Goldeneye, in lichen form

Running backwards into the Devils Dyke Pub to get out of the fierce hail certainly wasn’t the intended end to today’s outing. We had been caught out on a grand scale; a band of completely unforecast precipitation left our clothes so sodden that not even a hot chocolate and four-cheese pizza could warm me up. But was it worth it?

Birders may be used to the sight of a goldeneye floating out on a windswept gravel pit or reservoir at this time of year. Although the diving duck breed in trees, the nesting sites are solely in cavities in larger trunks and at latitudes further north than the UK. So, how many British birders can say that they’ve seen a goldeneye in a tree? I doubt many of them – yet as of this morning I can, but not sensu stricto.

The goldeneye lichen, Teloschistes chrysophthalmus, is named after the bright orange apothecia borne on blue-tinged stalks. The apothecia are disks containing the asci, which in turn contain the spores which will be carried on the wind to colonise new sites. Indeed, this is likely to be how the goldeneye lichen arrived in the UK. In the 19th century there were several sporadic records along the South Coast, and this decreased to only two in the 20th century. Yet, since 2007, recolonisation has been in full swing and there have been records from most South Coast counties along with an outlier in Herefordshire. It is still a fairly rare species, but definitely on the increase. It is not completely known what might be driving the recolonisation. Increasing temperatures could be a factor, yet in the early 19th century when well-established populations could be found in the south, it was relatively much colder than modern times.

RSCN3560

The bright orange apothecia really stood out on this drab, dull day

For this sighting I am indebted to @apeasbrain who first found the lichen last weekend and who provided brilliant directions (only the one individual plant has been found so far, like a needle in a haystack). However, it turned out that despite the lichen being the main instigator for my visit to Devils Dyke, it was not the only highlight. Just past the Hawthorn on which the lichen is growing, the path descends into a copse of Ash trees. On one of these trees I managed to spot some movement, out of the corner of my eye. At first glance I took it to be a ladybird larva, but I knew something wasn’t quite right. On arrival home, I realised it was in fact a pre-adult Endomychus coccineus, known vernacularly as the False Ladybird. This was a species I’d been wanting to see for months, so it’s a bit embarrassing that I didn’t recognise it immediately – but coupled with the Teloschistes, the incredibly painful scramble back to the pub once the hail set in was absolutely worth it.

RSCN3619

Teloschistes chrysophthalmus becomes my 100th lichen and Endomychus coccineus my 250th beetle. Together they put me on 69 new species for the year so far, a good pace I think!

Advertisements

Skulker

As many of you will know, I am a trainee bird ringer and have been since 2014. Involved in the complicated process is putting a small, lightweight ring on the leg of a bird, on which is inscribed a unique number. This enables individual birds to be recognised if they are later recaught or found dead, allowing ornithologists to learn more about their migration and biology.

In my four years of being a ringer, I’ve had the chance to ring a wide variety of bird species, ranging from over 100 Blue Tits to some scarcities including Yellow Wagtail, Redstart, Wheatear and Wood Warbler and larger birds such as Stock Dove and Woodpigeon. However, last Sunday’s ringing experience will probably go down as one of my favourites so far.

Fellow Sussex young birder Mya Bambrick and I arrived at Knepp Estate, south-west of Horsham, at 6am. There we met my trainer Tony Davis who had already set up four mist-nets around a field consisting of mainly bramble and willow scrub. This is a fantastic habitat for migrating birds as well as several scarce breeders due to the amount of cover the scrub produces and the blackberries which ripen at exactly the right time to fuel many migratory passerines on their southward journeys. The mist-nests are ideal for catching birds as they are fine enough to be invisible to birds flying between bushes, which fly into the net and fall into a pocket from which they are extracted by licensed ringers.

