Tuesday, 30 August 2016

Swallows passing through

In the last four weeks we have been catching swallows in a local reedbed on one evening per week and have now processed 330 birds.  The first three catches, each around 100 birds, were comprised almost totally of juveniles with the initial catch mainly recently fledged birds.  Each week has seen the plumage of the juveniles advance and last week more birds near to completing their post juvenile moult were caught. 
In the first three weeks we caught very few adults (one or two each week) but yesterday with only 22 swallows caught there were 4 adults, all females, perhaps indicating that the breeding season for the adults is just about completed. 
Perhaps more surprisingly, even though the reedbed has been an attractive roost for swallows every evening, none of the birds has been retrapped - they have all moved on quite quickly. 
The islands have recorded a light swallow passage to date and my notes suggest that the first third of September is peak swallow migration time but these ringing notes suggest that the passage has been going on for the last month although perhaps in smaller stages and in smaller groups which we hardly recognise as migratory movement.

Tuesday, 26 January 2016

A few interesting recoveries

The BTO have just sent through a few recoveries with an interesting mix :-

A young female Blackcap ringed in Milford Haven on 25th November 2014 and presumably wintering there was killed by a cat on 23rd December 2015 in Les Nouettes, Forest, Guersney in the Channel Islands and was presumably wintering there having been back to Denmark or Germany or somewhere east for the breeding season.

A Woodcock ringed by Paddy at Llanmill on 5th February 2013 was shot 373 Km north and west at Cloongoonagh, in Co Sligo, Ireland on 22nd December 2015.  As many Woodcock seem to be quite site faithful in subsequent winters this is one that definitely overshot.

A Goldcrest ringed at Grimston, on the cost in the  East Riding of Yorkshire on 12th October and possibly having just arrived there after crossing the North sea was retrapped at Pwllchrochan just 5 days later early on the 17th October having travelled over 400Km.

Other interesting recoveries are a second year Herring Gull from Caldey seen at Radipole on the south coast - very few are found outside Wales and a Manx Shearwater chick from Skokholm eaten by the Valero Refinery Peregrines

Monday, 4 January 2016

2015 round up

All of a sudden it is a new year and three months have gone by since the last post - I think this is mainly down to the wet weather which has put a damper on any netting activities. It has been particularly frustrating that our new wader colour ringing programme has got off to such a slow start. 

We now have three new colour ringing schemes approved for curlew, redshank and oystercatcher but since two successful netting sessions in October when 18 waders were fitted with colour rings it has not been possible to put a net up.

The colour ringing is part of a long term study aiming at getting a better understanding of how these species use the estuarine habitat, their survival and site fidelity etc. All three species have declining populations with curlew recently added to the red list of Birds of Conservation Concern. The cost of the rings and some of the equipment has been funded by the Crown Estate.

All the Pembs schemes use a plain orange ring and a numbered ring that reads upwards

Late October and early November saw some busy netting sessions with good numbers of thrushes and goldcrests caught at the Preseli woodlands. In total 125 blackbirds, 63 redwings, 76 goldcrests were caught including a control that had been ringed in Cornwall two weeks earlier. In addition, a sparrowhawk, a second yellow-browed warbler, 4 bramblings and black redstart added variety.

Adult male brambling

1st winter black redstart

2nd year male sparrowhawk

Further south at Mullock, 4 firecrests were ringed during a single net round during October but this species did not feature at the two Preseli sites.

Thursday, 1 October 2015

Siberian surprise

At the woodland  CES site at Llandilo this morning a single net was opened, mainly as a form of distraction to alleviate the monotony of sitting at the computer writing reports. There wasn't much around really, with most of the summer migrants having left and even the resident birds seemed to be elsewhere, so it was a very pleasant surprise to pull a yellow-browed warbler out of the net! With up to 74 of these recorded in a day on Fair Isle recently, it is perhaps not surprising that they are starting to turn up in the south west, but it is nevertheless a nice bird to get on your local patch.

Among the 20 or so other birds caught there was a control great spotted woodpecker, LH96113 (already entered into IPMR) so hopefully will find out where that came from soon.

