Archive for the ‘Ringing’ Tag

Early September 2014 – a ringing update   Leave a comment

 

 

Just a quick blog update before, once again, I go on my travels, this time to northern Madagascar, however the Air France pilot’s strike has already caused problems and threatens to wreck the whole trip.

The settled dry, easterly conditions have been good for ringing at Dulston, although it has been a bit on the windy side at times. Since the start of September we have ringed nearly a thousand birds with Blackcaps occurring in unprecedented numbers (550 in the first 18 days of September). Over the last few days there has been a large movement of Meadow Pipits and close on 100 have been ringed.

IMG_0019 Yellow Wagtail

We also have done some ringing at Lytchett Bay. Sedge Warblers were still present at the start of the month and we ringed a few Yellow Wagtails at dusk one evening.

IMG_0030 Mipit

Meadow Pipits have been ringed in large numbers over the last few days. The whitish fringes to the unmoulted median coverts with the centers forming a downward pointing tooth indicate it is a first year bird. Another first year feature is that the  unmoulted greater coverts are not very dark centred and have a diffuse brown fringe. Contrast them with the two longest tertials which are darker with a better defined fringe.

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The heavily streaked flanks and long hind claw are good features to separate Meadow Pipits from Tree Pipits (which seem to have all left for Africa). The constant pheet-pheet-pheet call is a bit of give away too.

IMG_0033 Blackcap 3&4

Telling a first year male Blackcap (L) from an adult (R) involves checking for contrast in the wing coverts, fault bars on the tail and pointed outer tail feathers, all first year features. Additional pointers shown in this photo are, the presence of brown fringes to the crown feathers, a brown wash to the ear coverts and slightly less richly coloured eye.

IMG_0022 Wilwa abberant wing

This is the wing of Willow Warbler but an unusual one at that. Normally the longest feather is the 3rd primary (counted from the outside in – and remember that the 1st is vestigial and largely hidden by my thumb) but in this case it seems to be the 5th. However it can be seen that the 6th – 10th primary are unmoulted whilst 2- 5 are new, so is the 3rd still growing? I must admit I forgot to check this at the time. Adult birds should complete their moult before migration but this bird has either suspended its moult mid way though or is migrating with moult in progress. Not all birds fit the rules.

IMG_0020 ringing demo

We are asked to perform two public ringing demonstrations annually. One on the 14th was attended by about 20 people. Here Sean Walls is explaining  the use of radio tags on birds.

 

IMG_0034 Sparrowhawk juv male

It’s a shame that we caught this Sparrowhawk the day after the public demo, rather than during it. The pale eye and chestnut fringes to the feathers show it is a juvenile, the small size shows it is a male. Male Sparrowhawks are so much smaller than females that they take a different ring size.

 

IMG_0041 Redstart

We trapped a Common Redstart the day of the demo, but soon after dawn well before the public arrived.

 

 

DSCF4423 WEO and Christine

Last Friday our young friend Christine Arnold came round for a meal. She was about to return to teacher training college and was keen to catch up with our news. She has been staying on Brownsea Island and was most impressed that Bill Oddie was staying there as well. I don’t know if this is in his guise as Autumn Watch presenter or as a private holiday. Either way Christine was most impressed to be in the company of a wildlife celebrity and asked that I post this photo on my blog.

Posted September 18, 2014 by gryllosblog in Uncategorized

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1st – 22nd August – a ringing update.   Leave a comment

August can be one of the best times of the year for bird ringing, the weather is still mild, although a bit windy this year, autumn migration is in full swing and the variety of trans-Saharan migrants is at its peak.

I have spent as much time as possible ringing this month at Lytchett Bay and Durlston Country Park although the remnants of hurricane Bertha and getting up at 0430 everyday have proven to be obstacles.

Early in the month there were phenomenal numbers of migrants, especially Sedge Warblers on the move. A couple of visits to Lytchett Bay resulted in nearly 500 birds being ringed, most of them Sedges. Mid-month the weather changed to an unending run of westerlies and the numbers of birds present has been much lower.

