Reflections of Norway 2017
Still waters are always good for catching reflected images and during my recent visit to Norway I took some shots of plants and birds mirrored in forest bog pools. This first photograph is of a mossy hummock in a bog pool. As spring was late the seed heads of the cotton grass are only just forming and not open in their typical white fluffy form.
I saw several pairs of whooper swans, but none seemed to have bred this year. They usually lay their eggs early and the cold late spring must have put them off nesting this year.
Broad-billed sandpiper, the main species I was studying this year. These birds are very difficult to see in the bogs. They are the size of a large vole and run through the sedge like little mammals, preferring to hide within the vegetation than fly into the open. This one stands reflected in the water, so it is easier to see its reflection against the clear sky than the actual bird against the sedge.
In this shot of a wood sandpiper, it is possible to see the bird's feet under water. The shade of its body has cut out the glare of the light on the water surface, giving a true depth to the image.
My favourite picture is this one of the same wood sandpiper. The reflections of the twigs and spring leaves remind me of the 16-19th century Edo style of Japanese bird paintings, which portrayed the seasons so well.
Showing posts with label broad-billed sandpiper. Show all posts
Showing posts with label broad-billed sandpiper. Show all posts
Monday, 3 July 2017
Sunday, 12 July 2015
Superb camouflage
While studying waders in northern Norway I was repeatedly impressed by the adaptation of these birds in their use of camouflage as their main defense from predators. Camouflage only works well if an animal does not move, relying on their cryptic plumage patterns to conceal them until the very last moment as potential predators, including humans pass by. This tends to make them rather difficult to study.
One species of wader which breeds in mires on the tundra is the Broad-billed Sandpiper Limicola falcinellus and they are very easily overlooked. These birds, about Starling-size, forage on mats of sphagnum moss on the edge of mire pools, creeping through the sedges. Their plumage has a background of dark browns like those of the muddy surface, with pale stripes that resemble the blades of the sedges. They match their habitat exactly.
And if you think these are difficult to see, try to find the bird in the next photograph.
Another species that lives in these mires is the Jack Snipe Lymnocryptes minimus. Their plumage is like that of the Broad-billed Sandpipers, and the birds are of similar size. These two unrelated species have adapted similar plumages and behaviour, and they breed successfully, so their convergent evolution is evidence of the effectiveness of their survival strategy.
As I look down on these birds and admire their adaptation to their habitat, I often think to myself, how many have I walked past?
I study many cryptic species, but these waders are some of the the trickiest birds to find, they are true masters of the art of camouflage.
Superb camouflage |
While studying waders in northern Norway I was repeatedly impressed by the adaptation of these birds in their use of camouflage as their main defense from predators. Camouflage only works well if an animal does not move, relying on their cryptic plumage patterns to conceal them until the very last moment as potential predators, including humans pass by. This tends to make them rather difficult to study.
A Broad-billed Sandpiper hides amongst sedges |
One species of wader which breeds in mires on the tundra is the Broad-billed Sandpiper Limicola falcinellus and they are very easily overlooked. These birds, about Starling-size, forage on mats of sphagnum moss on the edge of mire pools, creeping through the sedges. Their plumage has a background of dark browns like those of the muddy surface, with pale stripes that resemble the blades of the sedges. They match their habitat exactly.
Easier to see if you can pick out an eye |
And if you think these are difficult to see, try to find the bird in the next photograph.
A Jack Snipe lies quiet amongst the sedges |
Even when seen close up they are not easy to discern |
As I look down on these birds and admire their adaptation to their habitat, I often think to myself, how many have I walked past?
From above, the stripes on the Jack Snipe resemble the pale old leaves of the sedge |
I study many cryptic species, but these waders are some of the the trickiest birds to find, they are true masters of the art of camouflage.
Once again, if it weren't for the eye.... |
Wednesday, 30 July 2014
Broad-billed Sandpiper
Following on from the previous post on birds in Norway, here is a brief update of the work done this year as part of a long-term study of Broad-billed Sandpipers Limicola falcinellus. These birds are difficult to find in their breeding habitat of extensive mires with floating mats of vegetation, which can be treacherous (to us), and over the years a tremendous team of expert fieldworkers have taken part in the project. This was my fourth season and I am grateful to my brother Rab Rae and Karl-Birger Strann for organising the study. Simon Foster and Shona Quinn were the other team members this year.
