Rapid Changes along the River

Wednesday 25th April 2018 saw rapid changes in the weather with one minute cloudy and cool and the next minute brilliant sunshine. The landscape seemed to change every day with the advancing hours but wildlife adapts quickly to the varying conditions.

Apple Blossom made a very sudden appearance with bees emerging to forage

amongst the flowers at the same time.

The day was cool, with clouds racing across - one minute bright sunshine with a clear sky, the next minute under cloud, instantly cooler for a minute before the sun reappeared. Most trees and plants had suddenly come into leaf, Hawthorn with blossom buds, taking over from the Blackthorn blossom. The riverside was suddenly carpeted in Dandelions attracting insects, and the flowers of Garlic Mustard were mingling with Wild garlic and Cuckooflower on the banks. The delay in growth of leaves on the trees has encouraged wild flowers to flourish this year. The old oaks were just springing into leaf but not yet casting dense shade. The young oak planted to replace a very old oak which fell in a storm several years ago had been hanging on to last-years brown leaves over the winter, as young oaks do - then suddenly, over a windy night all the leaves were blown away leaving a bare tree but with small leaf buds. Poplars were the only other trees not yet in leaf, with Ash trees only just showing signs of large buds coming into leaf

It is definitely an 'Oak before Ash' year.

The river was running fairly low but fast and there was plenty of water in the ponds but no sign of damselflies, the water wasn't warm enough. None have been seen on the river here yet either - last year's early sightings were quite unusual.

Despite the day's erratic weather, birdsong was continuous all along the river, with migrant warblers doing very well. Chiffchaffs were first to arrive back from their winter habitat and are now singing loudly (12) voices carrying far. Blackcaps arrived after the Chiffchaffs, returning to the same areas along the river, as before - choosing Blackthorn and willows to perch and sing over the riverbanks. (10 seen) Whitethroats are definitely more vocal than last year, singing strongly  from prominent perches (7), in short trees and bushes in more open positions. A single willow warbler was heard.

Singing blackbirds dominated the soundscape today - large numbers were present, some singing and the rest foraging for food to take back to young nestlings. It is at present a good spring for them with no lack of food to be found under last year's fallen leaves, even during the days of ice and snow (41).

After some silent days, song thrushes were singing again, with six heard and seen. Robins were occupied with feeding young and guarding territories, as many were silent and keeping out of sight with only 11 seen along the river banks. Like the blackbirds, wrens (32) were signing strongly most from visible perches with others flying to and fro across the river from bank to bank collecting food for young. Out and about, easily spotted amongst the fresh green leaves of large trees were the wood pigeons (33) often very inactive, as they can nest at almost any time during the year. In the same trees, magpies with fledged young were noisy as usual but always present in small numbers - six were seen.

Starling numbers vary a lot, today twelve were active, mostly just flying over, with herring gulls seen now and again, five flew over together. Four carrion crows were present, keeping a watchful eye on activities below them, perched on the top of oaks or just flying over, calling occasionally. Did they spot the grey heron flying low over the river? It was heard calling further downstream. Both herring gulls and carrion crows have been seen 'mobbing' a grey heron carrying its catch, a fish or frog, in the past - the noise distracting most riverside birds and mammals. Just one jackdaw was seen overhead.

A common buzzard was flying into the wind which was increasing, bringing more cloud with a short light April shower. The best place to find shelter from these showers is under a leaning, ivy-clad tree trunk when trees are not yet in full leaf - and this is where birds will hide as well, or disappear into the nearest holly bush.

A bird zipped low through the trees - a sparrowhawk attempting an ambush in a hedge holding a colony of house sparrows which today were more active than usual, chasing each other and bathing in the river where they gather during the day, low amongst some dense hawthorn thickets and old bracken  in good numbers (67).

