Billinge: 15th to 18th August 2016

Four similar sessions at Billinge on consecutive mornings produced smaller catches than of late. The number of Willow Warblers moving through the site has dropped markedly compared to the highs of last week and was largely responsible for the lower totals.

Willow Warblers - adult left and first year right. Adults generally have whiter bellies than first year birds but ageing this species also involves checking the wear and shape of the tail feathers.

The main target species was Tree Pipit and although 15 were ringed over the four mornings this was less than expected. The passage of this species usually peaks at the site in mid August but has turned out to be weaker than in previous years so far. It remains to be seen how things will turn out and hopefully there will be some good movements to come.

Tree Pipit

Robin is a species that doesn't get mentioned in this blog very often but one ringed on the 15th and another 3 on the 17th hinted at the dispersal and passage that will be a feature of September. The site doesn't hold many breeding pairs or wintering individuals, especially in the vicinity of the net rides, so the majority of birds caught are dispersing or on passage.

Less frequently caught species included a Nuthatch (the 2nd of the year), a Willow Tit (the 5th individual of the year but only the 2nd juvenile of the autumn) and a Reed Warbler (the 5th of the autumn with the previous 4 being in late July).

First year Willow Tit.

A view of the underside of the Willow Tit's tail and included for those interested in separating Willow Tit and Marsh Tit in the hand. It is all to do with the relative distances between the tips of the tail feathers and distance between the tip of the longest and shortest tail feather in particular. Willow Tits usually have more rounded corners to the tail and this results in more of the tips of the tail feathers being visible on the underside of the closed tail. This particular Willow Tit had a tail that was closer in appearance to that usually illustrated for Marsh Tit and demonstrates why separating these two species can be tricky for those who rarely handle them as they are more likely to consider such features.

First year Reed Warbler

Last but not least 2 Wood Pigeon nestlings were ringed on the 17th with the nest being noteworthy for being very low down in a hawthorn at just over a metre off the ground. A similarly low nest was found in the same area at this time last year and it is tempting to conclude that the same pair may have been involved in each case.

Combined ringing totals (retraps in brackets) for 15th to 18th August 2016 were: Woodpigeon 2 pulli; Goldcrest 2; Blue Tit 4 (1); Great Tit 3; Coal Tit 2; Willow Tit 1; Long-tailed Tit 3 (3); Chiffchaff 6 (1); Willow Warbler 29; Blackcap 3; Reed Warbler 1; Nuthatch 1; Wren 1; Robin 4; Dunnock 1; Tree Pipit 15; Chaffinch 8; Linnet 9; Yellowhammer 1; Reed Bunting 2. Total 99 new birds and 6 retraps.

Billinge: 14th August 2016

Just a quick post as I need to get some sleep ahead of another early start tomorrow. Another good session at Billinge produced 59 new birds and only 1 retrap in the form of a recently ringed Blue Tit.

Willow Warblers continue to move through the site in good numbers and topped the totals yet again with 28 ringed. The proportion of adult Willow Warblers has increased now that most have finished their moult and are migrating with 6 being caught today. Adult Willow Warblers do not hang around once they have moulted and may even start to fatten up in preparation for migration before the end of their moult.

Freshly moulted adult Willow Warblers

Adult Willow Warblers usually have a much whiter belly and stand out from the more lemon yellow juveniles.

The majority of Chiffchaffs are still in their scruffy juvenile plumage or in the early stages of their protracted post juvenile moult so it was a bit of a surprise to catch one that had completed its moult. It is not particularly early for it to have done so but it was well in advance of all the others that have been caught recently. The only Blackcap caught had also completed its post juvenile moult and both were a reminder of just how quickly the season is advancing.

1cy Chiffchaff looking much sleeker now that it has completed its pj moult.

I was hoping today would see the first good passage of Tree Pipits but again it wasn't to be and only 4 were ringed from a maximum of 4 or 5 recorded. It was very overcast this morning (even the odd spot of rain at one point) and there was very little in the way of wind so that may have suppressed movement. It is not often I wish for brighter conditions and a bit more of a breeze when I am ringing but that is what it might take to get more Tree Pipits on the move.

