Proposal (777) to South American Classification Committee

 

Note from Remsen: Below is the proposal submitted to, passed by, and adopted by NACC; see latest NACC Supplement in Auk 2017).  For NACC members’ comments on this proposal, see: http://checklist.aou.org/nacc/proposals/comments/2017_B_comments_web.html, proposal 2017-B-1).  Notice that the proposal was written in part for SACC.  Although A and B are extralimital, we still need to vote on them because the outcome affects how we view SACC-only species in terms of distribution.

 

Recognize additional species in the Aulacorhynchus “prasinus” toucanet complex

 

The AOU (1998) presently considers there to be just one species of Aulacorhynchus prasinus, which ranges from Mexico to Guyana and Bolivia. This taxon’s range combines the taxonomic oversight regions of both the North American and South American classification committees, so this proposal is designed to be submitted to both, with committee-structured voting sections at the end. This is easy to do biologically, because the taxa fall out fairly neatly split between North and South America. (The Panamanian blue-throated population breeding on Cerro Tacarcuna (subspecies cognatus) has (Hilty and Brown 1986) and has not been (Donegan et al. 2015) included in the Colombian avifauna.)

 

The AOU’s first treatment of this group in Middle America began with the geographic expansion undertaken in the sixth edition of the Check-list (AOU 1983). The historic treatments of the genus are given in Table 1 (from Winker 2016). In brief, evidence of hybridization caused massive lumping into a broadly defined prasinus from Peters (1948) onward, with recent genetic evidence of divergence causing some authors to propose that the prasinus complex is made up of as many as seven species (Table 1). These recent proposals have not been widely accepted; I summed the situation up as follows (Winker 2016):

 

“Renewed interest in this complex (Navarro et al., 2001; Puebla-Olivares et al., 2008; Bonaccorso et al., 2011; Del Hoyo & Collar, 2014) is beginning to rectify the absence of data, but the ensuing taxonomic changes recommended have either been based on a different species concept (Bonaccorso et al., 2011) or have inadequately considered the hybridization and intergradation (e.g., Navarro et al., 2001; Puebla-Olivares et al., 2008; Del Hoyo & Collar, 2014) that have been integral to supporting the “post-Peters” taxonomy. These latter works have recommended elevation of numerous A. prasinus (sensu lato) taxa to species status (Table 1), but they did not address the reasons for lumping in the first place: evidence of hybridization. There has also been heavy reliance on a single molecular marker (mtDNA) for species delimitation in the A. prasinus complex (Puebla-Olivares et al., 2008; Bonaccorso et al., 2011). This is problematic because mtDNA can be misleading about species limits and relationships between populations due to gene-tree/species-tree mismatches and because genetic distance is not a reliable indicator of species limits (Avise & Wollenberg, 1997; Irwin, 2002; Funk & Omland, 2003; Degnan & Rosenberg, 2006; Cheviron & Brumfield, 2009; Galtier et al., 2009; Ribeiro, Lloyd & Bowie, 2011; Toews & Brelsford, 2012; Pavlova et al., 2013; Peters et al., 2014; Dolman & Joseph, 2015; Morales et al., 2015). Thus, species limits in the group remain uncertain (Table 1).”


 

Table 1. Treatments of species-level diversity in the genus Aulacorhynchus. Taxa historically recognized only as subspecies are not included (see text for these taxa in "prasinus"). An X means the taxon was treated as a species, a dash indicates not available to be treated yet, and a blank indicates that the taxon was not considered.

 

Nav. et al. (2001)g

 

 

 

Sclater

S & G (1896)a

Sibley &

Short &

P-O et al. (2008)g

Dickinson &

del Hoyo &

 

(1891)

B & C (1912)b

Cory (1919)

Peters (1948)

Monroe (1990)

Horne (2001)

B. et al. (2011)g

Remsen (2013)i

Collar (2014)

Winker (2016)

