Wednesday, May 30, 2012

The news broke yesterday that Giselle's ringing trainer had caught and ringed yet another MEGA, this time in the form of a Western Orphean Warbler (well done Chris!). So we were faced with the uncomfortable indecisiveness of whether to traverse the country (again), in the hope that it would stick around long enough for us to see it, or to remain faithful to the Bardsey patch. Luckily, we didn't have to make the decision as the warbler was not seen today and the news from Nant was that of a Bee-eater! Luckily Rich was nearby and got on it immediately, but I (Giselle) was birding the gorse at the opposite end of the Island. It was observed flying South across the Island towards the farm, so that's where we gathered. Then the news came that it was back at Nant! So we ran. I (Giselle) don't usually run. It was a battle of both mental and physical strength, but we got to Nant just in time to see it fly around the northern edge of the mountain.

It came back quickly and we could hear it calling from the Maritime Heath. Then a Peregrine was observed swooping down over where we heard the calls. Then, silence, with good views of a Peregrine carrying an unidentified bird over the mountain. Did it survive? Did the Peregrine opt for an unsuspecting Wheatear? We'll never know! The only previous Bardsey record came in the July of 1984. (c) Richard Brown

Monday, May 28, 2012

Following a brief Black Kite, it all got a bit grotty. Although I (Giselle) am in disagreement with everyone on the Island because I think they're great. Locally referred to as "Grot-finch", Collins prefers to call them Common Rosefinch, and this little tinker appeared in the Withies yesterday after an unusually quiet period, where even the Spotted Flycatchers appeared to have moved on. Admittedly not as attractive as a scarlet plumaged male, this bird made its way up to the feeding station at the Obs, where it soon found itself in the Heligoland trap. 

The breeding range of Common Rosefinch has expanded Northwestwards during the twentieth century and they are now a regular breeder in Norway and Denmark, with sporadic British records since the 80's. Not bad for a species which overwinters in Southern Asia. Wallace (1999) noted conspicuous morning and evening movements of Common Rosefinch across the Kyzylkum Desert, a patch of some 115,000 sq.miles between Kazakhstan and Uzbekistan and the 11th largest desert in the world. From this arid land, Common Rosefinch can reach Western Europe in as little as 10 days. (c) Richard Brown

This stunning male Firecrest appeared in the same place as the Rosefinch. This is only the second record of the year, but this still beats 2011 in which only one bird was recorded. Weighing on average the same as a 20p coin, this species struggles during hard winters and the cold temperatures in the winter of 2010-2011 probably go some way to explaining their scarcity last year. Interesting Firecrest Fact Number 1: A Firecrest specimen dating from the Pleistocene was found in Spain. Interesting Firecrest Fact Number 2: The left wing bone of fossil species Regulus bulgaricus was found in Bulgaria from a period roughly 2.6 - 1.95 million years ago. It is believed that bulgaricus is ancestral to the Common Firecrest R.ignicapilla, with Goldcrest diverging  from this lineage in the middle Pleistocene. (c) Richard Brown

Those of you who have been following our blog since last May should remember the excitement that occurred when a rather knackered looking Puss Moth appeared on the Island. To fill the rest of you in, this scarce Bardsey moth had appeared on some rushes in the middle of a grazed field where it had dropped its eggs in one clump. This is unusual for this species as they tend to lay only 1-2 per leaf. We took some of the eggs in, thinking they might be sterile but with a hope that they would hatch. And they did! And they ate and they ate and they ate until they were giant green caterpillars with pink faces and weird tales. Then they each made brilliantly camouflaged cocoons on some dead logs, and this was how they would over-winter. But as May progressed we started to worry about 'the boys'. Surely they should be emerging. But we didn't give up hope, and on Thursday, the first of the boys emerged from his chrysalis, as a beautiful Puss Moth!

We have since had a further four boys hatch out. Quite how they make their way through their rock hard protective cocoon is a mystery to us. A hairy little hole is the only sign that the Puss Moth has left, the rest of the shelter remaining solid. A final little surprise came when we tried to handle one of the new boys - it squirted a red liquid all over our hands. Yet another amazing anti-predator adaptation by these stunning creatures (could they have more anti-predator defences that any other beast?) (c) Giselle Eagle

Tuesday, May 22, 2012

Now is the spring of our discontent. Scarce birds are feeling very much a thing of the past at the moment. Even the passage of common migrants has slowed to a trickle. A Firecrest, a Marsh Harrier and a pair of Tufted Ducks have all made brief appearances, spicing things up somewhat, although only really in a Bardsey context. One bird however, again only seen for one evening, was really quite something. Despite giving good views, the identification will probably never be resolved.

