Tuesday 1 October 2013

How can both of these birds be Ruffs?

RUFF  Combatiente  Philomachus pugnax

As reported yesterday, whilst at the Rio Velez I cam across a pair of grey waders feeding together in the shallow water and, at first glance given the marked difference in their respective sizes, immediately thought one Redshank and one Greenshank.  At that point I lifted my binoculars to take a closer look.

"Normal" looking Ruff with yellow legs
Certainly the larger bird had darker legs, almost a blue-grey reminiscent of Audouin's Gull, but the beak was all wrong; short like that of a plover.  So, time spent on this individual trying to establish what other large wader had dark legs despite the body markings which suggested a Ruff.

Very large Ruff with darker legs
Having "sorted" the larger bird I then looked at the small individual, noticing that it was well-marked with a closed ring above the knuckle of the right leg and a coloured and lettered ring on the opposite leg.  Again, no sooner had I taken a closer look through the binoculars than I once more had to change my identification from a juvenile Redshank to a second Ruff; very obvious once I looked at the beak and the overall colouring.

Ruff marked "PO"
But the question remains; why the marked difference in sizes between the two birds which wee feeding close together?  The smaller bird looked fine for a Ruff in size terms but the second was at least 25% larger - but with the same markings and bill size other than the darker legs.

The two Ruffs together with the larger individual to the right
So, the question is can anybody out there help me solve this conundrum.  Is it two Ruffs of marked size difference or am I missing something?   Please leave your comments or email me at: rcnwright@gmail.com.  (I really must get the new "Facebook" site dedicated to my blog/website up and running which would make this much easier for birders!)

Smaller Ruff wearing red ring with white number tag

Larger Ruff with grey-blue legs


 
 
Check out the accompanying website at http://www.birdingaxarquia.weebly.com for the latest sightings, photographs and additional information.

2 comments:

  1. Hi Bob, Large ones a male and small one a female or reeves. All the best Mick

    ReplyDelete
  2. Hi Bob, I hope this comment finds both you and Jenny very well. 25 days to finishing full time work.....what shall I do then.....ah!!! I know, let's do more birding!!!!. Anyway Bob, superb blogs as usual and an interesting puzzle you raised regarding your Ruffs. Having researched 'Collins Bird Guide' I can concur with Mick's comment that there is a marked sexual size difference and males are somewhat larger than the females or 'reeves".
    I will be going out at 0700 this morning to see if there is any evidence yet of any autumn Thrush movement.
    How has raptor migration been with you? I have seen a few Marsh Harriers and Hobby passing through but no Honey Buzzards sadly this year.
    2 Common Cranes seen from my garden in September was a poser for me. Were they wanderers from the Norfolk Broads population or genuine european migrants.......I like to think the latter given the height they were at, also, I beleive the Broads birds are quite sedentary....interesting food for thought Bob.

    Take care for now and love to Jenny

    Paul

    ReplyDelete