|Alternative English names: Pied-billed
Grebe (subspecies of)
Alternative scientific names: Podilymbus podiceps (subspecies
Spanish names: Zambullidor de Atitlan
Mayan names: Poc
This species was previously known only from Lake Atitlan in
southern Guatemala, where it is extinct in its pure form.
There has been a lot of debate in recent years about the exact
status of the grebes that are still found on Lake Atitlan.
In 1989 Anne LaBastille announced that the Atitlan Grebe,
or Poc as it known locally, was extinct. However, this was
after having just recorded two pairs of them. The assumption
was presumably that this was not a viable population and that
they could not recover. Her book ‘Mama Poc’ makes
interesting reading for anyone interested in the birds of
the region. It is probably the most closely monitored and
understood decline and extinction of any bird species. However,
many people have wondered whether they are still present;
for instance, it may not be known how long the individuals
last seen by LaBastille could have lived, though a later study
by Laura Hunter also led to the announcement of their extinction.
Unfortunately, I have not yet had the chance to read any of
her work. The problem is made more difficult by the fact that
there are now Pied-billed Grebes on the lake. A trip report
by Graham Speight mentions the confusion in the situation
and describes how the warden was claiming that there were
still 62 pairs of Atitlan Grebes on the lake in 1990. Apparently,
according to Grebes of the World (which I have not had the
chance to see) in 1986 an attempt was made to round up the
remaining birds as part of a captive breeding program. During
the round up 36 of the birds flew away. As the Atitlan Grebe
was flightless, this implied that these birds were hybrids.
Howell and Webb describe seeing a large grebe in May 1989,
along with a smaller bird that clearly was a normal Pied-billed.
They discuss whether there may have been hybridization between
the two forms and that the original pure Atitlan Grebes may
now be gone. They also raise doubts about whether they were
ever a true species.
During my visits to the lake I tried to track down some of
the people that worked with Anne LaBastille and Laura Hunter.
Even amongst many of the people who worked on the project
there was a difference of opinion, though this seemed mostly
to arise because they were unfamiliar with the situation regarding
the Pied-billed Grebe and they were still reporting the Poc
to be present, because they were misidentifying the smaller
species. Probably my most reliable contact was Edgar Bauer
Jr (who runs the Posada Lodge Chuitinamit across the bay from
Santiago, tel 232 8677). He and his father, with the same
name, worked closely with LaBastille for many years and he
was present when she made her last survey of the lake. He
is adamant that there are no pure Atitlan Grebes on the lake
anymore though he says that there may still be some hybrids.
I searched most of the main reedbeds on the western half of
the lake. The only grebes I saw were near San Juan. Unfortunately,
at the time I had not seen that any Pied-billed Grebes for
awhile, so I found it difficult to comment on the condition
of the birds I saw. From what I can gather, the Atitlan Grebe
was bigger than Pied-billed Grebe, had a darker head, was
flightless, had a bigger head and bill and kept its summer
plumage of dark bill band and bib throughout the entire year.
My lack of experience makes the size difficult for me to judge,
but my rather poor photos show the grebes beside some Ruddy
Ducks (which were a bit smaller) and some American Coots (a
bit bigger). The bill size and shape is also hard to judge.
It seems that the drawings in Peterson and Howell and Webb
may be a bit of an exaggeration when you compare it with the
photo of an Atitlan Grebe that was given to me by my guide
Guillermo (it was taken by Anne LaBastille and I do not yet
have permission to use it. I include it here with some trepidation
in the hope that she will not mind it being used for non-profit
purposes in a discussion of the species she worked so hard
to protect. If anyone has her contact details, can they please
send them to me so I can contact her directly). The birds
I saw did not appear to have particularly dark heads and had
a distinctly darker crown that was offset by a paler face,
which is a Pied-billed feature. However, all the birds I saw
were in full summer (alternate) plumage between the fourth
and the sixth of January. According to ‘The Sibley Guide
to Birds’, Pied-billed Grebes should only be in summer
plumage between February and September, though he is talking
about birds in North America and it may be different further
south. I have seen Pied-billed Grebes in full summer plumage
with stripy young in southern Honduras as late as early November,
so this may be normal for the region.
I leave you to look at the photos and decide for yourselves.
I would be interested in any comments from people who are
more familiar with the species than I am.
This site has info and says it has the call of the Atitlan
Grebe, but I could not play the recordings
‘Historic updates’ on the Atitlan grebe contain
some good information. Seven pages of information presented
as a case study for a school activity.
There is a lot of info in The Anne LaBastille papers, which
are held at Cornell.
One specimen is mentioned in the collection of the Natural
History Museum of Los Angeles County
LaBastille, A. (1974) Ecology and management of the Atitlan
Grebe, Lake Atitlan, Guatemala. Wildlife Monographs No. 37.
Hunter, L. A. (1988) Status of the endemic Atitlan Grebe
of Guatemala: is it extinct? Condor, 90, 906-12.
Howell, S. N. G. and Webb, S. (1995) A guide to the birds
of Mexico and Northern Central America. Oxford University
LaBastille, A (1990) Mama Poc: an ecologists account of the
extinction of a species. W. W. Norton and co.
Land, H. C. (1970) Birds of Guatemala. Livingston.