Here is the second SACC proposal, from 2011, which was rejected:
Proposal (503) to South American Classification
Committee
Treat Myiopsitta
luchsi as a separate species from M. monachus
In this proposal, I am revisiting
territory that Nores covered in the rejected proposal #93. However, more evidence is now available, both in the form of a molecular
study (Russello et al. 2008) and in the accessibility of voice information that
suggests real genetic and vocal differences between the Bolivian intermontane
taxon luchsi and the remainder of Myiopsitta monachus.
Molecular study: In their Figure 2 (reproduced
here), Russello et al. (2008) provided a network of haplotypes of mtDNA
(control region, 558 bp) from all named taxa within Myiopsitta (monachus
N=38, calita N=9, cotorra N=16, and luchsi N=14; plus 64
birds from feral populations in US of unknown taxon) mostly from toe-pad
sampling of AMNH specimens).
The network showed little uniqueness
of haplotypes among the taxa within Myiopsitta with the strong
exception of luchsi, which shared no haplotypes with any of the
other named taxa (the localities from which specimens of cotorra,
the closest geographic representative of lowland birds to luchsi,
were taken were from Matto Grosso, Brazil, and central Paraguay). Russello et
al. (2008) took this result to mean that luchsi is a
monophyletic and diagnosable group that has been reproductively isolated from
the rest of the members of M. monachus, despite being reported only
175 km away from the nearest population of M. m. cotorra, and
proposed that it be accepted as a distinct Phylogenetic Species (and more
subtly suggesting that the names cotorra and calita be
synonymized with monachus, at least if one follows the PSC).
Nesting: As the proposed English name
‘Cliff Parakeet’ suggests, this species does seem to be entirely restricted to
breeding sites on cliffs, despite the presence of trees and telephone poles
within its range that could allow it to nest in the same manner as its lowland
counterparts. However, luchsi, based on my personal experience with it,
is considerably rarer than lowland monachus within its range, and its
nests are smaller affairs that cluster around bromeliads and other low plant
growth along steep cliffs. I have only an experience of N=1 with nesting
colonies, but the one I know has remained stable over a ten-year period, with
only about 2-5 pairs nesting within a complex, and perhaps only 2-3 nest
complexes comprising the colony. Photographs of nests are available here:
http://www.flickr.com/photos/8013969@N03/6202463428/
Voice: In his comments to Proposal,
Van requested voice information to change his decision. I think that is now
easier to provide than it was seven years ago. See the following:
http://www.xeno-canto.org/species/Myiopsitta-monachus
Listeners are likely to be impressed
by the rather distinct vocalizations of luchsi in comparison to the
lowland forms of M. monachus. The typical calls of cliff-nesting luchsi
are consistently higher-pitched, less grating, and generally shorter in
duration that those of the lowland birds.
Recommendation: Whereas I agree with Van’s
comment in Proposal #92 that taxa in Bolivia’s dry intermontane valleys are
morphologically distinct from those in the nearby open lowland habitats, there
is evidence of continued genetic introgression for at least one of these
(Brumfield 2005, involving Thamnophilus caerulescens, one of the
species specifically named in Van’s comment). Meanwhile, Myiopsitta
(monachus) luchsi shows no such introgression (Russello et al. 2008).
Plumage, vocalizations, and nesting behavior differ (the last despite the
presence of nesting substrate similar to that available to lowland M.
monachus) between luchsi and other populations of monachus.
Short of having overlapping populations, I think these data are sufficient to
suggest that luchsi and other populations of monachus are
distinct enough to be accepted as separate Biological Species. I recommend a
vote of YES, overturning the results of Proposal #92.
Literature Cited
Brumfield, R. T. 2005. Mitochondrial
variation in Bolivian populations of the Variable Antshrike (Thamnophilus
caerulescens). Auk 122:414-432.
Russello, M. A., M. L. Avery, and T.
F. Wright. 2008. Genetic evidence links invasive monk parakeet populations in
the United States to the international pet trade. Bio Med Central Evolutionary
Biology 8:217 (pp 1-11). PDF here: <http://www.biomedcentral.com/1471-2148/8/217>
Dan Lane, October 2011
______________________________________________________________________________________
Comments from Pete Hosner: “I saw proposal #503 on
the SACC page. I was also struck by the difference of luchsi vocalizations
from the lowland forms. I'd like to point out some of my recordings at LNS for
further examples for the committee:
http://macaulaylibrary.org/audio/132533
http://macaulaylibrary.org/audio/132535
http://macaulaylibrary.org/audio/132537
http://macaulaylibrary.org/audio/132538
http://macaulaylibrary.org/audio/132540 (probably the best one)
Comments from Stiles:
“YES – the new genetic data, coupled with the differences in plumage and
vocalizations (the two do sound recognizably distinct) favor splitting luchsi from monachus;
again, the burden of proof is now on those who would lump them.”
Comments from Robbins:
“YES. The new genetic and vocal
information along with the described plumage morphology supports recognizing luchsi
as a species.”
Comments from Pacheco: “YES. Given
the new information (vocal, specially) added to the case I am in favor of
the split.”