It was on the first net-round when I noticed that there was something slightly different in the bottom pocket of one of the mist-nets. It didn’t take long for me to realise that it was a Grasshopper Warbler. Grasshopper Warblers, so-called due to their bizarre song which resembles that of a stridulating grasshopper, is a localised breeding species found mainly in fens and coarse grassland and is not often found in high density. However, while researching for this blog post, it was good to learn that they are showing a positive population trend with the UK population experiencing a 23% increase in numbers in the 14 years between 1995 and 2009. This is thought to be as a result of improved survival rates in the wintering grounds of west Africa. Particular preference is shown by British Grasshopper Warblers towards Senegal and The Gambia, which we have learnt from recoveries of ringed birds in those countries. However despite this recent increase, this is in comparison to a proportionally larger decrease which took place in the years prior to that period. Only a few decades ago, this species used to be found in a greater range of habitats than to which it is currently restricted.

DSCN0113.JPG

The Grasshopper Warbler

Grasshopper Warblers (often shortened to just Gropper) are renowned for the difficulty involved to see them. They have skulking habits, only really coming out into the open when the males sing their distinctive song. Most of the time they remain hidden in thick vegetation. In fact I’ve only seen this species twice before, and both times the birds were located by the loud song. The first time was a bird claiming its territory in May 2014 in a sand dune in Budle Bay, Northumberland and the second had probably only just arrived in the UK in April last year, when I found one singing in a garden at Selsey Bill in West Sussex from a small clump of ornamental pampas grass. In fact in the past 20 years Tony had only caught two or three, highlighting how lucky we were to catch this reclusive skulker.

DSCN6897

This was my only photo of a Grasshopper Warbler before Sunday, from Northumberland. This photo illustrates how hard-to-see Grasshopper Warblers are usually. And this one was, in relation to most other sightings, ‘showing well’!

Sussex Rarities – Hairstreaks & Clubtails

This morning, having heard some exciting news on the website of the Sussex branch of Butterfly Conservation, I found myself in Ditchling Common Country Park, scanning bracken after bracken with my binoculars. I was looking for a Black Hairstreak or two. The windy and overcast conditions were not conducive to my hopes of sightings along the lines of the day-count of 98 that was made earlier in the month!

These numbers are quite extraordinary considering the fact that this species was only confirmed to be found in Sussex just over a week ago. Following a few battered individuals found at the same site last year, a survey has been undertaken to determine the presence of this colony. Its appearance here is particularly notable as this site is far from the existing distribution of this species in the UK. It is thought to be confined to a band of clay soil in the Midlands, mainly Cambs, Northants and Oxon.

The closest Black Hairstreaks have previously come to Sussex is Surrey, where they were introduced in the middle of the 20th century. However, the habitat at the introduction site was destroyed and the species disappeared there. The species is not known for their long distance movements or dispersal at all, in fact patches of identical habitat to where they are found elsewhere on the same site often go uninhabited due to the reluctance of the butterfly to travel long distances. Therefore it is thought that this colony is also an introduction similar to the Surrey one, although despite it only being discovered very recently it is likely that the species first appeared in the 1990s – this is because the expanse of the population at Ditchling Common suggests that it has been expanding for quite a while. It’s so slow that the rate of expansion, even of a healthy population, is estimated to be only about a kilometre per decade!

Now, back to this morning. The foodplant of the Black Hairstreak is Blackthorn, and it was in abundance at the country park. This was especially true at a corridor that extends from the fish pond south-west to the Folders Lane East. This was where we focused our searching, which turned out eventually to be the right idea. At 10.30 the sunshine finally made a prolonged appearance and the wind died down slightly. This appeared to trigger the daily emergence of the hairstreaks to warm up on the bracken. The first one we found was perched at quite a gradient on one of the fronds, perfectly angled towards the sun. After a few minutes of sitting very still, it switched sides rather in the fashion of a sunbather aiming for an even tan. As it had not yet gained enough thermal energy it was being quite ‘co-operative’, allowing for great views. This sighting was repeated with up to three other Black Hairstreaks, a very satisfying way to see a new butterfly species for me: not a common occurrence!

DSCN6290 (2)DSCN6279 (2)DSCN6282 (2)DSCN6286 (2)

Although the sexes are hard to differentiate on physical appearance, it is likely that those we found were females. The males will emerge earlier, in order to have established a territory prior to the emergence of the females. They will fiercely defend their territory, which is usually centred around an oak known as the ‘master oak’, and approaching the end of the flight period this activity will render them quite battered and damaged. It is likely that this species is past its peak already this year. The species’ very short flight period is one reason why this colony may have remained undiscovered for such a long period of time. Years where the population is dramatically increased compared to previous and following years are also characteristic of this species. It is likely that this year is one of these ‘boom years’ which is what may have lead to this year being the one in which this colony was finally discovered. So if you haven’t yet had a chance to visit this true Sussex rarity, I would recommend that you do so sooner rather than later. Their short adult stage will be over before the end of June, and in future years there probably won’t be as many as there have been this year.

