Sunday, 30 August 2015

Billinge 30/08/15

This morning's weather was perfect for ringing, flat calm with a thin veil of broken high cloud, and with August coming to a close it was perhaps the last chance for a good catch of Tree Pipits. I had 3 nets set up shortly after first light and the morning got off to a reasonable start with 6 Swallows that were caught as they exited their roost in the willows. There hasn't been a big Swallow roost this year but small numbers of around 20 or 30 have roosted at the site since early July.

Juvenile Swallow and a pale one at that. This bird lacks the usual rusty coloured throat and forehead

This juvenile Swallow has the more usual rusty coloured throat and forehead. It is also a younger bird and still has prominent gape flanges.
There was little in the way of visible migration but 12+ Tree Pipits were recorded and more than made up for the lack of other birds on the move. Six of these Tree Pipits were caught bringing the total ringed this autumn to 55 which is only 1 short of the total ringed last year. The number of Tree Pipits moving will fall rapidly over the next 2 or 3 weeks but there is still a chance I will catch a few more yet. I hadn't been sure if the number of Tree Pipits ringed and recorded last year was due to an exceptional set of circumstances (good breeding season plus prevailing weather) as it was the first year I had ringed at the site. However, the similar numbers ringed and recorded this year show that it is a regular occurrence and confirm that the site is one of the best for the species in the whole of the Northwest, if not the best. Other birds moving south during the morning were 25+ Siskins, 3 Grey Wagtails and 1 Tree Sparrow.

The first of the six Tree Pipits ringed this morning and the 50th of the autumn.
While there didn't seem to be much of anything about in the bushes a few birds filtered through resulting in a fairly steady catching rate throughout the morning. It became clear that the majority of Willow Warblers have now migrated as only 2 were caught while the number of Chiffchaffs showed an increase as is typical at this time of year. A Reed Warbler was the most unusual capture being well away from the nearest wetland habitat and is only the 3rd to be caught this autumn. The final total of 42 new birds and 2 retraps was really quite good all things considered.

Reed Warbler
Ringing totals (retraps in brackets) for 30th August 2015 were: Tree Pipit 6; Reed Warbler 1; Whitethroat 2; Blackcap 6; Chiffchaff 11 (1); Willow Warbler 2; Long-tailed Tit 1; Blue Tit 1; Chaffinch 1; Greenfinch 1; Goldfinch 1; Lesser Redpoll 1; Yellowhammer 1; Reed Bunting 1 (1). 

Tuesday, 18 August 2015

Stealth Pipits and 'acredula' Willow Warblers

I wasn't sure if the flat calm and overcast conditions of yesterday morning (17th) would produce much in the way of a Tree Pipit movement over Billinge and initially there was no sign of any passing overhead. The bushes also seemed largely devoid of warblers so I thought I would be in for a quiet morning. However, to my surprise and relief the first net round produced 2 Tree Pipits with a 3rd bird being seen flying out of the net ride. Subsequently I did start to hear the occasional call of a Tree Pipit overhead but many more must have been moving than these calls suggested as another 11 were caught over the following 3 hours. The total of 13 ringed is the best catch so far this autumn and equals highest of last year which was achieved on 14/08/14.

A few of the Tree Pipits have been carrying passengers in the form of ticks like this bird.
I have previously noticed that migrating Tree Pipits don't call as frequently as is often thought and this allows many birds to pass by unnoticed or unidentified. If I hadn't been ringing I would have probably only recorded 7 or so flying over and certainly not the 20+ that must have been involved. Apart from the Tree Pipits there was little else around with only a few warblers being caught, seen or even heard. Although warblers were lacking in both quantity and variety this was offset by quality in the form of 2 Northern 'acredula' type Willow Warblers. These cold grey looking individuals lacked any yellowish-green tones to the upper parts or yellow and yellow wash to the supercilium or underparts as can be seen from the photos below.

This was the more cold and greyer looking of the 2 'acredula' Willow Warblers. The underparts were mainly white but with a very slight pale grey-brown wash to the under-tail coverts, flanks, upper breast and throat. Both 'acredulas' were aged as adults.
The second acredula type was almost identical to the first but with a very slightly browner hue to the upper parts.

