Proposal (511) to South
American Classification Committee
A). Split Eudyptes
moseleyi from E. chrysocome
B). Add E. moseleyi
to the main SACC species list
Background
Crested penguins breeding chiefly at the remote
subtropical “maritime” Tristan da Cunha and Gough Islands (ca. 85% of the population), along with small numbers at Amsterdam
and St. Paul Islands (taxon moseleyi)
have, until fairly recently, been treated as a subspecies of the well-studied
subantarctic Rockhopper Penguin E.
chrysocome. A growing number of recently published papers have induced most
authorities to accept moseleyi as a
separate species. Subspecies filholi
of subantarctic Heard Island and Macquarie Island has not been recorded in the
SACC region, and its taxonomic position is controversial. This proposal is
necessary due to the post-1995 appearance of documented vagrant Eudyptes [chrysocome] moseleyi
penguins at the Falkland Islands.
A NO vote for part a) disqualifies a vote for
part b). If added to the SACC list, a decision on an English vernacular name
will also be required, because at least five different names are available.
(A). Split Eudyptes
moseleyi from E. chrysocome.
Evidence
Jouventin (1982) provided sonograms of moseleyi and chrysocome showing that the former has considerably lower-pitched
frequency calls, and first drew attention to differences in behaviour, noting
also the better known distinctions in morphology (moseleyi is larger) and plumage (moseleyi has exceedingly long laterally splayed head plumes, unlike
the short, narrow plumes in chrysocome
and several other Eudyptes penguins);
visually these penguins look very different. He suggested that moseleyi could be elevated to species
rank.
A more thorough study (Jouventin et al. 2006) included DNA sequences of
the ND2 gene and mitochondrial control region, breeding cycle, further studies
of voice and of head ornamentation; the conclusion reached was that moseleyi warrants species rank, and also
considering that “divergence in mating signals …. may
have been enough to isolate these taxa without the need for morphological
differentiation.” Jouventin et al.
(2006) synthesized the vocal and morphological evidence as follows: “The
northern populations have a much lower-pitched nuptial call (2-3 kHz for the
maximum frequency vs. 6-7 kHz in the southern populations) with a completely
different structure (longer modulated phrases and fewer syllables), and longer
(79-81 mm vs. 66-68 mm) and denser yellow crest feathers than the southern
form.” Biogeographically, the main breeding areas of moseleyi (subtropical) and chrysocome
(subantarctic) are separated by the Subtropical Convergence, which divides
subantarctic and subtropical waters (see the especially synthetic Fig. 1 in
Jouventin et al. 2006).
Thereafter, Banks et al. (2006) analysed 1441 nucleotides of three mitochondrial
genes to 1) reconstruct the phylogenetic relationships, and 2) to compare the
genetic distances between the Rockhopper taxa and compared this with the
uncorrected pairwise distances between other sister penguin species.
Phylogenetically, all three taxa (moseleyi,
chrysocome, filholi) were monophyletic with the latter two representing a
sister position to one another. With regard to the genetic distances, in the
first gene (ribosomal), chrysocome–moseleyi was more divergent than Spheniscus mendiculus–S. humboldti (two
species on the SACC list), and S.
magellanicus–S. demursus, both of
which showed a similar divergence as chrysocome
– filholi. The cytochrome b
analysis showed a similar genetic distance between chrysocome–moseleyi compared
to filholi–moseleyi but slightly less than E.
pachyrhynchus–robustus and mendiculus–humboldti.
In the final gene test (cytochrome oxidase), chrysocome–moseleyi came
out as being more divergent than
mendiculus–humboldti, than E.
chrysolophus–schlegeli and chrysocome-filholi, each of which showed a
similar divergence. In synthesis, genetic (mtDNA) data supports the split of moseleyi from chrysocome, but the position of filholi
is more open to alternative interpretation.
Demogin et
al. (2010) studied the reversed hatching asynchrony comparing the egg size
dimorphism in the three Rockhopper taxa, finding that chrysocome has considerably larger volume eggs and higher breeding
success than either moseleyi or filholi.
In addition to the above, there are also
published data on host-exclusive and non-exclusive lice in the different
Rockhopper taxa if anyone needs more evidence.