A. sulcatus

_

_

_

_

_

_

_

_

_

A. erythrognathus

_

_

ssp. of sulcatus

ssp. of sulcatus

ssp. of sulcatus

ssp. of sulcatus

ssp. of sulcatus

ssp. of sulcatus

A. calorhynchus

_

_

_

_

ssp. of sulcatus

ssp. of sulcatus

ssp. of sulcatus

ssp. of sulcatus

_

A. derbianus

_

_

_

_

_

_

_

_

_

A. whitelianus

_

_

_

ssp. of derbianus

ssp. of derbianus

_

_

_

A. haematopygus

_

_

_

_

_

_

_

_

_

A. coeruleicinctis

_

_

_

_

_

_

_

_

_

A. huallagae

– c

– c

– c

_

_

_

_

_

_

A. prasinus

_

_

_

_

_

_

_

_

_

_

A. wagleri

_

_

_

ssp. of prasinus

ssp. of prasinus

_

ssp. of prasinus

_

_

A. caeruleogularis

_

_

_

ssp. of prasinus

ssp. of prasinus

ssp. of prasinus

_

ssp. of prasinus

_

_

A. cognatus

– d

– d

ssp. of caeruleogularis

ssp. of prasinus

ssp. of prasinus

_

ssp. of prasinus

ssp. of caeruleogularis

ssp. of caeruleogularis

A. albivitta

_

_

_

ssp. of prasinus

ssp. of prasinus

_

ssp. of prasinus

_

_

A. griseigularis

– e

– e

– e

ssp. of prasinus

ssp. of prasinus

_

ssp. of prasinus

ssp. of albivitta

ssp. of albivitta

A. lautus

– f

_

_

ssp. of prasinus

ssp. of prasinus

_ h

ssp. of prasinus

ssp. of albivitta

ssp. of albivitta

A. cyanolaemus

_

_

_

ssp. of prasinus

ssp. of prasinus

ssp. of atrogularis

ssp. of prasinus

_

ssp. of atrogularis

A. dimidiatus

_

_

_

ssp. of prasinus

ssp. of prasinus

ssp. of atrogularis

ssp. of prasinus

ssp. of atrogularis

ssp. of atrogularis

A. atrogularis

_

_

_

ssp. of prasinus

 

ssp. of prasinus

_

ssp. of prasinus

_

_

 

a. Salvin & Godman (1896) treated only Middle American Aulacorhynchus, which at the time were considered Aulacorhamphus.

b. Brabourne and Chubb (1912) treated South American members of the genus (then considered Aulacorhamphus

c. huallagae was described by Carriker (1933).

d. cognatus was described as a subspecies by Nelson (1912).

e. griseigularis was described as a subspecies by Chapman (1915).

f. lautus was described by Bangs (1898).

g. Navarro et al. (2001), Puebla-Olivares et al. (2008), & Bonaccorso et al. (2011) together included most Middle American and South American Aulacorhynchus taxa.

h.  though not included in either study.

i. Treatment matches the South American Classification Committee (Remsen et al. 2016).

 

 


There are six color-based groups in the prasinus complex, within which some have additional described subspecies. These major groups have been recognized through much of the history of the taxon (Table 1) and were reaffirmed by the analyses of del Hoyo and Collar (2014). The characters upon which they are based are given in Winker (2016: table 2) and can be seen in the accompanying Plate.

 

Fig1_smallerIn Winker (2016) I tested the hypothesis that these are “cookie-cutter” (i.e., morphologically nearly identical) toucanets differing mostly in coloration. I also examined specimens carefully for phenotypic evidence of hybridization.

 

Text Box: Figure 1. The six major, color-based taxonomic groups of the Aulacorhynchus “prasinus” species complex, from top to bottom: A) wagleri; B) prasinus (nominate prasinus and warneri, the full-bodied bird, are portrayed): C) caeruleogularis; D) albivitta (griseigularis and nominate albivitta are portrayed); E) cyanolaemus (yellow-tipped bill); and F) atrogularis.A couple of key factors were central to my treatment of the group. First, these birds move about considerably during the nonbreeding season, providing hypothetical opportunities for gene flow across zones of nearest approach. “For example, in south-central Mexico (Oaxaca), A. prasinus and A. wagleri breed within about 100 km of each other, a distance that A. prasinus individuals appear to move routinely away from their breeding areas, e.g., at the base of the Yucatan Peninsula (e.g., Land, 1970; Jones, 2003), which does not seem unusual for an arboreal frugivore (see also discussions in O’Neill & Gardner, 1974, and Navarro et al., 2001).” (Winker 2016). The hitherto unrecognized (although published by Puebla-Olivares et al. 2008) gene flow between albivitta and atrogularis in NE Ecuador indicates that this hypothesis has merit. Second, I considered that the likelihood of successful gene flow/reticulation between two lineages decreases with increased anagenesis or adaptive divergence, arguing as follows (Winker 2016):

 

 “Effective lineage reticulation requires that hybrid offspring have equal or greater fitness than offspring of pure parental forms. Also, gene flow must occur frequently enough to overcome the differentiating selective factors likely to be operating on largely allopatric populations (and this relationship is nonlinear; see Winker, 2010 for discussion). The more differences there are between populations in morphology, the more differences there are likely to be in selective factors operating on these populations and the more difficult effective gene flow is likely to be between populations; at larger scales this results in the general correlation between morphological difference and reproductive isolation (Mayr, 1963; Price, 2008).”

