Thursday, 20 February 2014
Tuesday, 4 February 2014
Saturday, 1 February 2014
Aythya fuligula - Tufted Duck
Males
On the Fishing Lake by the cafe block at Haysden Country Park on the 27th of January 2014, there were a couple of nice Tufted Ducks, Aythya fuligula, 2 males. This bird below, one of the two, does not have an obvious crest, but I think must still be older than a first winter juvenile, as there is no barring on the flanks. The water droplets still clinging to the feathers may indicate that the bird has recently surfaced and the crest may then be slicked down in consequence.
Other interesting ID features of Tufted Ducks are the interestingly shaped head with the high forehead on a relatively narrow neck. The bill has a good solid black tip or nail (across the cross-section of the bill, looking as though it "has been dipped in ink"). There is more than a hint of a whitish stripe across the front of the bill of this bird, contrasting with the light blue-grey on the rear part of the bill. This feature is very variable apparently.
The bird is said to sit low in the water but with its tail above the surface, and I think I would agree with this from this picture to some extent - it looks as though its sitting a bit lower in the water at the moment, perhaps after a dive. It may be that the tail is being splayed out and held just pressing down on the surface of the water. Deep yellow eye, perhaps slightly out of focus. The contrast between the dark wing and the white sides is nice and distinct, a beautiful bird indeed, moving well across the water!.
On the main Gravel Pit, Barden Lake, other individuals were keeping themselves out of trouble. This one looks very much at rest, but with its eyes open! I think that the wings are most easily seen from this angle, with the two sets of primary feathers forming a valley down the back between the two wings. It also looks to me as though the flank feathers somewhat overlie the sides of the wings, giving that fringed effect to the rear of the white sides. The tail sits slightly cocked in this picture, with the bird sitting still on the siurface of the water.
It's amazing how the droplets of water remain attached to the feathers!
Females
The females show the same amount of darkening at the tip of the biill, with sometimes a little light band just behind. The main part of the bill is a lot darker in the female than in the male. Some of the females show a scaup-like white patch at the base of the bill, although not quite so extensive, and I rather think quite a lot of them show some degree of lighter brown in that area, like the one in the duck below. This duck, 27th January 2014, is in winter breeding plumage, and the bird will probably now undergo a partial moult just before nesting.
This female, at Barden on 31st January 2014, by contrast appears to have only minimal lightening of the feathers at the base of the bill.
While this one has a little bit more. This one also has the white triangle under the tail, as though its gone early (1st February, 2014) into the summer plumage. There may be more to be thought about here.
Here is a quizzical look from this Barden female (1st February 2014):
This picture, taken at on the 2nd of March 2013, shows the female (behind) in nesting plumage with the light triangle at the rear of the flank. This is very early in the year, very odd indeed. The male may be dipping its head slightly downwards in display. Quite a golden light that afternoon! See how much lighter the male bill is.
First Year
There is some support for the idea that first year males once they finish their late summer moult can still be distinguished from the adult males by some remaining barring on the flanks. The extent of this is unclear, but very obvious according to pictures from the Chichester Harbour Ornithological Group. Here is a male at Barden on the 31st of January 2014 that is showing just one blackish mark in the middle of the flank. Definitely a male from the length of the crest in my view, although it may not be excessively long and perhaps just a glitch, as it may just be one feather. The colour of the darkening is right but the extent appears pretty limited.
So the question is, where are all the first year birds?
and the answer is, they may be there if you look! This was a bird on its own by Coot Point on the very same day, that I had earlier ignored (!), and when you look at it, it is either dirty or somewhat dark on its flanks - a likely first year bird then, and perhaps the slightly shorter crest as well as the slightly lone behaviour might back that idea up!
Feeding
According to the BTO, "the rapid expansion of the Tufted Duck in Britain during the late 19th/early 20th century is probably due to the colonisation of Britain by Zebra Mussels (brought into London docks in the 1820s)". The birds are omnivorous, feeding mainly on mussels, insects and plant material taken from the muddy bottoms of the water bodies they are on, diving anywhere between 4 - 15 metres down. It breeds better if there aren't excessive numbers of fish.
This male at Barden on the seems to have this lump stuck to the inner surfaces of its bill. Most of the material collected from the bottom of the lake is eaten beneath the surface.
Behaviour
In this picture, taken at Barden on the 19th January 2013, the tail of this male is clearly seen to be splayed out, and apparently pressed down against the water surface. I would imagine that this would tend to stabilise pitch while the duck is paddling forward, keeping the head down and steady, rather than pitching up and down. Incidentally here you can see that the tail is actually a dull black in comparison to the true black of the rest of the plumage.