Comments from Cadena:
“NO. Honestly, I am unimpressed by the genetic differences. True, there is no
haplotype sharing, but luchsi is only 4 mutational steps removed from
the rest of taxa in sequences of the highly variable control region (note, by
the way, that some haplotypes of luchsi are two mutational steps from
each other). I obviously do not advocate the use of a genetic (mtDNA) yardstick
to establish species limits, but this level of divergence from all other
subspecies is quite shallow. And then, of course, such divergence may simply
reflect the effect of geographic isolation and need not imply reproductive
isolation between forms, which is what we typically focus on. That samples from
relatively close localities differ genetically based on mtDNA says little about
gene flow given the nonrecombining nature of this marker; distinct phylogroups
may persist even within a single panmictic population following a period of
geographic isolation and differentiation with subsequent secondary contact.
Nuclear DNA data would be crucial to truly ascertain whether there is gene flow
between luchsi and other forms. On the other hand, vocal data do appear
quite suggestive, but, unless I am missing something, they have not been
rigorously analyzed nor published in the peer-reviewed literature. Many
proposals for splitting taxa have not been accepted owing to lack of published
data, so if we want to be consistent, this reasonable proposal will need to
wait for the completion of a published analysis of vocal variation.”
Comments from Stotz:
“NO. The genetic evidence is not
sufficient by itself to split this taxon.
Although the nesting site evidence and voice seem like they would
establish this as a distinct species, this material is unpublished. I’d like to wait for a publication with the
voices seriously analyzed.”
Comments from Pérez:
“NO. I was going to vote YES on this but
Daniel’s and Doug’s comments on lack of published and more formal vocal
analyses convinced me on the contrary. I think data are suggestive of two
distinct species. but we need to be consistent in our criteria for evaluation
of proposals. Similarly, addition of nuclear data to the molecular data set
would be great, though the pattern of monophyly found in Russello et al.
(2008)’s study was based on a fair sample size.
Comments from Zimmer:
“A somewhat reluctant NO. The vocal
differences and fairly stark differences in nesting biology are very suggestive
to me that more than one species is involved.
Unfortunately, as has been noted by others, none of this has been
formally analyzed or published, and in similar cases with even stronger
rationale for splitting, we have pretty consistently voted to wait for a
published analysis before acting. In
this case, there is published genetic data advocating a split, but as Daniel has
pointed out, this data is not so impressive on close inspection. I do think that time will prove that there
are two biological species involved.”
To
illustrate the plumage differences, here are some photographs from Macaulay. The top one is monachus from Buenos
Aires by Adrian Grilli, and bottom one is luchsi from dpto. Cochabamba
by Paul Bartlett:
Note
especially the differences in the chest-breast area in terms of scaliness and
color.
New
information:
Del
Hoyo & Collar (2014) treated luchsi as a separate species based on
the Tobias et al. point scheme as follows:
“Usually regarded as conspecific with M.
monachus, but treated as separate species in HBW (and this is supported by
recent genetic analysis (1) ) on basis of characters now scored as follows:
uniform (unbarred) and much paler grey breast and crown (also no bars on
mantle) (3); pure buffy-mustard vs yellow-tinged grey mid-belly (2); stronger
green in all areas (1); bluer tail and darker flight-feathers and wing-coverts
(ns[1]); darkish mark on base of upper mandible (ns[1]); cliff-nesting vs
tree-nesting habit (1) (which, incidentally, may be related to apparently
longer claws). Monotypic.”
Note
that the “recent genetic analysis” was considered minor and insufficient
evidence by SACC. Clearly, the
expectation for an isolated population, one that also has plumage differences,
is that it will also be differentiated at the neutral loci that could be
sampled in 2008, regardless of taxonomic rank of the populations.
Peter
Boesman and Shaun Peters simultaneously alerted me to the fact that after del
Hoyo & Collar (2016), an analysis was published by Boesman (2017), who
corroborated many of the differences noted by Dan, presented many sonograms,
and concluded:
“I conclude that the voices of Monk
Parakeet and Cliff Parakeet show some clear differences, further supporting
their treatment as two species.”
I
have listened to all the recordings of luchsi on xeno-canto: https://xeno-canto.org/species/Myiopsitta-luchsi
I
have also listened to about 20 of monachus on xeno-canto from Argentina
and Brazil (skipping recordings from feral populations: https://xeno-canto.org/species/Myiopsitta-monachus?pg=1
I
can hear what I would consider to be consistent differences between the two,
precisely as described back in 2011 by Dan and further documented by Boesman
(2017), so I am convinced that two species are involved. I recommend that everyone take a few minutes
to listen to some recordings of each at the xen-canto links above.
Discussion
and Recommendation:
We
now have a much larger N of “published” online recordings of luchsi, and
we also have Boesmans’ synopsis. Given
that splitting them is not a novel taxonomic treatment, I think it is ok to relax
our standards slightly in terms of requiring a formal quantified published
analysis for a change in classification.
Cory (1918) treated luchsi as a separate species, and Peters (1937),
as was his practice, lumped them without any explicit rationale. Of course, Cory treated many taxa as species
that we now consider species, so that doesn’t count for much. Nonetheless, all these recordings in my
opinion trump Peters (1937) and place burden-of-proof on its treatment as a
subspecies.
