Purbeck mason wasp

In the UK the rare Purbeck mason wasp (Pseudepipona herrichii) is found only in the Isle of Purbeck, Dorset.

The female excavates a nest burrow in bare ground on heathland and later seals it with moistened clay.

Wasp with excavated soil

Purbeck mason wasp (Pseudepipona herrichii) excavating nest burrow on heathland. Dorset, UK.

She stocks her burrow with the larvae of a small moth which feeds mainly on bell heather.

Purbeck mason wasp: prey

Purbeck mason wasp (Pseudepipona herrichii) with Acleris hyemana moth larva prey at nest burrow entrance. Dorset, UK.

The adults chew distinctive holes in the heather flowers to obtain nectar which their short tongues could not otherwise reach.

Wasp drinking from heather

Purbeck mason wasp male nectaring on bell heather. Dorset, UK.

The Purbeck mason wasp is thought to rely solely on the larvae of Acleris hyemna, but in 2017 I photographed this female provisioning her nest with what appears to be the moth Acleris notana.

Purbeck mason wasp: prey

Purbeck mason wasp (Pseudepipona herrichii) with moth larva prey (Acleris notana?) at nest burrow entrance. Dorset, UK.

One small victory for citizen science?

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RSPB Panels

Interpretation panels

Interp panels at RSPB Arne

The RSPB’s reserve at Arne in Dorset recently requested the use of my wetland wildlife photos for their new seasonal interpretation panels. They also commissioned a stitched panoramic landscape image to highlight landmarks visible from their stunning observation point overlooking Poole Harbour.

Featured above are the southern hawker dragonfly, osprey, wasp spider, raft spider and marsh harrier, all of which can be found on the Arne reserve at different times of the year. Well worth a visit.

Raft Spider Life Cycle

Raft spider on pond surface

Raft spider on pond surface

You’d think that arachnids and water was an unhappy combination, but one species of European spider has made boggy ponds their home.

The raft spider (Dolomedes fimbriatus) is the UK’s largest native spider – its body growing up to 2cm long.

It uses the water’s surface like other spiders use their webs – feeling for the vibrations of potential prey with front legs extended. Using this technique it hunts tadpoles, insects and occasionally small fish:

Raft spider eating damselfly

Raft spider eating damselfly

When alarmed, the water repellent hairs on the raft spider’s legs enable it to dive beneath the water, trapping a bubble of air to keep it alive until the coast is clear and it cautiously re-emerges:

The wetland pools favoured by raft spiders are increasingly rare in this country. On the RSPB’s Arne reserve in Dorset their habitat is lovingly preserved, and offers wildlife watchers easy access from the nearby heathland trail:

Boggy pond habitat

Boggy pond habitat

On a good day dozens of raft spiders at various stages in their life cycle can be witnessed at the pond’s edge.

1. Sex

The female raft spider is often considerably larger than the male and mating is a dangerous business. He approaches her cautiously, waving his front legs tentatively to judge her receptiveness:

Male raft spider approaches female

Male raft spider approaches female at her den

She may rush out to scare him off on numerous occasions, after which she retreats and the process begins again, the male edging closer all the while. It’s a nerve jangling thing to watch, let alone participate in.

2. Birth

The female spins a silk bag to contain the fertilised eggs, which she carries about beneath her body, keeping it just warm and moist enough to ensure their survival:

Raft spider carrying egg sac

Raft spider carrying egg sac

Then, when the baby spiders are ready to hatch, she lashes the egg sac to vegetation at the edge of the pond and the tiny hatchlings emerge:

Baby raft spiders in nursery web

Baby raft spiders in nursery web

Mum typically lies in wait nearby to ensure that her young ones don’t come to any harm:

Raft spider guards her hatchlings

Raft spider guards her hatchlings

This phenomenon of hundreds of spiderlings crowded together for their own mutual safety is only really appreciated up close:

Raft spider hatchlings

Raft spider hatchlings closeup

But soon the young raft spiders are large enough to fend for themselves and disperse around the pond.

3. Death

Raft spiders are not fussy eaters. When times are tough and food is scarce, or when too many raft spiders compete for the same local resources, they may even turn to cannibalism:

Not such a pretty sight!

