The problem with a lot of invertebrate life at the Weymouth Wetlands is that it doesn’t have common names. Misumena vatia is a superb looking spider and belongs to the crab spider family. It’s often found on either white or yellow flowers where it sits and waits for hungry insect to stop for a feed. They then pounce on their victim sinking their fangs into it. Their venom quickly paralyzes their prey which allows them to catch quite large insects such as hoverflies.
As you can see from this image taken earlier today at Radipole, it doesn’t exactly blend in with its chosen flower though regardless of that, it’s still caught a rather juicy hoverfly. Had it been on a white flower it probably would have been overlooked but thankfully we didn’t!
For one week now we have had a very large, (10 lbs+/- in the old scale) sea trout marauding the Wey just to the north of the concrete bridge. Usually a mere five minutes investing gazing into the murky shallows will result in at least a couple of slow, regal glide-bys or the occasional burst of power chasing prey or seeing off anything elbowing in on 'his' patch. Mullet are chased away and diving tufties given short shrift. Luke and I (while spectacularly failing to film said fish) were treated to a full breach, presumably after nailing some item of prey on the surface or perhaps to dislodge parasitic sea lice.
The fellow in question patrolling his patch. Photo Allan Neilson.
Interestingly migratory sea trout and the purely freshwater brown trout - such a familiar sight in our Dorset chalk streams - are in a sense one and the same sharing the Latin name 'Salmo Trutta'. The sea trout develops salt secreting glands to enable its eventual passage into sea water. A sea trout in salt water is faced with the problem of osmosis causing dehydration and salt loading. In fresh water, the problem is effectively reversed as the water is nearly devoid of salt and therefore the fish has to tackle the problems of salt loss and water loading. These problems (very basically) are tackled by the trout drinking copiously when in saltwater and not at all in fresh water, while peeing virtually continually to prevent it from effectively blowing up.
Added to this an alteration in kidney function and various other physiological quirks enable sea trout to live in both fresh and sea water. Whether the brown to sea trout trigger is environmental or hereditary, (or something entirely different) I haven't a clue but I know a man who will so watch this space. Anyway it is an impressive fish and strangely sedentary, showy and worthy of a five minute gaze beneath the watery sheen.
Sorry for the recent dearth of blogtivity, we have been experiencing some technical difficulties since the alterations were made to the community pages.
There is a good deal to report however, not least on and around the sand martin wall. Last Wednesday Luke and I watched a single sand martin reccy-ing the joint. For the 20 or so minutes it wove patterns in front of the wall, swooping in close then banking away or hovering close - seemingly peering into the carefully contrived burrows.
By the weekend birds were going into the wall and chattering excitedly - much as we were watching them. It may have taken them a wee while but it seems that finally the Sand Martin Wall is deserved of its title!
Wall + sand martins = Sand Martin Wall. Picture Allan Neilson.
This morning although I couldn't say for sure it appeared that the kingfisher brood had fledged as I twice saw an adult bird fly with fish behind, rather than into, their nest burrow. Sure enough some visitors to the hide were later able to confirm that juveniles have been on the wing later on in the morning, so dual celebrations are due!
Interestingly Allan Neilson, who spent a long time watching for wall developments over the weekend, witnessed one of the adult kingfishers seemingly eyeing-up one of the sand martin burrows as presumably the existing burrow must by now be fairly rank. So who knows what next?
Just a quick post to alert readers to the presence of a little brown bird at Lodmoor. It's a rather special brown bird though as it’s pretty rare in the UK and makes a really (or should that be reely?) weird sound. It was singing and showing occasionally early this morning which is typical as they tend to sing and are most active at dawn and dusk. It has been occasionally singing throughout the day but for a chance to see the elusive blighter, head towards beachdown way this evening.
Here's a link with a short recording on it, though I must admit it’s not the best recording I’ve heard of this species. The first bit isn't the song, the buzzing sound towards the end is what you would be listening out for. http://www.rspb.org.uk/wildlife/birdguide/name/s/saviswarbler/index.aspx
Here's a picture of one taken in Spain. photo courtesy of RSPB Images.
This species used to be a breeding species at the Weymouth Wetlands. It was first recorded in Dorset in 1973 and was seen at Radipole Lake. It was then suspected breeding at both reserves in several years during the late 70's and 80's though has been quite scarce since then.
This sensational picture of a peregrine carrying a common tern was captured by our regular visitor Dan Dench on Lodmoor last week. It is a perfect illustration of the peregrines’ sleek, powerful aerial prowess honed over thousands of years of evolution.
Peregrine with tern and crow in pursuit.
In certain quarters raptors get a bad press (at best) for doing what nature intends them to do. It is easy to get drawn into the emotion of predation but it is an essential part of every food chain throughout the world. There is seldom a case of there being too many predators as, if there were very soon there would be too few prey and they would starve - natures balance… sadly it seems that we are the only obvious exception to this rule!
Fur and feathers can further cloud our judgement. The sandeels preyed upon by the tern and the zooplankton consumed by the sandeel are predators and prey alike but their place in the food chain excites less passion than a sparrowhawk taking a robin or, say, a peregrine taking a tern.
This is the first time I’ve known of a peregrine taking one of our common terns and as the colony reaches its peak towards the end of this month the chances of a repeat are lessened considerably. With well over 100 birds on the islands that will defend their air space mob handed and will harry, hassle and drive off all potential threats to them and their progeny.