The Riverside at Night

Last night, August 29th 2016, prompted by the sighting at midday the previous day of a Daubenton's bat happily foraging for insects over the river - not in broad daylight - but in deep, murky gloom  - I decided to check on the riverside wildlife at night. It was a clear warm night, quite dry and no wind to rattle the leaves. Certainly at this time of the year the river comes to life at night..
Common pipistrelle (Pipistrellus pipistrellus) are usually one of the earliest species to venture out to forage after sunset - often with the western sky still light. This evening several were detected and seen around the very old oaks on the river at the edge of a hedge which they use as a 'flyway'. The sky rapidly became dark and several Soprano pipistrelles (Pipistrellus pygmaus) were detected amongst the others. They are very slightly smaller but can be detected by the higher frequency of their echolocation calls and the call rapidity. Pipistrelles usually fly quite low and can come very close, giving the impression that they are on a collision course with the observer! A single Noctule (Nyctalus noctula) was detected away from the trees, hunting far higher up - and another high flyer was probably a Serotine bat (Eptesicus serotinus) closer to the trees - with a slightly higher frequency than the low frequency call of the Noctule. Walking along the river towards the area where the 'midday' bat was seen revealed the presence of bats certainly identifiable as Daubentons bats (Myotis daubentonii).
These bats were in the deep shadows unlit by path lighting filtering through onto the river.
Good numbers of bats were present along this section of the river and another survey will be done after rain as soon as possible whilst the weather is still warm and insects are plentiful.

Moths are a common prey of bats - therefore vegetation with night scented flowering plants attracting moths will also attract bats.
Honeysuckle (Lonicera periclymenum) or woodbine is a good example, sustaining long-tongued bees during the day and attracting moths during the night.

Honeysuckle in flower attracting bees - and moths at night - in turn attracting bats…

Same Honeysuckle plant pollinated by bees and moths, now a mass of red berries attracting birds.

August/September

Day into Night - a morning in August

Today, 28th August 2016 there was a distinct change in the weather, with a freshening breeze and dark clouds alternating with lighter clouds and glimpses of sun. I did not expect to see butterflies or dragonflies around in the gloom, with most areas swept by an unusually strong south west wind.

After a hot and humid spell with no rain for a week it was a welcome change on the riverside.

One wild plant which is seldom affected by lack of rain here, Purple Loosestrife, usually thrives with its roots in or very close to water - on the edge of a pond or a river bank.

The weak sun didn't last long and dark rainclouds drifted in. The river was clear and flowing well but very low with plants in good condition, the long grass still green with wild flowers such as Musk Mallow, Purple Loosestrife, Knapweed, other thistles and Bird's foot Trefoil still present. The latter has done very well this year, establishing good-sized clumps attracting insects. Blackthorn leaves are turning now and some are falling, leaving good-sized fruits. Some Hazel leaves are also turning yellow now but there is a good crop of hazelnuts on most trees, even some on the young trees. Even the young oak planted where the ancient oak fell, has some acorns this year. The old Field Maples are covered in winged seeds ready to 'fly' soon and Hawthorn haws are turning red , those not yet plundered by squirrels. Rose hips too are turning red, the older Rosa canina climbing high into the canopy, providing easy to forage fruits for the winter birds.

Hazel nuts ripening unseen on a young Hazel tree on the river bank.

Most are plundered by hungry grey squirrels well before they ripen!

Robins (17)  were starting to sing now, mostly still quiet, short songs, from birds quite close together, no sign of urgent territorial disputes and loud competition yet, with many birds still not bothering to sing at all but sometimes utter high contact calls or alarm signals. Most were staying put under the canopies of old trees, in cover from possible downpours. Blue tits (32) an great tits (8) were active under the dense canopies of the old trees, collecting insects, mostly very quiet, not easily visible. Blackbirds (8) were even more elusive. hiding in the shadows of the thickets, only giving themselves away with alarm calls, certainly no singing. Even wrens (6) were scarcely seen today and then only when they started to sing or gave alarm calls from under the tree roots on the banks, with one dunnock seen 

lurking in the dark.

