Billinge 29/10/17 and a bit on ageing Redwings too.

A cool northerly breeze and relatively clear conditions contributed to a fairly low-key session at Billinge this morning. A few thrushes were moving early on and most of those that were ringed were caught in the first hour. Otherwise it was fairly quiet which, combined with single figure temperatures, gave the morning an end of season feeling.

Only 1 Lesser Redpoll was caught today but, interestingly, it was another that had a yellowish-orange poll rather than the usual red colour and is the 3rd to be caught with this pigmentation variation this month.  It has been a relatively poor autumn for Redpolls so far with only 37 caught to date. The ages of these birds suggest they have had a poor breeding season as 20 (including today's bird) have been adults, only 15 were first-year birds and 2 were left unaged.

Adult Lesser Redpoll

The 3rd to be caught with an 'Amber' poll this month.

Far fewer Redwings and Fieldfares have been recorded this autumn due to the lack of easterly winds but the same can't be said for migrant Song Thrushes. Their numbers have held up surprisingly well and are only a little down on the number recorded last autumn. Another 3 Song Thrush were ringed today and all 3 were obvious 'continental' birds.

Continental Song Thrushes don't get much more obvious than this one. Cold grey toned above, more extensive white below and smaller than our warmer brown British subspecies 'clarkei'. 

Ringing totals for 29/10/17 were: Goldcrest 8; Blue Tit 2; Blackbird 1; Song Thrush 3; Redwing 14; Greenfinch 1; Lesser Redpoll 1.


I have been meaning to post some photos on ageing Redwings as I have encountered a few interesting individuals recently but here is one from the 27th and another from today to ponder on.

The very plain wing (lack of well defined pales spots on any of the greater coverts and lack of tertial markings) suggest it is an adult but see the image of the tail below. 

Two old tail feathers in an otherwise adult tail show this bird to be a first-year. This bird appears to have undergone a very extensive pj moult and had it replaced all the tail feathers this bird would have been indistinguishable from an adult. According to the literature juvenile Redwings rarely replace any tail feathers as part of their pj moult and if they do it is only supposed to be one or two. This bird obviously didn't read the literature and perhaps we shouldn't be surprised as many species are having more extensive pj moults these days which is probably linked to climate change. There is also the possibility that it replaced most of its tail feathers following accidental loss but the fact that it appears to have replaced all its greater coverts and tertials suggest a more extensive pj moult is the more likely cause of the tail feather replacement.

A very well marked wing with well defined pale tips to the greater coverts, especially the outers, and large, fairly angular pale tips to two of the tertials but what does the tail tell us.

The tail feathers are fresh, broad and quite rounded with some almost being square ended so it is clearly an adult. 

Here is the whole bird just in case you didn't think the wing and tail could be from the same bird. It is just a very well marked adult.