral names are “inaccurate.”  If that were so, then the vast majority (>90%?) of plumage-based English names of sexually dimorphic birds would be inaccurate.  To deny the use of a name that was descriptive for only one sex or the other of a sexually dimorphic species, would, in practice, be to deny the use of virtually any attempt at a plumage-based name.


“More importantly, English names in the punctatus group do reflect phylogenetic relationships in their use of the compound group name of “Slaty-Antshrike”.  To retain “Slaty-Antshrike” as part of the name for atrinucha, when multiple data sets pretty emphatically demonstrate that it is not a member of the Slaty-Antshrike group, would be both misleading and inaccurate, and definitely unscientific.  The English name of atrinucha had to be changed, and for reasons of possible confusion with another taxon, simply dropping the “Slaty” and going with “Western Antshrike” was also going to prove less than ideal.  “Black-crowned Antshrike” reflects a feature of the male plumage that is not diagnostic, but is completely accurate, and it dovetails nicely with the scientific name of the bird.  I see no compelling reason to change to anything else, and reverting to “Western Slaty-Antshrike” as the authors of the proposal advocate, is, in my mind, untenable.”


Comments from Jaramillo: “NO – the problem is that atrinucha is not a Slaty-Antshrike but belongs in a different group, so retaining the Slaty-Antshrike part of the name was misleading. One could argue that retention of the name tanager, robin, finch, blackbird is misleading for many other species and we live with it. However, these hyphenated names imply a direct taxonomic relationship between all of the members that share the name.”