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Arne Claypit Reclamation

The Arne peninsula in Dorset juts out into Poole Harbour, separating the Wareham channel from the main body of water. Right out at the tip, concealed by the remains of ancient oak woodland, lies a former ball clay pit.

The extraction company Imerys finished mining the deposit in 2008, and since 2010 have been restoring the area as part of their mitigation agreement, before transfering ownership of the site to the RSPB, who manage the surrounding nature reserve at Arne.

Arne Claypit

Arne Claypit

I was asked to document this reclamation process on behalf of the RSPB, in particular the flooding of the claypit basin with water from the harbour to create a saline lagoon habitat for wading birds and other species.

With mining activities ended the pit was re-profiled with heavy earth-moving equipment, and a layer of topsoil deposited above the expected final water level in the summer of 2011.

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Next a channel was cut through the embankment to join the claypit with the harbour at the south end of the site. On especially high tides the water from the harbour would flood this channel to gradually fill the lagoon.

This process was expected to take many months and it was decided to document the process with a timelapse camera.

We surveyed the best location for the camera – somewhere with a wide view of the pit, a glimpse of the harbour in the background, a small island in the middle ground and some vegetation in the foreground to provide varied visual interest.

Unfortunately this necessitated pointing the camera due south, so we also calculated the position and angle of the sun in future months to try to minimise its dazzling effect on the camera’s lens and sensor.

Arne claypit timelapse project plan

Arne claypit timelapse project plan

The pit itself is off-limits, but there is public access to the surrounding area and it is too remote to monitor. Exposure to the elements over such a long period was also a consideration, so an expensive DSLR setup was not a practical option, and a relatively cheap-and-cheerful alternative was sourced.

The pit filled much more rapidly than the engineers had predicted and in April of the following year, after only 7 months, the rising water had achieved its final level.

The following video sequence shows events over that period, compressed to just 1 minute, using stills taken at 3 hour intervals:

The island habitat is already frequented by shelducks, and sika deer regularly visit its shores. It will take longer for the waters to settle and for other species to establish themselves.

It’s hoped that the regular interchange of water with the harbour will prevent the process of eutrophication, which would otherwise make the lagoon inhospitable. The suspension of clay particles in the water can be a serious problem in this respect.

Arne Claypit Sequence

Arne claypit reclamation stills sequence

Whether this industrially exploited area becomes the wildlife oasis hoped for, only time will tell.

With thanks to Mark, Rob, Damon, James and Em at RSPB Arne.

White Sika Winner

I was exceedingly pleased to learn last week that my image of a white sika deer won the RSPB’s ‘Picture Arne’ photo competition, judged by wildlife broadcasting legend Mr Chris Packham!

White sika deer

Blondie

There are several white sika in the area surrounding Poole Harbour in Dorset. They are a ‘white morph’ since they don’t have the red eyes one would expect in a true albino.

Sika deer (Cervus nippon) are not native to the UK but escaped from captivity on nearby Brownsea Island some decades ago, since when they have made the Isle of Purbeck and surrounding area their home.

The RSPB’s reserve on the Arne peninsula supports a number of scarce species – most notably the dartford warbler (Sylvia undata), but also heath-loving reptiles such as the sand lizard and smooth snake.

I stumbled across this scene late one sultry August evening last year whilst returning home from another photographic project. The young sika stag was browsing in a meadow, accompanied by a small group of other more conventionally coloured deer.

Taken with the Canon EF 100-400mm lens.

BBC Wildlife Magazine: Peregrine

One of my recent peregrine photos appears in this month’s edition of BBC Wildlife Magazine, illustrating an article about the remarkable international success of this species across a range of different environments – both wild and urban:

BBC Wildlife Magazine - Peregrine in Flight

My image of juvenile peregrine in flight top centre. Taken along the Dorset coast last summer.

Available now at all good newsagents! 🙂

A Dorset Christmas

Dorset Wildlife Trust’s new collection of Christmas cards for 2011 includes one of my recent landscape photographs:

This was the wintry view from Swyre Head in the Isle of Purbeck looking west to Kimmeridge Bay, and Lulworth beyond, back in December.

