Tuesday 18 January 2011

The question no one is asking!

Sadly no Birding at the minute due to this week being my exam week at uni. I hope to break this dry spell at the weekend with a trip to Moore NR however. For now, I will leave you with this!:

With the recent events that have occured at Rainham Marshes in London, regarding the presence of a Large Larid sp, World War 3 has broken out on everyone's favourite battleground, Birdforum.
For those of you not in the know, Thursday became a day of panic when Dominic Mitchell reported and blogged about a potential candidate for Slaty-backed Gull at the refuge tip next to Rainham Marshes. This bird looked like a superb candidate for this species so, friday saw the 'big names' of birdwatching descending on the the tip in search of the bird in question. It was seen again and the all important flight views and other characteristics were seen and photographed. Saturday saw the bird vanish, but according to Lee Evans, at least 25 birders are adement the bird was still present if not for part of the day.
A thread on Birdforum ( > >thread here< < ) about the ID of the bird started as a semi-civilised debate about all the features and how classic the bird looked. After the bird had left and people were claiming the bird from the Saturday, carnage broke out and abuse was thrown across the forum. If it was in person, it would definitly have been like a saloon bar fight.

'Lewis20216' wrote:
'"Whistling Swans" with too much yellow than typical
A first year "Slender-billed Curlew" in an undescribed plumage
A grey Varied Thrush
A "Slaty-backed" Gull at the "pale end of the spectrum"
various inconclusive "Elegant Terns" (saw some real ones at the weekend, "ours" are not typical of the median appearance...)

Perhaps birds with plumage & structural abnormality are more prone to vagrancy? Makes you wonder...I hope.

Good luck.

Alan'

Above - 'grey' Varied Thrush, Nanquindo, Cornwall. November 1982(John Miller)

This comment was posted during the middle of the fighting and I noted it, thinking is was an excellent point.
There have been several bird that have turned up that have appeared almost perfect candidates for vagrant birds, but have shown characteristics not regularly seen on classic individuals of that species.
The Varied Thrush that turned up in Cornwall is a great example of this. The pale morph bird that turned up showed a very very rare plumage in this species, yet the only British record (the only European record) was of this morphological variant.
You have to ask the question could this variance could well have something to do with their reason for vagrancy?
I don't exactly have the answer, but I suppose one of the reasons I can think of is that these individuals are outcast from their population so are almost forced to relocate, this could cause their migratory range to increase dramatically which could therefore force them to venture across seas and oceans in search of new habitat.

I am studying Zoology with Animal Behavior at university currently, so I suppose I could look further into this matter as my course progresses.
For now, I hope someone reading this has a simple answer, or has somebody got the guts to tell me that staying in my room revising has got the better of me and I'm talking utter nonsense!

*Also brought to my attention by John Miller is the 'long-billed' Siberian Thrush, the first British record on the Isle of May, Fife in 1954'. At the time, this was a first for Britain and is it just a coinsidence that it happened to be an 'unusual' individual?

3 comments:

Lancashire and Lakeland Outback Adventure Wildlife Safaris said...

Good post Zac - there is an outside gentic chance that the mutation(s) that changes the plumage characteristics also changes the migratory/dispersal patterns, either timing, direction or distance or a combination of two or more of these. It's certainly not beyond the realms of possibilty.
Something you may well examine later in your course.
All I learnt from my degree was that moorhens like food but don't like being food!

Cheers

Dave

Zac Hinchcliffe said...

haha I think your course sounds pretty self-explanatory. It does however sound quite fun! What did you study?

Zac

Lancashire and Lakeland Outback Adventure Wildlife Safaris said...

Believe me Zac sitting in the freezing Bure Marshes in the middle of winter for hours counting how many times a minute flocking and non-flocking moorhens pecked at the grass wasn't fun. Ah the joys of learning ecology in the 70s!

From the thread it looks like someone has found some papers alluding to your/our thoughts - nice one!
Hope the SBG takes up ressidence at Fleetwwod tip!

Cheers
D