Stonechats

There’s a walk we used to do when my wife worked in Cardiff; it started at Llantwit Major station and followed the Nash Brook down to Cwm Nash, emerging onto the beach through a huge notch in the cliffs. There was a café there – a couple of leathery surfers wouldn’t look out of place lounging by it. The first image represents the view to the left.

The limestone pavement and cliffs run all the way to Nash Point, where there is a lighthouse and a foghorn to warn mariners of the considerable perils of Bristol Channel. I was a strict manual camera user then, shooting only slide film, probably Kodachrome 64 in this case. The image is scanned from a slide so it’s grainy but the point of the image is the grandeur of the beachscape.

A path rises up the cliff from Cwm Nash and takes you along the top with spectacular views and when we visited, Choughs, corkscrewing and calling up and down the sheer faces, red talons extended and red bills agape. I wish I had tried to photograph them but I was all set up for landscape and thought success most unlikely. The landscape by Nash Point was crossed by old stone walls and studded with gorse bushes, and it resounded with sharp and insistent percussion. Wrens perhaps? Not quite the right sound. And then we were able to see a small bird, and then a pair of them, perching and dipping, then making short swooping flights to another perch nearby. As we advanced, they would work around us and follow us back into their territory. Stonechats of course, unmistakeable with hindsight and a good look at the book.

Stevenston is a good place for them closer to home and that’s where most of my pictures come from. There’s rough ground all along the top of the beach with a great range of perches and, or so I would imagine, a lot of insect habitats. We’ve also seen them regularly on the way up the Kilpatrick Hills. Even with up to a year between the visits, the Stonechats are never far from where we saw them first.

I had assumed from these regular-as-clockwork sightings that Stonechats were sedentary but Callion (British Birds, 2015, 108, 648-659) shows otherwise in a rigorous study of a Cumbrian population in which there was considerable mobility between breeding and wintering territories, and further afield.

Small birds which eat mostly insects are very vulnerable in hard winters. Stephen Moss wrote a nice piece about them in the Guardian in 2013 (though with a truly awful illustration) and there is an interesting account of their wintering behaviour in Cheshire and on the Wirral, based on work carried out by the BTO and using ringing data. The executive summary involves a combination of shocking levels of Stonechat mortality, mitigated by southerly migration followed by furious levels of breeding activity to restore numbers.

Stonechats always command a vantage point; no skulking in the lower branches for them. Naturally, a Stonechat would find the highest point of a rose bush for a perch (a female this time, above), all the better if it’s atop some prettily coloured rosehips for that extra inch or two, or – below – on the most slender stalks in the parched grassland with the best view of the surrounding microforest.

Once seen, never forgotten and always a most cheering sight. Some more poised and nicely posed Stonechats follow in the gallery.

Sanderlings

A visit to a a very cold Stevenston on Saturday last afforded a sighting of a small flock of Sanderlings. There were close to fifty individuals in repose on the old pipeline which runs out into the sea next to the point. They look tawnier than they should in the photograph because of the golden hour light of a very sunny winter morning.

The tide had turned and was falling and soon, it seemed that the right kind of shore had been revealed and the Sanderlings took to the wing to reach it, landing elegantly and beginning their sprints along the sea’s edge.

The beach wasn’t busy and the Sanderlings seemed relaxed – I kept my distance (so there is some unwanted pixellation in most of these images). My RSPB book tells me that Sanderlings should not be disturbed while feeding in winter. They’ve a lot of fuelling up to do, increasing their body masses by up to 60% to get them to northern Greenland or north east Canada. Some fly non-stop, others put down in Iceland for a day or two. Reneerkens et al. (Wader Study Group Bulletin, 2009, 116, 2-20) reviewed the (then) current knowledge in 2009.

There was another occasion on the east coast when the Sanderlings came to me. It was during a visit to North Berwick on a very cold November day. I was aware of a white procession in the distance at the water’s edge and I lay on the sand in preparation; in time, they passed by quite close to me. I had a much shorter photographic reach at the time but the proximity of the birds and the brightness of the day was really helpful.

I’ve never tried to video them but there is excellent resource on YouTube; I particularly liked this BTO Bird ID video which captures their frenetic activity really effectively.  I think the sequence around 0:45-1:00 must be an optical illusion. I mean, is it me or are they going backwards at speed? Presumably not but it really looks like it. I also liked Sergey Shkarupo’s video of juvenile Sanderlings (of which more later).