 

Text Box: Figure 4. The mtDNA topology of the relationships among the six major subspecific groups, following Puebla-Olivares et al. (2008). Taxa labeled with a “(+)” are non-monophyletic in mtDNA. Values between the major subspecific groups are the between-group mean genetic distances between them.

Another important factor that I considered that did not seem to have been adequately addressed before is that named subspecies in this group do not represent equivalent levels of divergence. Historically, it seemed that commonly observed intergradation between named forms within the major color-based groups (among the more minor forms) led to observations that hybridization was common, but this seemed to cloud a thorough understanding of the full distribution of hybridization in the whole group, i.e., it is not just where birds hybridize, but where they do not and what phenotypic characteristics accompany these phenomena. I focused on the major groups and made pairwise comparisons between them.

 

Fig4My results (from 578 specimens) showed multiple and complex morphometric relationships between pairwise comparisons of neighboring forms. These differences were different between the sexes and the differences were different between populations, and only a small percentage of the variation observed could be explained by geography (in females only, latitude and longitude explained < 6% of variation). As it turned out, degrees of morphometric differentiation were highly correlated with genetic distance (R2 = 0.67), as predicted by the processes of anagenesis and speciation (Winker 2016: figure 5). Neither geography nor phenotypic plasticity is likely to explain the degree of differences found. “Concordant shifts in suites of mensural and other morphological characters are precisely what we would predict to occur between individuals representing genetically disjunct, locally adapted gene pools. Consequently, this evidence suggests that this is what they are, and at these levels of morphological differentiation (morphometrics, coloration, and pattern) we would usually consider these groups to be full biological species.” But that conclusion does not include consideration of hybridization.

 

Evidence of hybridization between members of the six color-based groups occurs phenotypically between cyanolaemus and atrogularis, and (genetic evidence only) between atrogularis and albivitta. The frequency of gene flow was loosely inferred by using phenotypic evidence of hybridization as a surrogate. Gene flow appears to be substantial between the two most closely related taxa (0.7% divergence), cyanolaemus and atrogularis, and rare (zero phenotypic evidence) between albivitta and atrogularis (4.2% divergence; genetic data of Puebla-Olivares et al. 2008). There is no evidence for Haldane’s rule occurring (genetic incompatibilities so extreme as to result in higher levels of mortality in hybrids of the heterogametic sex—females in this case). There was no evidence of hybridization among the North American forms (3-5.1% divergence), nor between North and South American forms (6.7% divergent).

 

“Hybridization per se is not sufficient evidence for conspecificity, and in this group I find the lack of hybrids at most zones of potential crossing of major subspecific groups to be more compelling in the determination of species limits than its clear and seemingly routine presence at one—particularly in light of the repeated evidence of varying suites of morphological characters changing abruptly across these zones. However, I do consider that the apparent frequency of hybridization between A. atrogularis cyanolaemus and A. a. atrogularis warrants a conservative approach to their separation at the species level, and thus I do not recommend doing so without more evidence. In short, morphologically there is no evidence for hybridization between five of the major subspecific groups, despite likely opportunity, especially in northern Middle America. This is coupled with pronounced morphometric differences between these groups, suggesting group-specific ecological adaptation in addition to whatever social selection factors have likely caused the rather dramatic head and bill color differences.” (Winker 2016). In other words, I doubt these taxa exist in total allopatry, and the genetic evidence between albivitta and atrogularis would seem to support this supposition, yet intergroup hybrids seem to be rare except between the two most closely related forms, cyanolaemus and atrogularis.

