Friday, 31 October 2014

Spindles, Bats and Admirals

October 31st 2014  20degs C, 65% humidity, southerly breeze, hazy sun all day.


The Spindle fruits are the most prolific they have ever been,
as yet untouched by birds which have been choosing Hawthorn
berries and sloes first. 

Today's report follows - first - good news about bats!
After  a long spring and summer monitoring the new bat boxes installed early in the year, there is now strong evidence that bats are roosting in the boxes. There was no sign of use during the previous check early in October but the cooler and longer nights have caused bats to seek out warmer roosts.
The boxes are checked using binoculars during good daylight and this time evidence was clear - marks on the vertical surface of the wood underneath the entrance slot indicate bat droppings, produced by bats roosting inside the boxes. See entry for 29th September 2014 for more about bats here - and go to  Hills Farm Conservation Group News entry for February 2014 - bat box installation.   



Red Admiral butterfly feasting on the nectar of Ivy flowers
having to fend off many other insects - bees, wasps and hoverflies
all concentrating on this rich autumn food supply.

Friday 31st October 2014
Still very warm with a southerly breeze, thin clouds and continuous sunshine. Ash leaves falling now in abundance leaving ash keys on some trees but Oaks still retaining their light green and yellowing leaves. No acorns have been seen for some time, either in the trees or on the ground. Field Maples are also losing their bright yellow leaves whilst under the trees bright green Cow parsley is already pushing up through the carpet of fallen leaves. The air very damp and humid, with the river flowing quiet fast after rain earlier in the week.
Robins are mostly in full song or uttering alarm 'tics', now easily seen but their plumage harmonising with autumn colours (16). As usual dunnocks are still keeping a low profile with just one singing. Hawthorn leaves suddenly start shaking, revealing a grey squirrel reaching out to the last remaining berries hanging over the river. Another squirrel was 'barking' in an oak - there will be a lot of competition for food this winter which promises to be a lean one for wildlife dependent on nuts and acorns. Versatile woodpigeons usually do well in any conditions although a close flock of at least 50 were seen flying high over the river, possibly to join large flocks seen leaving the coast in recent days. Perhaps they know more then we do! Several were staying put in the oaks here however (14).
Goldfinches are at present cheerfully singing in the ivy whilst others are busy in small groups flying across to forage on the seed heads of thistle seeds on the 'reptile' field. (28). Magpies, always giving the impression of a sense of purpose, flew across from a roof (3) into trees and a carrion crow called loudly.
Three jackdaws and four rooks were seen investigating the terrain from the air but departed on finding no freshly cut crops to feed on.  A noisy bunch of 8 herring gulls drifted over and later 18 black-headed gulls followed them.  About 15 Starlings were seen, seeking some choice mud to land on and those other mud-lovers, the pied wagtails, were gathering on a roof, calling (8).  A small flock of linnets (10) flew over, finding foraging good amongst the seed heads. House sparrows are now more vocal after the long summer, chattering in thickets, hedgerows and brambles (60) - no shortage of food for them at present with dried up blackberries and other seeds, in addition plentiful small insects savoured especially by this year's juveniles. Chaffinches, although seldom numerous here, are now calling (4). Blue tits (28) are active, investigating every hiding place for insects, with great tits (15) now in fine plumage  and a silent wren which flew whirring across the river to call from the opposite bank, the only wren seen today.
Blackbirds were seen moving along behind a thicket, feeding on hawthorn berries, with a few more out on the damp grass (14). Some were probably new arrivals and three certain newcomers arrived suddenly, flying across and landing on a fence, looking around at the new landscape. These were  the first redwings seen this autumn; they may just be passing through on their way west. A single chiffchaff, a summer visitor late to leave, or maybe deciding to overwinter here, was catching insects in a typically agile manner around some brambles.
A nuthatch, first heard calling in the distance, flew into an old oak, continuing to call loudly and persistently. Looking up into the oak, it was obvious why - a blue tit was disappearing into a hole which was probably a potential nest site for the nuthatch. The blue tit however was only interested in catching insects and flew off as the nuthatch approached.  Three more nuthatches were seen and heard along the riverside trees (4). Another welcome sound was the loud call of a green woodpecker on its grassy field and a call from a second bird in an oak further south (2). Their call is meant to carry far and wide in woods and fields as they can range over a large area. Not so the tiny treecreeper, which has a quiet thin high call unlikely to be heard far from its local patch of trees. Today there was a fine view of one foraging, creeping along the underside of a horizontal branch stretching from an old oak high over the river , its subtle plumage catching the sun.
Further south along the river bank, characteristic small calls came from a willow still holding most of its leaves. At first there was no sign of the birds, then tails appeared, jumping amongst the dry leaves - a family long-tailed tits (8) were foraging for insects, following each other into a field maple and working their way high up into the canopy.
It still had the feeling of a hot midsummer day, with a Comma butterfly seen on the bank, five Red Admiral butterflies, some chasing - and a lone Migrant Hawker dragonfly.

