Proposal (624) to South American Classification Committee

 

Treat Cacicus flavicrissus as separate species from Cacicus cela

 

This proposal is to split Cacicus flavicrissus (P. L. Sclater, 1860) together with Cacicus vitellinus (Lawrence, 1864) (both as the Saffron-rumped Cacique) from Cacicus cela (as Yellow-rumped Cacique).  Recent authorities have treated flavicrissus and vitellinus as subspecies of Cacicus cela, notably Howard & Moore (1994), Dickinson (2003), and Fraga (2011).  They are as follows:

 

vitellinus  from central Panama south to northern and central Colombia: east to Santa Marta Mountains and south to Tolima on western Slope of Eastern Andes;

 

flavicrissus west Ecuador south to northwestern Peru (Tumbes).

 

cela   Colombia: eastern lowlands east of the Andes, including north to coast near Santa Marta Mountains, most of Venezuela, Guyana, Surinam, French Guiana, south to east Ecuador, eastern Peru south to lowlands of Santa Cruz, and Brazil (Amazonia from northern borders south to Mato Grosso do Sul).

 

However, one should note that Fraga (2011: 749),although he followed the precedent of three subspecies, stated: “Races form two distinct groups, separated by the Andes. Western group (vitellinus and flavicrissus) possibly represents a separate species., differing from single-species “cela group” in plumage, colour and voice.”

 

Given that the two groups are separated for most of their range by the Andes, gene flow between them must have ceased some millions of years ago. In terms of plumage, Fraga (2011: 749-750) stated: Male [cela] is mostly black with slight bluish gloss; lower back, rump, uppertail-coverts and read abdomen yellow; various amounts of yellow in upper-wing, affecting great coverts and some medium coverts; uppertail mostly black from above with yellow at the upper edges, undertail yellow, iris blue, bill ivory; legs blackish.  He continues (2011: 750): “Race vitellinus has yellow parts of plumage richer, more orange-yellow than [cela], also wing patch smaller, bill greyish at base; flavicrissus is very like previous, but smaller.”

 

In terms of voice, Fraga (2011:750) mentions some striking differences: ”[Cela] is an outstanding mimic of many birds, including parrots,…woodpeckers,…,many passerines and others, even of mammals. Its variable song often starts with a harsh double-note,”k’wek-k’wok” followed by imitations. Males of race vitellinus not known to mimic but still have varied song repertoire.”  Clear differences between calls is clear from the following spectrograms, and the calls themselves can be heard on my website (worldbirdinfo.net):

 

 

 

 

Spectrogram of Call of Saffron-rumped Cacique Cacicus flavicrissus vitellinus

Darien, Panama. Thanks to Linda Macaulay

 

 

Spectrogram of Saffron-rumped Cacique Cacicus flavicrissus flavicrissus. Guayas, west Ecuador

 

 

Spectrogram of Call of Southern Yellow-rumped Cacique Cacicus cela. Call taped at Cojedes Venezuela by Ted Parker

 

 

They similarity of the calls of the two taxa placed in Saffron-rumped Cacique should be obvious, as should the difference of both from that of the Yellow-rumped Cacique.

 

We may finally turn to genetic evidence. In Figure 4 of Powell et.al, (2014:106) the node uniting Cacicus cela cela and Cacicus cela vitellinus is relatively deep.  It is deeper than the node uniting Cacicus sclateri and Cacicus koepckeae. It is also deeper than the clade uniting Cacicus haemorrhous and Cacicus (was Clypicterus) oseryi. Looking further afield, it is deeper than the nodes uniting many species of Psarocolius.

 

I believe that this body of information justifies the split of Cacicus flavicrissus flavicrissus (P.L. Sclater, 1860) (with subspecies  Cacicus flavicrissus vitellinus Lawrence, 1864), Saffron-rumped Cacique, from the now monotypic Cacicus cela (Linnaeus, 158),Yellow-rumped Cacique.

 

References

Powell, Alexis F.L.A., Barker, F. Keith, Lanyon, Scott M., Burns, Kevin J., Klicka, John, Lovette, Irby J.  (2014) A comprehensive species-level molecular phylogeny of the New World blackbirds (Icteridae) Molecular Phylogenetics and Evolution 71: 94-112.

 

Fraga, R. M, (2011) Family ICTERIDAE (New World Blackbirds) in Del Hoyo, J., Elliott, A., D. Christie, D. (eds), Handbook of the birds of the world,16, Tanagers to New World Blackbirds, Barcelona: Lynx Edicions, pp.684-810.

 

 

 

 

John Penhallurick, Feb. 2014 (revised March 2014)

 

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Comments from Cadena: “NO. For one, there are no published analyses of vocalizations with proper sample sizes, sufficient geographic sampling, statistics, etc. to back this up. Also, based on these oscillograms (note they are not spectrograms) it is hard to visualize how different songs really are. Also, see my comments on proposal 616 regarding genetic distance.”