Blue tits (46) and great tits (17) were also very active with both species nesting, finding the habitat perfect for raising young with plentiful supplies of insects and especially nutritious - spiders. Some of the male great tits were also singing loudly. Just one long-tailed tit was seen flying, others are most likely still feeding young. Nesting dunnocks have chosen a site close to a great tit nest site but on the opposite bank- the contrast is interesting - the foraging dunnocks are easily overlooked, being very well camouflaged compared to the very bright great tits. Five dunnocks were seen but maybe there were more! A nuthatch pair command the old ash tree close by, always observant but now seldom calling, as they too are nesting. Of the finches, goldfinches were the most numerous (about 35) singing together in groups, most well hidden in dense thickets and trees. A   bullfinch pair were easily seen foraging, pecking at fresh new leaves, silent, as they probably have a nest nearby. At last - two greenfinches were heard singing, with a distant chaffinch heard too.

Three linnets flew across into the top of a Maple.

The day was notable for the numbers of Hoverflies over the river and large numbers of Orange-tip butterflies chasing over the river banks, some perching on their caterpillar food plants:

Garlic Mustard - food plant of the Orange-tip butterfly caterpillar

Garlic Mustard is this year present in large patches on the river bank

(not to be confused with Wild Garlic which is much stronger-scented):

Wild Garlic  - No - not a butterfly caterpillar food-plant.

Heatwave in April..

The next few days saw the Riverside gradually heat up, with unique weather conditions bringing a short-lived false start to summer.

The 15th April 2018, after a cool night, was overcast with dark clouds and threatening rain - however the riverside was again lively with a blackcap singing in Blackthorn but in a different location to the previous day whilst a buzzard circled over the river, gradually coming closer. A treecreeper flew across low to the base of a bare tree and worked its way upwards. Wrens, blue tits and great tits were calling and a fine male bullfinch flew across from a 'house sparrow hedge' where the colony was singing, into a hawthorn on the opposite bank. A great-spotted woodpecker called from a bare ash tree whilst below, a robin was collecting some fresh green leaves, carrying small bunches in its beak from the river bank up into an ivy-clad mound. A song thrush was seen bathing for some time in the river, perching on a floating twig island. It then flew off to a higher branch to preen and dry off.

More windy and damp days followed - but by the 18th it had become considerably warmer and at last butterflies emerged, firstly a fast-flying male Orange-tip showing up brightly over fresh green bank vegetation, then a brilliant male Brimstone butterfly.

Cuckooflowers were now appearing in clumps along the banks and in the wild field - an important food plant for the Orange-tip caterpillar :

Cuckooflower (or Lady's Smock) on the river bank April 2018. 

Orange-tip females will be ranging the river banks selecting these plants on which to lay their eggs.

The butterfly caterpillars will then feed on these during the summer. They will then leave to hide in dense vegetation to pupate and spend the coming 10 or 11 months in chrysalis form before emerging as adult butterflies in April the following year.

The following day, 19th, was very hot and sunny and many more of these butterflies were seen.   

Friday 20th April was another very fine day with the opportunity to do a survey of the South area during the morning as so much was happening. The full survey covering north and south will following the next post.