Wednesday, 5 August 2015

Identity crisis

As in recent years, the mid summer period has been dominated by a nightjar population study at Brechfa Forest with a view to better understanding any potential effects of wind development. This is in association with Tony Cross who initially worked at the Brechfa site for many years before taking on two other intensive projects at sites in South and Mid Wales see http://midwalesringers.blogspot.co.uk/.

Whilst trying to catch nightjars for ringing and radio tagging, it is very common to catch a few swallows going to roost in the sitka stands during late July and August, though we have never caught a house martin. So whilst extracting a white-rumped hirundine from a mistnet last night I thought -  oooh a new species of by-catch for Brechfa! But as it changed angle it began to look more swallow-like. After a brief bit of even more excitement, I thought "what about a juvenile red-rumped swallow?!" but this idea was quickly quashed by the lack of any collar, so hybrid house martin x swallow it had to be,

The back end looked very much like a house martin with a deeply forked tail

The front end was more like a swallow though the amount of red above the bill was much reduced and the gorget was very pale

The feet were much paler than on a swallow with the faintest trace of the white feathering found on a house martin

Back to what I should have been doing, the nightjars are nearing the end of their breeding season, which has been a challenging one for them in terms of weather. There have been prolonged unseasonal cold snaps in the first half of June and late July and some very low night time temperatures e.g. 4.5degC last week. The wind has also been an issue with very few nights suitable for netting making capturing adults for radio tracking difficult. Nevertheless, the study has gone very well and productivity looks set to be very similar to the last two years largely due to lower levels of nest predation than usual compensating for any losses due to bad weather. One of the most satisfying moments of the study is when at the final nest visit, the fledged young are sat tucked up with an adult.

Adult female and two juvenile nightjars

Tuesday, 7 July 2015

Interesting Recovery

We have just received details of a Sedge Warbler which we caught at Mullock on 20th July 2014 - presumably on passage at that time.
It was ringed at the Reserve N'Diael, Senegal on 5th January 2014 so was wintering there and returned to the UK for the breeding season.  We do not often come across birds ringed in their wintering quarters so this is a nice record.

Friday, 3 July 2015

Stormie Ringing

The Teifi Ringing Group came and helped out on Wednesday with a successful Storm Petrel Ringing session and they have already posted some details. 

One of the things we were looking at is the wear and moult patterns on the wings of the birds and of the 101 new birds caught one with very worn wing feathers throughout and with dark chocolate brown wings generally looked like a good candidate for a 2014 returning juvenile.  Another bird looked like it had replaced all its secondaries but nothing else and many showed wear and fading on the greater coverts and tertials - which is to be expected if they are almost a year old and are fundamentally protecting the other wing feathers when the bird is at rest. 

One of the controls was a French ringed bird,  the first time we have caught a bird with a French ring, and the two other controls were ringed on Skokholm on 26th and 30th July 2014 - so they are back in local waters.

Wednesday, 17 June 2015


A new constant effort site (CES) was started in woods at Llandilo in May. So far, five visits have been made and everything looks good in terms of numbers of birds caught for carrying on long-term. Like many woodland CES sites, the catches are fairly modest in terms of numbers, especially if you compare it to scrub/reedbed habitats.  So far 22 species have been caught and there has been an average of 32 birds per visit though catches should increase as juvenile birds become more mobile.

Five nets are set in willow/alder carr and sessile oak woodland. Nets only catch well where the canopy is <20ft

Although the catches are modest in terms of numbers, they have been perfect for training sessions
Blackcap is the most numerous species caught, 28 individuals so far

Newly fledged young blackcaps (right) are have noticably duller brown caps than adult females (left). The first Juvs are only just starting to be caught, slightly later than most years

The kestrel colour-ringing is continuing and so far 18 chicks have been ringed from four nests
Young kestrels usually clamour to be first in line to get their colour-bling, but these were well-mannered and formed an orderly queue 

A brood of three yellowhammers was a bonus find, a scarce bird nowadays.