The species has two recognised races divided by their breeding ranges; the western nominate race breeds in Scandinavia and nearby Russia, and the eastern sibirica race breeds in a largely unknown range somewhere in Siberia. The main difference between the races, if they are different, is size, the latter being larger. The highest numbers of wintering birds are found in Asia and as far south as Australia, while the winter range of the western race is described as coastal and estuarine mudflats from Africa to India. All rather vague, and is there an overlap between the races' wintering ranges? There are many unknown details of this elusive wader.
The birds are only in their breeding grounds from May to July, taking advantage of the abundant invertebrate life in the arctic mires to raise their young. Apart from their display flight when they first arrive they are largely unseen or heard. They spend their time weaving through the dense growth of sedge, they are small, about the same weight as a bunting, and perfectly camouflaged for the habitat, so they are very difficult to find, let alone study.
The breeding behaviour of Broad-billed Sandpipers in this study has been described and published by Rae et al 1998, but conservation of a migratory species requires knowledge of their movements, behaviour and habitat requirements at both ends of their distribution. So, we have begun a study of their migration using geolocators. These are tiny, 0.6g devices, Intigeo-W65 from Migrate Technology, which have up to two years recording time. As these birds return to their same breeding areas each year it is planned to catch the birds again next year, remove the geolocators and download the data which will show where the birds have been during the non-breeding period.
Another aspect of the bird's life which is not clearly understood is the difference in plumage between adult and first-year breeding birds. It is important to know the age of birds when studying them as younger and older birds can behave differently. Most descriptions of the Broad-billed Sandpiper plumage has been of birds caught on wintering or passage grounds, when they are not fully moulted into their summer colouring. From our work so far, we seem to be able to confirm that birds in their first year have three dark outer primary feathers (four including the reduced 11th). This is because they are freshly moulted feathers, in about March, not long before the birds flew north, and they contrast with the paler older primaries which were moulted at the end of the previous year. However, not all first year birds have this feature, and if they have all-old primaries, they resemble older birds which moult all their primaries over one period at the end of the previous year.
So, we are looking for other possible patterns in the bird's plumage which might help distinguish between young and old birds. One feature, might be the colouring of the feathers on the back, rump, scapulars and coverts, which are black with rich rufous edges in the full breeding plumage. Perhaps there are differences between the ages there, but further study is required to test this.
It only took minutes to catch the birds in a mist net (once they had been found, which can take days), measure and tag them. Then they were off, back into the mire where they disappeared again. We saw them a week later with chicks, which are even smaller and more cryptic to see.
By now, both the adults and their fledglings will be ready to fly south. So if anyone sees a colour-ringed Broad-billed Sandpiper do please report where and when. Help add a little bit of information to this secretive bird.
The broad bill |
The species has two recognised races divided by their breeding ranges; the western nominate race breeds in Scandinavia and nearby Russia, and the eastern sibirica race breeds in a largely unknown range somewhere in Siberia. The main difference between the races, if they are different, is size, the latter being larger. The highest numbers of wintering birds are found in Asia and as far south as Australia, while the winter range of the western race is described as coastal and estuarine mudflats from Africa to India. All rather vague, and is there an overlap between the races' wintering ranges? There are many unknown details of this elusive wader.
Broad-billed Sandpiper breeding habitat in northern Norway |
Broad-billed Sandpipers are inconspicuous as they creep through the sedge-covered mires |
The birds were ringed with individual-colour combinations of rings and fitted with a tiny geolocator (above the knee) |
One-year old birds have dark outer primaries |
The primaries on birds more than one year old are all a similar pale (faded) brown colour |
By now, both the adults and their fledglings will be ready to fly south. So if anyone sees a colour-ringed Broad-billed Sandpiper do please report where and when. Help add a little bit of information to this secretive bird.