 

Bonaccorso and Guayasamin 2013 PLoS ONE Aulacorhynchus systematics and the origin of Pantepui montane biotas-7Voice is an important reproductive isolating mechanism (RIM) in at least some Aulacorhynchus, (Schwartz 1972, Haffer 1974). However, I think it would be a mistake to consider it the only or even the most important one, despite its utility in some cases. In Winker (2016) I did not discuss RIMs, but the treatment relied more on the likelihood of postzygotic RIMs (increasing evidence of morphological divergence making successful hybrids and reticulation less likely) than on prezygotic ones (of which voice could be an important one). From a subjective view, vocal divergence does not seem to be evolving as quickly in the prasinus complex as it has among other Aulacorhynchus species in South America. The South American radiation of the species haematopygus, whitelianus, derbianus, and sulcatus likely began after that of the prasinus clade (~4.5 Mya vs. ~5.2 Mya; Bonaccorso et al. 2013, figure inserted here). But (subjectively) in the former group vocal divergence has been more rapid (Schwartz 1972).

Bonaccorso et al 2011 Zoological Scripta Aulacorhynchus-8Donegan et al. (2015) relied exclusively on voice in maintaining all prasinus taxa as one species, mostly reiterating prior work (though providing more sonograms) of Haffer (1974) and Short and Horne (2001), which downplayed phenotypic differences (not adequately explored, in my view) and relied rather heavily on voice. Inadequate attention has been paid to the fact that the vocally similar taxa hybridizing to a degree to be considered conspecific (e.g., cyanolaemus-atrogularis and sulcatus-calorhynchus; Schwartz 1972) are among the most closely related in the genus (Puebla-Olivares 2008, Bonaccorso et al. 2011: fig. 2, inserted at right). And, again, there are additional quite striking morphological characters changing besides bill and throat colors. In addition to the mensural characteristics found in Winker (2016), there are characters like eye-skin color changes and the basal upper mandible encrustations in adult wagleri that increase the likelihood of other RIMs being present in the absence of vocal differences. So, despite vocal similarities among prasinus taxa, I consider the steadily increasing morphological differences with increasing genetic distance (Winker 2016: fig. 5) and the absence of phenotypic evidence of hybridization across most zones of closest approach to warrant species-level splits.

 

More work is needed in this group. Voice, for example, although notably similar throughout the prasinus complex’s range (Haffer 1974, Donegan et al. 2015), does show some likely pace differences between wagleri and prasinus (Winker 2016). Also, given the current evidence it seems likely that population genetic studies will show low rates of historic gene flow across more of the zones of closest contact.

 

Using the biological species concept, I suggest that consideration of all of the available evidence indicates that we should recognize five species in the A.prasinus” complex (A. wagleri, prasinus, caeruleogularis, albivitta, and atrogularis), each with any associated named subspecies (Appendix).”

 

South American forms, where all of the hybridization thus far recognized (between the major color-based groups) occurs, remain the least certain, and future work may change the perceptions outlined here.

 

Recommendation: Unsurprisingly, I recommend voting Yes on all of A-G below (A, B, E, F, and G for NACC, and C, D, E, F, and G for SACC).

For now, I will include in the proposal an up or down vote on the English names given in the Appendix of Winker (2016). Should either of those two votes fail while the split votes pass (NACC or SACC), we will need to further address those issues.

 

NACC:

A) A yes vote would recognize all three major Middle American forms (prasinus, wagleri, and caeruleogularis) as full biological species. [DID NOT PASS]

 

B) Should the vote on A pass, we need to adopt English names for these taxa. A yes vote here would accept the English names for these taxa proposed in Winker (2016), i.e., Northern Emerald Toucanet (A. prasinus), Wagler’s Toucanet (A. wagleri), and Blue-throated Toucanet (A. caeruleogularis). The only change from historic usage is in adding “Northern” to the first. Different historic treatments are given below in Table 2. [Northern Emerald-Toucanet was name adopted for the Middle American species]

 

(More NACC below...)

 

SACC:

C) A yes vote would recognize two South American forms (albivitta and atrogularis) as full biological species.

 

D) Should the vote on C pass, we need to adopt English names for these taxa. A yes vote here would accept the English names for these taxa proposed by Winker (2016), i.e., Southern Emerald Toucanet (A. albivitta) and Black-throated Toucanet (A. atrogularis). The first gets around throat-color problems both within the group and with the fact that the white color of the nominate form’s throat matches that of prasinus sensu stricto. The second, however, does not, in that the subspecies cyanolaemus has a blue throat. Different historic treatments are given below in Table 2.

