Monday, 31 January 2011

Icing on the cake: January's Lothian highlight

The first month of the year is coming to its end already, and I see on Bubo listing that I am well off the Lothian list pace. My running total of 88 species reflects a January with limited time for birding beyond my local patch. As a combined force, Lothian listers have logged 130 species in the county this year already and Tony O'Connor leads the current table up at 112. Of course, it is not a competition, I keep telling myself - just some fun. Nevertheless, quite a few of these should be easy targets for me in the next few weeks - I am yet to see Goosander, Whooper Swan or even Pochard. I also note that there are three species that feature on several lists that I have not yet seen in the county - Taiga Bean Goose, Green-winged Teal and Smew - maybe I should put some effort into seeing these in early February...

I did add a couple of new species today thanks to a deviation on the school run and a lunch hour in Holyrood Park, Edinburgh.

On both visits the Iceland Gull was showing well, on St Margaret's Loch in the morning and on Dunsapie Loch at lunch time. It could be enticed into flight with some carefully thrown bread crusts, though it seemed unable to compete with the screaming Black-headed Gulls for the scraps.

This bird is in first winter plumage, though this term is sometimes avoided for gulls like this one that have no post-juvenile moult (all the feathers here are un-moulted first generation juvenile feathers). The lack of moult may be related to the short nature of the Arctic summer. So what term would be better than first winter? Second calendar year (2CY) is maybe no better, given how different this bird will look in ten months' time, so possibly 'first generation' is best of all. Whatever we call it, it is certainly a strikingly beautiful young gull.

I had travelled to Galway in December in the vain hope of getting good views of this white-winged cracker. Little did I know that a month later there would be such an accommodating individual within a couple of miles of home!
The subtlety of the bird's markings could be best appreciated on the tail. The white primary feathers and long wings make this bird unmissable in flight.

The Iceland Gull could be tempted by bread, but it always seemed that little bit slower off the mark than the Black-headed Gulls and Common Gulls.
On the water, the long white primaries made the bird equally distinctive, and in good light, the bird's iris could be seen to be chestnut brown rather than black. This colour will lighten over the coming months to the very pale eye typical of adult Iceland Gull. The 2CY bill pattern already seems well developed.

Too slow to get to the bread, the bird started foraging, though it did not seem to be successful.
A great bird and one that I hope hangs around for the next few months...

Another bonus while feeding the gulls this morning was this Common Treecreeper in the trees around St Margaret's Loch. Another Lothian year tick for me.

A Common Raven  over Arthur's Seat at lunchtime was a good bird for the city centre.

Finally, here is a Carrion Crow with de-pigmentation showing that there is more than one 'white-winger' in Holyrood Park today!

Sunday, 30 January 2011

Gulls: no-show Norwegian and Iceland

A quick trip up the road to Alnwickhill water treatment works turned in to a long stake-out today. Soon after I arrived one of my target birds dropped in to my field of view - a colour-ringed Common Gull! For most folk, this would probably not be the most exciting of events, but it is something I have been actively looking for locally over the last couple of months. Today's bird had a white ring with black lettering, but frustratingly it moved out of view just as rapidly as it appeared and I could not be sure of the combination. I'm fairly confident that the first letter was 'J', which could indicate that it was ringed in Norway. Three cold hours later the bird still hadn't returned and I returned home disappointed, but with the consolation of having seen my first Linnets and Lesser Black-backed Gull of the year, as well as some less regular species at the site: Great Black-backed Gulls, Goldeneye and four Waxwings.

Once home I found out that I had been watching the wrong Edinburgh water-bodies this weekend - a first winter Iceland Gull had been seen since Friday at Dunsapie and St Margaret's Loch in Holyrood Park. With the light beginning to fade I decided that it might just be worth the couple of mile trip up to St Margaret's. By the time I arrived, most gulls had flown to roost and only a handful of Black-headed Gulls were still at the loch in the twilight. Never mind, it will probably return, so I read some Mute Swan colour rings in the fading light.

As I returned through the park, I paused to photograph the sunset and was pleased to notice that there was a Northern Fulmar high up over Our Dynamic Earth. Another appeared and the two birds began chasing and interacting like a pair of giant swifts careering through the twilight. It may have been cold, but it was a warming reminder that spring is not far away.

Black-headed Gulls and signs of spring

A quick trip to the nearest duck pond today, in lieu of 'real birding', gave me fifteen minutes to look at Black-headed Gulls. In particular, I was looking at the pattern on the trailing edges of their wings, having noted this bird a few days ago that had a distinct step in the black trailing edge. This bird was very distinctive in flight and I wanted to see whether this was a common variant.

There were about 140 Black-headed Gulls at Blackford Pond, Edinburgh, today but I couldn't find one with quite as distinct a step in the black trailing edge, though there does appear to be variation in this characteristic.

