On Sunday 24th August a mass movement of migratory birds was taking place along the river. Conditions were ideal, with little wind and plenty of food in the form of insects in the river bank trees.
Autumn is fast approaching and after several heavy downpours, most of the summer butterflies have disappeared, leaving the Speckled Woods to command the banks.
A Speckled Wood butterfly on the bank
Thin high cloud on 24th allowed hazy sunshine to dry up the heavy dew on the ground after a cold night. There was no wind to disturb the quiet morning along the river, already feeling autumnal with nettles rapidly dying off, ripe sloes on the Blackthorn, rosehips turning red, hawthorn laden with ripening berries, green acorns on the oaks, winged Field Maple seeds turning brown, Guelder rose berries mostly red now. Purple loosestrife, honeysuckle, rosebay willowherb and musk Mallow still flowering together with hedge bindweed flowers hosting innumerable small insects such as bees and hoverflies.
There had been no rain for several days and the river was flowing quite low - but rain was forecast for the following day.
With no wind, the sound of robins (26) tic-ticking and trying out short bursts of song in preparation for establishing territories was the most notable, with other birds mostly silent. Woodpigeons (60) were mainly busy feeing around the new 'scrape' (basin 5) but one was glimpsed amongst leaves feeding a juvenile in a well hidden nest and one or two others were wing-flapping and cooing. Crows (9) were also busy foraging on the scrape.
Blue tits were very numerous (70) foraging amongst thickets, occasionally bickering, their numbers increased by many juveniles, a result of a very successful breeding season. Great tits too have had a good summer with juveniles now off to fend for themselves (22). The cold nights affect some birds more than others - house sparrows were invisible for the first hour, only becoming active as the sun warmed up the hedgerows when some began to move around and sing (30). Chaffinches stayed out of sight and silent, only one was seen flying across the river. Blackbirds, (4) usually easily seen, kept under cover. One flew into the ivy, silently and a juvenile dropped down amongst the sloes, warming up in the sun, preening silently whilst another was seen preening inside dense blackthorn, a safe place when a bird is moulting. A dunnock was seen here low under the bush.
Normally one would hear them before seeing them but three bullfinches were seen, all silent, two flying into a thicket and another into an oak.
Overhead, a large group of herring gulls glided over (60) quickly lost over the horizon, then later a group of black-headed gulls flew over, more active and closer to the ground (27). Noise filled the sky -three biplanes flew over in a group, probably a stunt team heading for an air show...
Down on the river bank in dry undergrowth, I spotted several ants nests - good foraging for the green woodpecker, heard jaffling from the 'reptile field' where it has its traditional feeding grounds in a location untouched by the plough for decades, allowing large colonies of ants to survive year on year. A scuffling amongst the river bank vegetation revealed a bank vole quickly disappearing into a hole low on the bank. One day we'll see the water voles again, we hope! Close by there was a short burst of song from a wren, with glimpses of two others further along - another common bird at present in hiding. A female mallard was making its way upstream when a sparrowhawk made a low dash across to the bank, an attempt to ambush a sparrow failed this time.
A clear call from a buzzard (2) at the margin of the wild field broke the silence but the bird moved quickly from its perch and was later seen - a very good view - gliding in circles above the river. Another more distant buzzard called from high up, taking advantage of the thermals as the day warmed up.
As time moved towards midday, the riverside became more noisy, with the loud insistent calls of a nuthatch, with another heard tap tap tapping in an oak - tapping open the shell of an acorn or nut, wedged in the fork of a branch. Four nuthatches were seen, only two vocal. Two magpies and a jay were creating a disturbance with loud raucous cries, probably a dispute over territory and food whilst a 'charm' of goldfinches (15) flew across into a chattering hawthorn, one adult goldfinch on the very top branch singing in the sunshine with others below him, mostly juveniles in various stages of disorderly plumage. Some with speckled fronts and black tail feathers, others plain brown with faint yellow wing-stripes.
More young were seen in a conifer, this time goldcrests (6) - all heard before being seen - tiny high calls. They are usually always busy foraging amongst the pine needles but the juveniles were seen chasing each other around the tree. In the same area another family - of long-tailed tits (6) were seen following each other from tree to tree, ignoring the most exciting and numerous occupants of the riverside this day....
WARBLERS
In unprecedented numbers, chiffchaffs and willow warblers,were seen all along the river this day, accompanied by a few blackcaps (4).
Chiffchaffs were the most numerous (55) and willow warblers (38) the most I have ever counted here, or anywhere!
River bank Willows at this time of the year attract large numbers of small insects which in turn attract the warblers. Chiffchaffs were foraging upside down collecting insects, tumbling down, chasing, wing-flicking, their fly-catching skills exceptional, approaching their prey from all angles, far more agile than the more predictable spotted flycatcher. Most of these birds were probably juveniles, fattening up for their first long journey south and knowing rain was coming. A few took seconds to preen in the sun but contact calls were made in flight, a short 'hweet'. They were also feeding on insects in the old Oaks, Field Maples and Hazel but the most popular by far were the river bank Willows. Willow warblers were busy feeding with the chiffchaffs - distinguishing them whilst so active is not easy especially at this time of the year when they are not 'singing' but only making contact calls. These calls are usually disyllabic - 'hwee-eeet' compared with the chiffchaff's single 'hweet'. Blackcaps were making alarm 'chinks' perched in the blackthorn and willows.
INSECTS
Apart from the small flying insects over the water and aphids on the leaves and stems, 3 Southern Hawker Dragonflies were seen flying along the bank undergrowth brambles and up into the field maple and 2 Common Darters were warming up in the sun. Migrant Hawkers were flying about 3 meters up in the Willows and Brown Hawkers were flying strongly along the trees in sun and shade.
These Dragonflies would all be foraging for insects too!
Once the sun had warmed up the river banks, the Speckled Wood Butterflies appeared (14) ranging high and low over the river and into the trees. Two Large White butterflies were seen and 5 Green-veined White butterflies, with just one Small Tortoiseshell seen.
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