The Last Day of April

Tuesday 30th April 2019 - there could hardly have been a better example of an April day here -

and near perfect for a survey, no wind, sun with small cumulous clouds drifting across the blue sky, hardly any noise apart from the sound of a distant garden mower for a few minutes. Birdsong dominated the soundscape.

The morning started cool, with Hawthorn and fruit tree blossom now fully in flower and grassed areas covered in Daisies and Dandelions whilst Wild Garlic still covered the shady woodland and river bank areas and Cow Parsley now growing tall along the hedges.
It is proving to be the best spring for Cuckooflower and Garlic Mustard on banks, with many new plants springing up in new locations, last year's seed from old plants having germinated well.
Holly Blue butterflies together with Orange-tips have dominated the banks and are still most numerous. Both species are very restless, Organge-tips ranging ceaselessly along the vegetation and Holly Blues ranging everywhere, high and low:

Holly Blue butterfly  - Celastrina argiolus -  on very small young bramble leaf - the butterfly is very small too.

Orange-tip butterflies have been numerous too but evasive. Below is a female probably investigating a suitable site for depositing an egg. The males are very easily identified with their bright orange wing tips but females lack the orange and can be confused with other white butterflies at a glance. The most obvious sign is that both males and females have patterned underwings - a mix of yellow and black appearing mottled green, seen when they perch closed on stalks - a form of camouflage

The Orange-tip female Anthocharis  cardamines is in the centre facing one of the flowers of the White Dead Nettle plant.

Like the Garlic Mustard plant, the leaves look rather like a common nettle but do not sting.

The first Orange-tip butterflies appeared here on Thursday 18th April 2019 - the same day as they were first seen downstream (Arun) at Pulborough. The first Holly Blues were seen on 15th April 2019.

(my observations - others may have seen them before this!)

It was easy to be distracted by many spring 'firsts' along the river but here is the result of the survey on 30th April:

House sparrows, more that 100 in total all along the riverside, in hedgerows, thickets, clumps of brambles and down on the river, bathing. Easy to locate by their song or chatter. Some were even sand-bathing along the dry path. Their numbers are increasing now, with fledged young following the adults from roof nests to the river banks. The constant background sound of house sparrows was drowned out by several other species, blackbirds numbering 48 were very active, with some singing long songs whilst other males chased each other or foraged, collecting food for young in the nest. Some song thrushes (10) were singing the loudest and most continuous song, most choosing Ash trees, not yet in leaf, to perch on, so that their song travels far and clear along the river rather than being muffled. Others were well advanced with nesting, seen carrying food for nestlings low and far into the undergrowth.

 Some robins were still singing whilst others were silently collecting food (total 14). Most are nesting, which accounts for the lower numbers. Wrens seemed to be singing as usual, with 33 seen all along the banks, making their songs echo. At this stage they were choosing prominent perches for maximum effect. Three dunnocks were seen chasing but none were heard singing today. Goldfinches were also quiet with only short songs heard from around 10 in a thicket. Once the young are fledged they'll form a larger group and forage, roost and sing together. There were only two chaffinches seen in the trees today. A single goldcrest darted into a conifer where it disappeared, probably into its nest on an outer branch.

About 30 woodpigeons were active too, many searching out choice buds which are always at the ends of thin branches. Bouncing woodpigeons were a common sight. Four calling collared doves were occupying trees with dense leaf cover.

Blue and great tits (22 and 13) were less visible now that nesting is occupying almost the whole population; keeping out of sight whilst visiting nests is a priority and flight distances are as short as possible, although great tits are always more adventurous and visible when selecting choice insect food for their young. Long-tailed tits (28) have already successfully raised young and several family groups were seen in different areas following each other through the willows, oak, brambles and blackthorn.

 The loudest song, apart from the resident birds, was the song of the chiffchaff, usually the first migrant warbler to arrive here in the spring (14), Almost all were singing loudly, pausing now and then to snatch insects from blossom and fresh leaves. Easily overlooked as well camouflaged with dull green-brown plumage, they make up for it in persistent song, definitely unmistakable.

One of the young fruit trees in blossom, with clumps of cuckooflower nearby attracting early pollinators such as bees and hoverflies. Seed heads on last year's wild grasses were still attracting finches in the same area.

Common whitethroats (8)  - migrant warblers, arrived some time ago and have settled in their usual territories, singing and displaying whilst blackcaps (15) have chosen territories all along the river and could be heard singing from treetop perches and amongst the river willows. The large 'clouds' of summer insects over the river always attract them when feeding young and later fruits and berries are eaten whilst the birds are preparing to leave for their winter habitats in the autumn. Amongst the singing warblers a singing garden warbler was heard but remained elusive.

In the air above the river, two house martins were seen over a drainage basin and three common buzzards circled over to the north, two displaying. Crows were few in number, (5) one seen carrying a heavy object, probably part of a packed lunch. It was very good to see more than 50 starlings in small groups fly-catching over the river. They are skilled in this but need just the right calm weather conditions where insects are trapped between low cloud and the warm river. Overhead 8 herring gulls flew across, above three jackdaws from the woods. Seven magpies in twos and threes chased into trees and three nesting nuthatches were seen, unusually silent. A Jay sneaked quietly behind a hedge and a loud raucous call came from a grey heron fishing down on the river bed which was disturbed by a carrion crow.