Most recent authorities have accepted the moseleyi split and sometimes also the filholi split, based principally on the
work of Banks et al. 2006. The one
exception is Christidis and Boles (2008), who stated “Genetic distances between
the northern [moseleyi] and southern
[chrysocome] forms were about half
that between E. chrysocome (sensu lato) and E. chrysolophus.’’ Note that I was unable to find this data in
Banks et al. 2006, or in any other
paper; indeed this statement actually contradicts the study of Banks et al. 2006. They went on to state… “The
observed level of difference between northern and southern forms of E. chrysocome is comparable to those
between the pairs E. chrysolophus-–schlegeli
and E. pachyrhynchus–robustus
(Ritchie 2001), which are here treated as conspecific.” Oddly, the Ritchie (2001) paper deals with
DNA markers relating to Pygoscelis
adeliae. I am at a loss to explain or qualify any of the comments made by
Christidis and Boles (2008), which appear to be erroneous.
Recommendation
I would suggest that the collective evidence
strongly favours a YES vote that would recognise Eudyptes moseleyi as a valid species. A NO vote would imply that
SACC has to review the validity of various penguin species on its main list and
Hypothetical list, with a view to lumping, in particular Spheniscus mendiculus into S.
humboldti, S. magellanicus into S. demursus, E. robustus into E.
pachyrhynchus (there is a reasonable case for this anyway), and E. schlegeli into E. chrysolophus.
(B). Add Eudyptes
moseleyi to the main SACC list.
Evidence
Matias et
al. (2009) documented the first four records of Eudyptes moseleyi at the Falkland Islands, coming from East
Falkland from late November to late December 1995, and again in late November
1996, at Kidney Island in mid December 2004, and at New Island in late November
2004 with two published photographs from New Island and McBride Head, East
Falkland. The diagnostic, long splayed and drooping head plumes and
blunt-tipped supercilium in both photographs leave no doubt regarding the
identification while the ventral flipper pattern, visible in one photograph,
provides yet more diagnostic features. Subsequently, another bird was
photographed on the Falklands in December 2009, and another in December
2010-January 2011; photographs available on Internet.
Recommendation:
I recommend a YES vote to add E. moseleyi
to the SACC list as a confirmed vagrant (V) to the Falkland Islands. A NO vote
would refute the identification of the published records.
Literature cited
Banks, J., Van Buren, A., Cherel, Y.
& Whitfield, J.B. 2006. Genetic evidence for three species of Rockhopper
Penguins, Eudyptes chrysocome. Polar Biology 30: 61–67.
Christidis,
L. & Boles, W.E. 2008. Systematics and taxonomy of Australian birds. CSIRO
Publishing, Collingwood, Australia.
Demongin, L.,
Poisbleau, M., Raya Rey, A., Schiavini, A., Quillfeldt, P. Eens, M. &
Strange, I.J. 2010. Geographical variation in egg size dimorphism in rockhopper
penguins. Polar
Biology 33:469–476.
Jouventin,
P. 1982. Visual and vocal signals in penguins, their evolution and adaptive
characters. Advances in Ethology 24:
1-149.
Jouventin, P., Cuthbert, R. &
Ottvall, R. 2006. Genetic isolation and divergence in sexual traits: evidence
for the Northern Rockhopper Penguin Eudyptes moseleyi being a sibling
species. Molecular Ecology 158: 3413–3423.
Matias,
R., Catry, P., Pearman, M. & Morrison, M. 2009. Vagrancy of Northern
Rockhopper Penguins Eudyptes moseleyi
to the Falkland Islands. Marine
Ornithology 37: 287–289.
Ritchie,
P.A. 2001. The evolution of the mitochondrial DNA control region in the Adelie
Penguins of Antarctica. Massey Univ., Palmerston North, New Zealand.
Mark
Pearman, October 2011
__________________________________________________________________________
Comments from Robbins: “YES,
to elevating moseleyi to species
level. All data suggest that this is a
split long overdue. Also, yes to adding
this to the SACC list.”
Comments from Stiles: “YES. There seems to be good evidence from a
variety of sources for this split, along with adding moseleyi to the SACC list.”\
Comments from Pérez: “YES. Complete evidence supports this split, including morphological,
genetic, and behavioral information. Christidis and Boles (2008) were against
the split, based on genetic distances, but this seems to be a mistake because
Jouventin et al. (2006) showed the complete opposite pattern. Also YES to
adding this species to the SACC list. Observations of both taxa (E.
chrysocome and E. moseleyi) in Falkland Islands, assuming lack of
morphological overlap (as suggested by evidence given by Mark in the proposal),
support species status. However, it would be interesting to do a population
genetic study in Falkland Islands to confirm there is no genetic introgression
between these taxa, as I don’t think published evidence discard this
possibility (no more than five E. chrysocome individuals (no moseleyi
for Falkland Islands) sequenced; Banks et al (2006)).”