 

NACC and SACC:

 

E) Should the “A” and/or “C” votes above fail and we do not agree to recognize three and/or two species in each clade, respectively, it occurs to me that we should at least split the group into the two major clades, prasinus (North America) and albivitta (South America). Their nearest-approach neighbors in Panama and Colombia are phenotypically and genetically the most divergent, and they’ve been apart for a long time: an estimated ~1.7 Mya (using the 2% rule on the mtDNA data of Puebla-Olivares et al. 2008) or ~5.2 Mya from Bonaccorso et al. (2013). For a visual, see C and D in the accompanying Plate (Fig. 1 in the proposal) and the specimen photograph inserted below (Fig. 2). A yes vote here would, if the A and/or C votes above fail, recognize just two species in the prasinus complex, whose English names might be...

 

F) Northern Emerald-Toucanet (A. prasinus) and Southern Emerald-Toucanet (A. albivitta). A yes vote here would accept these names should we only agree to split the complex into two species.

 

G) Finally, I propose that we adopt the sequence of taxa given in Winker (2016: appendix, copied below), which follows both geography (N-S) and taxonomy and can be taxonomically adjusted to accommodate the votes above.

 

Table 2. English names for prasinus taxa.

Cory 1919

 

(names all subspp.)

HBW 2014

Winker 2016

A. prasinus

Emerald, Southern Emerald

Emerald Toucanet

Northern Emerald Toucanet

A. wagleri

Wagler's Toucanet

Wagler's Toucanet

Wagler's Toucanet

A. caeruleogularis

Blue-throated, Goldman's Bl-thr.

Blue-throated

Blue-throated Toucanet

A. albivitta

White-throated, Grayish-blue-throated, Plumbeous-throated

Grayish-throated

Southern Emerald Toucanet

A. griseigularis

A. lautus

Santa Marta Toucanet

(subsp. of albivitta)

A. cyanolaemus

Gray-throated Toucanet

Black-billed

(subsp. of atrogularis)

A. dimidiatus

Ridgway's Toucanet

(subsp. of atrogularis)

A. atrogularis

Black-throated

Black-throated

Black-throated Toucanet

 

 

DSC_0197

 

Figure 2 (only in proposal). Typical males of caeruleogularis (LSU 104668) and A. albivitta lautus (LSU 90407), the most proximal North and South American forms.

 

Appendix (from Winker 2016)

         Suggested taxonomy.—Because I have examined all of the described taxa in the complex, this revision includes subspecies (although quantitative analyses were not undertaken below the level of the six major groups). Given below are species, subspecies, authors of original descriptions, type localities, and notes pertaining to each species. Distribution is not included, because I did not examine all existing specimens and can add little of substance to distributions set forth by the authors cited herein. The species sequence given follows the relationships in the mtDNA tree of Puebla-Olivares et al. (2008) but with the two major clades flipped to better accommodate the group’s geographic distribution (as I have also done in Fig. 4).

         Genus Aulacorhynchus (green toucanets), subgenus Ramphoxanthus

 

Aulacorhynchus wagleri (Sturm in Gould 1841:pl. 16 (heft 2, pl. 6)). Wagler’s Toucanet. no type loc. [= Guerrero and Oaxaca, Mexico].

Aulacorhynchus prasinus (Gould 1833). Northern Emerald Toucanet.

     A. p. prasinus (Gould 1833). Mexico [= Valle Real, Oaxaca].

     A. p. warneri Winker (2000). Volcán San Martín, Sierra de Los Tuxtlas, Veracruz, Mexico.

     A. p. virescens Ridgway (1912:88). Chasniguas, Honduras.

     A. p. volcanius Dickey and van Rossem (1930:53). Volcán de San Miguel, Dept. San Miguel, El Salvador.

 

Notes: A. p. stenorhabdus (Dickey and van Rossem 1930:52) and A. p. chiapensis (Brodkorb 1940) are considered synonyms of A. p. virescens; variation among them appears to be clinal (see also Monroe 1968). Wetmore (1941, notes in USNM) considered chiapensis as “doubtfully separable,” but recognized stenorhabdus. See notes under A. albivitta regarding the English common name.

 

Aulacorhynchus caeruleogularis (Gould 1854:45). Blue-throated Toucanet.

 

A. c. caeruleogularis (Gould 1854:45). Veragua [, Panama] [= Boquete, Chiriquí; Wetmore 1968:508].

A. c. cognatus (Nelson 1912:4). Mount Pirri (at 5,000 feet altitude) head of Rio Limon, eastern Panama.

Notes: A. c. maxillaris (Griscom 1924:2) is considered a synonym of A. c. caeruleogularis (cf. Wetmore 1968:509). See Wetmore (1968) for citation of the name caeruleogularis appearing first in the Zoologist in 1853; no description appears there, however, the reference being a report of what occurred at two meetings in February 1853 (“D.W.M.” 1853). Olson (1997) provided more notes on these occurrences in relation to Gould.