Juv Willow Warbler (trochilus) with extensive yellow wash to underparts.
Adult 'trochilus'

Two views of the coldest 'acredula' above a juv 'trochilus'. lower left and adult 'trochilus' lower right. 
Separating the races isn't always straightforward as there are some complications caused by intergrades where their ranges meet. To make matters worse some Willow Warblers that breed in eastern Scotland are said to be greyer than your typical British breeding Willow Warblers. Having said that both of these birds look very good for 'acredula' even if it is safest and the convention to describe them as 'acredula' types in the absence of DNA confirmation. Wherever they have come from I have no doubt that it is a long way north and east of Billinge.

I returned to Billinge this morning in the hope of another good catch of Tree Pipits. Again there didn't appear to be any on the move but like yesterday they must have been in stealth mode as I ringed another 7 despite only faintly hearing one bird flying overhead. There were a few more warblers around compared to yesterday and these included the 4th Garden Warbler to be ringed this autumn. All in all two good days that had elements of both quality and quantity.

Tree Pipit. One of the magnificent 7 from today.
This morning's Garden Warbler - the 4th of the autumn.
Combined ringing totals (retraps in brackets) for 17th & 18th August 2015 were: Tree Pipit 20; Robin 1; Whitethroat 4; Garden Warbler 1; Chiffchaff  5; Willow Warbler 15(1); Goldcrest 3; Long-tailed Tit (2), Coal Tit 1; Blue Tit 1(1); Great Tit 1; Chaffinch 2; Goldfinch 1;  Linnet 1.

Sunday, 16 August 2015


What I thought would be a terrific weekend for Tree Pipits turned out to be a bit of a disappointment in that regard with a total of only 5 caught over both days. Surprisingly at least 10 were moving south yesterday despite showers coming in off Liverpool Bay compared to just 3 in the the wall to wall sunshine of this morning. Anyway another 5 ringed is better than none and I still think there is a chance of some good movements to come.

The bird of the weekend turned out to be something completely different and was a bird I had never seen before. However, it wasn't a rarity and was instantly recognisable as a hybrid Greenfinch x Linnet or Linnet x Greenfinch. There was no reason to believe it was an escape as it wasn't ringed or showing any indications of ever having been kept in captivity. It is a first year bird and still undergoing its post juvenile moult with Linnet being the most dominant plumage type coming through. The legs were also more Linnet like but the bill is closer to that of your typical Greenfinch and it also called like a Greenfinch on release. A strange bird indeed and you can see some plumage and structural characteristics of the two species in the photographs below.

More of a juvenile Linnet type head plumage but with a Greenfinch type bill.
Bill and head shape are like that of a Greenfinch, mantle and wing coverts like a Linnet and primaries with yellow outer webs like Greenfinch.
Tail was a bit of a mixture of Linnet and Greenfinch patterns with some yellow just showing
Odd looking to say the least.
Size-wise it was a bit bigger than a Linnet but a bit more slender than your typical Greenfinch.
The primaries are quite Greenfinch like and the wing length of 86 mm is within the normal range for Greenfinch but at the very top of the range for Linnet.

Not Frankenstein's monster but certainly an odd job of a bird that looks pieced together. 

Friday, 14 August 2015

Tree Pipits get going.

I was joined by Kieran Foster of MRG (Merseyside Ringing Group) at Billinge yesterday morning with the conditions looking good for a movement of Tree Pipits. After a slow start we were not disappointed and 9 Tree Pipits were caught from an estimated 15 going south during a four hour period. Kieran had only ringed one Tree Pipit previously but he won't be saying that any more.

The number of Tree Pipits moving over the site had been in low single figures up to yesterday so this marked the first day of strong passage for the species this autumn. The next week should see the peak movements in this part of the country so, fingers crossed, there should be more good days to report. Obviously the weather can always throw a spanner in the works but the forecast is looking favourable over the coming days and hopefully the birds will think so too.

One of yesterday's Tree Pipits.
Other birds were in fairly short supply and there seemed to have been a general clear-out of warblers but the usual flock of about 80 Goldfinch remained. Ringing totals (retraps in brackets) for 13/08/2015 were: Tree Pipit 9; Robin 1; Song Thrush (1); Blackcap 2 (2); Chiffchaff (2); Willow Warbler 5; Chaffinch 2; Goldfinch 1; Linnet 1; Reed Bunting 2.