I did notice a couple of birds with hoods now showing quite distinctly. The hood, which is a characteristic of summer/breeding/alternate plumage develops as a result of wear to the pale tips of the head feathers. These pictures show the range of head colouration in the birds today, from almost completely hooded to almost completely white-headed.

Another sign of spring noted today were the Snowdrops coming into flower in Craigmillar Castle grounds. I think that Mary, Queen of Scots, probably missed seeing these flowers by moving away from the castle in December 445 years ago, although she probably had other things on her mind...

Thursday, 27 January 2011

Northern Gannets

Interest in Gannets has been heightened this week with a report of a possible Australasian Gannet off the English east coast. In Lothian we are fortunate to host an estimated 50,000 breeding pairs of Northern Gannets on Bass Rock - for most months of the year there are a lot of Gannets passing offshore. So many that when seawatching off this coast I'd say it is normal practice to set the brain to 'ignore-all-gannets' mode.

It is possible to land on the Bass to observe and photograph the birds at close quarters, and although the trips do not come cheap, I would recommend the experience. (For trips see the Scottish Seabird Centre in North Berwick.) I was lucky enough to participate in one of these trips to Bass Rock in June 2007. The weather was cold, windy and overcast with heavy showers threatening. We were advised that landing may be impossible, and while that turned out not to be the case, the conditions for photography were far from ideal. No shots of gleaming birds against azure sky for me.

Here is my best shot from that day. It took about 50 minutes of a stealthy approach lying down in Gannet guano to get this image of two birds with North Berwick Law in the background. Even then I had to photoshop an awkward third bird's beak out of the right hand side of the picture. (Is that cheating? and should I have gone the whole hog and removed the three blurry flying birds as well?... )

The following flight shots of adults were taken on a pelagic trip off Newcastle in September 2010 organised by Martin Kitching.

Clearly I was having trouble getting the wings in shot...

Here are some younger Northern Gannets. The first is a first summer bird and the second a second summer bird.

It is interesting to see the difference in extent of white plumage between these two birds - just a few body feathers in the first year (above) and then head, body, lesser coverts of the upperwings and uppertail coverts in the second year (below). The latter can be particularly striking birds.

Finally, here are some slightly older birds that show predominantly adult type plumage but with dark secondaries and tail feathers. These birds appear to aged as 3rd year birds (using data from birds of known age) in Bryan Nelson's monograph although the illustrations show some other darker feathers in the body and coverts. However, a rare variant of 4th year birds is described in the Collins guide for birds with completely white body plumage and coverts.

It is birds in this plumage that can resemble Australasian Gannet or Cape Gannet. The first of these birds was photographed in June 2007 at the Bass Rock. I have tentatively aged this striking bird as a 4th year with its adult body feathers and coverts combined with many black secondaries using the Collins' criteria. Both wings had a classic piano-key look that allowed easy confirmation as a Northern Gannet. The second photo, taken as this bird came in to land on the rock, revealed that only the central pair of tail feathers were yet to moult.

The second bird, photographed on the pelagic off Newcastle in September 2010 looked considerably more interesting as it approached the boat. Only as it passed overhead and away could the extent of immature feathering on the upper and underwing coverts be seen. This would appear to be aged as a 4th year bird according to Collins, but a 3rd year according to Nelson's ringing data. Maybe both ages can show this plumage, however, notice that the underside is finely spotted with black, a feature that seems to be absent from the bird above and maybe consistent with an earlier age. The second picture shows a paler secondary on the right hand side, presumably this feather would show up as a nice white secondary in a shot of the upper wing.

So, other than the presence of the white secondary feather in the right wing, how would a 3rd/4th year Australasian Gannet or Cape Gannet differ from the bird above? Well, without direct experience of the species, I can only guess, but I would imagine that the smaller size of either potential vagrant may well be one of the first real clues to its identity. The Northern Gannet is larger and bulkier, being adapted to foraging in a colder climate.

In a view like the one above, a Cape Gannet would usually show an all dark tail but would certainly show a much longer black gular stripe extending from the base of the bill down the centre of the neck. The gular stripe of would be about twice the length of that shown in the bird above. The gular stripe is bare skin and its length allows the Cape Gannet to loose heat more efficiently in arid breeding colonies.

Separating this bird from an Australasian Gannet would maybe be more tricky, although I think that the gular stripe is narrower in that species compared to the bird above, although that would be a very difficult distinction to make in the field (and possibly is incorrect). On the other hand, the Australasian Gannet has a darker grey iris which may stand out in comparison with the strikingly pale iris of the Northern Gannet.

For more on the separation of Australasian and Cape Gannets see this thread on BirdForum, particularly for a nice head shot of both species together at a colony in South Africa.

