Christmas Bells

Christmas Bells
Christmas Bells - Blandfordia nobilis

Thursday, August 06, 2009

A rare glimpse of a Mangrove Heron

OK, I know that "Mangrove Heron" is the old name for this bird, but I find it hard to call this bird a "Striated Heron" - for this form shows only a thin white patch on its rufous chest - hardly my idea of "stripes". I prefer the old name of Mangrove Heron. (Butorides striatus) As usual, the "scientific name" is shown, to avoid complete confusion.At the risk of boring everybody, this is the problem with international rules of nomenclature for birds. Birds which have a wide distribution, as happens with many sea birds, and "waders", as well as some migrant Australian birds which travel into Asia, are meant to carry the name first ascribed to them. So names which were popularised in Australia, in the old-fashioned Bird Books (in this case "Mangrove Bittern") have been forced to give way to the international names. This bird was described by Linnaeus as Butorides striatus. That name was given to this bird by Linnaeus, in 1758, so clearly it was not from an Australian specimen (prior to European settlement of Australia). This bird is recorded from Africa, North and South America, Asia and the Pacific, as well as Australia, down to Mallacoota in far-eastern Victoria. It is uncommon south from Sydney. So this is an interesting record for Bermagui, NSW (Baragoot Lake) on Friday 31 July 2009, at 2:30pm.

I will report this "sighting" to the Canberra Ornithologists Group, as someone there will be able to tell me how to officially record this sighting (other than on my Blog and David's Blog).*** See update, below.

I should acknowledge that when I first saw this bird I thought it was a "Reef Heron", but when I developed the images, several days later, I realised how much rufous this bird has, thus ruling out that original ID. The "Reef Heron" is slaty grey (or white). It is now officially classed as an Egret. (Pacific, or Eastern, Reef-Egret).

My clearest photo of the Striated (or Mangrove) Heron.
It shows the hunched posture adopted by this bird.
It also shows the light green patch of skin in front of the eye,
which is typical of this species.
Click to enlarge the image.
In further "old-fashioned" bird language, this pose is typical of many "Bitterns". Wikipedia explains what I mean: "Bitterns are a classification of wading birds in the heron family Ardeidae. Species named bitterns tend to be the shorter-necked, often more secretive members of this family." Many Bitterns adopt this hunch-backed pose, when "skulking around" looking for food. But this bird was out in the open. But the hunch-back appearance is normal for this species.

My Blogging colleague David Young has reported on this sighting, with a very nice photo. So, this report serves as confirmation of David's record. David was standing closer than I was, and his image is nice and clear, and shows the rufous colour very well.

It seems that juvenile birds are prominently striped. Also, as with many birds which have a wide range, there are local variations in colour. There are apparently 22 sub-species recorded, of which two are recorded in Australia. There is a full page of Australian images of this species showing the variability of this species.

This bird appears to fall into the group described as a "rufous morph" (colour variant). This image shows the rufous colour better than my others.Here is a photo of this bird in flight, showing its habit of flying with the neck bent (tucked in).By contrast, here is a White-fronted Heron in flight (calling as it flies). This image was taken at the same coastal inlet, a mere minute or two before the Mangrove Heron flew in, and then flew out again.
This is my "art photo" for the day. I love the shadow on the sand as the bird flies away.If you click to enlarge the image, you can clearly see the shadow of the beak, and even of the feet and the separate shadow of the hind toes. How sweet is that?

The bird's shadow looks like a delta-wing plane - revealing the inherent efficiency of its flight, created by adopting what looks to us as a slightly awkward pose. Nothing off the sort - it is aerodynamically efficient!

*** Update:
This record has now been reported on Birds Australia's "Birdline NSW"
See this link.
My report is registered on Friday 31 July - the date of the sighting.
Anyone can join. The posts are "moderated" and it might take 24 hours to get your name "registered" and your record published. They will send you a log-in once you have joined, but my report was accepted on the basis of what I sent in, just by applying for registration. In other words, prior registration is not required.
So, as I said, anyone can report an unusual sighting.
Obviously, a clearly recognisable image and a decent locational report, etc helps to maintain the standards which one would expect of Birds Australia.

8 comments:

David said...

Hi Denis,

Thanks for the confirmation of the sighting.
I hope to see more of your shots from the trip soon.
Careful what you post of me
(good side only please) :)
Remember I still have the ones of the cliff climbing :)
cheers,

Dave

Denis Wilson said...

Hi David
A few more photos still to come, of the trip.
No more photos of you to be published, though. But, don't worry, David, you only have good sides!

tilcheff said...

An extremely interesting post as usual, Denis!
I love the last photo with the B2 Stealth shadow too.
Regards!

Snail said...

That's an excellent sighting! I saw one at Cairns ages ago, but only after someone pointed it out ... right under my nose.

Denis Wilson said...

Hi Snail
Thanks.
Probably more usual in Cairns, than Bermagui.
Still, they are always nice to see.
Denis
PS I met up with Dave Rentz last weekend in Canberra, at CSIRO Entomology seminar on moths, and we mentioned you, now in FNQ.
Cheers
Denis

Denis Wilson said...

Hi Nickolay
Thanks for the commnent.
We obviously both like unusual effect of the shadow.
Normally one tends to think of Herons as awkward looking, in flight, but that aspect shows how efficient the pose really is.
Glad you liked it too.
Denis

Shane Kneipp said...

I have just seen my first Mangrove Heron on mudflats just in front of the Queensland Art Gallery in Brisbane. I have hung around the Brisbane River for years, but have never seen one before.

Denis Wilson said...

Hi Shane
Nice to hear of your encounter with a Mangrove (Striated) Heron.
Brisbane would be more usual range for this species than Bermagui (South Coast, NSW).
But always a nice bird to identify.
Cheers
Denis Wilson