Black Hairstreaks are not the only entomological rarity I’ve had the good luck to see in Sussex this month. At the beginning of the month I took a walk along a small stretch of the River Rother, near Fittleworth in West Sussex. Having been advised about their presence there by Amy Robjohns and Olly Frampton, I was on the lookout for Common Clubtails, a species that isn’t actually as common in the UK as its name suggests. On the British Dragonfly Society website it is described as “extremely local”, only being found on a few rivers in Wales and southern and central England.

DSCN5863

However, its scarcity on a national basis was certainly not evident along this tranquil, luscious river in the mid-morning sun. Along only a few hundred metres of the river we managed to find at least 10 either hunting along the river or perched on bankside vegetation and overhanging willows. The vast majority were males which were patrolling their recently acquired territories while many females would be seeking protection in the nearby woodlands away from the water. They will soon return to mate and lay a new batch of eggs, which will complete their immature stages in the silty riverbed within 3-5 years.

DSCN5904DSCN5877

The invasion continues

This winter Europe has been host to an avian phenomenon I wasn’t even aware was possible. Hawfinches in the UK are very rare and elusive birds, mainly confined to large areas of forest such as the Forest of Dean and the New Forest. Indeed, in February 2017 I hitched a lift with Josie Hewitt for a two hour journey to the New Forest especially to see these birds, and it’s funny to think how oblivious I was to the fact that it would become clear by the end of the year that it was an unnecessary trip.

I don’t think anyone is quite sure why, but this winter Hawfinches have truly irrupted from their core European breeding grounds. The areas where these usually strictly forest-dwelling birds have been recorded over the past few months is incredible, including the Moroccan Sahara, Kuwait and Alaska! In Sussex, where hardly any are seen outside of West Dean Woods, flocks have surpassed 100 individuals at locations scattered across the county. I am not aware of any previous such invasions of this species, so it definitely feels like a once-in-a-lifetime experience.

Last weekend, I was ringing at fellow trainees Dave and Penny Green’s garden near Wisborough Green. I had heard that there were one or two Hawfinches visiting their large Yew tree, so I was fairly hopeful that some brief sightings would enliven our ringing session a little more. However, it soon became clear that my expectations were far too low! We were treated to an almost constant presence of Hawfinches throughout the day, at least 6 I think and possibly up to 10 were visiting the Yew at one point. This allowed for some absolutely brilliant views of this normally tricky-to-see species.

RSCN2236

Beautiful male Hawfinch

As you can see from the photo, Hawfinches have a massive bill. These have evolved to crack really hard nuts and seeds, such as cherry stones which they can easily crack. They certainly are attractive, chunky finches and I do hope that the invasion continues, and perhaps there’ll be a bumper breeding season for them here in the UK!

Pectoral Sandpiper

Last Sunday afternoon I sat in the West Mead hide at Pulborough Brooks, with my binoculars focused on the far right corner of the pool directly in front of me. Among the Lapwings and the Teal was the silhouette of a Pectoral Sandpiper in terrible back-lighting.

There was no mistaking that this was a bird I was very pleased to see. One challenge of mine for this year is to get to 200 bird species for BBC Wildlife Magazine’s #my200birdyear, and this was my 193rd. Furthermore, Pulborough Brooks is exactly where I saw my first and only previous Pectoral Sandpiper, over 3 years ago. On that day in 2014 the Pectoral Sandpiper was so distant I didn’t even attempt a photograph, however this time this one was unusually close.

RSCN0891

The lighting was really poor, but at least I attempted a photo unlike my previous sighting three years ago!

