Category Archives: Themes

People? What are they?

I’m stretching my geographical boundaries a little farther than normal to the northwest with this post, but I think the subject deserves it. This is a juvenile Long-billed Dowitcher (Limnodromus scolopaceus), which turned up last week on Rhaslas Pond, just east of Merthyr Tydfil, and has spent the weekend entertaining birders and photographers at point-blank range. Rhaslas is a small artificial reservoir in the middle of bleak moorland, which goes to show that rare (i.e. lost) birds can turn up anywhere.

Right Left

Long-billed Dowitcher is generally thought of as a North American bird and those occurring at this time of year are most likely to have originated in the Canadian Arctic and been brought across the Atlantic by low pressure weather systems. However, there is also a significant population in Arctic Russia, and some Long-billed Dowitchers occurring here, particularly adult birds in late summer, probably come from that direction. The third possibility is that once here, they stay and migrate up and down the East Atlantic flyway, with godwits or other European shorebirds.

There are much better photographic efforts than mine on the Cardiff Bird Club blog. The photo below shows just how close everyone was able to get (the red arrow points to the bird); indeed, while I was there it kept walking towards the photographers rather than away from them.

People

Arctic-bred shorebirds have been known on previous occasions in Britain to be just as tame: there was a Buff-breasted Sandpiper (Calidris subruficollis) in Somerset a few years back which allowed an equally close approach, for example. Most famous of all is an Upland Sandpiper (Bartramia longicauda) which occurred on the Isles of Scilly in the 1980s which was so tame it took a worm out of a birdwatcher’s mouth. These birds are invariably juveniles on their first southbound migration and the theory is that because they’ve never seen people before, they don’t associate us with danger: bad news for the individual bird, but great news for birdwatchers.

Little Gulls at Chew Valley Lake

These two Little Gulls (Hydrocoleus minutus) were at Chew Valley Lake this afternoon. Usually, when Little Gulls turn up at Chew, they feed over the centre of the lake, way beyond camera range, but for some reason, these two birds chose to frequent Herriott’s Pool, the small body of water separated from the main lake by the A368.

CVL Little Gull adult CVL Little Gull juvenile

These two are a non-breeding-plumaged adult (left) and a juvenile (right). Little Gull is the world’s smallest gull, much smaller than a Black-headed Gull (Chroicocephalus ridibundus). Adults have deep dark grey underwings, and the pale grey upperwings lack the finger of white along the front edge that Black-headed Gull shows. In breeding plumage they have black hoods and pink-washed underparts. Juveniles have a contrasting pattern of black, grey and white, lacking the gingery-brown tones of juvenile Black-headed Gulls. The black stretches from wing-tip to wing-tip across the back (the bird in the picture above has its wings fully outstretched; when the wings are in normal beating mode, the black forms a ‘W’ shape). Juveniles moult into first-winter plumage later in the autumn, replacing the black on the upperparts with pale grey, but the black on the wings remains, so the W is a good feature throughout the winter (note that juvenile and first-winter Kittiwakes have a similar pattern, but as long as you have a Black-headed Gull nearby for a size comparison you shouldn’t get the two confused).

Little Gulls do not regularly breed in Britain. Their main breeding colonies lie to the east of us, in marshes from eastern Europe and Scandinavia into Russia. They mainly occur in Britain on migration, in April and May, and then again from August to October. Flocks at Chew Valley Lake are usually of single-figures, or occasionally into double-figures. These numbers are typical for large wetland sites in Britain. There are two areas in Britain which regularly attract much large numbers, however: the Mersey coast, and the east Yorkshire coast. The former often attracts hundreds, and the latter has been known to host thousands. Small numbers of (usually first-summer) birds oversummer in Britain, mainly on the east coast, and occasionally make nesting attempts, although so far these have all been unsuccessful. Interestingly, breeding Little Gulls have successfully colonised the east coast of North America in the last hundred years, so the establishment of a British colony may be a possibility one day.

For more information on birds at Chew Valley Lake, Rich Andrews’ CVL Birding website is highly recommended.

Whinchats

I bumped into three Whinchats (Saxicola rubetra) this afternoon at Stockwood Open Space, in the thistly rough grassland between the sports pitch and the main path. One of them was co-operative enough to enable me to get a photo.