Very much like a Willow Warbler on first inspection, the very dark legs quickly suggest that all is not quite right. Then a closer inspection of the wing formula reveals six emarginated primaries. So it's a Chiffchaff that looks like a Willow Warbler. The bird was silent throughout which is unfortunate if anyone was leaning towards the possibility of Iberian Chiffchaff. And what about the possibility of a Willow Warbler x Chiffchaff hybrid? Such beasts have occasionally been documented but S.C. Norman's 1994 look at a probable hybrid showed a wing formula with only five emarginated primaries. Answers on a postcard please (or just leave a comment). (c) Richard Brown

The Manx Shearwaters are having a bit of a hard time of it at the moment. The dark skies around the new moon period saw hundreds of birds attracted to the Lighthouse and a few were fatally injured. To add to their woes, a pair of crafty crows have summoned the courage to enter the nest burrows to retrieve the Shearwater eggs. At least 17 have so far been extracted. (c) Richard Brown

Perhaps taking a leaf out of the Manxy book, the Ringed Plovers have decided to nest in a little cave this year. This has been documented elsewhere and is usually linked to enterprising birds experiencing increased productivity if they nest where stock can't trample their eggs. However this particular pair have never lost eggs to sheep. It seems more likely to us that the appalling spring weather drove our Solfach pair to nest somewhere sheltered. (c) Richard Brown

These savage little owls have been recorded eating prey up to the size of Moorhen and Lapwing. However they are probably not responsible for the massive decline in Moorhen numbers evident this year. This pair generally takes invertebrates with an occasional Slowworm or Wheatear thrown in. At this time of year the male will be doing the hunting as he leaves the incubation duties to his female and takes food into the nest burrow for her. (c) Richard Brown

Tuesday, May 15, 2012

Despite the rather unpromising weather situation, yesterday turned out to be a bit of a decent day. Two Turtle Doves and a Crossbill were frequenting the area around Nant, so we headed up there to open a net sheltered by the Plantation. Despite the fact that the area had already been well birded, two skulking Reed Warblers had avoided detection but soon found the bottom shelf. We can't help but wonder what else must sneak through undetected! No doubt there must be a Subalpine Warbler lurking somewhere. A few Redpolls were also caught including two more Northwest looking individuals and a Lesser Redpoll bearing a French ring. Then, just as we were considering some well-earned food, the Subalpine Warbler finally materialised!

The rather skulking female Subalpine Warbler stuck to scrub around the Limekiln and nearby hillside. Approximately 80% of British records are in the Spring, probably due to returning birds overshooting their breeding grounds and a circular migration route which takes them away from the UK in the autumn. (c) Richard Brown

The Turtle Dove is the only pigeon in the world to undertake a truly long-distance migration. It is also the only migrant which crosses the Sahara but remains almost wholly granivorous throughout its life. The entire British breeding population winters between Senegal and Ethiopia. Sadly the British population is declining at a rate faster than nearly all other species. It has been suggested that this is due to a shortened breeding season which reduces the number of nesting attempts, this as a result of increased herbicide use which reduces food availability. It may also be due to increased non-breeding mortality, particularly due to hunting. (c) Richard Brown

Nominate race Common Crossbills breed in a massive area stretching from Europe to Japan. They breed mainly from November to April when Spruce seed is at its most abundant. The larger billed species of Crossbill tend to breed later when there is an abundance of Scots Pine seed. This individual has a rather prominent double wingbar formed by pale tips to the median and greater coverts. But this isn't particularly unusual in Common Crossbills. (c) Richard Brown

Sunday, May 13, 2012

There are two subspecies of Ruddy Turnstone. Arenaria intepres morinella breeds in Northern Alaska and Arctic Canada, wintering in coastal areas of the Southern United States, the Caribbean and Northeast South America with a few as far South as Tierra del Fuego in Argentina. A.i.intepres breed in Western Alaska, Greenland, Scandinavia and areas of Northern Russia. Birds of this subspecies breeding in Western Alaska winter on Pacific Islands and along the Pacific coast of North America, but birds of the same subspecies breeding from Greenland eastwards, over winter in Europe. To complicate things slightly, birds over wintering on the west coast of Central and South America may be either subspecies. Our Turnstone encounters in the Caribbean were with the smaller, darker morinella.

A summer plumaged bird of the nominate form passing through Bardsey. (c) Richard Brown

So Turnstones which have had a leisurely winter in the laid-back Caribbean are faced with an epic migration to their tundra breeding grounds in Northern Alaska and Arctic Canada. One of the most important East coast stop-over points as they make their journey North is Delaware Bay. During the spring migration this area hosts an impressive population of spawning Horseshoe Crabs which Turnstones, along with many other American waders, feast on. Gorging on crab spawn prepares the birds for the last leg of their journey to their breeding grounds, where food is somewhat limited when the birds first arrive. Each Ruddy Turnstone can eat in excess of 18,000 Horseshoe Crab eggs a day. Studies into their weight gain at this stopover point have found that, relative to their arrival weight (94.6-98.6g), they increase in weight by an average of 55% before moving on, gaining an average of 7.2g per day. Each Spring the waders stopping over in Delaware Bay are colour tagged, allowing birds to be tracked without having to be repeatedly captured.

