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 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
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
On a good day dozens of raft spiders at various stages in their life cycle can be witnessed at the pond’s edge.
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 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.
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
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
Mum typically lies in wait nearby to ensure that her young ones don’t come to any harm:
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 closeup
But soon the young raft spiders are large enough to fend for themselves and disperse around the pond.
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!
Post-industrial landscape reclaimed for wetland wildlife at RSPB Arne
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. Since 2010 they have been restoring the area as part of their mitigation agreement, before transferring ownership of the site to the RSPB, who manage the surrounding nature reserve at Arne.
See immersive 360 degree view.
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.
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.
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.
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.
My image of an osprey with freshly caught bass was Highly Commended in the RSPB’s Picture Arne photo competition judged by BBC TV presenter and naturalist Chris Packham:
Osprey with fish. Arne, Dorset.
The RSPB’s reserve at Arne lies on the shores of Poole Harbour in Dorset. The ospreys are regular visitors on their migration south to Africa for the winter.
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 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:
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:
Ospreys are regular visitors to Poole Harbour in the autumn, on route to Africa where they flee for the winter. These birds are especially well adapted for catching fish and extraordinary to watch.
We’re very lucky to have such magnificent neighbours but I’m not sure that many inhabitants of nearby Poole and Bournemouth realise they exist, let alone where to find them.
The National Trust have a wildlife hide at Middlebere on the edge of a channel running into the harbour. It’s tucked away in the woods opposite the RSPB’s reserve at Arne. In season the ospreys can regularly be seen commuting up and down the channel on fishing expeditions. Great to watch through binoculars and scopes, but for photographic purposes they remain a long way off.
Having watched them from the hide on a few occasions I became familiar with a regular perch nearby. It looked accessible and there was decent cover nearby, so I determined to get closer.
On more than one occasion I observed ospreys perched in the branches of a dead tree after arriving on site. However ospreys are quite happy to spend hours sat in the same location and are difficult to approach. This was the closest I managed to get with a long lens without spooking the bird:
Perched osprey (Pandion haliaetus)
To get any closer I was going to have to get into position early one morning, before the birds became active, and wait for them to come to me. Several times I hid my gear nearby, tripod-mounted camera at the ready, and waited fruitlessly for a bird to appear.
On this particular occasion I was late to arrive and could see an osprey already in position.
Osprey (Pandion haliaetus) in dead tree
Having snapped a few long distance shots I might have turned back at this point but they’re beautiful birds to watch, even at a distance.
By the time I’d crept to the next viewing position the osprey had flown, but I seized the chance to scurry into position deep in the reeds, close to the dead tree perch, and hurriedly assembled tripod, camera and improvised camouflage. Pulling the reeds back over my head I settled in for what I thought might be another long, uneventful afternoon.
But within 20 minutes I saw a large bird flying in low over the reedbed. Through the binoculars I could make out a large wriggling shape in its grasp. It could only be a returning osprey!
I ducked down out of sight and watched the perch on the camera’s LCD monitor. Nothing. Wrong branch! Swivelling the lens to the left brought this majestic osprey into focus, a freshly caught bass pinioned in its enormous talons:
Osprey (Pandion haliaetus) with freshly caught bass
Over the next hour I was privileged to watch this mighty bird devouring its meal at close quarters, and captured some memorable stills and video footage in the process:
Canon 550D | Canon EF 100-400mm f4.5-5.6 L | Adobe Premiere Pro
The reedbed was enveloped in low cloud or mist and – together with the hissing sound of the reeds in the gathering wind – the conditions heightened an already surreal, unearthly atmosphere. Something I will never forget.
Dom Greves Digital / Blog 