This design and others are available to purchase from the Dorset Wildlife Trust’s online shop in packs of 10, with profits going to the charity.

The snow did not settle for long, and by the following afternoon was in rapid retreat.

Images of Durlston

I was delighted to be voted Winner in the Spring / Summer 2011 ‘Images of Durlston’ photo competition earlier this month, with this image of a juvenile peregrine patrolling the clifftops:

Juvenile peregrine in flight

Juvenile peregrine in flight on clifftops

Durlston Country Park and Nature Reserve is located on the south coast of Dorset just outside Swanage.

I was fortunate enough to be a regular volunteer at Durlston for more than 2 years. This shot was taken on a brief return visit in July of this year, with a Canon EF 100-400mm lens and a bit of luck.

Two peregrines fledged in the area this year and could regularly be seen from the coast path over the summer – alternately terrorising the nesting seabirds on the cliffs below and testing their new wings in mock aerial combat with each other, and with their increasingly unamused parents.

Avocet City

Symbol of the RSPB in the UK, the avocet was extinct as a breeding species by the mid 19th century, only returning to these shores during the second world war after the flooding of East Anglian marshes for coastal defence restored ideal wetland territory for the birds. Since then the reintroduction and careful managment of this scarce habitat elsewhere in the UK has proved to be a major conservation success story.

Hundreds of avocets overwinter on the south coast of England in Poole Harbour – the second-largest natural harbour in the world. In autumn they can often be found huddled together in the lagoon on Brownsea Island close to the busy shipping lanes at the harbour entrance. As winter draws on the birds seem to disperse, favouring the more sheltered harbour channels. The Middlebere channel to the south of the Arne peninsula is a particularly popular location.

Avocets in Poole Harbour

Avocets gather in Poole Harbour

My main goal on this day was to film and photograph some winter finches along the crop trail managed by the RSPB’s wardens on the Arne Reserve. However it quickly became overcast and I wandered off in the direction of Coombe Heath to see what wading birds were on the Middlebere channel instead. By the time I reached the viewing screens the clouds had cleared and a ‘raft’ of several hundred avocets was beautifully lit in the low winter sun:

Avocets

Raft of avocets on the Middlebere channel from Arne

Unfortunately the birds moved off before I could set up my tripod for video but one of the RSPB’s wardens kindly pointed out a sheltered spot near the shore where I could get a closer view of their new location.

As I sat and watched the light on the harbour just got better and better with each passing minute. The calls of the waders could be clearly heard in the still air and, as the tide turned, the raft of birds gradually dispersed in my direction, scouring the mud for tasty morsels:

Hen Harrier Fox Ambush

We’re lucky to have at least two male hen harriers overwintering on the shores of Poole Harbour this year. They’re visually quite distinct from the female hen harrier and other local raptors like the buzzard and marsh harrier. From a distance they might be mistaken for a gull as they patrol above the reed beds.

On this particular afternoon I’d been sat in a freezing hide at Middlebere overlooking a channel off the harbour with several other people. The male hen harrier passed the hide on 2 occasions as it hunted, and we were well pleased.

As the light began to fade and the temperature dropped so my companions began to leave. As dusk approached it was just me and my camera when this fella chose to alight on the neighbouring fenceline:

Hen harrier

I couldn’t quite believe my luck. It was clearly aware of my presence but seemed entirely unbothered. The bird continued to survey the reeds from its vantage point for some minutes. I hurriedly assembled my tripod and mounted the camera to switch to video mode. At which point this happened:

The harrier clearly spotted something edible in the reeds and swooped in to grab it. Either it missed, or the prey got away at the first attempt, but the harrier did not give up and flapped around after it in the reeds.

Seeing this grounded raptor the local fox recognised a golden opportunity and rushed in while its back was turned. Foxy must have come within a couple of feet of success. In the slow motion sequence you can see the harrier attempt to lift off, with the prey in its grasp, but gets snagged on the reeds with almost fatal delay. What appears to be a small mammal, probably a vole, then falls from its clutches as it finally gets airborne.

The slightly dejected, but still rather smug looking fox, then sauntered off right past the hide:

Fox

Wily fox walks away