 

Aulacorhynchus albivitta (Boissonneau 1840:70). Southern Emerald Toucanet.

 

A. a. lautus (Bangs 1898:173). San Miguel [Sierra Nevada de Santa Marta], Colombia.

A. a. griseigularis Chapman (1915:639). Santa Elena (alt. 9000 ft.), Cen. Andes, Antioquia, Col.

A. a. phaeolaemus Gould (1874:184). Concordia, in Columbia [sic], and Merida, in Venezuela [= Concordia, Antioquia, western Colombia; Hellmayr 1911:1213].

A. a. albivitta (Boissonneau 1840:70). Santa- de Bogota [, Colombia].

 

Notes: Chapman (1917) inexplicably omitted the occurrence of the species (endemic subsp. lautus) in the Santa Marta region. More detailed study is needed to resolve problems in the status, relationship, distributions, and nomenclature of phaeolaemus and griseigularis (see Chapman 1917, Haffer 1974). The English name for this species given by Cory (1919:377), White-throated Toucanet, is only appropriate for the subspecies albivitta, and thus is more appropriate at the species level for A. prasinus (sensu stricto, though not used there). The other subspecies of albivitta are all grayish or grayish-blue on the throat. Del Hoyo and Collar (2014) suggested Grayish-throated, but this overlooks both white-throated birds and those with blue in the throats. Accordingly, I have suggested more fitting English names for this species and A. prasinus.

 

Aulacorhynchus atrogularis (Sturm in Gould 1841:heft 2, pl.2 & text). Black-throated Toucanet.

 

A. a. cyanolaemus (Gould 1866:24). Loxa [=Loja] in Ecuador.

A. a. atrogularis (Sturm in Gould 1841:heft 2, pl.2 & text). Andes of Peru [=Chunchamayo, central Peru; Cory 1919:380).

A. a. dimidiatus (Ridgway 1886:93). No loc.; suggested by O'Neill and Gardner (1974:703) to be along the eastern foothills of the Andes of central southern Peru.

 

Note: Recognition of A. a. dimidiatus follows O'Neill and Gardner (1974). A. a. cyanolaemus is blue-throated (Fig. 1).

 

Literature Cited

American Ornithologists’ Union (AOU). 1983. Check-list of North American birds (6th ed). Lawrence, Kansas: American Ornithologists’ Union.

American Ornithologists’ Union (AOU). 1998. Check-list of North American birds (7th ed). Washington, D. C.: American Ornithologists’ Union.

Avise J, Wollenberg K. 1997. Phylogenetics and the origin of species. Proceedings of the National Academy of Sciences USA 94:7748-7755.

Bangs, O. 1898. On some birds from the Sierra Nevada de Santa Marta, Colombia. Proceedings of the Biological Society of Washington 12:171-182.

Boissonneau M. 1840. Oiseaux nouveaux de Santa- de Bogota. Revue Zoologique 1840:66-71.

Bonaccorso E, Guayasamin JM, Peterson AT, Navarro-Sigüenza AG. 2011. Molecular phylogeny and systematics of Neotropical toucanets in the genus Aulacorhynchus. Zoologica Scripta 40:336-349.

Brabourne L, Chubb C. 1912. The birds of South America. Vol. I. London: Taylor and Francis.

Brodkorb P. 1940. New birds from southern Mexico. Auk 57:542-549.

Carriker MA Jr. 1933. Descriptions of new birds from Peru, with notes on other little-known species. Proceedings of the Academy of Natural Sciences of Philadelphia 85:1-38.

Chapman FM. 1915. Diagnoses of apparently new Colombian birds. IV. Bulletin of the American Museum of Natural History 34:635-662.

Chapman FM. 1917. The distribution of bird-life in Colombia: A contribution to a biological survey of South America. Bulletin of the American Museum of Natural History 36:1-729.

Cheviron ZA, Brumfield RT. 2009. Migration-selection balance and local adaptation of mitochondrial haplotypes in rufous-collared sparrows (Zonotrichia capensis) along an elevational gradient. Evolution 63: 1593-1605.

Cory CB. 1919. Catalogue of birds of the Americas. Part II, No. 2. Field Museum of Natural History Zoological Series 13:317-607.

