Ferruginous Ducks

A female Ferruginous Duck turned up in the Norfolk Broads a couple of years ago.  Eventually news of its presence reached the news services and lots of people went to see it.  Most of them were happy with the ID but one or two of the locals who'd originally found it and watched it for prolonged periods felt that it wasn't quite right - and was therefore a hybrid.  Last winter it returned, this time accompanied by what was certainly a hybrid, but the identity of the original bird was still doubted by some people.  I've heard three reasons cited why this bird may have been a hybrid:

1. The head shape was wrong, looking too rounded for much of the time and lacking the peak that is associated with pure Ferruginous Ducks.  My own views confirmed that this was the case - although on occasion it could look quite peaked, most of the time it looked very round.  But was this really wrong for females?  Certainly a male looking like this would and should arouse suspicion, but I wasn't quite convinced it was wrong for a female.  However I wasn't experienced enough with females to be sure.
2. The bill shape was considered not quite right.  Personally I thought it looked ok: although at some angles it sometimes looked a bit dubious I couldn't see anything hugely concerning in the bill shape.
3. The white on the belly had been observed to be too indistinctly-bordered for a pure Ferruginous Duck.  I got a couple of brief views of its belly and to be honest I didn't think it was too indistinct.  Sure it wasn't as neat and tidy as it can be on a male, but it wasn't bad.

Personally I suspected it was the genuine thing, a pure Ferruginous Duck.  But although I've seen a few Ferruginous Ducks they've all be in the UK where any record is tainted with the possibility that it's escaped from a collection and may not be pure.  Also most of the birds I've seen have been males.  I simply wasn't experienced enough with wild female Ferruginous Ducks to be able to make a watertight case for it being a pure bird.  It certainly wasn't a first-generation hybrid but a hybrid backcrossed with Ferruginous Duck would be feasible in captivity and some people felt this was the most likely ID.

Ferruginous Duck, Cockshoot Broad, 12th November 2011

In Sicily I got the opportunity to study a number of Ferruginous Ducks in the wild that were free from the curse of uncertain provenance and were unlikely to be hybrids (at least not all of them!).  I learnt the following:

1. The rounded head shape shown by the Norfolk Broads bird was perfectly normal for female Ferruginous Duck.  Just like the Norfolk bird, the females I observed in Sicily changed their head shape according to posture, sometimes looking peaked but most of the time looking rounded.  I could see no difference in head shape between the Norfolk bird and the birds in Sicily. 
2. The apparent bill shape varied too.  Some birds, some of the time, seemed to have much less impressive bill shapes than the Norfolk bird.  Of course this has more to do with angle to the observer than anything else, but there did seem to be a little variation in the bill shape - some females seemed to have fractionally shorter and more concave bills than expected.
3. Females seen in flight and rearing up clearly showed variation in the belly pattern.  Some were less well-defined than the Norfolk bird.  One bird was much less so, although I did wonder if the poor definition on that bird wasn't caused by dirt rather than actual plumage pattern.

 Ferruginous Duck, Granelli (Sicily), 1st May 2012

Ferruginous Ducks, Granelli (Sicily), 29th April 2012

I noticed a couple of things about the males too that I've sometimes wondered about when I've observed this on birds in Britain:

1. The head can look rounded on males too, though with prolonged viewing it always reverted to the classic peaked shape.
2. The contrast between the breast and the flanks varies according to angle to the light.  The same bird can change from having no discernible contrast whatsoever between the colour of the breast and the colour of the flanks to having such a strong contrast that it made me think for a moment that I must have found a hybrid. I knew this was the case on some of the British birds I've observed but it was reassuring to see that it was also the case on genuine wild birds in Sicily.

Ferruginous Ducks, Granelli (Sicily), 29th April 2012

Lots more photos of Ferruginous Ducks from Norfolk and from Sicily at http://www.gobirding.eu/Photos/FerruginousDuck.php

More on Sparrows

I just posted about the variation in sparrows on Sicily, but there's one more thing that aroused my curiosity. Some of them seemed to have some grey in the crown.  Now for a species that was once half House Sparrow that might not seem very unexpected, but I've never seen a photo or description of an Italian Sparrow with grey in the crown.  I might expect it in northern Italy, where any ongoing gene flow with House Sparrow is most likely to be prevalent, but not in Sicily.

So two questions.  

Firstly, was this really grey in the crown, or was it just buffy-grey tips to the feathers that are remnants of juvenile plumage?  Or do adults have buffy-grey tips to the crown feathers at all in winter?  I think nearly all the photos I've seen of Italian Sparrow have been taken in spring and summer (when most visitors go to Italy I suppose), so maybe it's perfectly normal, just something I've not come across before?

