Tuesday, 16 August 2011

RSPB ARNE 14TH & 15TH AUG 2011

Carol and I have wanted to visit the RSPB reserve at Arne in Dorset for a long time. With reasonable weather being forecast we decided to go early on sunday morning. The plan was to stay overnight at Wareham and do a coastal walk in the area on monday. It was a good plan and these are some of the creatures we saw.
I have to say that I was a bit disappointed by the lack of birds at this stunning reserve, but i'm not really too surprised because that seems to be the case all around at the moment. Green Woodpecker, Willow Warbler, Common Tern and of course Buzzard were soon seen but the first half of our walk around the reserve was dominated by a visit to a small pond where something very different was found to be lurking.

The lovely creature above and below is a Raft Spider, Dolomedes fimbriatus, or Swamp Spider
as it's sometimes called. They are impressive beasts who sit on the water or partly on a piece of vegetation, often with their front legs resting on the surface in a hunting position. Their prey will be detected through their legs by the detection of small vibrations made on the water.

I really like the dimples on the water in the picture below where the surface tension is bent but not broken by the weight of the spider's legs. I believe these spiders are fairly common in the south in heathland ponds and streams but very isolated elsewhere in the country.

This great little pond was also home to a few Small Red damselflies, two of which are pictured below. Common Darter and Emperor dragonfly were also present.

While watching the Raft spiders I also found my first ever Wasp spider, above, so two firsts in half an hour. This is another stunning species that is again found mainly in the south of the country but I think is gradually spreading northwards.

The picture above shows the underside of the female and also I think probably the male of the species who is much smaller than the female. He's understandably careful when mating as the females often eat their suitors during the act. These spiders shed their skin before maturity and the males usually make their advances to the female after this process when her jaws are still soft. Smart move. Also in the picture you can see the characteristic zigzag web or stabilimentum on the main orb web which this species is known for.

Very close by I found this cluster of what appear to be a nursery web of baby Raft spiders, left click for a closer look. Directly beneath the nursery web was the spider below, who I think is probably their Mum.

We eventually tore ourselves away from the pond and continued our walk round the reserve. From the hide overlooking the tidal stretch of water we watched Curlews, Little Egrets, Oystercatchers and some distant Godwits. Unfortunately the Osprey that habitually stops here on it's journey south hadn't turned up yet, a bit early really.

Another first for me were the Grayling butterflies, above, who were in good numbers across the site. As you can see they are fantastically camouflaged. Maybe that's why they never open their wings at rest.

I noticed a very large insect fly by us and as I looked I thought I saw a piece of blue string or paper hanging from it. Luckily it came down not too far away and I was amazed to see that the blue thing was in fact a damselfly that the creature had just caught, how gruesome is that. The creature is in fact a Robber fly, probably Asilus crabroniformis, one of the largest flies we have. It's large proboscis is used to pierce their prey as in the picture and it's said that they can suck their meal dry in ten to thirty minutes, nice.

Arne is home to a large population of Sika Deer, pictured above and below. They're an introduced species which at first sight look not unlike Fallow Deer at this time of the year. The last birds to make the list included a nice female Redstart, a pair of Ravens who were being harassed in the distance by a bird of prey, possibly a Hobby, a flock of Siskins and surprisingly a good sized flock of up to fifteen Mistle Thrushes who were feeding on the berries of Mountain Ash trees.

On monday we did our coastal walk starting and finishing at Worth Matravers a beautiful village in the fantastic Dorset countryside.

As we walked along the high cliffs a Raven, above, suddenly appeared and cruised alongside us for a few brief moments. I raised my camera and fired off a couple of quick shots and while I did so a Peregrine, below, suddenly appeared not far behind it. Both birds were calling loudly but I don't know the reason why. I just wish i'd had time to try and sort the camera settings out beforehand. Never mind, what I got was better than nothing.

It's good being a bit of a novice with all this wildlife because it means I still manage to find quite a few 'firsts' quite easily. And this weekend proves the point as yet another one turned up in the shape of the Wall butterfly pictured below. In fact it wasn't just one Wall butterfly but probably a dozen or more during our walk.

This is a great walk, one of the best Carol and I have done in a long time. But it had it's strenuous moments as you can see from the picture below.

We had just walked down all these steps, and with trembling legs we had to climb up an identical staircase on the other side of the valley. A stone bench was welcome relief at the top where we sat and watched Cormorants, Great Black-backed Gulls, distant Buzzards, a pair of Stonechats and a Wheatear as we sat and recovered before returning to the car.

We still had n hour or so to spare before we needed to leave Dorset, so we decided to have a last quick look at the pond at Arne. All was pretty much the same as we'd left it the day before except for one damselfly, below, who posed nicely on a twig over the water. A male Emerald I think, one of my favourites.


Marianne said...

Great report and pics, Phil. It's a gorgeous part of the world, and you didn't do too badly for birds given the time of year. The Peregrine and Raven were probably shouting at each other - these two species tend to have quite an antagonistic relationship. Lovely butterfly shots, and that Raft Spider - WOW!

Greenie said...

Phil ,
Enjoyed that post very much , and obviously Carol and yourself did too .
Some great first sighting species , which is always a treat , and great pictures too .
Really like the tiptoeing Raft Spider on the surface tension .
The coastal walk , up and down narrow paths , reminded me very much of the north coast of Jersey .
Sounds like Arne will have to be visited , soon .

Anonymous said...

Smart pics of some smart species there. Phil.

Alan Pavey said...

Great post Phil, the Spiders are great, I agree it's nice finding firsts and sorting out the ID's. Sounds like a reallygood weekend all round :-)

Rob said...

Cracking photos of fascinating species Phil. I particularly like the Raft Spider and the Robber-fly with its prey.