 

Comments from Dan Lane: Although I am actually of the mind that flavicrissus (presumably also including vitellinus) should be separated from cela at the species level, I am sorry to say that the present proposal does not offer the information necessary to support such a move. First of all, in Powell et al. (2013), C. c. flavicrissus is not included among the taxa compared in the tree constructed. This, and the caveats that Van gave in proposal 616 (that a family-wide phylogenetic paper with only one or two samples per taxon taken from distant points in their distributions, etc.), means that Powell et al. (2013) is not a work that can be used to support a taxonomic change of this nature. Secondly, listening to Xeno-canto, I found a cut of C. c. vitellinus that seems to include imitations (see http://www.xeno-canto.org/47092, in which I hear imitations of Campephilus vocalizations). Certainly, that doesn’t mean that these taxa shouldn’t be split, but it does mean that the argument using strictly the presence/absence of imitations or geographic voice variation needs to be more thorough (not to mention, use larger samples and homologous vocalizations and take into account the fact that these are oscines!). The three waveforms (not spectrograms) posted in the proposal are fairly useless in making a case here as the source recordings are not available on <http://worldbirdinfo.net/Pages/BirdMediaView.aspx?BirdID=40718&Source=%2FPages%2FBirdsSearch.aspx%3FBirdField%3D0%26BirdSearch%3Dcacicus%2520cela> as far as I can tell, which also severely hampers their usefulness in making any argument. Finally, according to Hilty and Brown (1986, Birds of Colombia), C. c. cela is found north of the Colombian/Venezuelan Andes (so the Andes are not the barrier between the two groups that the proposal makes them out to be) to the north flanks of the Santa Martas, and at the same time, C. c. vitellinus is found to the western and southeastern flanks of the same range. With anthropogenic habitat conversion perhaps allowing for the expansion of these disturbed-habitat-loving species to spread further, it may be possible to use this region as a natural laboratory to see how the two interact (if they actually come into contact) with one another. A more densely sampled molecular study of these three taxa, with perhaps an associated comparison of a larger sampling of vocalizations (carefully screened to compare only homologous vocalizations) may be able to make the argument that was attempted in the present proposal. As it is, I am afraid the evidence provided here is cannot support the case.”

 

Comments from Remsen: “NO.  Although I thank John for provoking discussion on this an illuminating the need for additional data and analyses, the data at present are inadequate for changing the classification, for reasons noted above by Daniel and Dan.”

 

Comments from Stiles: “NO. Again, I think that a good case could be made for this split, but the data presented here are not sufficient to justify it at present.”

 

Comments from Nores: “NO, for the reasons given by Lane and Daniel The cis- and trans-Andes distribution of the two taxa is not correct. Moreover, it is a complicated procedure to use genetic distance to assess species status. I don’t consider that genetic data are (yet) useful in evaluating species limits.”

 

Comments from Zimmer: “NO, for reasons elaborated by others.  A more thorough, quantitative vocal analysis is required.”

 

Comments from Jaramillo: “Comments from Jaramillo: “YES. Again, there are problems with this proposal as others note, but some details regarding song differences are clear and known. Cacicus cela does not mimic during all song types, but one specific song type known as the harsh song, which is aimed mainly at rival males. I could not hear the possible mimicry that Dan mentions, but he has a way better ear than I do! Even if mimicry is done at times by flavicrissus, it does not do it consistently and as part of a separate song type as cela does. Apart from the mimicry issue, the song structures are very different between the two species, and behavioral papers have published information on songs, which I summarized below in our Icteridae book. I am sure more is known now, but I have not kept up.

 

“Perhaps most importantly is that the ranges of these two taxa practically touch, they are not separated by the Andes as noted in the comments made by a couple of folks. Yet there are specimens from these areas, and there is no evidence of intergradation. To me there are several important points here 1) genetics suggest a deep division between the two 2) songs differ in structure, quality, and perhaps cela has a song type entirely missing from flavicrissus.  Calls are also consistently different. 3) Ranges nearly touch, no evidence of intermediates. 4) Other taxa of caciques and oropendola currently considered separate species are less distinct than these two.

 

“Below are parts from our Icteridae book, which is not a common one on the shelves, but summarizes a lot of what was known then regarding these birds”

 

VOICE The repertoire of vocalisations in this species is huge making a summary of their vocalisations somewhat futile. In addition, C. c. cela is an adept mimic. Song: The primary song (‘cela song’) is usually made up of four syllables, the first of which is a screech typical of Yellow-rumped Caciques. The following notes are variable. It lasts under two seconds in duration. Each colony has a song (or several songs) specific to the colony and all males conform to these songs while at the colony. The colony song changes from year to year, and sometimes within a season. While in full display another song is used (‘harsh song’), this is more complex and continuous, not discrete. This longer song that can last up to 20 minutes includes many loud whistles and it is here that this cacique (form C. c. cela) will incorporate mimicry of local birds, frogs and assorted noises. The harsh song is extremely variable, but includes the ‘tchak’ notes typical of this cacique. The loud volume and varied nature of the song may be its most distinctive features. Females rarely sing the ‘cela song’ but never sing the ‘harsh song’. It appears that ‘harsh song’ is aimed mainly at other males and has some aggressive or threatening significance, while ‘cela song’ is correlated with slight alarm and may function to advertise the presence of the male to females (Feekes 1981).

