And now, to coin a phrase from Monty Python's Flying Circus, it's time for something completely different. Over the past 18 months, my species of the week blogs have looked at a variety of Minsmere's characteristic species, from birds to butterflies, mammals to trees, even fungi to digger wasps. Most have been relatively easy to spot, at least in season, although for some of the trickier species you may need to ask our lovely volunteer guides for a bit of help.

This week, in a slight departure from the norm, I have chosen a species that few visitors will be lucky enough to see. One that until the weekend I hadn't even heard of, but that having done a bit of research about looks and sounds amazing.

The species I'm talking about goes by the amazing name of sea mouse, but it's not a mouse. In fact, it couldn't be more different. The name probably derives from the appearance of this creatures when they are found washed up on our beaches - usually dead. Yet this fascinating sea creature is actually a worm!

 I know, I find that hard to believe too, but a quick on-line search confirmed that this is indeed the case. Despite their appearance, they are a type of polychete worm, closely related to the lugworms that are so popular with sea fishermen. There are several different species of sea mouse, which are also known by their Scientific name: Aphrodite.

Sea mice (I believe that's the correct plural) are widespread in the Mediterranean and Atlantic coasts, where they burrow into the sandy or muddy seabeds. They are most likely to be found washed up dead on our beaches, but the one pictured, left, was lucky. Our warden, Paul Green, found this one yesterday, and it wriggled in his hand as he picked it up, so after taking a quick photo he released it back into the surf.

They are usually about 10-15 cm long, though can grow bigger, and are covered in long hair-like bristles that appear to change colour form iridescent green to purple. Sea mice are predators and scavengers, so form a vital part of the marine food chain. 

Now I know what these creatures are, I may look a bit more carefully next time I'm searching the tide line, or searching in large rockpools with my son. I'd be interested to know if anyone else has found one of these, or any other interesting marine life washed up on our shores.

While most visitors probably won't see a sea mouse, there are plenty more species to spot this week. The bitterns are still in the reedbed, but they have become a bit more elusive in recent days. Perhaps they've eaten most of the big roach from the ditch in front of Island Mere Hide. Alternatively, the fish could simply have moved to deeper water with the drop in temperature. Otters are also still being seen most days at Island Mere.

Elsewhere in the reedbed, you might here a squealing water rail, and should spot a marsh harrier or two quartering the reeds. Check the harriers carefully, though, as a ringtail hen harrier was seen again this morning. At least one great white egret remains, too, being seen most frequently in North Marsh.

The drake scaup remains, but has moved to the Scrape, where it is often seen in close company with a female pochard. The scaup was also seen this afternoon on the infamous Pool of Despair - the pool behind South Hide that has attracted a number of rare visitors in recent years. Here, it was seen alongside the seven remaining whooper swans. The two Bewick's swans were on the South Levels on Friday but have not been reported since.

 Other birds on the Scrape include four avocets, about 15 black-tailed godwits, up to a dozen snipe, 20 dunlins, one or two pintails and large flocks of wigeons, gadwalls, teals, mallards, shovelers and shelducks. An impressive flock of 350 barnacle geese came in to roost this evening (photo by Jon Evans), while eagle-eyed gull watchers continue to pick out the odd yellow-legged or Caspian gull among the roosting herring and great black-backed gulls on South Scrape.

The snow bunting hasn't been spotted in the dunes for a couple of days, but at least one Dartford warbler remains in the gorse near the sluice. Likewise, the yellow-browed warbler has moved on from the Sluice Bushes, but small flocks of goldcrests, redwings and fieldfares can be seen both there and in the North Bushes. Bullfinches are often spotted in the latter location too.

Finally, winter is a good time to look for some of our commoner, but often overlooked species, such as marsh and coal tits on the feeders, green woodpeckers and jays around Whin Hill or treecreepers near South Belt Crossroads.