Proposal (403) to South American Classification Committee
Elevate Pyrrhura
griseipectus to species rank
Effect on South American CL:
this would recognize P. griseipectus as distinct from P. leucotis,
overriding part of Proposal #306.
Background: SACC has recently reviewed the status of several Pyrrhura of the picta-leucotis group
based on genetic analysis of mtDNA by Ribas et al. Among the results was the
downgrading of P. griseipectus to a subspecies of P. leucotis
based on SACC considering them closely related because they were not
reciprocally monophyletic in the mitochondrial DNA analysis, "similar in
plumage, and more or less weakly differentiated ecologically".
Reassessment of available information: SACC adopts the biological species
concept, which we all acknowledge to be problematical and vulnerable to
subjective assessments. Also, we think that the differences between P.
leucotis and P. griseipectus should have been described in better
detail for a proper evaluation. This may have affected judging the status of Pyrrhura
griseipectus.
Full species status for P. griseipectus can be
argued based on the following:
1 - Sorting lineages from the evidence in Ribas et al (2006) is problematical
and, although reciprocal monophyly is desirable, this is not a determining
condition to consider an allopatric taxon as part of another. Care should be
taken in such analysis, since recent work on Monarcha flycatchers (and other taxa) has shown that very small
genetic differences may be sufficient to promote speciation. It should also be
mentioned all specimens of leucotis and griseipectus used in the
analysis were captive and the risk of hybridization in such conditions is not
beyond doubt.
2 - P. griseipectus shows diagnosable plumage characters from P.
leucotis or P. pfrimeri summarized by Olmos et al. 1998, 2005,
and further elaborated here:
a - Head color: leucotis
has a blue suffusion on the forehead (sometimes extending to above the eyes),
nape and sides of the neck, the rest of the head being buffy-gray; griseipectus
only has the blue suffusion on the sides of the neck, the crown being entirely
grey.
b - Auricular patch: cream to
yellowish in leucotis, most birds showing a buff tinge; pure white to
cream, and notably larger, in griseipectus. In the latter, the ear-patch
connects with the pale breast (see photos of live birds below).
c - Eyering: dark blue in leucotis;
variable, ranging from whitish to slaty in griseipectus.
d - Breast feathers: in leucotis
these are green with a blue suffusion, more intense near the neck, and with a
broad pale grey or buff subterminal band and black terminal one; in griseipectus
the breast feathers are dusky grey with a broad cream to pale buff terminal
band.
These color differences result in strikingly different birds, no overlap in
character condition being noticeable in the specimens we have studied either in
collections or in the field. Photos of specimens showing the breast pattern are
attached. See also the following for photos of live free-living P.
griseipectus and P. leucotis.
Pyrrhura griseipectus:
http://farm3.static.flickr.com/2526/3721048452_a07a76ab5d_o.jpg
http://farm1.static.flickr.com/78/220557854_bd27b9ec6c_o.jpg
http://farm4.static.flickr.com/3234/3064136225_2c613eb16c_o.jpg
Pyrrhura leucotis:
http://farm3.static.flickr.com/2655/3720173909_e90c138870_o.jpg
http://www.wikiaves.com.br/foto.php?f=4531&t=s&s=438
http://www.wikiaves.com.br/foto.php?f=888&t=s&s=438&p=1
3 - Besides color differences, P. griseipectus has a significantly
longer bill and broader and deeper mandible (Olmos et al. 1998). This
results in a more robust bill and the birds looking distinctly larger-headed
compared to leucotis, which certainly reflects ecological differences.
These are also evident in the different habitats and ecological and
biogeographical settings in
which the taxa live.
4 - P. leucotis is a bird of the lowland Atlantic forest from southern
Bahia to Rio de Janeiro (which might be considered as a discreet endemism
center defined by species such as Cotinga maculata), whereas P.
griseipectus is restricted to montane forest enclaves that have strong
Amazonian affinities in otherwise semi-arid Ceará and
Pernambuco.
In between there are thousands of kms that include a whole endemism center
devoid of any Pyrrhura (the Pernambuco Center) despite the presence of
Atlantic forest, which should have a taxon of the group, and the area from
Bahia de Todos os Santos to the mouth of the São Francisco river, which some
might consider a discrete subcenter
based on endemic taxa such as Pyriglena atra. So, from a biogeographical
standpoint, P. griseipectus is a quite particular entity that should be
considered distinctive from P. leucotis.