One of today's Tree Pipits.

An interesting Reed Bunting was caught in that it was one of those birds that can easily catch out the unwary and it would almost certainly be wrongly sexed if just being viewed at a distance with binoculars. Even in the hand it looked like a male at first glance having a largely black head and blackish bib and it even had a noticeably white collar. However, careful examination revealed it to be a well worn adult female with a brood patch. The state of the brood patch suggested she was in the later stages of a breeding cycle and had probably just fledged a late brood. That was supported by the calls of recently fledged Reed Buntings that were heard near to where she was caught. Having said all that I am sure there will be some people that will find it hard to believe that it is a female and not a male given its appearance.

Adult female Reed Bunting looking rather male like. The cloacal shape and brood patch confirmed it was a female. It also had a very short wing length.

Ringing totals for 14/08/2016 were: Goldcrest 3; Blue Tit 4 (1); Great Tit 3; Coal Tit 1; Swallow 1; Chiffchaff 4; Willow Warbler 28; Blackcap 1; Whitethroat 1; Wren 1; Robin; Tree Pipit 4; Chaffinch 3; Bullfinch 1; Goldfinch 1; Reed Bunting 2. Total 59 new birds and 1 retraps.

Fabulous forty.

It looked like there would be a few hours of suitable weather this morning but it was still a case of fingers crossed and a final check of the rainfall radar before setting off. I headed up to Billinge a little later than planned but still had the first net set up by sunrise and another two nets soon after.

We are just at the start of the main migration period for Tree Pipits and most will have gone through by the end of August so I want to get out whenever the weather looks suitable, even if it's only for a couple of hours. It is also the peak time for Willow Warbler migration so that just added to the incentive to get out this morning

Three Tree Pipits were caught in the first couple of rounds which was a really promising start but unfortunately none were caught or seen after that. A check of the rainfall radar on my phone showed that a band of heavy showers had developed to the north of the site and that may have been the reason they stopped moving.

One of today's Tree Pipits was this cracking adult.

Tree Pipit adult (left) and first year (right).
There doesn't appear to be a great deal of difference in the coverts of these two birds but the first year has paler fringes to the median coverts, greater coverts and tertials and they are more abraded. Many first years replace some median or greater coverts so there is often some contrast between the new and old feathers. However, the first year on the right hasn't replaced any of its coverts so there is no contrast to be seen in this particular individual. 

While Tree Pipits didn't move through in any number the same couldn't be said for Willow Warblers. There didn't seem to be that many around at first but the final tally of 40 new birds and 1 retrap made it the hightest total recorded at the site. It all happened quite quickly with all but 1 being caught by 09:00. The retrap Willow Warbler was originally ringed as a juvenile in July 2014 and was caught again in April 2015 but not handled again until today.

The tips of this Willow Warblers tail feathers had snapped off along the line of a fault bar.

A closer look at the tail. Fault bars are a line of weakness that can develop in feathers due to a shortage in nutrition when the feathers are growing. In extreme cases the feathers can snap along the line of weakness. There were 2 other similar examples in the Willow Warblers caught this morning.

Chiffchaff was a notable absentee today with none caught or present in the vicinity of the nets. This was quite a surprise as I expected to catch a few with so many Willow Warblers being on the move. If it hadn't been for the Willow Warblers it would have been a very quiet day although I would have been happy catching the 3 Tree Pipits on their own.

Ringing totals (retraps in brackets) for 09/08/2016 were: Blue Tit 1; Great Tit 1 (1); Long-tailed Tit 1; Willow Warblers 40 (1); Blackcap (1); Whitethroat 3; Tree Pipit 3; Goldfinch 2; Reed Bunting 1 (1). Total 52 new birds and 4 retraps.

Billinge: 6th August 2016

I was joined by a trainee from Merseyside Ringing Group at Billinge this morning and we had 3 nets set up in the top willows just after sunrise. The weather was near perfect for most of the session with no wind to speak of and broken cloud keeping the sun off the nets most of the time. A breeze did pick up towards the end of the morning but the catching rate had already slowed by then and we were thinking about packing up anyway.