The weather has to change soon, with bats and butterflies moving to hibernate then hopefully we'll see the arrival of more winter migrants.


Meanwhile the rivers flows clear, reflecting leaves still green.



Tuesday, 28 October 2014

Oaks in October

We started to get an idea of the age of the riverside oaks on our latest meet on 26th October 2014.
Measuring the girth of the main trunks of each oak was not as easy as it may seem as most of the trees grow out of the river banks. Five of the oaks were successfully measured without anyone falling into the river however. It was a very dark morning so these photos were taken today, Tuesday 28th when the light was far better. Using the Woodland Trust table as a guide, the age of each tree was estimated.

This oak was probably just a sapling in 1783,
during the reign of George III
(The date of the first manned hot-air balloon flight in Paris)


This oak started growing around the year 1724,
during the reign of George 1st
(Invention of the chronometer by John Harrison 1726)


A fine oak, this was a sapling around 1839,
during the early years of  Queen Victoria's reign 
(The year when John Herschel took the first glass plate photograph)


This oak started growing not long after the one above, around 1869,
during the reign of Queen Victoria
(The year ballbearings were invented and the Suez canal opened)


The oldest oak measured so far was a sapling in around 1698,
during the reign of William and Mary 
(The year the Eddystone Lighthouse was first lit)


More to measure, so this may not be the oldest!















Wednesday, 22 October 2014

October Contrasts

So far, October has been a month of contrasts with mists and warmth, gales and cold fronts moving through. It has also shown a glut of berries and a dearth of acorns, heavy rains and dry earth.


Hazel leaves brighten the riverside still but Hazel nuts
are long gone.



A Hover fly (Eristalis pertinax) feeds on abundant ivy flowers, together with
many other insects. Ivy is a very valuable plant, the flowers providing 'out of season' 
food for wildlife, the evergreen leaves providing cover all the year round, for
nesting birds in the spring and shelter for roosting birds and bats. This Hover fly 
imitates a drone Honey bee, pretending to be a stinging insect to avoid predators.
Like a true bee, it is a useful pollinator.