This level of activity raises questions about energy accounting – or the benefit versus cost of feeding in this way. I can’t do the physics but I did discover something about Sanderling prey species. Reneerkens et al. have some useful information about diet, some of the information obtained the hard way by prising apart Sanderling pellets and analysing the contents. A wildlife project based in Oregon gave me this (my italics): “Because their quarry is small and all but indistinguishable beneath the sand, sanderlings must make several probes with each dash….They tweeze the just-wetted beach because it is softer, and because the invertebrates themselves come up to feed in the wavebreak. The window of opportunity is narrow, indeed—a mere wave’s breadth of time. Sanderlings appear frenetic in their feeding simply because it is the only way to get enough to eat.”

A bit more detail came from animalia.bio : “Sanderlings feed on invertebrate prey buried in the sand in the upper intertidal zone. In North America, this diet largely consists of the isopods Excirolana linguifrons, Excirolana kincaidii, and the mole crab, Emerita analoga. When the tide is out, these crustaceans live in burrows some way beneath the surface. When the tide comes in, they move into the upper layers of sand and feed on the plankton and detritus that washes over them with each wave. They then burrow rapidly down again as the water retreats. They leave no marks on the surface, so the sanderlings hunt for them by plunging their beaks into the sand at random, consuming whatever they find. Their bills can penetrate only 2 or 3 cm (0.79 or 1.18 in) and as the water swirls around and retreats, the sand is softer; this makes it easier for the birds’ beaks to penetrate further. In the spring, when much breeding activity is taking place in the benthic community, there may be as many as 4000 invertebrates per square metre, but their average size is smaller than later in the year. The birds appear to rush madly around at the edge of the surf, but in reality they are maximising their chances of catching as many prey animals as possible when they are at their most vulnerable near the surface.”

Benthic in this context refers to the uppermost layer of seabed, irrespective of the depth of water which covers it. UK waters host different species of isopods (species very similar to wood lice), for example Eurydice pulchra (Speckled Sea Louse). Haustorius arenarius and Corophium volutator (European Mud Scud) (which look more like shrimps) are also small (sub-centimetre long) burrowers in the sand. The British Marine Invertebrates Group tell me that Eurydice is similar to the Excirolana species.

In trying to find something out about these species, I’d first headed to the bookshelf; my copy of The Young Specialist Looks At Seashore (Burke, London, 1963) gave me Corophium volutator but not the other two species and I was puzzled, but then I noticed that the text had been adapted from Was find ich am Strande? (Keller, Stuttgart, 1961). I’m prepared to believe that there may be some species variations between Atlantic and Baltic coasts, and I much prefer the directness of the German title.

My only sight of Sanderlings in summer plumage came in Shetland, fleetingly. The pure white is still there but the brown and russet spangling on the upper part of the body is delightful.

Juveniles have very dark spangling on the upper body; I’m lying in the wet again for this one, with the young bird probing away in the soft sand of Aberlady Bay.

It was with me for quite a long time before it flew away – how long and graceful the wings look. I think these are my best foot shots too – Sanderlings are the only sandpiper lacking a backward-pointing fourth toe, which isn’t easy to see in the field. I was very happy to have the opportunity.

Dunnocks

‘”Unobtrusive, quiet and retiring, without being shy, humble and homely in its deportment and habits, sober and unpretending in its dress, while still neat and graceful, the Dunnock exhibits a pattern which many of a higher grade might imitate,with advantage to themselves and benefit to others through an improved example.’ With these carefully chosen words, the Reverend F. O. Morris (1856) encouraged his parishioners to emulate the humble life of the Dunnock Prunella modularis. His recommendation turns out to be unfortunate. We now know that the Dunnock belies its dull appearance, having extraordinary sexual behaviour and an extremely variable mating system. The result of the Reverend Morris’s advice would have made the relationships on current television soap operas appear dull by comparison.”

N. B. Davies, British Birds, 1987, 80, 604-624

Professor Nick Davies FRS started his 1987 paper with a bang – what a great introduction. I think I can honestly say that writing about sigmatropic rearrangements or ring-closing metathesis reactions (as I did) provided no opportunities of this kind and I suspect that even had I been able to write one, reviewers would have done away with an opening paragraph of this level of impact out of sheer jealousy. Alas. The rest of the Morris (F. O. Morris, A History of British Birds,  London, 1856, 4, 8-13.) is quite engaging; I was able to download the relevant volume from archive.org.

Here is the line drawing from the Morris. I couldn’t do any better myself but it certainly has its limitations.

Davies studied a colour-ringed population of Dunnocks in the Cambridge Botanic Garden. It must have been demanding work keeping track of these tiny birds as they foraged on the ground and disappeared into the undergrowth. The diagram summarises the key features of the “extremely variable mating system” from the paper.

Davies recorded and quantified instances of all four arrangements, and discussed the advantages and disadvantages accruing to the two sexes.

