Billinge: 6th to 22nd April

I have been up to the ringing site at Billinge twelve times since 6th April but the catches have been quite small, hence the lack of blog posts about individual visits.  While the catches have been small they haven't been without interest and what you don't catch can be as important as what you do, or at least that is what I tell myself.

It looks like being another poor spring for Redpoll passage but that is hardly surprising as last autumn was very poor for Redpolls going south so a poor showing the following spring is no big surprise. Having said that you have to put the effort in to find out and I can certainly say I have put the effort in with only 18 Lesser Redpolls caught over twelve visits. One of the Redpolls caught on 10/04/2019 was a retrap that had been ringed at the site on 13/08/2017 as an adult female so perhaps a bird that breeds not too far away.

The most interesting Redpoll, for me at least, was a little adult male caught yesterday (21/04/2019). I say little as its wing length was 69mm which is fairly small or very small for a male of any race. We still don't know what to do with Redpoll species and races because they don't play by the rules as we would like to apply them. If my understanding is correct they should all be lumped at a genetic level, every last one of them, into one species because they are not distinct enough genetically despite their varying appearance. Arctic, Common, Lesser or whatever you want to call them they are all far more similar on the inside than they appear on the outside but that is what makes them even more fascinating. While they may be similar on the inside the difference on the outside largely determines where they will breed and that is why we like them so much.

A bit or quite a bit greyer than your typical Lesser and probably breeds well north of Billinge.

Broad white fringes to the greater coverts, tertials and inner webs of tail feathers.
A touch of tram lines up the mantle too.

Broad white fringes to the greater coverts and tertials.

Broad white fringes to inner webs of tail feathers.

Unstreaked under-tail coverts which is normally a feature of Arctic Redpolls.

Pure white, unstreaked, under-tail coverts, including the feather shafts. If you hadn't seen the rest of the bird you could be thinking Arctic Redpoll. I have seen Lesser types like this before so not as exceptional as it may appear.

The first Willow Warbler was noted on the 6th and it was good to find that 9 of the 20 that were caught between the 10th and 22nd were retraps. Of the retraps one was originally ringed in 2016 and eight were originally ringed in 2017. On the other hand Chiffchaffs have been thin on the ground this spring with only 3 caught but all were retraps - one from 2017 and two from 2018. Blackcaps have put in a pretty good showing so far with 12 caught - 10 new, 1 retrap and 1 control. The retrap was ringed as a first-year in August 2017 and the control was ringed 16 km away at Woolston Eyes in April 2018.

Unusual captures were a pair of Mistle Thrushes that found their way into one of the nets on the 16th and were a first to be ringed at the site. However, the highlight of the period, and what made the effort worthwhile, was the capture of six Tree Pipits with the first caught on the 13th.

Tree Pipit 19/04/2019

Tree Pipit 21/04/2019

The twelve visits yielded 54 new birds, 18 retraps and 1 control as follows (retraps in brackets): Lesser Redpoll 17 (1); Willow Warbler 11 (9); Chiffchaff  (3); Goldcrest 2 (1); Blackicap 10 (1) +1 control; Robin 3; Long-tailed Tit (1); Tree Pipit 6; Mistle Thrush 2; Bullfinch 1 (1); Dunnock 1; Yellowhammer 1; Willow Tit (1).

Rapid Goldfinch movement.

Earlier this month, in a blog post titled 'fatties', I mentioned catching some Goldfinches at Crawford that had significant fat deposits. I went on to say that they were migrants that would be heading much further north to breed and presumably to somewhere in Scotland or Northern Ireland. Since then I have caught other Goldfinches at Crawford with varying amounts of fat and I recently received a recovery report for one of them. Goldfinch ACF5670 was ringed at Crawford on 07/04/2019 at 09:20 and was subsequently caught by a ringer in Leswalt, Stranraer, Dumfries and Galloway just 2 days later on 09/04/2019 at 14:00.