015

At this time of year, all ages and both sexes of Whinchats look pretty much the same, with a buffy stripe above the eye (the supercilium), dark droplet-shaped markings on the upperparts, and pale orangey-buff underparts. Spring males, however, are boldly marked, with a distinctive head-pattern (a white supercilium and dark cheeks) and the orange on the throat and breast is more intense, like this bird.

Whinchats don’t breed around Bristol: these birds are on migration, south to their wintering areas. After they leave Britain, these birds are likely to move south through France to Spain or Portugal, where they will feed up, ready for a flight across the Sahara to their wintering zone in the savannah from Senegal eastwards; returning birds in the spring are usually seen from the second half of April.

Autumn Ladies-tresses on Bristol Downs

There are a few flowering plants that wait till the end of the summer before flowering, and Autumn Ladies-tresses (Spiranthes spiralis) is one of them, never flowering before August and continuing well into September. This is probably the least conspicuous of the orchids which are found in the Bristol area, typically only reaching about ten centimetres tall. The photos below show the way in which the tiny flowers spiral around the stem, a feature reflected in its scientific name.

ALT2 ALT1

I visited the colony on Bristol Downs today, and counted at least 87 plants – although among these were many which weren’t in full flower yet, which I only noticed when I was on my knees next to plants which were in flower, so as I will have no doubt missed other similar individuals, I’m confident the total population here is well into three figures.

Here’s the location: right next to the circular road which runs around the Downs.

Autumn Ladies-tresses is a plant of very nutrient-poor limestone and chalk grassland. In most locations, sheep do the work of keeping the habitat conditions right; on the Downs, in the absence of sheep, the grassland has to be managed by mowing and raking off the cuttings. On the side of the colony closest to the road, the soil has been badly eroded by runners; fences have been erected to encourage people off of this part of the site, in the hope that it will regenerate.

The Downs as a whole are a bit of a curate’s egg botanically, even if you discount the areas which are formally set aside for sports. Although it is certainly the largest area of limestone grassland around Bristol until you reach the Mendips and Cotswolds, that doesn’t necessarily mean it’s good-quality limestone grassland throughout. Some areas are good – I found a few Harebells (Campanula rotundifolia) growing in another spot today, for example – and the stone workings on the southeast side have some botanical interest, as does the area around the observatory. However, other parts are quite species-poor. With the right management to reduce the nutrient levels, though, the Downs could certainly become a lot richer, and complement their neighbour the Avon Gorge.

Roesel’s Bush-cricket

It’s the time of year when orthopterans are out in force just about anywhere with any decent vegetation. There are four families represented in Britain: grasshoppers are common and familiar; the larger bush-crickets (which many people just refer to as “crickets”) are less conspicuous but still common; then there are the groundhoppers, which take a bit of searching for, and the true crickets, which are just downright rare. This diversity is the reason for going ever-so-slightly jargony with that first sentence: there isn’t really a single good shorthand name, the best compromise probably being “Grasshopper and crickets”.

They are quite an easy group to get to grips with, as there are only about 30 species in Britain, and the species featured in Vic Savery’s photos below is an easy one to identify: the long antennae and chunky body are characteristic of a bush-cricket, and the pale crescent around the edge of the side-panels of the thorax are a dead giveaway for Roesel’s Bush-cricket (Metrioptera roeselii).

 cricket  cricket 1
Roesel’s Bush-cricket, 12 August 2013, Avonmouth, Bristol, Vic Savery (naturenutz.net)

When the last national Orthoptera atlas was published back in 1997, Roesel’s Bush-cricket was largely confined to the Home Counties, with isolated outlying coastal populations in a few other areas. However, like a number of other species of bush-cricket, its populations have expanded since then, and it now occurs around Bristol. It is well-established in Wiltshire and Gloucestershire and has also spread into Gwent in the last decade. Robert Cropper’s 2011 book “The Orthoptera and allied insects of Somerset” documents surprisingly few Somerset sites: a strong population around Bridgwater possibly marks the southwestern edge of the current British range, although the range expansion is no doubt ongoing, so I’m sure that the species will reach Devon soon if it hasn’t already.

The song of Roesel’s Bush-cricket is a high-pitched buzzing, pitched at around 22 kHz. If like me, your hearing has deteriorated to the point where you can’t hear sounds which are that high-pitched, you’ll need to use an electronic detector to track one down. Vic tells me there were three or four singing at his site, on Kingweston Lane near Avonmouth. In all likelihood there are other sites elsewhere in the city too.