Tuesday, 25 January 2011

Great Black-backed Gulls

A small selection of photos of Great Black-backed Gulls taken in September 2010 off Newcastle on a pelagic trip with Martin Kitching's Northern Experience. Impressive birds, always keeping close attendance on the lookout for discarded fish.

Jumping cholla cactus, Joshua Tree National Park

I parked the car at the cholla cactus garden right next to this sign. Better warn the kids I thought as I got out of the car. Too late, within seconds one of them had skipped through the fence, and was merrily picking up a piece of cactus that had 'jumped' off one of the main plants.

"Don't touch that!", I yell, and my shout causes her hand to twitch. This is when she starts yelling...

Calm down, I tell her wondering why she is making such a fuss. "Its only a few spines!" and the plant seems to be barely attached to the side of her hand. So I hop over the fence, and grab the cactus in order to remove it.

At this point I understand her pain. The spines are improbably sharp, they penetrate deeply and they are microscopically barbed. We are now locked together and in real pain. At this point I realise I have to grasp the nettle and grab the cactus even more firmly in order to pull each of the barbed spines out of her hand. This works, but leaves the plant very firmly attached to me.

Without warning I am assaulted by a stick-wielding offspring number two. A carefully aimed blow fails to dislodge the cactus, but instead drives more spines deeper into my flesh. "Stop it!" "Sorry, I was just trying to brush it off with this branch." Of course, without experiencing the piercing grip of the cholla cactus it is difficult to understand how un-brush-off-able the plant actually is, so I try to be grateful for the attempted help. But fail.

The stick does help in the end though. I jam the cactus between the stick and the fence and then, with tears in my eyes, rip my hand away from the spines. Each point gives up with a struggle, pulling the skin into a point before release. Many of the tips stayed within the skin to be pushed slowly to the surface over the next few weeks.

So, take care if you are visiting this fearsomely impressive plant, as I am not sure that even the Cactus Wren would fancy a close encounter with it.

Sunday, 23 January 2011

Common Crossbill on Sanday

Mountain biking this morning at Glentress, in the Borders, and the spruce trees seemed to be full of Common Crossbills. We watched two birds at close range perching on one of the poetry-inscribed stones at the edge of the red trail. One looked a typical female type but the other was a lovely (young male?) with pale body feathers and a bright yellow rump. I was wishing that I had binoculars or camera with me - although they might not have been very helpful at other moments...

I grew up with Common Crossbills being regular birds in the trees around the house and, as a result, they are one of my favourite birds. While flocks were seen on a seemingly daily basis, and prolonged views of feeding birds could be had regularly, it was a rare event that really good close views could be obtained.

Strangely, after a childhood surrounded by conifers, my best ever view of a feeding Common Crossbill was on the virtually tree-less Isle of Sanday, Orkney, in the summer of 2009.

We had just arrived at a cottage that we had rented for the week at the Peedie Sea and to welcome us a Common Crossbill flew in to watch me unpack the car boot. It appeared to be a second year male, as it was pretty red but also showed quite a number of immature feathers, and it also showed a thin but distinct wing bar caused by narrow pale fringes on the greater coverts. After sitting on the fence for a while it was soon tucking into grass seed and it fed in the area on and off for the next few days. Hopefully it made landfall elsewhere later in a more suitable habitat...

Friday, 21 January 2011

Angel wings

I put the wrong yeast in the bread-machine the other day. Well, I'll take the loaf to Duddingston Loch after the school run as a treat for the ducks. "Don't kill one with that thing", I was advised. Fair enough since the loaf was like a brick.

The Canada Geese at the Loch seemed particularly appreciative and given that it has been a tough winter I didn't mind feeding these friendly brutes rather than saving morsels for other birds. A little too close for the lens perhaps, but I still get a kick from getting views of any birds like this.

Even feral geese...

One of the Canada Geese kept a little further away. It was suffering from angel wings - a distinctive developmental problem where one, or in this case, both wings are twisted and protrude from the bird sideways. I felt a little sorry for this one, but it did not seem to be particularly interested in my offerings. Nevertheless, look on the bright side, I thought, the condition provides a good view of the black tail, white uppertail coverts and black rump which are normally concealed from view...

It turns out that, while this developmental condition is not well understood, it is not necessarily thought to be genetic. Instead, it is hypothesised that it is a condition brought about by an inappropriate diet - a diet excessively rich in protein. Angel wings occurs in populations of wildfowl that are fed by humans and it is suggested that excess protein in the food provided by humans causes excessively fast wing feather growth in young birds. This increased feather bulk and mass causes the young developing wing-tip to twist at the carpo-metacarpal joint and the wing then develops in an inappropriate position.

Looks like this bird was right not to take my bread after all.