In contrast, looking at this heavily cropped picture taken on the 2nd of March 2013 at Barden, the tail is held horizontally above the surface of the water, and not particularly splayed. Coincidentally or not, this bird is completely still, not swimming forward at all.
Diving
This male, on the 31st January 2014, is rolling to its right as it dives. The tail has been pushed downwards nearly vertically to act as a brake and aileron, as the feet get to work propelling the duck into the dive. You cam see the disturbance in the water rear and left of the duck of the first stroke.
Breeding
This male, on the 31st January 2014, is rolling to its right as it dives. The tail has been pushed downwards nearly vertically to act as a brake and aileron, as the feet get to work propelling the duck into the dive. You cam see the disturbance in the water rear and left of the duck of the first stroke.
Breeding
These two birds look as though they have paired up, with the female in complete winter breeding plumage - I cannot see the paler patch at the rear of the flank of the summer nesting plumage. The birds were cruising down the ditch towards the cafe car park at Leybourne Lakes on the 18th March 2013. There is an amazing size difference between this male and female. I do wonder why the make is holding his head so high, maybe this is a display related to neck thickening. The eye is quite obvious, and perhaps the male has closed its pupil to increase the iris size.
The plumage on the female is the general winter breeding plumage. There will be a post-breeding moult before nesting of the body and tertials March-May. Nesting and incubation would then often be in late May, with incubation through to late June, and taking care of the young through the next about 50 days. Then there is a moult of the wings (and tail) about July-August when she will be flightless.
Rough weather
This female is braving the waves at Barden on the 31st January, 2014, and the water is demonstrating its strong surface tension as it slops around her chest.
Its interesting to see how far back this same female is holding her head on her body.
Pressures
There is increasing pressure to develop many existing water spaces in Britain for recreational activities. This trend will increase disturbance to water bird populations. This paper considers these problems and suggests the sorts of information which are needed for formulating multi-purpose amenity plans for water spaces, where a conservation interest exists. The study at the Brent Reservoir in north-west London has shown that a few species of wildfowl, e.g. Anas platyrhynchos, Aythya fuligula, Aythya ferina, still use the reservoir in autumn and winter despite an intensification of sailing activities. This use and the successful breeding of Podiceps cristatus and other species of water birds depends on the existence of a large enough part of the reservoir which is shallow and marshy and not accessible to boats. As there is some suggestion that larger flocks are more sensitive to disturbance than smaller ones, refuges may be made more effective by proper screening.
Sailing on reservoirs and its effects on water birds Original Research Article Biological Conservation, Volume 11, Issue 1, January 1977, Pages 49-58 L.A. Batten
Population
The Tufted Duck colonised the UK as a breeding bird in 1849, assisted by the arrival of the Zebra Mussel and increasing eutrophication of our natural waters a couple of decades before. Its breeding and winter populations are still increasing and it is interesting to speculate on its continued success. In Northern Europe its population in Northern Europe has tailed off a bit, and the NI wintering population has correspondingly decreased as well.
Monday, 27 January 2014
Barden Lake at Haysden slowly drying out again as the floods recede slightly.
The water level in Barden Lake has slowly and gently dropped, and you can now walk all the way around, muddy though it is. On the Fishing Lake by the cafe block, there were some a couple of nice Tufted Ducks, Aythya fuligula, 2 males. This bird does not have an obvious crest, but I think must still be older than a first winter juvenile, as there is no barring on the flanks. The water droplets still clinging to the feathers may indicate that the bird has recently surfaced and the crest may then be slicked down in consequence.
Other interesting ID features are the interestingly shaped head with the high forehead on a relatively narrow neck. The bill has a good solid black tip or nail (across the cross-section of the bill, looking as though it "has been dipped in ink"). There is more than a hint of a whitish stripe across the front of the bill, contrasting with the blue-grey on the rear part of the bill. The bird is said to sit low in the water but with its tail above the surface, and I think I would agree with this from this picture to some extent - it looks as though its sitting a bit lower in the water at the moment, per haps after a dive. Deep yellow eye, perhaps slightly out of focus. The contrast between the dark wing and the white sides is nice and distinct, a beautiful bird indeed, moving well across the water!.
On the main Gravel Pit, Barden Lake, other individuals were keeping themselves out of trouble. This one looks very much at rest, but with its eyes open! I think that the wings are most easily seen from this angle, with the two sets of primary feathers forming a valley down the back between the two wings. It also looks to me as though the flank feathers somewhat overlie the sides of the wings, giving that fringed effect to the rear of the white sides. The tail sits slightly cocked in this picture.