Here is the record for early October:
Sunday 5th October 2014 
The morning was sunny after rain the day before but a lot colder - seeing the first frost of the coming winter, with no wind. The early sun was just reaching the maples and ivy, warming up the leaves and attracting hover flies but no butterflies at first. Rose hips and hawthorn berries shone in the sun, more evident now that leaves were thinning. Some rose hips could be seen as high as the top of the Hawthorn thickets after a summer of rapid growth.
It was good to hear robins singing now, challenging each other, sorting out their winter territories along the river banks (21) whilst blue tits (39) and great tits (22) were also more in evidence than last month, a few of the latter calling.
Numerous blackbirds were active, not singing but most making their way south amongst the river bank thickets, savouring the sloes on the blackthorn on the way, obviously new arrivals, whilst our resident blackbirds looked on, having fed well in late summer on plentiful fruits (25). House sparrows, which stay put all year, were noisier now, bickering and calling from the hedges (36) and one chaffinch was heard calling whilst others were seen flying across (6).
Starling numbers had also increased, winter visitors probably joining the existing small colony. An old Maple was whistling loudly, the starlings hidden from view whilst more birds wheeled around above, coming to land in a day-roost thicket nearby (60).    
Goldfinches (13) flew into an ivy-covered area and more into a blackthorn thicket from the field margin where they had been foraging and 2 long-tailed tits were seen high in the top of an oak.
A great spotted woodpecker flew across and dived into the tree, still in full leaf, whilst 2 juveniles sat in a nearby thicket, the female clearly visible, preening for a while. A squirrel gave a loud scream but the woodpeckers sat silently, unconcerned. Two more, adults, were seen flying south, calling (6).
Nuthatches are always early establishing their nesting accommodation which they will guard and prepare over the winter. Today two were seen flying, perching and calling around the old trees.
Wrens were still mostly hiding out of sight but one was seen flying low down over the river, another two gave alarm calls and one tried out a very short song (7). Down under Hazel tree roots along the bank two dunnocks were seen foraging together with great tits and two more were seen in undergrowth further along (4). Quiet calls behind a blackthorn thicket came from two bullfinches which declined to show themselves today but one goldcrest was briefly heard and seen in a conifer.
Most of our summer warblers had left but two blackcaps (males) were seen foraging quickly in the blackthorn, maybe new arrivals or maybe summer birds staying on, briefly appearing in the sunlight.
After an unusually cold night, remaining chiffchaffs were very active catching insects, making their rapid 'U turns', contact calling, never still.
In the blue sky herring gulls were circling, with no wind to battle against (41), a few carrion crows were seen (7) with two rooks and 8 jackdaws.  A lone pheasant was heard in the undergrowth and two wary collared doves looked down from a branch whilst small groups of woodpigeons sat in trees or flew across the river (27). 5 Magpies foraged on the damp field. Shots rang out from the fields beyond, indicating that woodpigeons were being targeted - but no large numbers were seen to fly up and the shots didn't last long.
The day was warming up and eventually 4 buzzards glided into view, two circling around each other, gliding, over the river and two, also keeping each other company, were seen further away. Below them, closer to the ground, about 15 house martins were flying together, feeding on insects. They will be off this month on their long journey south.
In the warmth, the butterflies began to appear, a male Brimstone, two small copper butterflies, 3 Red Admiral butterflies and 8 Speckled Woods, the autumn butterflies.
A rather scarce small bird, a marsh tit, was seen preening in a sunlit thicket before disappearing.
 and a Roe deer moved into the undergrowth nearby, silently.

The stars of today were clearly a fine kingfisher - a bright blue flash flying in a gap where the sun shone just above the surface of the clear water, heading upstream - and a grey wagtail, almost as quick flying along the river, showing off its very long tail and flash of yellow.


Monday, 29 September 2014

A Storm with Bats

Friday 19th September - the evening was very warm and humid with no wind and the sky clouding over after sunset causing a swift change in the atmosphere with distant storms appearing.
Lightning lit up the clouds every few seconds all around us but no rain fell here on the riverside.
The air was filled with insects, mainly moths and 'daddy-long-legs', easy prey.

A warm and humid evening as the sun set over the riverside.
Very large numbers of bats were active from the start, before the sky darkened and the storm clouds
gathered and threatened rain. Common Pipistrelle mixed with a few Soprano Pipistrelle bats were the most numerous and the hunting was easy. Daubenton's bats were detected in darkness near the bridge, close to the water whilst the Pipistrelles hunted along their flyway hedge and down to the old oaks, around and back. A few Noctules, the large, high-flying bats were seen approaching the river, just visible, before 
plunging into the darkness of the old thicket. The ivy was starting to flower, attracting a host of insects.
Thunder rumbled and lightning flashed but was sufficiently distant to be of no danger. The riverside remained dark apart from some areas where new road lamps flashed their intrusive light through branches, like searchlights.
It was very good however to detect so many bats foraging along their traditional flyways where they have hunted for hundreds of years, establishing roosts in the old welcoming oaks year on year.
It's our task to protect the old oaks and the riverside ecology for bats -  fragile creatures which depend on the continuity of this very special habitat for their survival in our world. 