Thursday, 13 August 2015

Willow Warbler recovery

I recently received the recovery report for the control Willow Warbler that I caught on Billinge Hill on 7th August and it had been ringed at Leighton Moss 29 days earlier. Not a particularly long or fast movement but interesting nevertheless. Willow Warblers migrate through the Billinge site in good numbers and 157 have been ringed so far this autumn. There has been a fairly constant turnover of birds since mid-July and this recovery is the first to indicate the origin of some of those birds.

Willow Warbler migration across the country is peaking just about now and this first year bird may have already moved on and reached the south coast or be even be further south in France. Not bad for a bird that may only be about ten weeks old, yes little more than ten weeks old and on its way to sub-Saharan Africa.

While on the subject of Willow Warblers the following image shows the tail of a young bird that must have had a severe fault bar that caused the tip of the tail to break off. The two complete tail feathers are replacement feathers and show how much of the other feathers has snapped off. Fault bars are caused by periods of poor nutrition when the feathers are growing and are testament to the grotty summer we have had.

IY Willow Warbler tail. The juvenile tail feathers have sheared off along the line of a fault bar. The 2 complete feathers are newer replacements and are easily recognised by being darker and more glossy.
Adult Willow Warblers have or are just about to complete their moult now and can often be recognised by having whiter bellies than first year birds. It is not a totally infallible criteria, as a few intermediates do occur, but is true in most cases. The condition and shape of the tail feathers is usually the clincher where there is any doubt.

Willow Warblers: First year left and freshly moulted adult right.

Friday, 7 August 2015

TREPI time

August started off fairly quiet with unsettled weather holding up many migrants but a welcome change in the weather to clear conditions overnight and this morning was just what was needed to get passerine migration going again. The sharp drop in temperature overnight resulted in pockets of mist and a heavy dew this morning and it was like walking through a car wash as I made my way through the saturated bushes to the net rides at Billinge.

I soon had three nets up and a couple of Sedge Warblers in the first net round made for a good start and indicated that some new migrants had dropped in. Catching was fairly steady and mainly involved the usual species but an adult Garden Warbler was also notable, being a scarce passage migrant at the site, and only the second to be ringed this autumn. Also of interest was a Willow Warbler that was wearing a ring from elsewhere and is the first of this species to be controlled at the site.

Sedge Warblers don't breed at the site and only a few turn up on passage. It is always interesting to catch migrants like this in bushes on a dry hillside rather than in their usual lowland wetland habitat. 
Adult Garden Warbler

Control Willow Warbler. If you are using rings starting with the letters HLA then the details of its capture today will be coming to you very soon.
Now it was around this time last year that I started to catch Tree Pipits at the site and I soon discovered that it was an exceptional location for the species with a total of 57 ringed and over 133 recorded during autumn 2014. As I hadn't ringed at the site previously I didn't know if it was going to be a regular occurrence or if 2014 was a 'one off' due to exceptional circumstances including the particularly productive breeding season of 2014. I caught the first Tree Pipit of last year on August 4th and today has provided the first really good conditions for the species to be on the move this autumn so it was a delight when 2 turned up pretty much on cue and both were caught. Now I don't want to count my Tree Pipits too early but it certainly is a promising start.

The first Tree Pipit of autumn 2015 and hopefully the first of many

One interesting aspect of the Tree Pipit passage at Billinge last autumn was that it started and peaked earlier than at many of the well watched coastal and inland 'vis mig' sites. It will be interesting to see if the same happens this year.
Ringing totals (retraps/controls in brackets) were: Tree Pipit 2; Sedge Warbler 2; Whitethroat 1; Garden Warbler 1; Blackcap 7 (3); Chiffchaff 5; Willow Warbler 8 (2); Goldcrest 1; Blue Tit 2; Great Tit 2; Treecreeper 1; Chaffinch 7; Goldfinch 2. Total 46 comprised of 41 new birds, 4 retraps and 1 control.

Whilst walking between the nets I noticed that a group of caterpillars had defoliated one of the small willows.

Spot the caterpillars
The culprits were these Buff-tip (moth) caterpillars.