MB

 

Members Login
Username 
 
Password 
    Remember Me  
Post Info TOPIC: Redpoll Taxonomy


Status: Offline
Posts: 149
Date:
RE: Redpoll Taxonomy


Even with a good look Mike certain birds are left as Redpoll sp. Very muddy subject, but brilliant.

Cheers
Jason

__________________
A Tale of 2 Halves


Status: Offline
Posts: 839
Date:

Mike Passant wrote:

I found it interesting as a follow up to Simon Ladd's query about the plumage distinctions between Lesser and Mealy Redpolls to peruse the link recommended by Ian.
This took me to a detailed account by L.G.R Evans supported by a good range of photographs of both forms for various photographers.
I also felt that some refreshment would be of benefit to me also, and to be honest I learned something new; i.e. the significance of the presence or not, of an eye ring.
Despite a good selection of Lesser, Mealy and a few Arctics being on show for many weeks here in Co. Durham last year, with a constant turnover of individuals at the feeders, even after many hours shivering in the cold, it was still far from easy to be confident about identifying every individual with total confidence.
What did emerge as a consensus view, (with which I strongly concurred) was that "good" clear cut specimens came as something of a relief to the observer who managed to get onto a good "Arctic", as it was obvious that with so much variation on show across well over 100 individual birds present we felt that the big unanswered question was ;- how much "gene flow" existed between these very closely related forms, and that of course led to the old chestnut of "what actually is a species, and how much geagraphic isolation is needed to evolve a new species, ( in other words, - how long is a piece of string?)
Caution therefore should still be the watchword with "odd" Redpolls, and the prudent observer should be wary of expecting to identify every putative Mealy or Arctic on little more than a glimpse.

Regards,
Mike Passant






The Coue's Arctic Redpoll at Titchwell being a perfect example of this and indeed a bird that is subject of much debate as to it's actual true identity.

__________________


Status: Offline
Posts: 1070
Date:

I found it interesting as a follow up to Simon Ladd's query about the plumage distinctions between Lesser and Mealy Redpolls to peruse the link recommended by Ian.
This took me to a detailed account by L.G.R Evans supported by a good range of photographs of both forms for various photographers.
I also felt that some refreshment would be of benefit to me also, and to be honest I learned something new; i.e. the significance of the presence or not, of an eye ring.
Despite a good selection of Lesser, Mealy and a few Arctics being on show for many weeks here in Co. Durham last year, with a constant turnover of individuals at the feeders, even after many hours shivering in the cold, it was still far from easy to be confident about identifying every individual with total confidence.
What did emerge as a consensus view, (with which I strongly concurred) was that "good" clear cut specimens came as something of a relief to the observer who managed to get onto a good "Arctic", as it was obvious that with so much variation on show across well over 100 individual birds present we felt that the big unanswered question was ;- how much "gene flow" existed between these very closely related forms, and that of course led to the old chestnut of "what actually is a species, and how much geagraphic isolation is needed to evolve a new species, ( in other words, - how long is a piece of string?)
Caution therefore should still be the watchword with "odd" Redpolls, and the prudent observer should be wary of expecting to identify every putative Mealy or Arctic on little more than a glimpse.

Regards,
Mike Passant

__________________

Challenges are inevitable, but failure is optional.

Page 1 of 1  sorted by
Quick Reply

Please log in to post quick replies.

RODIS

 

This forum is dedicated to the memory of Eva Janice McKerchar.