Distinctive calls above came from a group of long-tailed tits amongst the leaves, at least 3 visible but probably more, following each other in the heights and  a high-pitched call from a treecreeper was heard but not seen. Heavier birds such as chaffinches remained hidden too, with abundant food in the trees there was no need for them to forage on the ground where they could have been seen. Only one was heard. The sounds of goldfinches in several places along the river course was most welcome, their singing a reassurance that all was well and sources of food plentiful. At least 50 were present, in smaller groups either flying, singing, across from one old field maple to another, singing from blackthorn thickets, their brilliant colouring, shining out from the darkness and more on the margins of seed-rich dry patches of plants. There were so many that a bullfinch flying across went almost unnoticed - but settled in the back of a hawthorn to call.

The weather has been perfect for house sparrows, birds that love the dry dusty ground, feeding on dry dusty seeds and perching in the sun preening their dry dusty feathers, although they need water too, so the shallow river and its 'sandbanks' are ideal for refreshment. A Blackthorn thicket on a bend in the river held several house sparrows preening and singing, easily visible and other groups were seen together elsewhere, at least 50 individuals. Looking more carefully at the sparrows in the Blackthorn, other small shapes appeared to moving around in the shady background. Three were juvenile blackcaps, their movements giving them away, working lower down amongst the branches, and focussing further behind them, two blackbirds moved like shadows, then several goldfinches could be seen too, starting to sing, whilst a different bird, small and fast moving busily foraged all over the same thicket - a chiffchaff.  On such a windy day the birds have sought out a sheltered corner and share the space available whereas on calm days they will spread out everywhere along the river. 

It was windy on the wild field but low down amongst the long grasses and amongst the young willows there was plenty of shelter and warmth - a whitethroat was seen flying into one from the riverside thicket - it will be off south soon and only return in late spring next year. Plenty of wild flowers are still flourishing here with the dominant scent now given by Water Mint (Mentha aquatic) - attracting many bees and other insects, growing in damp areas. Nearby the Fleabane is still flowering well.

 Bumblebee (Bombus pascuorum) on Water Mint

A green woodpecker was heard yaffling briefly in the distance and herring gulls (26) gathered overhead as it became darker with rainclouds approaching. Looking down on the shallow shady river it was so dark that a young moorhen was almost invisible, paddling downstream just making ripples in the water. As I was looking at it  - a bright splash of yellow moved on the bank - it was a fine grey wagtail tail-wagging it's way downstream walking on the shallow mud. foraging for insects at the waters edge, undisturbed amongst the roots under the steep banks. Could it still be collecting food for young? They do have second late broods as do not fly offat the end of summer. Suddenly a second grey wagtail flew very low across the river from the opposite bank and they both disappeared around the meander. Further along a great-spotted woodpecker gave a very short call from an old oak, whilst two rooks flew across over a conifer where a goldcrest arrived probably unaware of the much larger bird perched on the top - a young uncertain crow, looking out for the other 5 (total 6) along the bank where numbers of wood pigeons had gathered too, on the fence and banks of the drainage basin - about 50 were seen in various locations. A noisy jay hid amongst branches with 3 angry magpies not far away and three nuthatches called loudly from the old oaks.

The sky had become even darker as I returned to the river bank where I had seen the grey wagtails - now the oaks looked black and the water too and the rooted banks. Looking down, I saw something flying rapidly straight under along low over the water then turn rapidly and fly back then back and forth several times, appearing to catch flies here and there, small and brown with characteristic flight - not of a bird but a bat!

It was a Daubenton's Bat (Myotis daubentonii) which I have detected before on this stretch of the river but at night, not at midday!

They catch small aquatic invertebrates close to the surface of the water.

 It probably flew from it's roost to do some foraging as it had become so dark.

Green acorns on an oak - there may be a bonanza this year

Finally, on my way back I heard calls immediately above - it was a House Martin, flying alone under the low cloud, catching insects just before it started to rain.