A Full Daytime Record of Wildlife on the Riverside:
Sunday 21st September 2014
The morning was fine but much cooler with a fresh northerly breeze, very damp with heacy dew on the grass, the river flowing well after the rain a couple of days ago. Low cloud but with some blue sky allowed glimpes of the sun lighting up the bright yellowing of the Hazel leaves and Rosa canina now bare of leaves but full of rose hips. Most of this year's unusually prolific hedge bindweed was disintegrating with just a few bell-like flowers remaining, providing late nectar for insects such as hoverflies.
Despite the wind, there was a lot going on in sheltered areas, the river's meanders providing plenty of these. Chiffchaffs (6) were still active, some given away by their contact calls and others by small quick movements amongst the leaves, far quicker than the blue tits (15) and great tits (10) foraging nearby.
Robins (15) were now slightly more vocal, giving short songs, alarm 'tics' or high thin calls which sometimes are given as a prelude to full song. Only two wrens were seen, both giving short calls and finches were scarce too, with only two chaffinches and two greenfinches seen. House sparrows were very quiet today with no sound from the brambles, perhaps they were suffering from the sudden shock of a cold night as they remained in the most sheltered and sunny places on the along river(30). Blackbirds (7) were also keeping to the shelter of the banks none singing but one or two giving alarm calls. Tiny birds, goldcrests (2) need to feed  most of the day - one was see flying into the sunny side of a conifer and another was heard but unseen in another tree nearby. A great spotted woodpecker suddenly called out form an old ash and another was seen flying across the river (2). The other woodland bird, the nuthatch (3), usually remains quiet over the summer months but now one was heard calling loudly and two more were heard upstream in the oaks. Once nesting is over they advertise their presence to all inhabitants of the wood.
This coming winter will be hard for jays and squirrels as there are very few acorns on the oaks this year. The jays today (4) were clearly searching from tree to tree but will have to survive on other nuts and fruits.


The river banks and fields beyond

Above the trees a group of linnets suddenly flew across to a hedgerow (20), quieter than goldfinches which were remaining well hidden within the thickets. It was good to see house martins (16) flying in the distance, catching insects. There must have been some very large swarms of insects carried up into the air by the breeze as over 100 corvids suddenly appeared in the sky, turning and dipping in a chaotic flock, rooks (30), jackdaws (70) all intent on catching insects, perhaps flying ants. A group of crows (14) had been foraging on the slopes of the new basin but had given up and retreated to the field margin where the earth was softer. They were in the company of some woodpigeons although most of the woodpigeons (30) preferred to perch in the large trees, good vantage points catching the sun. A few herring gulls were seen in the air (10) and 3 magpies.

The star today was a fine hobby which dashed across the sky and out of sight behind a hedge - then a large group of crows flew up and rapidly disappeared. The hobby then reappeared over the hedge further downstream.
Good thermals today brought out the buzzards (4) - two were seen gliding over the hedgerow and oaks, flying close together, were carried south by the wind and out of sight, then reappeared, to be joined by two more buzzards and between them a kestrel taking advantage of the wind, distinguishable by its size and flight.
Down on the river a characteristic call caused me to look down to see a flash of yellow as a grey wagtail flew down along the fast flowing stretch of the river, its traditional habitat - and in a more sheltered corner a moorhen moved onto a bankside island, on its own now after rearing several young.
A commanding Southern Hawker dragonfly patrolled the river bank where small insects were numerous and in sunny areas Large White butterflies (3), a Green-veined White and a Comma butterfly were seen together with a bright male Brimstone (2) flying into the wild meadow where it was sheltered and warm and a second Brimstone flew up into a filed maple nearby. On the shaded, wooded banks, Speckled Wood butterflies were numerous, chasing in pairs or threes, flying high and low (19).
This cool weather turned out to be just an interlude as the heat and humidity rapidly returned, delaying the true autumn weather.