Upright Spurge in the Wye Valley

Yesterday I paid a visit to Ravensnest Wood in the Wye Valley, to see one of the rarest plants found in this area, Upright Spurge (Euphorbia serratula). As a native species, Upright Spurge is found in Britain only in an area centred on the Wye Valley and the Forest of Dean. It is also naturalised in scattered locations, mainly in southern England. Although a rare plant in Britain, globally, it is found eastwards to central Asia.

 030  033

Upright Spurge’s habitat is woodland on limestone, but not the dense dark parts: instead, it is found in the open, and does best on disturbed ground. Newly created forestry tracks and clearings are where it does best, particularly if limestone chippings are laid. Ravensnest wood held 500 plants in 1997, presumably when the access track there was very new. Yesterday I counted a much more modest 17 plants: along much of the track, grassland had become established, crowding the spurge out, and it was only present in areas where there was still very sparse vegetation. Here is a map of the location:

According to Sell and Murrell’s Flora of Great Britain and Ireland, the most authoritative reference work on Britain’s flowering plants, Upright Spurge occurs in only about 24 British localities. The densest concentration is around Tintern and so, predictably, it has acquired the local name “Tintern Spurge”. Other locations in the Wye Valley are spread throughout a 10km-long stretch from about Wynd Cliff in the south to around Whitebrook in the north. In the Forest of Dean, its main concentration is just to the west and north of Lydney. Much further east, it grows in Highnam Woods, just west of Gloucester. West of the Wye Valley, it occurs in Chepstow Park Wood and in Coed Wen Wood, east of Newport (note that the Grid Reference in Trevor Evans’ Flora of Monmouthshire for this last site is incorrect).

Seeds of Upright Spurge can lay dormant in the soil for years, possibly decades, and so if a site becomes overgrown, fresh disturbance can boost the population. At Highnam Woods, the RPSB does just that, using a rotavator, and so the population there is likely to be secure. At other sites, Upright Spurge has declined or even vanished, but could no doubt be encouraged to flower again if similar techniques were applied. How about it, Gwent and Gloucestershire Wildlife Trusts?

Lamplighters Marsh

Last week, I visited one of my favourite Bristol plant sites, Lamplighters Marsh. This is the strip of land between the Avonmouth railway line and the River Avon, from the M5 Avon bridge southeast to the former Lamplighters pub. It’s got a mix of habitats: lots of scrub and tall herb, one of Bristol’s few reedbeds, and areas of sparse vegetation (and the tidal Avon, a interesting site in its own right, is right next door). Here are a few photos of the site:

009 045
 043  033

Among the star plants here are a large population of Viper’s Bugloss (Echium vulgare) and a small population of Moth Mullein (Verbascum blattaria), both scarce plants in the Bristol area. Viper’s Bugloss occurs in a variety of habitat types in Britain: chalk and limestone grassland, at the coast in sand dunes, on shingle or cliffs, and in disturbed open ground such as that found in disused quarries or railway lines. Although Lamplighters Marsh could be described as coastal, the habitat here is more like the last of these, and in the Bristol area, it is not really a coastal plant, although in some parts of Britain it is exactly that. My visit was on a sunny evening and many bumblebees were visiting the plants.

018

Moth Mullein is an introduced plant. It is distinctive among the mulleins in having large flowers, and not being densely hairy or downy like many mullein species. It occurs in both white-flowered and yellow-flowered forms.  It has been recorded at several other sites in Bristol, but is very scarce away from the city.

038

Green Sandpiper

Autumn is here: the first of the post-breeding shorebirds are on their way south. At Slimbridge, while I was watching the Spoonbill, there were at least six Green Sandpipers (Tringa ochropus) feeding on the edges of the same pool. I was going to illustrate this post with my own photos, and then Vic Savery sent me this excellent shot:

 green sandpiper 4
Green Sandpiper, 1 July 2013, Slimbridge, Gloucestershire, Vic Savery (naturenutz.net)

Green Sandpiper is the earliest of our sandpipers to appear on southbound migration, always being seen somewhere locally from the end of June onwards, so no need to panic about winter being on the way just yet. Any freshwater wetland with reasonable areas of exposed mud will be graced by Green Sandpipers over the next few months. The birds turning up at the moment are adults, whereas juvenile birds will occur from August onwards (a pattern common to most migrant shorebirds). Green Sandpipers also overwinter in the region in moderate numbers, tending to inhabit shallow slow-flowing streams and ditches and marshy sites.

