Proposal
(700) to South American Classification Committee
Elevate Henicorhina leucophrys anachoreta to
species rank
Background: Recent studies based on genetic, morphological,
and behavioral data suggest that the two wren taxa in the genus Henicorhina (Troglodytidae)
that replace each other along elevational gradients in the Sierra Nevada de
Santa Marta, northern Colombia, are reproductively isolated populations (Caro
et al. 2013, see also Burbidge et al. 2015). However, the evidence has not yet
resulted in taxonomic changes recognizing their status as distinct species.
New information: In a recently published note (Cadena et al. 2015),
we summarized existing data and proposed to recognize the population inhabiting
higher elevations as a different species (H. anachoreta) from the
population occurring at lower elevations (H. leucophrys bangsi).The note
is open access and available here:
http://asociacioncolombianadeornitologia.org/wp-content/uploads/2016/02/MS1411.pdf
Recommendation: Based on the analyses in Caro et al. (2013) and
the data summarized by Cadena et al. (2016), I recommend voting YES to treating
H. anachoreta as a species distinct
from H. leucophrys.
Literature Cited:
Burbridge,
T., T. Parson, P. C. Caycedo-Rosales, C.
D. Cadena & H. Slabbekoorn. 2015. Playbacks revisited:
Asymmetry in behavioural response across an acoustic boundary between two
parapatric bird species. Behaviour 152: 1933-1951.
Cadena, C. D., L. M. Caro, P. C. Caycedo, A. M. Cuervo, R. C. K. Bowie & H.
Slabbekoorn. 2015. Henicorhina anachoreta (Troglodytidae),
another endemic bird species for the Sierra Nevada de Santa Marta, Colombia. Ornitología Colombiana 15.
Caro, L. M., P. C. Caycedo-Rosales, R. C. K. Bowie,
H. Slabbekoorn & C. D. Cadena. 2013. Ecological speciation along an elevational gradient in a tropical
passerine bird? Journal of Evolutionary Biology 26: 357-374.
C. Daniel
Cadena, February 2016
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Comments
from Remsen:
“YES. Parapatry without gene flow is as
good as it gets for species rank.”
Comments
from Stiles: “YES. The
strong evidence for parapatry without interbreeding justifies species rank for anachoreta.”
Comments
from Areta: “YES.
Results of playback experiments and vocal differentiation, lack of gene flow in
parapatry, morphological distinctions, phylogenetic data, and analysis of type
material all support recognition of anachoreta as a separate species.
The reasons behind the paraphyly of Henicorhina leucophrys are quite
interesting. I do not fear recognizing non-monophyletic species, and I agree in
that both faulty taxonomy and the speciation process in this group underlie the
observed phylogenetic patterns.”
Comments
from Pacheco: “YES. The
convincing evidence of parapatry without reporting of crossbreeding justifies
the proposal.”
Comments
from Claramunt: “YES. The concurrent break in morphology and
multiple independent genetic markers strongly suggests that these two
parapatric populations are two separate lineages. Intrinsic reproductive
isolation is also inferred by the lack of intergrades or hybrids in the contact
zone. Vocal data are more ambiguous; vocal variation looks like an altitudinal
cline, and playback experiments revealed that birds do respond to alien songs.
But little is known about the significance of these responses. Males may be
responding to alien songs because they may be defending territories from any Henicorhina
around to defend resources, regardless of species identity. This, in turn, may
promote vocal convergence rather than divergence, as in the case of Hypocnemis
peruviana and H. subflava, described by Tobias & Seddon (2009,
Evolution 63: 3168-3189). But whatever happens with the acoustic behavior here
does not affect the fact that all other evidence indicate that there are two
lineages that are differentiated genetically and phenotypically and are
reproductively isolated. Finally, that H. leucophrys become paraphyletic
after separation of H. anachoreta is problematic in principle, because
they cannot be considered two separate lineages if they are not reciprocally
monophyletic. However, I concur with Daniel in that this change is among the
first steps towards a revision of the leucophrys complex and may have to
accept some transitional taxonomies that include non-monophyletic taxa.”
Comments
from Jaramillo: “YES. Everything
lines up, parapatry, phylogenetic data etc. Observers in the field have been
noting that there is a different bird up top and down below in the Sierra
Nevada de Santa Marta for some time, so it is great to solidify that indeed
there are two species, and that they appear not to be each other’s closest
relatives. I think we are just hitting the tip of the iceberg with wrens, they
will be the new tapaculos with many cryptic species to come, but unlike
tapaculos the vocal data is much more complicated and difficult to decipher.
“The English
Name Hermit Wood-Wren has been proposed for H.
anachoreta, as well as Santa Marta Wood-Wren. A proposal for an English
Name will be needed. Maybe avoiding another “Santa Marta xxxx” would be good?”