 

      The form vitellinus is not known to mimic or to produce mechanical sounding noises. The vocalisations of vitellinus are said to be conversational and musical series of notes: ‘wick-a-weo’ ‘char-che-ar’, ‘chut-chu-chu’. Also gives a more muffled song, ‘Aaaghh-a-whaaghee’, or ‘cluuk-cluuk-whaaagooo’. Males of vitellinus sing five to eight songs types; all males in a colony share the same song types. The number of shared songs between colonies is directly proportional to the distance between colonies, nearby colonies share more song types. Dialects are stable during a breeding season, but some songs change gradually over the months. Less than half of the song types are present in a recognisable form during the next breeding season. Some new songs (17%) are introduced by dispersing males from other colonies, but for the most part new songs are derived from old songs (45%), the rest are of unknown origin (Trainer 1989). An analysis of song types of vitellinus in Panama discovered that of the seven types specific songs were associated with certain behaviours. One song was more likely to be sung by males in groups, while another was sung by lone males, another by flying males, another when supplanting another male while the rest were not so closely associated with specific contexts (Trainer 1987). There appear to be consistent rules that govern the sequence of song types given by males at the colony. Social interactions as well as social context appear to influence (or determine?) the organisation of song types at the colony (Trainer 1988). The form flavicrissus of the Pacific Coast is also not known to be a mimic. Calls: The common call of cela is a repeated harsh ‘tchak’ or ‘chaaak’, uttered more loudly and frequently when alarmed. Females utter a rough ‘rrrrrrr’, particularly when behaving aggressively. The subspecies vitellinus gives a standard icterid ‘chuk’.

 

GEOGRAPHIC VARIATION Three subspecies are recognised which fall into two groups: vitellinus (Saffron-rumped, or Lawrence’s Cacique) and cela (Yellow-rumped Cacique). [NOTE of correction here – I am not sure why I used the name vitellinus, if separated I gather that flavicrissus has priority] It is clear that there are consistent morphological, behavioural and vocal differences between these two groups and it may be determined that they are best separated as two different species in the future. The two groups almost come into sympatry in N Colombia, but no intermediate specimens are known.

 

      Yellow-rumped Cacique C. c. cela is found east of Andes. This is the most widespread subspecies, found throughout the tropical lowlands of South America east of the Andes as far south as C Bolivia and E Brazil. In Colombia, cela is found along the coast of Santa Marta, and comes quite close to the range of vitellinus. This population shows no evidence of intergradation towards vitellinus (Todd and Carriker 1922). Cela is described above.

 

      The Saffron-rumped Cacique is found west of Andes and is comprised of two subspecies. The race C. c. vitellinus is found from the Canal Zone in Panama east into W Colombia (south to the Rio Salaqui) to the western and southern base of the Santa Marta mountains, south to the middle of the Magdalena Valley. It differs from cela in being larger, with a bill showing a more strongly curved and broadly based culmen. The yellow of the body is a deeper colour, more orange, than on cela. As well the yellow on the coverts is much less extensive, being restricted to the innermost greater coverts. The yellow on the base of the tail is much less extensive, only covering the basal third or less on the outer rectrices. Wing Formula: P9 < P8 < P7 > P6; P9 » P5; P8 - P5 emarginate.

 

The other race in this subspecies group, C. c. flavicrissus occurs in the Pacific lowlands of Ecuador from Esmeraldas south to NW Peru (Tumbes). There is a gap in range between flavicrissus and vitellinus along the Pacific Coast of S Colombia. This form is like vitellinus in having less yellow on the tail than cela, but it has a larger yellow wing patch, like cela. It is smaller than vitellinus, has less of an orange colour on the rump, and a smaller bill which has a plumbeous coloured base. Wing Formula: P9 < P8 < P7 > P6; P4 < P9 < P5; P8 - P5 emarginate.

 

Comments from Robbins: “NO. Dan does an excellent job of summarizing all the shortcomings of our knowledge of the cela complex.  Until additional data are forthcoming, I see no unequivocal evidence for treating these taxa as separate species.”

 

Comments from Pacheco: “NO. Compartilhando da opiničo preponderante, aguardo uma publicaćčo que faća a análise das vocalizaćões, a partir de amostras em número apropriado e bem distribuídas geograficamente para uma decisčo consistente da situaćčo.”