Secondly, if it is really grey in the crown and not just the remnants of winter or immature plumage, does this occur throughout Italy?  I don't think I've ever seen it illustrated or referenced as within the range of variation of Italian Sparrow.

Italian Sparrow, Etna South, 25th April 2012

Italian Sparrow, Monteluce (Vendicari), 28th April 2012

When Italian looks Spanish

I was fascinated by the sparrows in Sicily.  Some of them looked like textbook Italian Sparrows while others looked pretty much like textbook Spanish Sparrows.  Apparently they're all Italian Sparrows, despite their Spanish appearance.  Many flocks contained both types of birds and anything in between.

If I've understood correctly, Italian Sparrows were originally hybrids between House Sparrow and Spanish Sparrow, but the hybrids have become so stable and isolated from both House Sparrow and Spanish Sparrow that they can now be considered a species in their own right.  The posh term is homoploid hybrid speciation, I think.  You can read all about  it here (which I discovered from this Surfbirds discussion - thanks to Brian & Alex).

I wonder though... are they really all that stable and isolated, all the way across their range?  For most of Italy, where they all resemble textbook Italian Sparrows (so far as I know - I've never been to most of Italy) that makes sense to me.  But here in Sicily, where I'd struggle to separate many of them from Spanish Sparrows, could it be that they are still subject to ongoing (or at least very recent) genetic exchange with Spanish Sparrows?  Or are some of them really Spanish Sparrows?

Anyway, here are some pics showing some of the variation:

Italian Sparrow, Siracusa, 23rd April

Italian Sparrows, Capo Murro di Porco, 2nd May

 

 

 

Italian Sparrows, Monteluce (Vendicari), 29th April

 

Italian Sparrow, Riserva Naturale Orientata Fiume Ciane, 23rd April

 

Italian Sparrow, Valle di Templi (Agrigento), 27th April

 

Italian Sparrow, Capo Murro di Porco, 3rd May

 

Italian Sparrows, Riserva Naturale Orientata Biviere di Gela, 28th April 2012

 

Italian Sparrow, Monteluce (Vendicari), 28th April 2012

 

Italian Sparrows, Granelli, 29th April 2012

  

Italian Sparrow, Etna South, 25th April 2012

Here are a couple of females... some of these looked more distinctive than some female Spanish Sparrows while I doubt if others could be safely separated from House Sparrow.

  

Italian Sparrow, Capo Murro di Porco,24th April 2012

 

  

Italian Sparrow, Etna South, 25th April 2012

Just a Pied Fly?

No, I'm not talking about the Yorkshire "Atlas Flycatcher" whose DNA surprised everyone, this is about a female flycatcher I saw in Sicily recently.

First impressions were a grey bird with a prominent pale collar and an obvious pale rump.  I knew Pied Flycatcher could show a pale rump but I'd never seen it so obvious on a Pied, and I don't recall seeing Pied with such a pale collar before either.  This bird had a white patch at the base of the primaries, bigger than on many Pied Flycatchers, and my suspicions turned to Collared Flycatcher.  I couldn't recall the finer details of what to look for in tail and tertial pattern so took some photos and hoped I'd be proved right when I got home.  I had a nagging doubt - I'd seen Pied Flycatcher with this much white on the primary bases and ideally I'd hoped to see more on a Collared.

Well I'm back home now and I think my doubts were well-founded. Here's why I now think it was a Pied Flycatcher, not my first female Collared...

• White at the base of the primaries not extensive enough - not reaching beyond the primary coverts
• White on the outer tail feather broadest at the base (where it extends on to the inner web) and fizzling out at the tip - should be the other way round on Collared apparently
• Although it gave the impression of having quite cold grey upperparts I think that impression was influenced by the grey nape and rump - the mantle and scapulars look quite warm brown in the photos
• I don't think the upper tail-coverts don't look dark enough for Collared
• Tertial fringes possibly not narrow enough for Collared?

 

Pied Flycatcher, Riserva Naturale Orientate Biviere di Gela, 28th April 2012

Now some questions:

1. Are the contrastingly warm gingery ear-coverts significant for its identification?
2. How normal is it for Pied Flycatcher to show such an obvious pale greyish collar and pale rump?
3. Do you agree it's just a Pied Flycatcher?
4. What do female Pied x Collared hybrids look like?

And now just for fun, here are a couple of straightforward vagrant male Collared Flycatchers from my archives:

Collared Flycatcher, Holme, 8th May 2011

Collared Flycatcher, Southwell, 2nd May 2009

Volcano

A few images of Mount Etna erupting to kick off this new blog:

Mount Etna, 23rd-24th April 2012