Thursday, 28 April 2011

Just back from another boat survey off the Western Isles.  This time last year a friend did this survey and had 3 White billed Divers so after the birds last month and the one in Jan we were obviously expecting to see them this month too.  I wasn't really expecting to see as many as we did though.  I have to stress that not all of them will be submitted as there was quite a lot of swell making it difficult to keep on them and even harder to get record shots of them.  We managed 3 definite birds and another 4 that were pretty likely to be White bills but the views were just not quite enough to submit a description for.

Here's a couple of them that Bill Aspin did manage to nail with the camera

This bird stood out at about 700 metres with bins the bill was so obviously long and pale

Even though it was close (about 250 metres) this one wasn't easy due to the light conditions.  We had 3 other birds like this including 2 together but Bill couldn't get anything with the camera to make them worth claiming.

Ken Shaw and Andy Carroll who have pretty much been instrumental in re-writing the status of White billed Diver have told me in the past that they like deeper water than Great Northern, based on birds they have found in spring from land on the west coast of Scotland.  BWP states that the usual depth for Great Northern is probably around 4-10 metres but that birds have been caught in nets up to 70 metres down.  Being on a boat with all sorts of electronic gauges we've checked the depth for Great Northerns and although it's only a small sample size they seem to be in water up to 25 metres deep.  The White bills however, including all the probables have been in water between 36.7 and 46 meters depth.  If the probables were all White bills that's a sample of 10 birds this year in water with shallower areas nearby that they appear to shun, we've also never seen one with a Great Northern, they do seem to keep apart from one another.  OK so it's not Martin Garner's Birding Frontiers blog but it's all interesting stuff.


Mike Watson said...

Sounds like a birding frontier to me! Well done to you and secret squirrel!

Yorkslister said...

Secret Squirrel? I NEED information about that name!

Mike Watson said...

Nothing sinister at all, A few local birders have commented that Secret Agent Bill never told us when or where he was going but all we have to do now is to read your blog to find out...Good work with the Yellow-bills, look forward to seeing some breeding plumage birds soon, Mike