The catching rate was fairly steady from the off with Willow Warbler being the most numerous species; the 27 new and single retrap caught being the highest day total of the autumn so far. Most of the juvenile Willow Warblers have completed or very nearly completed their post juvenile moult, as is to be expected by this date, so the capture of a recently fledged youngster in full juvenile plumage was a bit of a surprise.

This recently fledged juvenile Willow Warbler really stood compared to the freshly moulted  and very neat lemon yellow juveniles from earlier broods.

I didn't take any photos of today's juvenile Willow Warblers that had completed their pj moult so here is one from the other day for compaison.

Regular readers of this blog will know my interest in the occurrences of Acros at the site and Sedge Warblers in particular (link here). The capture of yet another adult Sedge Warbler only deepened that interest as it keeps the proportion of adults caught unexpectedly high. However, I am beginning to think the proportion of adults to juveniles recorded could be a true reflection of the population that migrates through the area, although the usual caveats about the small sample size needs to be borne in mind. Perhaps the proportion of adults caught on migration in reedbeds is lower than that in the overall population rather than the numbers at Billinge being too high.

Another adult Sedge Warbler - 3 of the six Sedge Warblers caught this autumn have been adults making it a total of 6 adults out of 16 in the last 3 autumns.

I was full of hope for a good movement of Tree Pipits following yesterdays capture of 3 but it was not to be and we had to settle for just one. While it was the only Tree Pipit recorded at Billinge today others were on the move as 2 were caught at Oxmoor, 17 km to the south and another at Woolston, 18 km south east (info from MRG).

Today's token Tree Pipit

A Garden Warbler, caught towards the end of the session, was the first to be ringed this autumn. They are not common in the area and only occur at the site as a relatively scarce passage migrant (6 were ringed in autumn 2014 and 4 in autumn 2015 with most records coming in August).

1cy Garden Warbler

I suppose I can't finish without mentioning tits again or I should say the lack of them. Once again they were very thin on the ground and none were caught which is exceptional for this time of year. A couple of Blue Tits were seen and both Willow Tit and Coal Tit were heard but that was about it.

Ringing totals (retraps in brackets) were: Goldcrest 1; Chiffchaff 7 (1); Willow Warbler 27 (1); Blackcap 5; Garden Warbler 1; Whitethroat 1; Sedge Warbler 1; Wren 1; Blackbird 1; Robin 1; Tree Pipit 1; Chaffinch 2; Goldfinch 1; Linnet 4; Lesser Redpoll 1. Total 55 new birds and 2 retraps.

Tree Pipits on the move.

I only had a couple of hours free this morning but I decided to make the most of it as the weather looked favourable for some Tree Pipit passage at Billinge. The first Tree Pipits were recorded going south on 4th August in 2014 and on 7th August last year so they were due. I was fairly certain I heard one calling in the distance on 1st August so today's settled conditions looked really promising and too good to miss.

I had 2 nets set in the top willows just after sunrise and things started fairly slowly with the capture of a few warblers and a juvenile Robin in the first couple of net rounds. The first Tree Pipit was heard at 06:40 and was in the net soon after. This was followed by a little rush of warblers, mainly Willow, and a few other birds then 2 more Tree Pipits were caught in the last round at 07:30.

The first of the 3 Tree Pipits caught today. All were first year birds.

The weather is looking good for tomorrow and I will have more time so hopefully I will be able to catch a few more. Now Tree Pipit passage has started it is time for me to start getting up at daft o'clock so I can get up to site and have the nets up by sunrise.

Ringing totals (retraps in brackets) for 5th August 2016 were: Goldcrest 1 (1); Willow Warbler 13 (1); Chiffchaff 1; Blackcap 3 (1); Robin 2; Tree Pipit 3; Lesser Redpoll (1). Not a bad total for the limited time available.

Billinge: 1st August 2016

A somewhat belated post but hopefully still of interest. The new month started much as last month ended with a session at Billinge producing a decent total of 36 new birds and 3 retraps. Once again Willow Warblers were the most numerous species and they accounted for nearly half the total with 15 new birds and 3 retraps. I don't know of any other ringing site in the area where Willow Warblers can still be caught in such good numbers and can also match Chiffchaff in the ringing totals at the end of the season, give or take a few. Why Willow Warblers occur at Billinge in such good numbers is a bit of a mystery but the combination of the habitats, topography and elevation of the area clearly play a part in attracting and funneling Willow Warblers and a several other migrant species through the site.