While birding our patch on Anguilla, we scanned through the regular flock of Turnstones and found two colour-flagged birds! 2EY was ringed on 22 May 2011 and A5U on 22 May 2009 both at Reeds Beach, New Jersey. It was the first time that 2EY had been seen since it was ringed, but far fewer birds are observed in Delaware bay during their Autumn migration, no doubt due to the absence of Horseshoe Crab spawn. A5U had returned to New Jersey each May since it was ringed but this was the first time that its wintering grounds had been located. This sort of information would be impossible to establish without the use of colour flags or more expensive tracking devices. A map of where the birds have been seen, and the place to report any sightings of similar flags, is at http://www.bandedbirds.org/

Wednesday, May 9, 2012

Having started so well, May has now become rather quiet. The first two Reed Warblers of the year have passed through, but a report of a probable Wood Warbler wasn't confirmed. A leucistic Wheatear provided some entertainment, as does the regular appearance of unidentified Redpolls. The general consensus seems to be that some Common Redpolls are passing through, but that some intermediate type birds are perhaps best left unidentified. The most interesting news came via a comment left by Si on this blog. It seems that our Red-rumped Swallow may have reached St Mary's, Scilly, on 6th May, four days after it tore across Bardsey. See http://scillyspider.blogspot.co.uk/2012/05/2-red-rumped-swallow-were-finally.html for some photos of a bird closely resembling our streamer-deficient individual.

The leucistic Wheatear that spent a few days in the field below the farm. Although clearly a leucisitc bird, having very pale feathers to the wing, the question of a 'leucistic what?' could be posed. When certain plumage features can't be used, separating Northern Wheatear from Isabelline Wheatear becomes a bit more of a challenge. The pale feathers are so much weaker than they should be that this bird's plumage is already completely shot, the bird looking a mess compared with the nice fresh Wheatears surrounding it. So field characters such as the relative spacing of the primaries and primary projection are of no use. The tail band is quite broad, but not as broad as in Isabelline. The face pattern is also very pro-Northern, with the supercilium pale in front of the eye and bolder behind. (c) Richard Brown

As with other sites, this year seems to be a remarkably good one for passage Blackcaps. The 226 Blackcaps ringed so far this year has already surpassed the best ever Bardsey year total of 205 recorded in 1988. That's a pretty good year considering that the trapping of passage migrants has been occurring on Bardsey since 1953. (c) Richard Brown

The Black-headed Gull mentioned the other day. It spent just a few minutes feeding behind the harrow, but as soon as the job was done the bird was off. Although mud and poor views mean that the darvic can't be fully read, the partial sequence is enough to know that this bird was ringed at Southport Marine Lake, Lancashire on 10 February this year. For more information see http://www.prestonsociety.co.uk/search/label/Black-headed%20Gull%20Study (c) Richard Brown

Several sites have noted that a higher than normal percentage of the Garden Warblers passing through this spring seem to have large pollen horns. This is perhaps as a result of the bad weather earlier this year stranding the birds in warm climates where foraging would result in such a build up of pollen. The horns are also well in evidence on Bardsey this year. (c) Richard Brown

At least we can dream. A few more educational shots from our time in the Caribbean. Least Sandpipers (taken on 16, 23 and 24 February), Semipalmated Sandpiper (both taken on 24 February), Semipalmated Plover (taken 24 February), Stilt Sandpiper (taken 2 February) and Spotted Sandpiper (taken 7 February). (c) Richard Brown

Friday, May 4, 2012

It's been a much quieter day today, but the first Turtle Dove of the year brightened the dull morning, as did another smart Snow Bunting. A Black-headed Gull with a blue darvic ring followed the tractor for a while and another silent grey Chiffchaff caused some head scratching.

Although this bird probably wintered to the South of us, some Snow Buntings winter further North than any passerine, with the exception of Raven. That's quite impressive as a Raven weighs about 31 times what a Snow Bunting weighs. (c) Richard Brown

A small number of Siskins have been trickling through. A first-year male two days ago carried the ring 12631205 which had been added somewhere in Belgium. The same day saw the Goldcrest DKN664, a British ringed bird, controlled at Nant. He was still there the following day. (c) Richard Brown 

Another problematic grey Chiffchaff was just North of the Observatory. (c) Richard Brown