Sedge Warblers are usually encountered in wetland habitats but can be seen on migration in scub and low vegetation.

Very common in the reed beds at Lytchett Bay with over 750 ringed this autumn, we have also trapped about 20 in the scrub at Durlston. Sedge Warblers winter in the Sahel, the arid region that lies to the south of the Sahara.

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The heathland at Lytchett Bay has recently been purchased by Dorset Wildlife Trust. We applied to renew our ringing permission with the new owners and they asked us to do a public ringing demonstration. We have only caught a few birds on the heathland but a ‘dress rehearsal’ at the adjacent reed bed has produced a large number of Reed and Sedge Warblers and required us to call in reinforcements to help. Unfortunately the remnants of  hurricane Bertha prevented the actual demonstration from going ahead.

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Whilst taking down nets at dusk we trapped this Brown Long-eared Bat. It might look undignified but this is the correct way to hold a bat, as it does not involve touching the delicate wing membranes.

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Kingfishers appear in the early autumn every year at Lytchett Bay. We presume they migrate down the local rivers to winter in Poole Harbour. In 2014 we have ringed 8 new birds and retrapped one from last year, showing that the single kingfisher seen on each visit is not necessarily the same bird. We have retrapped several in subsequent years, showing year on year site fidelity, but have also retrapped a Lytchett Bay bird in a subsequent winter at Fleets Lane in Poole indicating that this is not an inviolate rule. In this picture a pristine first year (L) contrasts with the ragged adult (R) which is the process of moult. Accurate aging is essential for an understanding of population dynamics which is one of the main investigations conducted these days on ringed birds.

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Grasshopper Warblers, with their graduated tails and long speckled undertail coverts are always a delight to ring. So far this autumn we have ringed 17 at Lytchett Bay and 7 at Durlston. Because of its secretive habits this species has one of the lowest recovery rates of all ringed birds and much is still unknown about its movements and life history.

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Lytchett Bay is the only site where we regularly ring Cetti’s Warblers. An inhabitant of scrub adjacent to wetlands this species is not a true migrant but young birds do disperse as shown by a recovery of one of our birds from Norfolk. The mouse grey-brown plumage, short wren-like wings, broken white eye-ring and just ten rather than the usual twelve tail feathers are all identification features, but most birders will know it by it’s incredibly loud staccato voice.

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We have ringed over 60 Garden Warblers this autumn, mainly at Durlston. It might look like the archetypal ‘little brown job’ to the uninitiated but the stubby bill, narrow grey shawl and plain upper parts with pale tipped remiges give a very characteristic appearance.

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Unlike almost all other members of the genus Sylvia, adult Garden Warblers moult in the winter in Africa rather than before migration. Thus an adult on migration will be more abraded than a young bird. This can be quite subtle, the faded tips to these primary feathers are caused by bleaching by the sun over time and thus belong to an adult bird. It has recently been shown that Sylvia warblers are not warblers at all but representatives of the  mainly Asian babblers.

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However caution is required when aging birds, the tail of this Garden Warbler might look abraded but this can happen in the nest. The presence of a growth bar shows that it is a first year bird. Changes in the availability of food whilst the tail is growing is reflected in the colour of the feathers. The fact that the growth bar occurs across all feathers means that all feathers grew simultaneously and therefore must be from a first year bird.

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Common Whitethroats (the full name is needed to distinguish it from the next species) is a common breeder at Durlston but migrants also move through the Park in some numbers. The dark eye and lack of pure white in the outer tail show that this is a young bird.

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Lesser Whitethroats are (as the name would suggest) smaller than the last species and also are much paler with white underparts, have a pale grey head and lack rufous in the wing. Small numbers breed at Durlston – we have ringed 12 so far this year.

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Breeding mainly in the west of Britain – Devon, Wales and SE Scotland, Pied Flycatchers are pretty scarce on migration where we ring, however the trapping area comprises mainly of low scrub and is not ideal for these arboreal birds.