It was a small female that wasn't particularly fat and weighed 15.2g at the time it was ringed and subsequently weighed 13.9g when it was recaptured at Leswalt. The weight difference of 1.3g gives some indication of how much fat it used to make the journey. The straight line distance from Crawford to Leswalt is 219 km but most of that direct route is over the sea, as can be seen from the map. Goldfinches generally avoid making long sea crossings and migrate overland as much as possible so it is unlikely to have taken the shortest direct route. If this bird took an overland route to Leswalt it will have travelled around 300km and possibly quite a bit further than that if it followed the convoluted coast of Northwest England and Southwest Scotland, even with a bit of a shortcut across an estuary here and there. There is also the possibility that it took a relatively direct route via the Isle of Man and there have been some recoveries that make that a realistic option but it still involves quite long sea crossings. One thing is sure it is an interesting movement for its speed whatever route was actually taken.





Goldfinch (Carduelis carduelis) Ring no: ACF5670
First-year Female   07-04-2019  Crawford, near Up Holland, Lancashire, England
Caught by ringer    09-04-2019   Leswalt, Stranraer, Dumfries and Galloway, Scotland
Duration: 2 days Distance: 219 km Direction: 317deg (NW)

11/04/2018: Ivy berry Blackcaps and continental Song Thrush.

I went up to Billinge first thing but there wasn't much doing so I packed up early and went to Crawford to top up the feeders. As I had my ringing gear with me I decided to put a net up there for an hour and as things turned out I am certainly glad that I did. There weren't many birds coming to the feeders, at least not while I was there, but the ivy berries worked their magic and I caught 6 new Blackcaps, all males. These 6 Blackcaps came hot on the heels of 5 that were caught at the site on the 7th and made me wonder how many have taken advantage of this particular abundance of ivy berries so far this spring or will do so while the they last.

Some parts of the ivy have been stripped of their berries but there are plenty left.

 Today's 6 Blackcaps came hot on the heels of 5 caught at the site on the 7th. Everyone is familiar with concentrations of birds on berries in autumn but less so with returning birds in spring. 

While it was good to catch the Blackcaps the highlight, for me least, was catching 2 Song Thrush as one of them was a small and very grey individual of the continental race (T. p. philomelos).

Continental Song Thrushes don't get any greyer than this one.

I would put money on this bird originating from a long way east. Song Thrush of the British race (T. p. clarkei) are much browner and are generally bigger.

There wasn't a hint of warm brown anywhere in its plumage.

Ringing totals (retraps in brackets) for 11/04/ 2019 were: Blue Tit 1; Long-tailed Tit (1); Blackcap 6; Blackbird (2); Song Thrush 2; Dunnock (1) ;Chaffinch (1).

Unexpected Blackcaps

I had a bit of a lie in today because the forecast was for heavily overcast conditions and little or no breeze that would last throughout morning. Luckily the forecast looked like it was going to hold true and I headed off to the baited site at Crawford at 8:00am under a completely grey sky and with little or no breeze to speak of. I didn't go earlier as there doesn't seem to be any advantage in setting up at dawn at this site now the days are much longer and had I thought the conditions would have remained the same throughout the day I would have opted for another afternoon visit.

First job was topping up the feeders and judging by how much the food had gone down since they were filled on Friday they were still being well used. I quickly set up the usual 18m net and I didn't have long to wait before the first bird was caught. There were a few Goldfinches and Tree Sparrows around but the first bird caught turned out to be a Blackcap. One had been singing while I was setting up and I assumed it was the bird I had first heard a few days ago (on the 3rd). A pair normally breed at the site so a singing Blackcap wasn't unexpected and nor was catching it. However, I didn't expect that 5 of the total of 20 birds caught over the next 3 hours would be Blackcaps (4 males and 1 female).