Sunday, 31 May 2015

47 and still counting

Since the last post, several visits have been made to the wheatear RAS site to try and bling up an acceptable minimum sample size of  50 individuals and this year success looks very likely; thanks to the dedicated efforts of Mike and Theresa we only now need to catch another three individuals to add to the total of 16 re-sightings and 31 new birds caught so far. Mind you, to reach this total we have had to accept "immigrants" - Teifi RG immigrants at that! The last individual to be added to the tally was a female wheatear originally ringed as a juvenile on 4th July 2014 at Carn Ingli by Karen (Teifi RG). It is only 8km as the crow flies from Carn Ingli and the date and age of the bird suggests that it was presumably born very locally to Carn Ingli before settling to breed within a few km here at Carn Breseb (v
ia Africa). This is the only recorded movement away from the site despite ringing 312 wheatears since 2008. It is also very appropriate that the bird was ringed by Karen who often makes the long foot-slog up the Preselis to help with the project.  Luckily the politics of the group welcomes migrants!

Karen's wheatear with added colours

The 2015 wheatear season is running much later that last year and is more on a par with 2013, an exceptionally cold spring with delayed breeding and small broods. Following a very sunny April, May has been relatively cold and quite windy so perhaps this has caused females to delay egg-laying, or even abandon and start again. So far no fledglings have been seen. Another potential cause of nest failure is predation. Wheatear nests are completely safe from corvids and at this site from foxes too - who often try to dig them out unsuccessfully, but it was clear from the response of three male wheatears that they absolutely panic in the presence of weasels. During one of the visits a weasel was seen systematically searching any crevice or hole it could find and up to three male wheatears were in attendance, all hovering within a foot or two and giving off a very agitated rattle-like alarm call. The weasel didn't seem to find anything and it later became clear that very close by a female wheatear must have been incubating a clutch that escaped predation.

A weasel on the prowl - probably looking for voles but three male wheatears were in a panic

Another unusual record this spring was a wheatear caught on 29th May in full moult - this normally starts at the end of |June or mid-July following breeding, but this bird must have started by 20th May. Whether this was caused by the cold weather combined with a failed early breeding attempt is not clear, but it is extremely unusual for an adult of any migrant passerine to be in moult this early.

Male wheatear in full moult on 29th May

Adult male

Tuesday, 5 May 2015

Wheatear RAS is on

Most adult wheatears that make it back return to the exact territory that they bred in during the previous season
This is the third season of the wheatear adult survival study (RAS) at Mynydd Preseli and it is very much hoped to get the sample of colour-ringed adults up to 50 this year. This is something that was the aim in 2013 and 2014 but annual totals of only 26 and 30 respectively were achieved. Rather than admit failure though, this underachievement has been classified as an essential learning-through-experience part of the project. The open habitat means mistnets are unsuitable so the birds are caught for colour-ringing in spring traps baited with mealworms.

A few things learnt:

Although some wheatears are caught readily, they very quickly become trap shy and if they witness another individual being caught they become highly suspicious of the traps and become very difficult to catch. During the egg-laying and incubation period the males usually mate-guard the females by following them about whenever they are off the nest, so it is difficult to find a time when females are on their own. Whilst females are on the nest, the males tend to sing and generally loaf around, so they don't spend much time feeding. They are only attracted to the bait when they need it, so on nice warm sunny days when they are often well fed, they ignore it.

If the nest is full of hungry chicks then both adults are much more likely to be tempted by the bait and this is when most birds are caught. However in 2013 the very cold weather in May meant that there were lots of nest failures, and those that were successful had small broods (e.g. brood sizes of 1 and 2 were frequent instead of the usual 4 to 7). The weather subsequently turned warm and dry and this left many pairs not that desperate for the bait.

Once the young fledge, the adults seem to switch from feeding them soft prey to adult insects and aren't fussed about eating mealworms, so they have to be caught before they fledge young. In 2014 the season was surprisingly early and about 50% of pairs had fledged young by the time of the first visit on 24th May.

The secret of catching all the adults lies in timing the catching effort to coincide with feeding nestlings, so regular reccy visits from late April onward are essential to keep a finger on the pulse of what each pair is up to.

Some of the colours fade whilst the birds are are in their sunny African wintering grounds. Red, in particular, fades to a sort of pinky-orange within a year making it almost impossible to tell from orange with certainty. Light blue seems to get much paler and can appear white. Luckily all the ambiguous combinations were not applied to the same sex, so all birds are still uniquely marked.

red over grey in May 2013

The same bird a year later

In 2014, 12 out of the 26 marked in 2013 returned (46%), and so far in 2015, 12 out of 30 have been confirmed, though not all territories have been checked so the figure will almost certainly rise.