On the river itself, several groups of mallard were seen in different places on the river, with a pair flying up then down again (a total of 10). These are not tame, and instantly paddle or fly away when encountered.

Butterflies:

In addition to the Holly Blue and Orange-tips, several Speckled Woods were seen, with a single Peacock, Green-veined White and Comma 

Hoverflies were seen in good numbers, with a few St Marks flies, bumblebees and large numbers of midges over the river - all a very good sign!

A Red-tailed Bumblebee Bombus lapidarius on one of the thousands of dandelions covering the grass.

  

More April 'Firsts' the second half of April

Monday 15th April - a fine day and another first - Holly Blue butterflies were seen ranging along the south-facing embankment. These were the first of many to be seen this month, in common with many other locations in Sussex. In early summer these butterflies seek Holly leaves on which to lay their eggs but those in the late summer prefer Ivy. Both plants are quite abundant here and of course are extremely good for many species of wildlife, providing food in the form of berries and evergreen shelter over the winter.

A calling common buzzard, a darting sparrowhawk, many blue tits, wrens, blackbirds, song thrush, bullfinch, chiffchaffs, two jackdaws and numerous house sparrows were seen as well.

Another 'first' was seen on 18th April - whilst watching Holly Blue butterflies along the bank, several Orange-tip butterflies appeared. These are also early butterflies but not usually so numerous. Like the Holly Blues, this year they have appeared in large numbers in other Sussex locations as well. 

This year their caterpillar food plants, Cuckooflower (or Lady's Smock) and Garlic Mustard have flowered early and prolifically, the Cuckooflower many weeks earlier than the Garlick Mustard.  The flowering Garlic Mustard over the past few days is now covering the river banks  (27th) and Orange-tips are still numerous.

Garlic Mustard (Alliaria petiolata (Brassicaceae) has leaves 

rather like nettles but smell of garlic when crushed.

Wild Garlic, which is also prolific along the riverbanks under trees at present, has wide fleshy leaves and white flowers but fills the air with the smell of garlic! This has no attraction for the butterflies:

Flowering Wild Garlic or Ramsoms (Allium ursinum). This dies down once trees are in leaf and the woodland floor is in shade, like Bluebells.

The Easter weekend was very warm and Oaks were rapidly coming into leaf but Ash trees were not as advanced - it's certainly Oak before Ash this spring. The Ash tree branches are full of large dark leaf buds but were not yet coming into leaf.

New Oak leaves (left), late Blackthorn blossom (middle) 

and new green leaves of Rosa canina (Dog Rose) 

Brilliant habitat for wildlife.

The next 'firsts' were the fruit trees all coming into blossom, although all being different some were much more advanced than others. Buzzards continued to appear overhead with the same small birds as previously mentioned still singing although with more evidence that many were collecting food for young in the nest.

April hasn't finished yet - a full survey will appear soon…

April 'Firsts' - the first half of April

April this year started off cool with traditional April showers, remaining mostly overcast with occasional drizzle until around the 10th of the month. It was good to observe the sudden bursts of blossom and trees coming into leaf almost overnight with something new every day.

Birdsong has been remarkable this month, with winter migrants well away and settled in their summer breeding lands and new summer migrants arriving in good numbers on favourable winds. They soon filled their chosen habitat with loud song.  By the 5th April migrant blackcaps and whitethroats were joining the resident song thrushes, blackbirds, great tits, wrens and robins in loud song. 

On 6th April two lively common buzzards were flying in circles together, displaying. A nuthatch was calling from an oak with numerous house sparrows chattering in the hedges below- all together with what was now the daily chorus of those mentioned on 5th.

Hawthorn blossom in bud - unlike Blackthorn, the Hawthorn 

leaves appear first whilst the blossom follows once leaves are fully 

open.

The Hawthorn blossom buds on this plant had already opened

(photos both at same time and date) in a less shady area.

April 8th 2019 was a special day, although damp, windless, misty and overcast. There was still much Blackthorn blossom cascading over the river banks but now with previously bare patches filled by fresh green foliage - mainly Hawthorn leaves without blossom yet, and very young Cow Parsley springing up. Many birds were very active and singing, adjusting the volume to intermittent background noise from the south site.

First there was a fine view of a male bullfinch, perched typically on Blackthorn in blossom. A female bullfinch flew across and into the thicket behind. Whilst looking down onto the river, a kingfisher whizzed along just above the surface, between the steep mud sides of the bank.  Looking up, a kestrel was seen attempting to hover, wings flapping fast as there was no breeze to provide lift. A small group of goldfinches flew across into the tops of the Ash trees, leaving another group singing in a Blackthorn thicket. Common Whitethroats, Blackcaps, Chiffchaffs were singing whilst several blackbirds and two song thrushes foraged on the damp grass. A nuthatch was calling, warning off a carrion crow and two wood pigeons.  Robins were very visible and singing loudly with wrens clearly nest-building under the banks. A pair of coal tits were seen in the same area on 10th.

Friday 12th - the first Swallows were seen here, flying low over the riverside in erratic flight, making sudden turns, hunting insects. In addition, three common buzzards were seen overhead and later a grey heron heading for a pond. The usual inhabitants  - wrens, song thrushes, dunnocks,  robins, blue and great tits were also seen.