Scrapes, plums and flaming O's

Probably not the most popular person yesterday as I collected samples of invertebrates from the scrape at Minsmere.  A flurry of birds and all were gone - apart from a couple of tame Pec Sands and 'Fiona' the Flaming O.  The invertebrate samples will help inform management, providing further information on the food resource available to birds in water of differing salinities.  More on this when the results are in.  A couple of Whimbrel and a fly-by Curlew Sandpiper added interest.

Back onto the path and the scrape-side bushes were dripping with ripe plums. There seems to be a bewildering array of ‘wild plums’ to be found in our hedgerows. Fruits of differing sizes and ranging in colour from yellow and red through to purple. The plum is thought to be the result of hybridization between the Sloe Prunus spinosa and the Cherry Plum Prunus cerasifera. Such hybrids and an array of back-crosses fall under the Wild Plum Prunus domestica heading, with various forms or subspecies. These late-ripening fruits at Minsmere seem to fall into the 'Bullace' category (P. d. insititia).  In a minute or two, enough were gathered to produce a tasty Wild Plum Frangipane - just like this.

Extreme vis-migging

Lower pic - the Lee Valley from Tower 42 - Walthamstow, the Girling, the George and beyond.

I’m not keen on heights but as Tower 42 is now only the 5th tallest building in London, at 600 feet, I thought I’d give it a go. We clambered up various steps and ladders onto level 47, the very top, with a splendid all-round view of London for a session of watching for visible bird migration over the city.

Everything looks very small from up there!  No doubt, the more eyes looking the better, but in 4 hours we recorded the following: 22 Lesser Black-backed Gull, 4 Buzzards, 3 Kestrels, 4 Sparrowhawks, 2 Peregrines, 5 Cormorants, 1 House Martin, 10 Swallows, 1 green balloon, 1 blue balloon, 1 Tesco bag and 5 flies.

An excellent morning that showed the potential if you could hit the right day. Many thanks to David Lindo for organising it all (as detailed here) and to the tolerant Tower 42 security guys for putting up with us.

Chipirones and carrots

The top priority as we pulled into Sant Carles de la Rapita was a plate of chipirones (fried little squid) and a cold beer. A plate of razor clams drizzled with oil and lemon soon followed, oh and some octopus 'a la plancha' of course. Several hundred Swallows moved south past the front of the harbour-side bar as we swallowed. The first of many Audouin’s Gulls drifted by. Another plate of chipirones? So started our weekend seafood extravaganza in the Ebro Delta in Spain.

After a long lunch we drifted out into the delta to work up an appetite. Rice fields everywhere; the wet harvested areas full of egrets and herons. Most of the delta is now given over to rice production but there are a few protected areas of wetland (but many are privately owned by hunters) that support tens of thousands of waterbirds. The brackish La Tancada lagoons held 300+ Greater Flamingos and many passage waders; Little Stints were everywhere and Kentish Plovers dotted about.

L'Encanyissada is a large shallow freshwater lake surrounded by reedbeds. Hundreds of duck, including Red-crested Pochard, and another 200+ Flamingo formed the main birdy backdrop. At least 150 Whiskered Terns hawked back and forth along the margins or perched on every stick that stuck out of the water. Little Bitterns and Squacco Herons flew hither and thither. A flock of 8 carrot-beaked Caspian Terns arrived in front of us. As dusk drew near, Night Herons appeared miraculously all around and straggling flocks of Purple Herons rose out of the reeds. Stomachs began to rumble. We were soon into the main event; sucking the juicy brains out of Mediterranean Red Prawns, slurping more clams out of their garlicky shells and working through a huge pot of mixed fishes in fishermans sauce thickened with a garlic and almond picada. Yum. A fine Rioja eased their passage.

The following morning we headed out to Riet Vell, where the SEO (Spanish Ornithological Society) have a site than produces organic rice. The harvested fields were left wet and held many waders; Temminck's Stints, Wood Sands, Curlew Sands, Greenshanks and LRPs were the most numerous. A quick look from the hide overlooking the reedy lagoon resulted in an eye to beak meeting with a Purple Gallinule.

Zig-zagging through the rice fields we arrived at El Garxal lagoon. Hundreds of terns (Common, Little and Sandwich) congregated along the shoreline, along with more Whiskered and another couple of Caspian Terns and many Med Gulls. Three flocks of Glossy Ibis, totalling around 200 birds, arrived off the sea and headed inland. Fan-tailed Warblers zitted up and down and Sardinians rattled. A Praying Mantis obliging sat on my finger, wondering if I looked like dinner. Dinner did you say? We eased back to a restaurant on the edge of some marshland. Is that a Moustached Warbler in front of those Penduline Tits? Never mind, here come the langoustines with green beans and basil (steady, that's enough of the vegetables), then the clams, the smoked eel and yet more crispy yet succulent chipirones.