Dunnocks are familiar in urban and suburban environments. A pair were regulars in my mother’s garden, in and out of an old rose on the fence, and sweeping the space of lawn and herbaceous border beneath a bird feeder. In Glasgow, I see them way below me on the ground in the back close quite often.  I see them hopping under cars in the local streets foraging for the tiny things they eat – Dunnocks specialise in prey items so small that other species see their pursuit as unprofitable. The individual I photographed by Maryhill Locks is clearly overfaced by the enormous potential meal before it.

Davies stresses their sedentary nature which means that they don’t range far; the individuals I see regularly will be within metres of their usual pitches. There is a house near to Cardross marked as Murrays on the OS map; without wishing to be unkind, you might decribe it as a project house. I saw the wing-flicking courtship behaviour for the first time on the rustic driveway to the house.

At first, I thought that the bird was injured and I regretted the photograph. I’m glad I was wrong. The bird hopped up onto a rock and started calling surprisingly loudly.

There always seem to be Dunnocks at Murrays, and many perches for them there. On our last visit, the landside was frozen really hard and the Dunnocks and Robins were foraging on the shore which had thawed a bit in winter sunlight, presumably releasing some tiny creatures for the foragers. The better images came from the perchers. Though the overall appearance of the birds doesn’t exactly set the pulse racing, the better images reveal a glorious range of textures.

Davies spoke about his work on The Life Scientific on Radio 4. He retained his interest in Dunnocks, watching a smaller population in the garden of his Cambridge house closely. In 2021, he published a short coda to his earlier work entitled “Male Dunnock kills the other male in a mating trio” as a Note in British Birds. He describes an almost cartoonish level of violence, reminiscent of the Joe Pesci characters in Martin Scorcese’s Goodfellas and Casino films and perhaps surprising in a small bird.

I will continue to watch Dunnocks, enjoy their precise quartering of their territories, and worry about them going under cars.

The last word goes to poet Tony Lopez (A Handbook of British Birds, Pig Press, Durham, 1982):

If its slumbers are disturbed, the Dunnock wakes with a snatch of melody. I have heard it sing when startled by the light of a passing cycle-lamp.

As well you might in Cambridge, where I was given my copy of the Handbook.

Eiders

I’m resisting the seasonal temptation to do a post about Robins. The BBC Your pictures of Scotland page has a couple of nice Robin images and we’ve some lovely Robin cards, but I’m going to keep my stock back for a future occasion. Instead, I’d like to look back in this short post to images made in May, a warmer time of year, even on the west coast. The winter connection arises from my first sightings of Eiders or I should say, hearings. The breeding call of the male Eider, commonly rendered as yar-oooo, begins to be sounded in the winter – once heard, never forgotten.

But my best sightings and photographic opportunities have occurred in the spring and summer months when the birds are close to the shore with young. I’m posting images from Troon (May), Cardross (June) and Stevenston (June). Ducklings in general are such a worry but the Eiders seem to make very promising crèching arrangements with good numbers of adult birds around the young ones. A walk from Ardmore Point to Cardross disturbed one of these groups (four young, three females and three males) which moved smoothly away from the tideline across a mussel bed.

My shallow dives into the literature tell me that there can be conflict between commercial shellfish producers and Eiders (great consumers of mussels). I’ve one image (from Montrose) of a female about to swallow a large shelled mollusc whole. The avian gizzard is a thing of mystery and wonder.

At Troon, the family group or crèche was extremely close inshore, near the old Lido; I lay on top of the sea wall in sniper position, shooting away while the young practised their Eider repertoire. I don’t think these images require much comment from me apart from an expression of my enthusiasm for their spectacular plumage.

Both sexes are beautifully marked and I can’t think of any other species which displays that strange shade of green found on the back of the drake’s neck. I think I’ve got the colour right but I prefer a dark print because the texture in the white feathers becomes visible. The water droplets also look more interesting when the image is slightly underexposed – there is a gradient of tone across them which I like. I found some really nice images at Birdfact and I think we have the same shade of green.

The image from Stevenston seems to contain a group of females but I thought there were significant differences in the sizes of the individuals, and in the patterns of white on the wing feathers. This suggests that some of them might have been juveniles; could there have been time for a brood to have grown to such a size? Perhaps someone will put me right. It seems that male Eiders take a few years to develop their spectacular formal dress.

Eiders seem to be very well studied by ecologists – I would definitely pick something big and easy to see and count if I was interested in populations (so definitely not little brown jobs). I found Vital rate estimates for the common eider Somateria mollissima, a data-rich exemplar of the seaduck tribe and I attempted to read it only to be confounded by the statistical nature of the analysis (I failed statistics in my first year at university, just can’t do it). I was hoping it would tell me how many young Eiders need to be produced every year per breeding pair to ensure a healthy population but I couldn’t find what I was looking for, alas. Eiders are monogamous and long-lived. Once the trains start up again, I’ll be back to the seaside listening out for yar-oooo…