Degnan JH, Rosenberg NA. 2006. Discordance of species trees with their most likely gene trees. PLoS Genetics 2:e68.

del Hoyo J, Collar NJ. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World, Volume 1, Non-passerines. Barcelona: Lynx Edicions.

"D. W. M." 1853. Proceedings of the Zoological Society [being a report of two meetings in February of this year]. Zoologist 1853:3860-3861.

Dickey DR, van Rossem AJ. 1930. Geographic variation in Aulacorhynchus prasinus (Gould). Ibis 1930:48-55.

Dickinson EC, and Remsen JV Jr. (Eds.) 2013. The Howard and Moore Complete Checklist of the Birds of the World, 4th ed., Volume 1 Non-Passerines. Eastbourne, U. K.: Aves Press.

Donegan T, Quevedo A, Verhelst JC, Cortés-Herrera O, Ellery T, Salaman P. 2015. Revision of the status of bird species occurring or reported in Colombia 2015, with discussion of BirdLife International’s new taxonomy. Conservación Colombiana 23:3-48.

Dolman G, Joseph L. 2015. Evolutionary history of birds across southern Australia: structure, history and taxonomic implications of mitochondrial DNA diversity in an ecologically diverse suite of species. Emu 115:35-48.

Funk DJ, Omland K. 2003. Species-level paraphyly and polyphyly: Frequency, causes, and consequences, with insights from animal mitochondrial DNA. Annual Review of Ecology Evolution and Systematics 34: 397-423.

Galtier N, Nabholz B, Glemin S, Hurst GDD. 2009. Mitochondrial DNA as a marker of molecular diversity: a reappraisal. Molecular Ecology 18: 4541-4550.

Gould J. 1833. A Monograph of the Ramphastidae, or Family of Toucans (part 1). London: The author.

Gould J. 1841-47. Monographie der Ramphastiden. Nuremburg.

Gould J. 1854. Description of a new species of Aulacorhamphus. Proceedings of the Zoological Society of London 1853:45.

Gould J. 1866. Description of a new species of toucan belonging to the genus Aulacoramphus. Proceedings of the Zoological Society of London 1866:24.

Gould J. 1874. On three new species of toucans pertaining to the genus Aulacorhamphus. Annals & Magazine of Natural History (4) 14:183-4.

Griscom L. 1924. Descriptions of new birds from Panama and Costa Rica. American Museum Novitates 141:1-12.

Haffer J. 1974. Avian speciation in tropical South America. Publications of the Nuttall Ornithological Club 14:1-390.

Hellmayr CE. 1911. A contribution to the ornithology of western Colombia. Proceedings of the Zoological Society of London 1911:1084-1213.

Hilty SL, Brown WL. 1986. A Guide to the Birds of Colombia. Princeton University Press, Princeton, New Jersey.

Irwin D J. 2002. Phylogeographic breaks without geographic barriers to gene flow. Evolution 56: 2383-2394.

Jones HL. 2003. Birds of Belize. Austin: University of Texas Press.

Land H. 1970. Birds of Guatemala. Wynnewood, Pennsylvania: Livingston Publishing Company.

Mayr E. 1963. Animal Species and Evolution. Cambridge, Massachusetts: Belknap Press.

Morales HE, Pavlova A, Joseph L, Sunnucks P. 2015. Positive and purifying selection in mitochondrial genomes of a bird with mitonuclear discordance. Molecular Ecology 24:2820-2837.

Navarro S AG, Peterson AT, López-Medrano E, Benítez-Díaz H. 2001. Species limits in Mesoamerican Aulacorhynchus toucanets. Wilson Bulletin 113:363-372.

Nelson EW. 1912. Descriptions of new genera, species and subspecies of birds from Panama, Colombia and Ecuador. Smithsonian Miscellaneous Collections 60:1-26.

Olson SL. 1997. [Review of] John Gould the Bird Man. Auk 114:540-541.

O’Neill JP, Gardner AL. 1974. Rediscovery of Aulacorhynchus dimidiatus (Ridgway). Auk 91:700-704.

Pavlova A, Amos JN, Joseph L, Loynes K, Austin J, Keogh JS, Stone GN, Nicholls JA, Sunnucks P. 2013. Perched at the mito-nuclear crossroads: divergent mitochondrial lineages correlate with environment in the face of ongoing nuclear gene flow in an Australian bird. Evolution 67:3412-3428.