Swallows continued to flood south, now joined by increasing numbers of Sand Martins, as more seafood headed in the same direction, washed down with a nice chilled Cava. More Audouin’s Gulls floated by. Sea Cucumbers anyone? A great weekend, shame we didn't have more time, I didn't try the oysters.

The full list:
Squid, cuttlefish, octopus
3 species of prawn
4 species of clam, including razors and tellins
Mussels
A spikey-shelled whelky-type thing
Eels
Hake, sole, monkfish, salt-cod, anchovies, sardines, fried baby fish.

Omophron beach

A good day: Omophrons, Lycopodiella, Bog Bush-cricket and Nike Air.

Mark, normally a docile sort of ecologist, has taken just a few paces onto the site before he kicked some water up from the small lake onto the adjacent sandy beach. The peace and quiet was broken by "f*****g hell" repeated 24 times at high volume. A small green and brown beetle looked up, wondering what the fuss was about. So started a visit to a new site for both of us, a redundant gravel pit in north Norfolk.

The beetle in question was Omophrons limbatum, a rare beast of bare, sandy freshwater margins with fluctuating water levels, previously known only from the Dungeness/Rye area and the Norfolk/Suffolk border. The gravel pit had tumbled back to heathland since excavation and looked worthy of much more scrutiny than we had time to give it. Looking up from the beetle, we noticed Sundew colonising the lake margins. Nearby, another local rarity, the Marsh Clubmoss Lycopodiella inundata was noted, probably at only its second Norfolk site. Up into the heather, and Bog Bush-cricket was added to an ever growing list of scarce species. Who says gravel pits are dull.  Nearby, Nike was announcing a new eco-range.

Ouse Fen comes of age (what a tinca!)

Ouse Fen from the air and at boat level; a stunning Tinca (Tench) and a not-so-stunning stickleback

Amongst the headline figure of 104 booming Bitterns in the UK this year was the smaller milestone of the first successful nesting of Bitterns at Ouse Fen (Needingworth Quarry) in Cambridgeshire. The partnership project between Hanson and the RSPB will eventually become Englands largest reedbed as the habitat is created following gravel extraction.  A day spent reviewing progress was very instructive. The aquatic habitat in the developing reedbed compartments looked superb, with abundant aquatic weeds including the scarce Fan-leaved Water-crowfoot and Hairlike Pondweed.

A search for the now redundant Bittern nest was easy enough, thanks to excellent triangulation by the guys recording the birds activities during the long watches required to prove breeding. The typical small woven platform of reeds was constructed in what would have been about 60-70 cm of water at the time. All the feeding flights were from the nest location across to ‘Phase 1’, the oldest reed compartment. A further couple of hours of electro-fishing provided the reason for this. The relatively young area of habitat around the nest has few fish as yet, just a few sticklebacks, but the more mature compartment supports a respectable fish biomass of around 21kg/hectare, mainly Perch and Roach. This is above the 10kg/ha considered to be the threshold for successful Bittern breeding. So why did she not nest where the fish were? The simple answer is that the dry spring had reduced water levels in the reeds in ‘Phase 1’, thus reducing the security of any nest. However, the story is even more complicated. There were no booming males heard at Ouse Fen yet there was a nest. At nearby Fen Drayton, there were 2 boomers yet no nest. It is likely that the dry spring also affected the reedbeds at Fen Drayton and as a result the female moved across to the wetter Ouse Fen to find a secure nest location. Thus she found a mate, a nesting site and a food source in three different locations.

The electro-fishing also produced a few Tench; surely one of the most stunning of our freshwater fish with those golden scales. Less visually attractive, although interesting in a rather gruesome way, was the high parasite load of the Nine-spined Sticklebacks. The photo above shows one poor specimen with a bulging abdomen containing a Schistocephalus tapeworm (S. pungittii is the usual species in this stickleback). If that wasn’t enough it also has myxosporidium cysts (a protozoan parasite) to contend with.

Family parties of Bearded Tits (one of three) and Marsh Harriers were additional evidence that this new site is coming of age. A single Garganey, a few Little Egrets and several Hobby all helped round off a pleasant day in a boat.