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In common  with the last species, we have only ringed a single Spotted Flycatcher so far this year, although their migration extends well into September, so there may be more.

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Tree Pipits are regular overhead migrants in late August – early September, usually just after dawn. The fine flank streaking, face pattern and (when you can see it) shorter claw length separate them from the similar Meadow Pipit. In the field the call is diagnostic. So far seven have been ringed at Durlston this August.

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Juvenile Blackcaps have a dark brown crown. This changes during the post juvenile moult to the familiar black of a male or tawny-brown of a female. Note the crown of this bird: this not a mixture of black first year and brown juvenile feathers but rather first winter feathers with brown tips. These will presumably abrade to give the pristine black crown by the spring.

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Most birds fly off immediately on release but some pause to ‘gather their bearings’. This Willow Warbler had a little rest on Margaret’s woolly hat before flying off into the nearby scrub.

29th Oct – 2nd Nov – bit more ringing.   Leave a comment

During this week the windy weather interspersed with heavy showers has continued. Not very conducive to our autumn ringing program but I have managed to get out on three occasions.

On the 29th our trainee Carol and I visited Holton Lee, the private estate on the south side of Lytchett Bay. I was keen to see how many of the birds I had ringed last winter were still coming to the feeders. The answer seemed to be not many, as only one Blue Tit and one Nuthatch out of the 142 birds we ringed last winter were re-trapped. Of course more of last years bird might be in the vicinity, just not coming to the feeders that morning, but it does show what a rapid turn over occurs, even among sedentary birds like tits, woodpeckers and Dunnocks from year to year due to natural mortality.

We trapped three Great Spotted Woodpeckers, all young males, a new Nuthatch, several Goldcrests and two Marsh Tits. There also seemed to be a new influx of Robins, as seven were ringed. Being highly territorial in the winter, it seems unlikely that they had been around for long as you would expect a resident bird to chose and defend a territory against all comers. Although a local breeder there is definitely an influx of migrant Robins every autumn.

PA290647-Marsh-Tit

There has been a significant decline in Marsh Tit numbers in recent years. This has been variously attributed to competition with increasing numbers of Blue and Great Tits for food and nesting sites and to the destruction of their favoured understory by a burgeoning deer population.

On visit a Durlston on the 30th we saw a good number of finches, Redwings and even a  few Swallows on migration. We ringed 35 birds, predominately Goldfinches. It would seem that the large numbers of migrant warblers we experienced since we commenced autumn ringing at the start of August is now over.

On the 2nd, Mick was joined by his friend and former trainer Mick Netherwood who was visiting from London. I have known both of them for many years since we used to ring at Chapman’s Pool, the annual visit for a week or so by the ‘two Micks’ was a firm fixture in the ringing calender. As I haven’t seen Mick N for several years, I joined them, although I have to admit the conditions weren’t promising. Increasing wind and showers meant we had to pack up by 0930 but although we only trapped 21 birds, we had a couple of corkers.

PB020654-Firecrest

This was the first Firecrest we have trapped at Durlston this autumn. Numbers of this, our smallest bird (along with Goldcrest), seem to be increasing with more breeding pairs being discovered. It is not yet known if the Firecrests that breed in the UK are represented among the migrants encountered on the coast but ringing recoveries have indicated that many of the migrant birds come from the near continent.

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The real surprise was the capture of this Yellow-browed Warbler. No longer a rarity, this species is best considered a scarce migrant. From 1968-84, 0-5 were recorded annually in Dorset, from 1985-99 up to 29, but these days over 40 are seen, with Portland taking the lion’s share. Probably a couple of thousand pass through the whole of the UK each autumn. Whilst the vast majority of the population breed in Siberia and winter in SE Asia, it may be that the most westerly breeding population is establishing a separate wintering ground in western Europe.