Pectoral Sandpipers breed in North America and Eastern Siberia, yet despite the great distance from their breeding grounds they are still the most common Nearctic wader to reach our shores each year, mainly during autumn. Sussex definitely seems to attract its fair share, and in my experience Pulborough Brooks seems to be the best site in Sussex for them at the moment. There may have been at least three at this wetland site this autumn, which is an amazing total for a bird that would have had to cross the Atlantic or the whole of Siberia and Europe to reach here.

I have about a month and a half to find seven more species to make 200 for the year. It is possible, although it will be difficult. There are quite a number of species I’m yet to see, but it will all rely on how lucky I am!

Slime Moulds: Fascinating and Complicated

It is without a doubt that the vernacular name ‘slime mould’ is not the most appealing, although the slime moulds themselves are often not the most appealing organisms to look at either. However, what they may lack in aesthetics they do make up for in pure ‘bizarreness’.

Taxonomy is the science of classifying living things into groups such as phyla, families and genera. And slime moulds, scientifically known as Myxomycetes (or ‘myxos’ for short), are a taxonomist’s worst nightmare. Their taxonomy is so poorly understood that even which kingdom they should be classified under is unclear. Some still class them as fungi, however others think they’re protists.

The reason why I find them so interesting is their behaviour when food is not plentiful. When there is a decent availability of nutrients, they will live single-celled lives; yet whenever food becomes hard to come by they will congregate together. Once they are in this state they will become able to detect food sources. When they congregate, they become noticeable, as they produce fruit bodies which release spores much like fungi. This helps these fascinating moulds to colonise new areas.

Yesterday, the last day of September, I was at a Sussex Fungus Group foray at Tilgate Park in Crawley. The diversity of fungi found was incredible, and we also came across this slime mould. It was identified as Stemonitopsis typhina, and what you can see in the photo are the immature fruit bodies. Given a short while, these fruit bodies will mature and release spores.

DSCN9729DSCN9728

However, not all slime moulds produce fruit bodies like this. Slime moulds can reproduce using gametes, asexually or a mixture of both. Far too complicated for me to understand at the moment! Perhaps as complicated as the fern reproduction I explained in a previous blog post. I think that there’s a lot still to learn about slime moulds.

 

Flower of the Illyrians

Yesterday, 2nd September, was the final field meeting of the year for the Sussex Botanical Recording Society at Chailey Common. Chailey Common is a good example of where conservation grazing has been put into place, in order to keep dominant vegetation to a level that won’t swamp more precious flora. Sheep, ponies and cattle are rotated around the commons in order to control plants such as birch, gorse and bramble that will degrade the quality of the heathland habitat if they get out of control.

It was great to see how this conservation grazing was working. It allows smaller and more fragile wildflowers to grow as well as others that may have been at risk from habitat loss. We recorded a good number of scarce and interesting plants, including Heath Milkwort, Scented Agrimony and Lesser Skullcap.

RSCN8909

Scented Agrimony, with subtly notched petals distinctive of this species.

RSCN8833

A flower of Heath Milkwort, so-called as farmers thought that allowing their cattle to feed on this plant would increase milk yields.

DSCN8794

The minuscule flower of Lesser Skullcap.

However there was one stand-out highlight, and that was a small patch of Marsh Gentians. Gentians are often a favourite of photographers as they have a photogenic beauty. I am not a photographer, but I did try my best with the following shots.

DSCN8739DSCN8762DSCN8759

The Marsh Gentian is quite a locally distributed plant, growing on wet heathlands rather than marshes. It does benefit from grazing, which is perhaps why some of its main strongholds are places like the New Forest and Ashdown Forest.

It is one of a number of Gentian species in the UK, in the genus Gentiana, including Autumn Gentian and Field Gentian. On a global scale it is cosmopolitan, with around 400 species; and some species are known to have been used in herbal medicines for quite a variety of ailments. These range from cancer to malaria to parasitic worms, however studies have been conducted that don’t prove that it has any benefits beyond a placebo effect! Despite this, the genus name Gentiana is in honour of the Illyrian king Gentius, who supposedly discovered the plant’s tonic qualities. What it is definitely known to be good for however, is as a dye, especially the Marsh Gentian.

 

Marsh Gentian is my 500th British plant and although summer is now over and most flowering plants are past their peak, there are still late summer and autumn species in bloom. Some of these I hope to see over the next few weeks!