5 - Although the information on vocal differences between the taxa is as
yet unpublished, the 'song' of P. leucotis and P. griseipectus
shows diagnosable differences allowing one to tell them apart based on
vocalizations only, with that of griseipectus being of a higher
frequency compared to leucotis.
This difference can be appreciated in the attached sound file,
sonogram,
and the table below:
|
1°
peak |
2°
peak |
|
Hz |
Hz |
P.
griseipectus #1 |
1913 |
3757 |
|
2031 |
4050 |
|
1971 |
4050 |
|
2031 |
4111 |
|
1857 |
3872 |
|
1857 |
3814 |
|
1942 |
3872 |
|
2001 |
3989 |
|
2125 |
4050 |
|
2031 |
3989 |
|
2001 |
3989 |
|
2093 |
4111 |
|
1971 |
3989 |
|
|
|
Mean |
1986 |
3973 |
SD |
81 |
112 |
|
|
|
P.
leucotis #2 |
1760 |
3520 |
|
1857 |
3814 |
|
1748 |
3234 |
|
1697 |
3434 |
|
1748 |
3332 |
|
|
|
Mean |
1762 |
3467 |
SD |
58 |
222 |
Recommendation:
The available evidence is enough to consider P. griseipectus a full
species distinctive from P. leucotis (and other species of the group).
Morphologically it shows both plumage, and structural differences rendering it
perfectly diagnosable (with no character overlap) from any other taxa in the
group, including P. leucotis. It is restricted to a particular habitat
with distinctive biogeographical history, being quite isolated from P.
leucotis. Vocal evidence, although in need of further study, shows
further differences between P. griseipectus and P. leucotis.
Literature cited
Olmos, F., P.
Martuscelli, and R. Silva e. Silva.
1998. Ecology and habitat of
Pfrimer's Conure Pyrrhura pfrimeri, with a reappraisal of Brazilian Pyrrhura
leucotis. Ornitología Neotropical 8:
121-132.
Olmos, F., W.
A. G. Silva & C. Albano. 2005. Grey-breasted Conure Pyrrhura griseipectus,
an overlooked endangered species. Cotinga
24: 77-83.
Ribas, C. C.,
L. Joseph, and C. R. Miyaki. 2006. Molecular systematics and patterns of
diversification in Pyrrhura (Psittacidae) with special reference to the picta-leucotis
complex. Auk:123: 660-680.
Fabio
Olmos, Ciro Albano, Alberto Campos, Weber Girão, & Jeremy Minns
July
2009
Comments
from Zimmer:
“YES. Following are my comments from the
earlier massive Pyrrhura proposal (#306) as regards Doug’s recommendations at
that time for the treatment of griseipectus
and leucotis as conspecific: I disagree with Doug's
recommendation on subproposal B. I agree that pfrimeri is
morphologically and ecologically more distinct from leucotis and griseipectus
than either is from one another. However, the morphological and ecological
differences between griseipectus and leucotis are at least on a
par with those between various members of the picta group that are here
being recognized as or recommended for separate species status. When this
yardstick is applied, in combination with the recognition of the formidable
disjunction between the ranges of griseipectus and leucotis -
which effectively means that the two forms are on independent evolutionary
trajectories - it seems that recognition as separate species is warranted. I am
not troubled by the lack of genetic evidence supporting this move - see Gary's
comments under Proposal #181, which nicely sum up the arguments against giving
too much weight to genetic evidence in matters of resolving species limits.’ ”
“I
think that Fabio and his co-authors of this proposal raise an interesting point
in noting that the ranges of griseipectus
and leucotis are separated by a large
geographic area containing Atlantic Forest and known to be a separate center of
endemism (the Pernambuco Center), which lacks any taxon representing this group
of Pyrrhuras. This complete disjunction really does suggest
different biogeographical histories for these birds. The biometric differences in bill size
certainly suggest different ecologies, and the vocal differences, although
still unpublished, present additional evidence.
Again, we run into the problem that no analysis presenting all this data
has been published, but I’ll go with my earlier position on this until
published evidence proves me wrong.”
Comments from Nores:
“NO. En mi respuesta a la
propuesta #181 yo puse: “Pienso que las diferencias de plumaje, genéticas y de
hábitat que existen son suficientes para separarlas, especialmente a pfrimeri.