Green Sandpipers nest in bogs from Scandinavia eastwards through Russia. Unusually for a shorebird, they nest in trees, in disused birds nests. Occasionally, pairs nest in Scotland. A lookalike species, Solitary Sandpiper (Tringa solitaria), replaces Green Sandpiper in North America. They have occured in southwest England after Atlantic storms in autumn several times, usually on the Isles of Scilly, but there was one in Devon a few years ago, so it’s possible that one could turn up near Bristol one day.

Here are a couple of my own Green Sandpiper photos as well, showing a Slimbridge bird in some different poses, and highlighting how birds can look different in different lighting conditions. You can also see, by looking closely at individual feathers, that this is a different bird from the one Vic photographed.

 Green Sandpiper Slimbridge 28 June 2013 b  Green Sandpiper Slimbridge 28 June 2013 a

A Spoonbill at Slimbridge

A Eurasian Spoonbill (Platalea leucorodia) is present at the Wildfowl and Wetlands Trust reserve at Slimbridge currently. I visited the site yesterday afternoon, and the bird hadn’t been seen earlier in the day but just after I arrived at the Tack Piece hides, it flew in and started feeding very actively on the shallow pools just in front of me, and then rested up and started preening … cue the camera, and here is a selection of the best photos from the 150 or so that I took.

235 219

Spoonbill is a scarce bird in Britain, although because they’re large and conspicuous, inhabit the sort of wetland sites that birdwatchers visit, and tend to hang around for days, weeks or months, they can give the impression of being more common than they really are. They are on the increase here however, and you stand a reasonable chance of finding one yourself if you spend enough time birding around the Severn estuary: I added Spoonbill to my “self-found list” with one on Goldcliff Pools in Gwent in 2009; this is the second one I’ve seen at Slimbridge and I’ve also seen birds at Steart. They are much less common inland, although my very first Spoonbill was at Chew Valley Lake over 20 years ago, and there was even one a few years ago on a small lake near Swindon.

087 084

Spoonbill numbers elsewhere in Britain have been building up for a while, and double-figure flocks are now seen in most winters in Poole Harbour, with other favoured sites including the Taw/Torridge and Tamar estuaries in Devon. However, East Anglia is doing even better, as birds have now established a breeding colony on the north Norfolk coast. All of this increase is fuelled by a burgeoning population in wetlands in the Netherlands.

227 070

Although their odd appearance might suggest that they occupy an ancient branch on the bird evolutionary tree, spoonbills are really just members of the ibis family that have evolved a specialised feeding technique and the apparatus to go with it. Spatulate bills seem to evolve quite readily in waterbirds, with Shoveler ducks, and a small shorebird, the Spoon-billed Sandpiper, also having them. There are five other species of spoonbill worldwide: two in Australasia, one in Africa, the gaudy pink Roseate Spoonbill (Platalea ajaja) in the Americas, and the endangered Black-faced Spoonbill (Platalea minor) in southeast Asia.You can see some videos of Spoonbills feeding on this page on the ARKive website.

Slender Speedwell

This is a patch of Slender Speedwell (Veronica filiformis), which I photographed by the footpath alongside the River Frome near Frenchay this afternoon.

 Slender Speedwell for blog 1  Slender speedwell for blog 2

Like its more common relative, Common Field Speedwell (Veronica persica), Slender Speedwell is not native to Britain. Originally from Turkey, it was introduced into Britain in 1808 as a rock garden plant, although was not widely grown until the 20th Century. It has since become widespread, with the only significant gap in its British distribution being in the highlands of Scotland. In Britain, it is often found as a lawn plant, and tends to spread from mown cuttings, rather than seed.

Like Common Field Speedwell, Slender Speedwell has relatively large (for a speedwell) pale blue flowers, each with a whitish lower petal, and these are arranged singly on the end of long thin stalks (pedicels) arising from the leaf-axils (the point where the leaf-stalk, or petiole, joins the main stem). The pedicels of Slender Speedwell are much longer than those of Common Field: at least twice the combined length of a leaf and its petiole. Also, the leaves are round to kidney-shaped, compared with Common Field’s more oval or pear-shaped leaves. The mat-forming habit and bright green leaves are also good clues to its identity.

For more images of Slender speedwell (and all the other British speedwell species), take a look at the links on the Web Resources page.