Peters JL. 1948. Check-list of birds of the world, Vol. VI. Cambridge, Massachusetts: Harvard University Press.

Peters J L, Winker K, Millam KC, Lavretsky P, Kulikova I, Wilson RE, Zhuravlev YN, McCracken KG. 2014. Mito-nuclear discord in six congeneric lineages of Holarctic ducks (genus Anas). Molecular Ecology 23:2961-2974.

Price, T. 2008. Speciation in Birds. Greenwood Village, Colorado: Roberts and Company.

Puebla-Olivares F, Bonaccorso E, Espinosa de los Monteros A, Omland KE, Llorente-Bosquets JE, Peterson AT, Navarro-Sigüenza AG. 2008. Speciation in the emerald toucanet (Aulacorhynchus prasinus) complex. Auk 125:39-50.

Remsen JV Jr, Areta JI, Cadena CD, Jaramillo A, Nores M, Pacheco JF, Pérez-Emán J, Robbins MB, Stiles FG, Stotz DF, Zimmer KJ. Version 14 April 2016. A classification of the bird species of South America. American Ornithologists’ Union.  www.museum.lsu.edu/~Remsen/SACCBaseline.html

Ribeiro AM, Lloyd P, Bowie RCK. 2011. A tight balance between natural selection and gene flow in a southern African arid-zone endemic bird. Evolution 65:3499-3514.

Ridgway R. 1886. Descriptions of some new species of birds supposed to be from the interior of Venezuela. Proceedings of the U. S. National Museum 9:92-94.

Ridgway R. 1912. Descriptions of some new species and subspecies of birds from tropical America. Proceedings of the Biological Society of Washington 25:87-92.

Salvin O, Godman FD. 1896. Biologia Centrali-Americana, Aves. Vol. II. London: Taylor and Francis.

Sclater PL. 1891. Family Rhamphastidae, pp. 122-160 in Catalogue of the Birds in the British Museum, Volume XIX. London: British Museum (Natural History).

Short LL., Horne JFM. 2001. Toucans, barbets, and honeyguides. Oxford: Oxford University Press.

Sibley CG, Monroe BL Jr. 1990. Distribution and taxonomy of birds of the world. New Haven, Connecticut: Yale University Press.

Toews DP, Brelsford A. 2012. The biogeography of mitochondrial and nuclear discordance in animals. Molecular Ecology 21:3907-3930.

Wetmore A. 1968. The birds of the Republic of Panama. Part 2. Columbidae (pigeons) to Picidae (woodpeckers). Washington, D. C.: Smithsonian Institution Press.

Winker K. 2000. A new subspecies of toucanet (Aulacorhynchus prasinus) from Veracruz, Mexico. Ornitología Neotropical 11:253-257.

Winker K. 2016. An examination of species limits in the Aulacorhynchus “prasinus” toucanet complex (Aves: Ramphastidae). PeerJ 4: e2381 https://doi.org/10.7717/peerj.2381.

Winker K. 2010. Subspecies represent geographically partitioned variation, a goldmine of evolutionary biology, and a challenge for conservation. Ornithological Monographs 67:6-23.

 

Kevin Winker, February 2018

 

Remsen: Synopsis for SACC voting:

 

A. Split Emerald Toucanet into two species, i.e. Aulacorhynchus prasinus (Middle America) Aulacorhynchus albivitta (South America).  (This was adopted by NACC.)

 

B. Adopt English names Northern Emerald-Toucanet and Southern Emerald-Toucanet for the two species above.  (A NO vote indicates you have a better alternative or that you voted NO on C.)

 

C. Split South American populations into two species, i.e. Aulacorhynchus albivitta (Colombia and Venezuela) and A. atrogularis (Ecuador to Bolivia).

 

D. Adopt English names Southern Emerald-Toucanet and Black-throated Emerald-Toucanet for the two species above.  Note that the group name Emerald-Toucanet was not used for atrogularis in the original proposal, but this would be required under our conventions.  (A NO vote indicates you have a better alternative or that you voted NO on C.)

 

__________________________________________________________

 

Comments from Stiles:

“A. YES - splitting the complex into two species, prasinus and albivitta, seems the best description as the evidence now stands.

“B. YES, these English names go well with this split.”

“C. NO - this split is not justified due to the close genetic relationship and apparently frequent hybridization between these taxa.

 

Comments from Robbins:

“A. YES, for elevating albivitta to species level.

“C. NO, until more data become available.”