Male Blackcap

Female Blackcap

Looking at other blogs and sightings reports there appears to have been a bit of an influx of Blackcaps into the region overnight and it is likely that some of the Crawford birds fall into that category. The glut of ivy berries in the hedge by the feeders probably helped by providing a good refuelling point for recently arrived migrants.

The rest of the catch was pretty much as expected in terms of species but wasn't without interest. Two of the Goldfinches were fat with the heaviest weighing 19.7g which was 5.3g heavier than the lightest Goldfinch caught. The retrap Tree Sparrow was interesting as it was the first one from a previous year and was originally ringed as a breeding female on 9th June 2016. It was also interesting because of the state of its plumage. It basically looked like it had been attacked by a mad hairdresser for want of a better description. Many of the barbs of the feathers of the underparts appeared to have broken off and other feathers were similarly affected to a lesser degree. As to the cause I have no idea but I have caught Blue Tits that were similarly affected in the past.

Female Tree Sparrow S144976

A close up of the junction between the affected and the seemingly unaffected feathers.

Many of the wing feathers had a ragged edge.

The tail was in a poor state, the breakages didn't follow any fault lines and appeared to be quite random. It is as if the feathers have become brittle and the breakages happened during preening and that is perhaps why the head and neck appear to be the least affected.

Ringing totals (retraps in brackets) for 07/04/2019 were: Blue Tit 1; Great Tit 1; Blackcap 5; Blackbird 1; Tree Sparrow 3 (1); Robin 1; Chaffinch 1; Goldfinch 4(2).

Fatties

I hadn't expected to do any ringing today but I had planned to go to the baited site at Crawford in the afternoon to top up the feeders.  As I was getting ready to go the wind dropped away completely so I decided to take advantage of the calm conditions and took my ringing gear too. It was 3pm by the time I got to the site and I quickly set up an 18m net after topping up the feeders. There were plenty of Goldfinches and Tree Sparrows around and first birds were caught as I walked away from the net.

A busy little session followed with 27 new birds and 2 retraps caught during the 2 hours the calm conditions lasted. It was interesting that 4 of the 10 Goldfinches caught were very fat and had bulging fat deposits in the tracheal pit and over the abdomen; these birds will be migrants that will be heading much further north and presumably to somewhere in Scotland or Northern Ireland to breed. One of the Blackbirds (a 2cy female) was similarly very fat and weighed a whopping 126.7g. A lean Blackbird weighs around 90g so this bird will have been carrying in the region of 35 to 40g of fat and will be migrating back to Scandinavia or somewhere further east fairly soon.

Female Blackbird

Blowing back the feathers reveals the tracheal pit which is normally deeply concave in a bird that isn't carrying much or any fat but has been completely filled with fat and is bulging in this individual.

This slightly more angled view shows the yellow fat is bulging by several mm and overlaps the pink breast muscles. The abdomen was similarly full of and covered in fat. This bird must be at or very close to the point where it is ready to migrate and it is likely to set off on the next suitable night.

Ivy Berries.
The hedge on one side of the ringing site is full of ivy which is currently covered in ripe berries. These berries help migrant Blackbirds fatten up in readiness for the long journey back to their breeding grounds.

A Blackbird ringed at Crawford in the winter of 2016/17 was caught by ringers on the island of Utsira, off the coast of Norway, in spring last year and gives an indication of where today's fat Blackbird could be heading in the coming days.

Blackbird (Turdus merula)   Ring no: LK25293
Ringing details
First year female   29-NOV-2016   Crawford, near Up Holland Lancashire, England
Finding details
Caught by ringer   29-MAR-2018   Sore Merkeskog, Utsira, Rogaland, Norway
Duration: 485 days Distance: 795 km Direction: 37deg (NE)


Ringing totals (retraps in brackets) for 03/04/2019 were: Collared Dove 1; Coal Tit 1; Song Thrush 1; Blackbird 4; Tree Sparrow 8; Robin 1 (1); Chaffinch (1); Greenfinch 1; Goldfinch 10.