I deliberately didn't put '?' as my feelings are not in the slightest inclination to question either the authenticity of the purity of our birds genes, nor it's origins.
We can never be 100% sure, but that is more or less true of nearly all, if not all Ferruginous Ducks that occur in Berkshire, unless a colour ringed bird can be traced to it's origins.
So, and I do not mean to sound defensive, there would be no point, but why have some people in the bird news community decided to slate this bird as escaped because it has a ring?
Do they know something I don't, did they somehow see the tiny numbers and letters on it's BTO type ring? No of course they didn't, it is just easier to make negative assumptions. But why I have no idea?
I have looked at all the reasons and arguments for it to be considered a hybrid and none of them add up, it is a genuine Ferruginous, most probably an adult male just completing it's moult from eclipse.
It doesn't especially add more argument to it being wild, but there is a fair bit to read if one wants to and evidence of bonfide ringing of wild birds...of course.
http://www.gobirding.eu/Photos/FerruginousDuck.php
http://pewit.blogspot.co.uk/2011/10/ferruginous-duck.html
And on to ringed birds, which there is little data:
http://cr-birding.org/taxonomy/term/3278
http://www.euring.org/edb/species-maps/sp02020.htm
The latter link reveals no birds have been recovered since 2010.
The following link is a 51 page study on the European conservation program in 2006
http://ec.europa.eu/environment/nature/conservation/wildbirds/action_plans/docs/aythya_nyroca.pdf
More data at
http://wildpro.twycrosszoo.org/S/0AvAnserif/anatidae/1acravan_aythya/aythya_nyroca/aythya_nyroca.htm#Measurement
Birdguides historic records
https://www.birdguides.com/species/species.asp?sp=027117
If you subscribe to ResearchGate you can download another study here
https://www.researchgate.net/publication/278361705_Diurnal_and_nocturnal_behaviour_of_Ferruginous_Duck_%28Aythya_nyroca%29_at_Lac_des_Oiseaux_north-eastern_Algeria
I went back for a proper look on Sunday. I watched it for a couple of hours. The "issue" I had (based on photos) was over the head shape, which didn't show a high forehead and peaked crown. I didn't see this in the field on Sunday either. However, this does depend on posture and the bird does look fine otherwise.
ReplyDeleteThe escape "issue" is a difficult one. Worryingly, the bird spent most of the time following a female Mallard, but had gone to sleep with the Tufteds when I left. Captive birds are often metal ringed. Google 'Ferruginous Duck Barnes'.
It's circumstantial evidence though and maybe the bird should get the benefit of the doubt.