No obstante, pienso que antes de tomar una decisión sería importante consultarle
a Ribas para que opine si griseipectus y leucotis son especies
diferentes, ya que él encontró una estrecha relación entre estas dos
especies." Ahora tenemos publicado el análisis de Ribas et al. (2006)
donde griseipectus y leucotis están juntos en un “clade” bien
soportado y presentan distancias genéticas bajas (0.5% para el citocromo b y 1.0% en la región control entre
individuos de griseipectus y leucotis), lo cual ha sido indicado por
Ribas et al. como una divergencia reciente de los dos taxas. También coincido con lo dicho por Douglas en
la propuesta #306 “They are closely related, similar in plumage, and more or
less weakly differentiated ecologically. Olmos et al. described them as more
distinct morphologically than are leucotis and pfrimeri, which
personally I don't see” Tampoco veo que la distancia que existe entre los
rangos de los dos taxas sea un factor tan importante para considerar a ambos
taxas especies. 700 km no parece una distancia tan grande para un loro y más
cuando ambas zonas pueden haber estado unidas o muy cercanas durante períodos
más húmedos que el presente. Hay muchísimos ejemplos de subespecies separadas
por igual o mayor distancia.”
Comments from Robbins:
“YES. After reading Kevin’s earlier comments
about morphological and ecological differences between leucotis and griseipectus
being on the same level as those in the picta group, which we recognize
as distinct species, coupled with Olmos et al.’s new comments, I support
recognizing griseipectus as a species.”
Comments from Jaramillo:
“YES. A nice
summary and convincing argument by Olmos et al. I appreciate the comments by
Kevin. Disjunctions like the one in this situation are an interesting data
point we don’t tend to think about in as great detail as we do about voice,
appearance and such. However, from my southern cone perspective it often is a
real pointer of where to look for potential unresolved taxonomic issues for me.
There are several taxa in Chile-Argentina where the distribution pattern alone
suggests good biological species may be involved, let alone the ecological
differences of the isolates (Accipiter
bicolor chilensis, Megaceryle torquata stellata, etc.).”
Comments from Remsen: “YES, but
with hesitation given the unclear species boundaries in Pyrrhura as a whole. My
interpretation of the arguments is that these two are “as different” or more so
as many other taxa treated as species in the genus, although without a rigorous
comparative framework, this remains a qualitative assessment. I hope Olmos et al. will publish the
sonograms – this could launch an investigation of voices in the genus to see if
these can be used in delimiting species.”
Comments
from Pacheco:
“YES. The set of information submitted by Olmos and colleagues to
support the reconsideration of the taxonomic treatment for griseipectus
is persuasive. They are important, in my opinion, vocal differences and the
obvious disjunction in the distribution between the two forms involved.”
Comments
from Bret Whitney:
“Yes.
I echo Remsen on
this one as concerns the “as different as...” idea. As for the “ecological” differences cited by
some of us, I really don’t see any or many.
This bird feeds on a wide variety of fruits ranging from introduced
plants to Cecropias (heavily on the latter, like all members of the genus),
nests in existing/natural tree cavities like all the rest, and flies around and
vocalizes like all the rest — it is simply an isolate of the picta radiation in the Barurité of
Ceará. I don’t doubt that some vocal
differences could be teased out among these picta-types
if worked over hard enough. Griseipectus has undergone some
modification primarily (I would argue) because it is genetically isolated and
small chunks that are isolated from larger blocks are going to develop
“differences” more quickly. In line with
its conservative morphological and vocal distinctions, it appears that genetic
differentiation of griseipectus is
slight relative to the whole group, all of which probably indicates a recent
isolation. Nonetheless, recognizing the biogeographical patterns
characteristic of eastern Brazil, it is on an independent trajectory at this
point and will continue to evolve as an integral species would. Thus, I think it is more appropriate to
recognize it today as an integral species than as, for example, a subspecies
that ornithologists at some indeterminate moment in the future, after the
genetic transitions add up to a more divergent story, will reevaluate as one
that’s now “gone far enough” to be classified at the species level. The alternative to recognizing it as an
integral species is to call it an incipient species — but I think the word
“species” is the best operative term in these cases of clear allopatry (no very
close relative abutting) with evidence of divergence among populations.”
Comments
from Stiles:
“YES.
Evidence from morphology, ecology, biogeography and vocalizations all point to
species status for griseipectus. I share Van’s misgivings in that there are a
number of taxa in this group that might well be deserving of species status as
well, but for which similarly detailed analyses are lacking. However, given that these occur in several
different countries over a wide area, it seems unrealistic to expect a global
solution to this problem in the near future, so perhaps a piecemeal approach on
a case-by-case basis is the best one can hope for at present.”
Comments
from Schulenberg:
“YES. I twice
earlier voted in favor of recognizing griseipectus as a species (Proposals 181,
306B), and so just am sticking to my position.”