YBW DCP SB

Today was the first date since the start of August where we haven’t trapped either a Willow Warbler or a Chiffchaff at Durlston. However in world terms YBW is perhaps the most numerous of the genus Phylloscopus, breeding across vast swathes of the Siberian taiga. This species needs to be distinguished from the very similar, but considerably rarer, Hume’s Leaf Warbler (with which it was once considered conspecific) but Hume’s is greyer, has a reduced median covert bar, all dark bill, darker legs and paler centres to the tertials and coverts. They also differ considerably in vocalisations, but that would have been of no use in this circumstance. Photo by Simon Breeze.

Posted November 2, 2013 by gryllosblog in Uncategorized

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22nd – 30th September – back home in Dorset.   Leave a comment

I returned from Fiji late on the 21st after a journey that lasted 47 hours and involved five flights. Although I have returned from the Pacific on previous trips, I have never felt so jet lagged, probably exacerbated by a nasty cold I picked up on route. My body stayed on Fiji time (eleven hours out), I would fall asleep each afternoon and then not sleep at night!

In spite of this I managed to visit Durlston on the 23rd, 25th and 26th to continue our ringing program, with several of our group away at the moment, I wished to ensure the coverage was as full as possible. We ringed good numbers of birds on the first two dates but the latter was curtailed by increasing wind and rain.

Feeling it would be too windy to ring on the 28th, I visited Portland Bird Observatory. There were very few birds about, but it proved to be an excellent social event, a chance to catch up with news and views from many of the Portland regulars, most of whom I have not seen since the spring. Also there was a chance to browse the Ob’s extensive natural history book store and of course I bought a couple of books.

One birder I haven’t seen for ages (mainly because he has been abroad for much of the year) is Paul Baker, aka Bagsy. Paul manages to update his blog daily, something I would like to do but have failed miserably to achieve. See http://bagsy-thecaptainslog.blogspot.co.uk/

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Bagsy poses with his eponymous new motor.

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I had better luck birding at nearby Lodmoor, here six out of a flock of seven Spoonbills were photographed flying over the marsh.

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Birders at Lodmoor seemed just as interested in a pair of Bar-headed Geese out in the middle of the marsh. Although a long distance migrant (breeding in Tibet and wintering in India) the chances of them being genuine migrants are close to zero.

IMG_3852-Med-&-BH-Gull

Up to 50 Mediterranean Gulls dropped in whilst I was at Lodmoor (at least four can be seen here with Black-headed Gulls). Once a scarce visitor to Dorset, now up to 100 pairs breed in the county and gatherings of up to 500 have been recorded in the Weymouth area.

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A winter plumaged Grey Plover at Lodmoor.

On the 29th Paul, Ian A and I ringed at Fleets Lane in Poole. We ringed about 45 birds. At this time of year most warblers have left with two exceptions, Chiffchaff and Blackcap. Unlike most migrant warblers that winter south of the Sahara, the majority of Blackcaps and Chiffchaffs winter in north Africa and the Mediterranean. Some over winter in the UK but these are thought (at least in the case of Blackcaps) to be birds from Europe rather than European breeders.

September ended with a very busy morning at Durlston. On a grey and misty morning, Chiffchaffs and Blackcaps just poured through the garden. As always, we had to manage our operation to cope with large numbers and had to close some nets. By midday we had ringed 225 birds, all but 17 being the of two species mentioned above. Also there were large numbers of Swallows and Meadow Pipits moving overhead, involving thousands of birds. Durlston has to be one of the best places in the UK to see the spectacle of autumn migration.

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A small number of Meadow Pipits were ringed. The photo shows the very long tertials that completely cover the primaries on the folded wing.

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At this time of year Chiffchaffs have replaced Willow Warblers as the commonest Phylloscopus warbler. We trapped a single Willow today compared with 77 Chiffs. Although superficially similar, Chiffchaff (left) is slightly smaller, has a shorter supercilium, shorter primary extension, browner flanks and has a more rounded crown.

Posted September 30, 2013 by gryllosblog in Uncategorized

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