As
for the other evidence, the plumage differences in my subjective opinion, now
that we have good photos of luchsi to admire, are similar or greater in
degree to those between many taxa of New World parrots treated as species. On the other hand, I think the difference in
nest sites is overblown as far as its significance. A cliff ledge really isn’t that different
from a telephone pole or an isolated tree.
Species with restricted availability of suitable nest sites can often be
quite flexible within certain parameters.
Within several parrot species, nest-site flexibility is well-documented,
e.g. see Romero-Vidal et al. (2023), and so this has no demonstrable taxonomic
importance. I regard the genetic data as
inconclusive: the genetic distance between them could be argued as evidence for
or against species rank.
Reasons
to vote YES for the split could be that differences in vocalizations are
strongly associated with, for better or worse, species rank in parrots, and
that given those differences accompanied by plumage differences consistent with
species rank within several genera of parrots, we have sufficient evidence to
treat them as species.
Reasons
to vote NO could be that all of the above may be true, but we still lack a peer-reviewed
publication on the vocalizations, but we have softened our stance on that
somewhat in recent years in that recordings themselves are available online
(and in this and many other cases, Peter Boesman has provided some
quantification.)
English
names:
Del Hoyo & Collar (2014) and others have used “Cliff Parakeet” for luchsi
and retained “Monk Parakeet” for the much more widely distributed and familiar
species. This fits with our SACC Guidelines on
English names,
and Cliff Parakeet is a good name, so I suggest that no English proposal name
is needed.
References: (see SACC
Bibliography
for standard references)
Boesman,
P. 2017. Notes on the vocalizations of Monk Parakeet (Myiopsitta
monachus) and Cliff Parakeet (Myiopsitta luchsi). HBW Alive
Ornithological Note 452. In: Handbook of the Birds of the World Alive. Lynx
Edicions, Barcelona.
Romero-Vidal,
P. et al. 2023. Nesting innovations in Neotropical parrots
associated to
anthropogenic
environmental changes. Ecology and Evolution 2023;13:e10462.
Van Remsen, July 2024
Comments
from Areta: “YES. This is a tough case by
which I am torn. The case is borderline and may be so forever. The two taxa
differ in plumage, vocalizations (although no rigorous study has been
performed), and nesting habits. Even though nesting habits can be seen as
labile in parrots (e.g., Psittacara
mitrata can nest in holes on cliffs or in trees in the same localities),
the truth is that despite available cliffs in monachus habitat and available trees in luchsi habitat, I am not aware of luchsi nesting on a tree or monachus
nesting on a cliff. There is also the communality of those nests: monachus nests are most of the time
massive buildings with many pairs in a single nest (with separate entrances and
breeding chambers), while those of luchsi
are mostly single pairs that place their nests in relatively close association
(or quite separately) on cliffs, but never have I encountered nests cluttered
together in a single structure as in monachus.
“Turning into genetic data, they are evidently
very recently diverged, and there is not a great comparative dataset to work
on. Yet, the fact that luchsi is restricted to Dry Inter-Andean Valleys,
add a bit more of evidence in favour of its recognition as a separate species.
“Confronted with the question of whether in the
event of meeting these two would interbreed, to me the answer is yes. Yet, I
cannot predict what would happen in terms of gene flow or breadth of a hybrid
zone. In an unexpected plot twist, I will vote YES to the split, while
recognising that the evidence is not perfect, while honouring the many
differences in plumage, life-history and vocalizations known between luchsi and monachus.”
Comments
from Robbins:
“YES. After listening to vocalizations on xeno-canto
and confirming plumage differences via photos at Macaulay Library, I again (as
I did in proposal 503) vote to recognize luchsi as a species.”
Comments from Andrew Spencer (voting for Remsen): “YES -
this is one of those cases where multiple lines of evidence all seem to support
a split. I do think the nesting differences are quite important here - there
are plenty of spots near where I've seen
luchsi that would be great locations for
monachus nests, and there are other locations with
monachus that luchsi would
probably be happy with too. So it's more than just sticking to the available
nesting substrates -- there's a real
preferential difference there. But foremost to me are the vocal differences,
which over the wide range of monachus, both
native and introduced, really don't seem to vary that much. And then you have
these bizarre sounding birds in one part of Bolivia. That is, I believe, a
situation unmatched in other parrot species (though happy to hear if that's not
true!)”
Comments
from Stiles:
“YES. The evidence is definitely borderline, but now sufficient, in my
view, to place the burden of proof on
those who would maintain luchsi as a subspecies of monachus.”
Comments
from Lane:
“YES. These two taxa are quite distinct, and my own observations (which I
offered in Prop 503) agrees with Andrew’s: that the substrates for tree or pole
nesting are available in the immediate vicinity of M. luchsi nests, but
they ignore them for cliffs. Voice and plumage additionally make this taxon
quite distinct compared to the remaining taxa within Myiopsitta.”
Comments
from Claramunt:
“YES. The combination of differences in plumage, nesting behavioral,
vocalizations, and genetics make a compelling case for the species status of luchsi.”