Monday, 15 September 2014

Autumn - Wild Reds

The dry autumn has brought brilliance to the riverside, the lowering sun picking out colours of wild flora and fauna even before most leaves have turned.


A Common Darter (Sympetrum striolatum) warming up on the stoney path -
not to be confused with the Ruddy Darter (Sympetrum sanguineum)
which has more of a 'waisted' abdomen, the male being even more 'ruddy'.

An increasing North wind kept birds under shelter on Sunday 14th September. The fields, recently shorn of their cereal crop had attracted large numbers of woodpigeons which were silently, solidly foraging, with only one or two in the air. Hundreds of crows, mainly jackdaws, were however noisily flocking low over the land, agitated and restless, foraging for a few minutes then scared into the air again. Two buzzards appeared over the oaks, wheeling low over the hedgerows, hunting. One flew into an oak to watch from a branch whilst the other allowed the wind to carry it high above and out of sight. Close to the bank, a grey heron flew leisurely along the course of the river, upstream to a favourite hidden foraging spot, away from the windswept fields.
A few robins were singing their plaintive autumn songs but keeping under shelter, although their bright red colours could be glimpsed amongst the red berries of the Hawthorn.
Blackcaps were hiding amongst the Blackberries, silent except for occasional cursing. They love the sun and one or two could not resist taking up perches where a gap in the thorns let through the sunlight.
This is the time of year when most are on their way to the south coast together with other massed warblers but some appear to remain with us over the winter or possibly their places are taken by migrants from colder north easterly climates.


Hawthorn berries (haws) are numerous this autumn

Chiffchaffs and even the odd willow warbler and whitethroat could be seen in the thickets foraging, feeding up for the long journey south although some of the chiffchaffs will remain with us, by now with expert local knowledge. Now their voices are restricted solely to the necessary contact calls or signals, usually monosyllabic or disyllabic.
A nuthatch was heard calling and a wren gave a short alarm signal from where it had slid out of sight down into the forest of stems on the bank.
Looking down at the clear shallow flowing water - suddenly a stunning view of a kingfisher flying just above the water between the high banks - brilliant blue viewed from above as it sped past the roots.
Several Common Darters were seen, perched on nettles in sheltered sun or warming up on stones and one Migrant Hawker dragonfly was patrolling the banks of the Arun and a colourful male 
Southern Hawker flew past me many times along the banks of the Brook. To complete the colourful scene, a bright orange Comma butterfly and a Red Admiral were also ranging along the bank side vegetation in the company of many very active Speckled Wood butterflies.


Guelder Rose berries will remain to brighten the riverside until
most other berries have been eaten during the winter.
The plants have done very well this year, mixed with Hawthorn, Blackthorn,
Rosa canina and Field Maple. These will all be kept Hedgerow 
height to provide habitat for wildlife along the river.



Thursday, 28 August 2014

Heading South - warblers on the move

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, 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.


Monday, 18 August 2014

August - and more Dragonflies!

Today was warm with intermittent sunshine but a lot cooler than last month. Dragonflies and damselflies can find conditions too hot and will hide away in the shady undergrowth when the morning heats up and will resume foraging in the evening. Numbers of insects have increased after heavy rain showers and birds and dragonflies are out hunting. Chiffchaffs are still quite numerous along the river, together with many just-fledged blackbirds and song thrushes.

An adult male Southern Hawker was taking a rest from patrolling the wooded area of the river bank:

clinging, quite motionless, onto an old nettle stalk.
(Compare this one with the July photo - that was
an immature one which had not acquired its full colours). 

It's body, although it looks bulky and heavy is really very light and is built for fast flying and quick manoeuvres, hovering and even flying backwards when foraging for insects, chasing or clashing with
opponents in territorial disputes.
Each male commands its own stretch of the river but butterflies don't recognise this and today I saw a Speckled Wood butterfly attempting to chase another Southern Hawker away.