Hi David,
Not enough time to address the bulk of your questions, but in my experience
Great-crested Grebes are very cosmopolitan in Australia. I've mainly seen
them on large bodies of fresh water, but have also seen them on nearly
every other type of waterbody you can imagine, including in the ocean at
the Murray River mouth (dodging NZ Fur-seals).
Cheers,
Chris
On Thu, Sep 13, 2012 at 11:02 AM, David Adams <> wrote:
> One the previous two days I spotted a Great Crested Grebe in breeding
> plumage on Wallaga Lake in Beauty Point. What a fantastic bird! This
> location is on the northern border of the Bega Valley Shire just south
> of the Eurobodalla shire. (The border is in the lake, I believe.) By
> road, Beauty Point is about 8km north of Bermagui.
>
> For historical reasons, sightings from this spot are of interest to
> the record keepers in both shires so I sent the info along. It sounds
> like this species hasn't been spotted in the Bega Valley Shire since
> 2007 or in the Eurobodalla Shire since 2008. Based on a suggestion,
> I'm posting a note here on Birding-Aus.
>
> I didn't manage to find the bird again today but it's overcast, windy
> and cold at the moment. The lake is large and complicated and there's
> plenty of other good habitat nearby. Hopefully, I'll reacquire it and
> can post again, if people are interested.
>
> When my wife and I first spotted the bird we were pretty surprised -
> we couldn't even remember seeing one in Australia before (I checked my
> notes and we've seen them here - but not in NSW or the ACT.) Is there
> anywhere in Australia that these birds can be seen reliably?
>
> I was impressed by how long these birds can stay under water - I
> didn't remember that detail. The bird disappears with virtually no
> trace and seems to be able to stay down for a minute or more, although
> I didn't time it.
>
> I'm curious about this species preferred habitats in Australia. I've
> seen grebe species around the world in fresh, brackish, and sea water
> - but I though of Great Crested Grebes as preferring fresher water. It
> seems that I'm wrong about this - but I want to include an observation
> about Wallaga Lake. For those that don't know the area, this is a
> tidally flushed lake so its exact composition and salinity changes a
> lot over time. It was blocked more often than not (extensive silting
> from decades of logging in the hills feeding the streams flowing into
> the lake) but the entrance to the sea has been open for about two
> years without interruption. The lake normally hosts good numbers of
> Black Swans (hundreds), three kinds of cormorants, spoonbills, Silver
> Gulls, Pied Oystercatchers, pelicans, and a range of other likely
> candidates in lesser numbers (Red-capped and Hooded Plovers, Little
> Terns, Caspian Terns, any other wader that passed through, etc.) Until
> this year I had never seen any kind of grebe species on the lake. Not
> once in the better part of 10 years - although I can easily find
> Australasian Grebes in fresh water nearby. Starting about a month ago,
> around two dozen Hoary-headed Grebes showed up. Neighbors have been
> stopping to ask me about "those little ducks". I suspect that the
> water composition has changed in some way (salinity? oxygen? algae?)
> to make it attractive to these species.
>
> Here's a slimmed down excerpt from the Bird Life fact sheet on the
> Great Crested Grebe (link further below):
>
> The species breeds on fresh or brackish waters with abundant emergent
> and submerged vegetation, showing a preference for non-acidic
> eutrophic [I think that this means "nutrient rich and oxygen poor"]
> waterbodies with flat or sloping banks and muddy or sandy substrates,
> usually 0.5-5 m deep and with large areas of open water. Suitable
> habitats include small pools or lakes, backwaters of slow-flowing
> rivers and artificial waterbodies (e.g. reservoirs, fish-ponds, gravel
> pits and ornamental lakes). In Australia the species also utilizes
> swamps, reservoirs, lagoons, salt-fields, estuaries and bays, and in
> tropical Africa and New Zealand it may breed on montane, subalpine and
> alpine lakes up to 3,000 m.
>
> While on the subject, below are some references for this bird - better
> details gratefully received.
>
> I noticed some posts about Great Crested Grebes recently on the
> Canberra birding list, including a link to the Canberra Ornithological
> Group's atlas data:
>
> A visual summary of the data on the COG database for Great Crested Grebe.
> https://docs.google.com/open?id=0B7cBqe3MzqSXZjJEaVI4YjlBV0k
>
> Two were spotted on Lake Tuggeranong on the 10th.
>
> Can anyone offer some background on the Great Crested Grebe population
> in Australia? I've had a look at the new atlas but it doesn't really
> clarify things for me. From a bit of Googling, am I correct in
> gathering that there are three (largely) non-overlapping supspecies
> globally? One in Europe and North Asia cristatus), one in Africa
> (infuscatus), and one here and in New Zealand (australis). That would
> explain the huge bands of territory between here and Asia that the
> bird doesn't reside in.
>
> Bird Life Fact Sheet
> http://www.birdlife.org/datazone/speciesfactsheet.php?id=3639
>
> Geographic differentiation in the Australasian great crested grebe
> Spoiler: They don't think that the NZ population is genetically
> distinct from the Australian population.
> http://www.doc.govt.nz/upload/documents/science-and-technical/DSIS34.pdf
>
> A nice summary page with a few photos:
> http://travelling-australia.info/InfsheetsP/Podiceps_cristatus.html
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