According to the BTO, "the rapid expansion of the Tufted Duck in Britain during the late 19th/early 20th century is probably due to the colonisation of Britain by Zebra Mussels (brought into London docks in the 1820s)". The birds are omnivorous, feeding mainly on mussels, insects and plant material taken from the muddy bottoms of the water bodies they are on, diving anywhere between 4 - 15 metres down. It breeds better if there aren't excessive numbers of fish.
The females show the same amount of darkening at the top of the biill, with a little light band just behind. Some of them show a scaup-like white patch at the base of the bill, although not quite so extensive, and I rather think quite a lot of them show some degree of lighter brown in that area, like the one in the duck below.
Sunday, 19 January 2014
Wet but bright at Haysden
The paths were still under water, but the sun was shining, and it was actually quite warm. The Gulls and geese were showing well, but it was very busy and there were few ducks to be seen.
This gull is stabilising itself with its wings, in order to duck its head below the surf\ace in a very rapid movement. A skirt of water flies up past its head!
This one is demonstrating its STOL capabilities
and this one looks as though its just blown a huge bubble!
Further around the lake, there were some Tufted Duck, Aythya fuligola, quite a way out on the water from the bird feeding stage. The males were showing off their crests dramatically, as in the picture taken below. This bird looks as though it is riding high in the water, with the tail clearly visible. It doesn't look as though it has dived for quite a while!
Labels:
bb,
Bird behaviour,
Birds,
Black-Headed Gull,
Duck,
Geese,
Haysden
Saturday, 18 January 2014
Sunnier at Leybourne
Odd title, but there you go, A fair bit on gulls here. I think I'm ready to try some species-specific blog pages for gulls, that will relate to my topic pages dated at the start of the year so that I can find them more easily!
Black-headed Gulls first.
This is an adult bird just moulting onto breeding plumage, with perfect "new moons" on the folded primaries caused by the appearance of narrow white tips to the primaries at this stage. These new moons disappear in the summer, as the primaries become black-tipped!
The extent of the breeding head pattern in this bird is quite well set out already, half way through January in a mild winter to date (18.01.14), in a bird that stood out as an early moulter compared to the majority. The white eye ring is already reasonably clear.
As an adult in winter plumage it has a dark red bill with a dark tip, not as drooping as a Med Gull. The legs are a dark red as well, and should become darker as the season progresses. I do wonder whether this due to an increasing deposition of melanin.
The light was not bad today and the mantle and coverts were a lovely attractive sea-grey colour.
A Herring Gull seen quite far away had a good black bar across the bill, quite a bit of brown on the wing, and not too much white spotting on the primaries. I couldn't see any dark tip to the tail, but if there was one there, it would certainly have been a 3rd calendar year bird, as opposed to a 4th.
Friday, 10 January 2014
Scaup at Conwy
2 pairs of Red-breasted Merganser, dozens of Teal and Mallard, 30+ Canada Geese, 1 Snipe, 4+ Little Grebe, 5+ Coot, and I also managed to see one drake Scaup, although I don't think I got a photo! Many small groups of starlings rocketing over and also several Redshank on the shore.
Scaup, or Greater Scaup, Aythya marila, is a very common fully migratory duck in the Northern hemisphere, some of whom winter in the UK and a very few pairs breed in Shetland, etc.. There is a complex courtship ritual, leading to a monogamous pair bond for the season. They breed communally and the male abandons the nest to moult after the duck has laid her eggs. The duck takes care of the nest and then the young.
Aythya are all diving duck, collecting shellfish and plants etc. from the seabed as well as insects,and then eating them on the surface, Easiest to spot in the UK wintering on estuaries, including the Dee, Solway, Forth and Moray, and may be gregarious.
I saw a pair at Cliffe Pools December 2012, once they had been pointed out to me. I found this drake on my own but I had seen it posted as a possible on the board in the reception building, so I was prepared to see it. Still a good bird, and I got a good enough view to see the dark green sheen on the black head.
Scaup, or Greater Scaup, Aythya marila, is a very common fully migratory duck in the Northern hemisphere, some of whom winter in the UK and a very few pairs breed in Shetland, etc.. There is a complex courtship ritual, leading to a monogamous pair bond for the season. They breed communally and the male abandons the nest to moult after the duck has laid her eggs. The duck takes care of the nest and then the young.
Aythya are all diving duck, collecting shellfish and plants etc. from the seabed as well as insects,and then eating them on the surface, Easiest to spot in the UK wintering on estuaries, including the Dee, Solway, Forth and Moray, and may be gregarious.
I saw a pair at Cliffe Pools December 2012, once they had been pointed out to me. I found this drake on my own but I had seen it posted as a possible on the board in the reception building, so I was prepared to see it. Still a good bird, and I got a good enough view to see the dark green sheen on the black head.
Subscribe to:
Posts (Atom)