Dear all,
with regard to several issues that are being discussed about the Rockhopper
Penguin split:
- The authors dated the split between both lineages of Rockhopper Penguin by
applying a range of estimates of mutation rates per nucleotides per million
years from previous studies. Please note that the authors applied widely
different estimates and arrived at a spectrum of divergence values ranging
from 680 000 years ago to 140 000 years ago. Even though these values are
very different from one another, they can all be considered "recent" in
terms of the split between two sister taxa. Roughly speaking, in most bird
lineages, the split between currently recognized sister species happened 0.5
- 3 million years ago according to present estimates.
- The authors only sampled individuals from Crozet and Kerguelen (both
pertaining to the new Southern Rockhopper Penguin) and Amsterdam and Gough
(both pertaining to the new Northern Rockhopper E. moseleyi). The subspecies
E. c. filholi is indeed the one that occurs on Crozet and Kerguelen, and was
therefore included by the authors. However, they point out that it is not
always recognized and is sometimes subsumed under the nominate form. Those
who recognize filholi restrict the nominate form to the Falklands, South
Georgia and nearby islands. The authors admit that they haven't sampled the
nominate form E.c.chrysolophus sensu stricto, and they suggest future
studies should concentrate on those populations as well. However, in the
meantime, anyone who accepts these authors' findings would have to maintain
filholi as a subspecies of E. chrysolophus (Southern Rockhopper).
- This study does have important conservation implications, as the Northern
Rockhopper Penguin turn out to be a bird in steep decline due to
human-induced overfishing and climate change (changes in sea water
temperature), with a current estimate of only 350 000 pairs. Before this
study, when all populations were lumped into one all-encompassing species,
the precarious status of the northern form went unrecognized. I believe that
any angry diatribe directed against the authors of this study is highly
inappropriate. Scientists are rarely (if ever) the recipients of
conservation money that goes into the protection of "their new splits". And
even people who are reluctant to recognize this new split should be
concerned about the survival of the Northern Rockhopper Penguin, whether you
view it as a subspecies, species or some other taxonomic unit. Accusing the
scientists of serving their own purpose (by demanding conservation money) is
akin to shooting the messenger!
Have a good day everyone,
Frank Rheindt
---------------------------------------------
============Frank E. RHEINDT================
DEPARTMENT OF GENETICS
University of Melbourne
POSTAL ADDRESS:
Museum Victoria - Sciences Department
GPO Box 666
Melbourne 3001
Victoria
Australia
Telephone: 8341 7426
Fax: 8341 7442
E-Mail:
LL: 4181 (Gra.pic.)
=============================================
From: Ian May <>
To: richard baxter <>
CC: birding-aus <>
Subject: Re: [Birding-Aus] Split of Rockhopper Penguin
Date: Wed, 07 Feb 2007 14:33:57 +1100
Here we go again!
How many have twitched this one?
Or perhaps "The findings have important conservational implications" is
code for "We want more money?"
or is Global Warming to blame.
Regards
Ian
richard baxter wrote:
For those on birding-aus interested.
Regards
Richard Baxter
Tony Pym <> wrote:
A paper in the journal Molecular Ecology by Pierre Jouventin et al has
shown, as expected, that the Rockhopper Penguin should be split and
recognised as two species, E. chrysocome and Eudyptes moseleyi . For
information, here's an abstract:
The taxonomic status of populations of rockhopper penguins (Eudyptes
chrysocome) is still enigmatic. Northern populations differ from southern
ones in breeding phenology, song characteristics and head ornaments used
as mating signals. We conducted a molecular analysis using mitochondrial
DNA sequencing to test if there is a gene flow barrier between northern
(subtropical) populations and southern (subantarctic) populations in
relation to the Subtropical Convergence, a major ecological boundary for
marine organisms. Sequences of the control region and the ND2 gene were
analysed in rockhopper penguins and in the macaroni penguin (Eudyptes
chrysolophus), a closely related species. Genetic distances and
phylogenetic analyses showed a clear split into three clades, two
rockhopper clades and the macaroni penguin. Moreover, ÈST and gene flow
estimates also suggested genetic structuring within the northern
rockhoppers. Our results add further support to the notion that the two
rockhopper penguin taxa, often considered as two subspecies, can be
recognized as two species E. chrysocome and E. moseleyi. The divergence in
mating signals found between these two taxa seems to have occurred
recently and relatively rapidly. Thus, the behavioural changes may have
been enough to isolate these taxa without the need for morphological
differentiation. The findings have important conservational implications,
since E. moseleyi is far less abundant than E. chrysocome, but more
populations may warrant an uplisting to endangered status if full species
status should be recognized for more subpopulations.
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