On 20th there were no clouds, a very slight breeze, the grass slightly damp with dew. The river level was lower but still fast-running. A large old oak was just coming into leaf, together with the Hazels and Willows. Wild Garlic was found growing in some new places together with Lesser Celandine almost certainly due to the upper storey remaining bare longer than usual allowing light on the under storey. Blackthorn was now covered in dense blossom and the grassed areas covered in brilliant Dandelions.
One can only hope that the profusion of wild flowers is allowed to flourish and provide pollinators with sustenance during the Spring.
House Sparrows singing  were encountered in their traditional colonies, in hedgerows, bramble patches and banks (about 60). Wood pigeons were not numerous, only 9 were seen, mostly in pairs. A pair of Carrion Crows were balancing in a tree top whilst a buzzard called from oaks on a wooded margin. Three jays were seen and heard chasing, with three magpies taking flight, the jay in this case being the more aggressive species. A nuthatch was heard calling loudly and continuously - the calls directed at unwelcome attention - it obviously has young to protect in the nest. Its mate was seen briefly amongst the branches (2).  Blackbirds were also vocal in protecting nests (14) or foraging in the damp grass and mud on the banks , with a single song thrush seen in deep shadows. Dunnocks are normally found lurking under vegetation in shade but today four were easily seen, two singing from prominent song posts.
Blue tits (34) were active with a few singing or calling and great tits (15) were easily seen when calling loudly but with some flying silently low over the river to nests in old tree roots. Robins were definitely nesting as fewer were seen than usual (10) but those seen were singing strongly. Goldfinches (about 17) were gathered in a loose group high in an old Maple, singing to themselves, occasionally flying out to forage.
A single male bullfinch gave a fine view, intent on feeding, gorging on the Blackthorn blossom near the top of a thicket, not easy to miss in the bright sunshine, balancing by flapping it's wings.

Blackthorn Blossom along the river April 2018

Warblers were doing well, with blackcaps (5) singing from the dense blossom of Blackthorn thickets and others from Willows just coming into leaf.  Song from Chiffchaffs (7) was the most penetrating - heard from just about every corner - not always the simple 'chiff-chaff' but sometimes  with 3 syllables such as 'chiff chiff chaff'. Just one willow warbler was seen, its song unmistakeable. Wrens won the day for singing however with 18 along the length of the river banks; there were certainly more present but nesting.
The most welcome were the common whitethroats which have arrived in good time, settling after their long journeys in their usual habitat, the bramble and low tangled scrub,  their songs also clear (4).
Butterflies - the first Commas were seen flying over young nettles on the banks and numerous Orange-tips were seen ranging along the banks, mostly males (orange wing-tips) looking for females. Peacock, Brimstone, Speckled Wood and Red Admiral butterflies were also seen. Large Bombus terrestris bumblebees were quite numerous as were smaller bees feeding on the numerous wild flowers and blossoming trees. Hoverflies were present in good numbers too.
A very active morning - and more for the end of April to come.

Spring for a Day

After a week of overcast days, often with long spells of fine rain, Saturday 14th April 2018 was much warmer, clear and bright after a misty start. Lesser Celandine and Wood Anemone were in full flower and seemed to be more vigorous, covering larger areas than in previous springs, perhaps because the plants have remained dormant for longer. Blackthorn blossom is prolific too this year.

Lesser Celandine 14th April 2018

Traditionally thought of as the herald of Spring as it is usually one of the first flowers to appear - towards the end of February in our warm southern land.

Some observations in a few minutes just walking along the banks:

A grey heron flying slowly over the river and above it, two circling buzzards.

Nuthatch calls carried far along the river, two birds communicating with each other, whilst song thrushes, at least three could be heard singing from different locations.

A male blackcap was singing a fine song very close by, at first completely obscured in a dense Blackthorn thicket. Moving gradually around, I had a very clear view of it near the top of a branch

surrounded by blossom where it continued to sing. Across the river, amongst the grassy clumps, a green woodpecker yaffled, and in the distance a great-spotted woodpecker could be heard signal-drumming.

Blackbirds were now singing full songs, with robins, dunnocks and wrens singing too, voices carrying far through the leaf-bare riverside. Soon their voices will be baffled by leaf growth. Great tits

and chiffchaffs called tirelessly and male house sparrows sang loudly, to be heard by birds perhaps in a neighbouring colony.   

Another flower usually seen in early spring is the Wood Anemone but although the flower buds appeared in March, this year it is flowering only now, as the sun appears through the bare branches of the old oaks:

Wood Anemone flowering under an old oak on the river bank 14th April 2018.

It is important to remember that this is a sure sign of ancient woodland and the plants confine themselves to the same areas, roots creeping extremely slowly year on year.