The birds were processed quickly and soon ready for release |
They all flew off back into the mire |
But where are they now? |
Sunday, 28 July 2013
Arctic waders
Adult Wood Sandpiper |
A pair of wood sandpipers, ringed and ready for release |
An adult Broad-billed Sandpiper is measured - the sexes are similar in plumage, but can be differentiated by size |
A Broad-billed Sandpiper nest and chicks lie hidden in a mire |
Broad-billed Sandpiper chicks in the nest |
Four Wood Sandpiper chicks, a typical brood size |
A single Wood sandpiper chick is extremely difficult to see when creeping through the sedge |
Thursday, 4 July 2013
Broad-billed Sandpiper
I have recently returned from a trip to Norway where I have been helping my brother Rab on a long-term study of the birds in the norther marshes, including the breeding biology of Broad-billed Sandpipers Limicola falcinellus. Typically of Arctic-breeding waders, these birds fly north to nest as soon as the snow melts and their breeding grounds are clear enough for them to feed and build a simple nest on the floating mires. The main function of their journey is to find a nursery area for rearing their chicks, and the whole breeding period from egg-laying to fledging is over in a matter of weeks, Then the birds fly south to their wintering grounds, which to date are unknown for the Norwegian population. To help answer this question we began tagging birds with geo-locators, and plan to re-catch the birds next year to download data which should indicate where the birds have spent the non-breeding period, the longest part of their lives.
One of the individual characteristics of wader species is the specific bill shape, and the broad bill of these sandpipers is not usually appreciated when seen in the field in profile. However, when the bird is in the hand, it is obvious. As these birds spend most of their time in their winter quarters, it is likely that their bill is adapted for catching certain prey there, giving them advantage over other species for a specific food source. The bill is not only broad, but has delicate flutings along its length, which suggest that the bill is a very tactile and maneuverable organ, not just a simple horny probe.
A Broad-billed Sandpiper in breeding plumage |
The broad bill |
The not-so-simple bill of a Broad-billed Sandpiper |
Saturday, 30 June 2012
Nordic Waders
Wood sandpiper
I am just returned from northern Norway where I was helping my brother, Skitts, with his long-term study of breeding waders. However, as in Scotland this spring, there have been almost incessant northerly winds there. This has led to a late thaw and emergence of plants and insects, and very few birds were breeding compared with the amount in years of more usual weather.
Wood sandpiper, which was caught and ringed
In one mire where there would normally have been twenty-forty pairs of wood sandpipers breeding there was only one pair with chicks. In some mires there were none. And it was similar story with spotted redshank and reeve. Red-necked phalaropes were particularly scarce, probably because they are surface feeders and as there were very few mosquitoes emerging they had no food supply.
Ringing a wood sandpiper chick.
Of the two main study species, jack snipe did not seem to be breeding at all, although several birds were seen displaying. And less than a quarter of the expected number of broad-billed sandpiper were breeding.
Adult, (1st year) broad-billed sandpiper caught and colour-ringed for identification in the field in subsequent years of study.
Unfortunately, a high proportion of clutches from the few that were laid were eaten by predators. This was probably mostly by hooded crows which were walking over the mies, in large flocks of twenty or more birds, feeding on emerging cranefly. They would have welcomed any eggs they came across in the process. We also saw several red foxes roaming the area, and they would have been likely predators too.
Wednesday, 29 June 2011
Ringing Broad-Billed Sandpipers
Today we were ringing Broad-Billed Sandpipers. This whole trip to north Norway has been focused on the study of these birds and other arctic-breeding waders, especially Jack Snipe. And the study has been ongoing for several years, led by my brother Rab, Skitts to the birders who know him, and Karl-Birger Strann of the Norsk institutt for naturforskning in Tromso. I have been a mere helper on this trip and am grateful to them both for a great experience, and to Ed Duthie and Harry Scott who have helped on this project before and have been a great lead on the birds of the area. All have made this an excellent excursion.
Today we were ringing Broad-Billed Sandpipers. This whole trip to north Norway has been focused on the study of these birds and other arctic-breeding waders, especially Jack Snipe. And the study has been ongoing for several years, led by my brother Rab, Skitts to the birders who know him, and Karl-Birger Strann of the Norsk institutt for naturforskning in Tromso. I have been a mere helper on this trip and am grateful to them both for a great experience, and to Ed Duthie and Harry Scott who have helped on this project before and have been a great lead on the birds of the area. All have made this an excellent excursion.
Adult Broad-Billed Sandpiper marked with a unique
combination of colour rings for ready identification
in the field wherever it is seen on the breeding area
or in its wintering grounds.
The chicks are incrediibly well camouflaged, their
white speckled down mimicing the water glistening
on the waterlogged vegetation where they live in the arctic mires.
And they are tiny, all four sit easily within the palm of a hand.
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