Adult Willow Warbler, some of the adults have completed their moult like this bird.

The attraction the site has for birds on passage was also demonstrated by the capture of another 2 Sedge Warblers, this time an adult and a juvenile. If the occurrences of Sedge Warblers only involved the occasional juvenile it could be simply put down to post juvenile dispersal which is fairly random in direction initially and sometimes leads to inexperienced birds being out of habitat. The fact that I catch more than just the odd one and adults as well a juveniles suggests there is more to it than that.

Juvenile Sedge Warbler

Interestingly 5 of the 15 Sedge Warblers ringed over the last 3 autumns have been adults and this is a higher proportion of adults than you would expect to catch at a lowland reedbed site in autumn. There is still time to catch a few more Sedges this autumn so that proportion could change but if I just use the ages of the 10 birds caught in autumn 2014 and 2015 adults still made up 30% of the total. I know it is only a very small sample size but it is still intriguing that such a high proportion of adults is involved, especially as the migration of adult Sedge Warblers is known to be more direct and involve fewer stops compared to that of juveniles. 

Adult Sedge Warbler

It was another very quiet day on the tit front but 2 or 3 Willow Tits were heard and one was caught and ringed.

Juvenile Willow Tit, the first to be ringed this autumn.

Ringing totals (retraps in brackets) for 1st August 2015 were: Willow Warbler 15 (3); Chiffchaff 5; Sedge Warbler 2; Blackcap 4; Whitethroat 2; Dunnock 1; Robin 1; Willow Tit 1; Blue Tit 1; Goldfinch 3; Lesser Redpoll 1.

Late July: a quick update.

I managed to get out to Billinge a few times during the period 24th to 31st July but some of the sessions were weather restricted. The generally unsettled conditions with bands of showers and spells of rain also had an impact on the number of birds moving through the site on some days so the combined total of 140 new birds and 16 retraps was quite good, all things considered. 

The main target species was Willow Warbler with a total of 45 ringed during the period. This brings the number of Willow Warblers ringed in July to 105 with 101 of those having been ringed in the last 2 weeks. This is a slightly better total than last year, when 84 were ringed in July, but the increase has been achieved through extra effort rather than there being more birds around. I am still of the opinion that Willow Warblers have had a relatively poor breeding season, locally at least.

Willow Warbler migration is getting into full swing.

 A late evening visit on the 25th, to check if any Swallows were roosting, revealed that only 30 or so were gathering to roost. These were harassed a few times by a young male Sparrowhawk and this caused them to settle in a different area of the willows but not before 18 had been caught and ringed.

Juvenile Swallow

Adult Swallow

Acros continued to put in an appearance now and again with another Sedge Warbler ringed on the 28th followed by single Reed Warblers on the 30th and 31st; all were young birds. 

Sedge Warbler

Reed Warbler

Bullfinches are starting to take advantage of the Knapweed and other meadow plants that are going to seed and this resulted in 4 juveniles and 3 adult males being ringed.

Male Bullfinch

Tits continued to be very thin on the ground, to say the least, but Long-tailed Tits finally put in an appearance with a party of 3 seen on the 28th one of which, a juvenile, was caught and ringed.

Combined totals (retraps in brackets) for the period 24th to 31st July were: Swallow 18; Chiffchaff 19 (3); Willow Warbler 45 (4); Blackcap 13 (5); Whitethroat 5 (2); Reed Warbler 2; Sedge Warbler 1; Goldcrest 4 (1); Blackbird 1; Long-tailed Tit 1; Blue Tit 4; Great Tit 4; Coal Tit 1; Chaffinch 4; Goldfinch 8; Linnet 2; Bullfinch 7; Reed Bunting 1 (1).

I don't see many dragonflies at the site as the nearest pond is some distance away but this Brown Hawker (Aeshna grandis) found its way into one of the mist-nets. 

Brown Hawker (Aeshna grandis)