Through my garden runs a stream called Hol Brook, one of the headwaters of the River Box.

It starts its life as a few farm ditches which join together added to by a couple of springs out of the clay hillsides above the village. Its course is interrupted by an earth dam causing it to swell into a lake, once used to breed trout for fishing, now shallow and silted up at one end and used by kingfishers for their own fishing.

Holbrook Lake overflows through a large drain, under two neighbours’ gardens and reappears at one edge of my own. From here it trickles through a series of ponds and, leaving the downhill side of our land wanders through many other gardens until it meets another local stream, The Spong, and shortly after joins the Box.Part

Much of the reason I have constructed a series of shallow pools along the stream bed is to slow up the flow and provide some water which does not vary in depth much all year, except in the tumultuous flows of winter flood. This naturally provides a habitat for a variety of creatures which I can observe through the seasons. 

Sometimes I sit on the bank side in the day, and using close focussing binoculars watch the never ending movements of the innumerable Water Shrimp (Gammarus pulex) but often I go down after dark and observe by torchlight. It is amazing how much you can see after dark. There are no reflections and your shadow does not even disturb the fish fry of Rudd (Scardinius erythrophthalmus) or Roach (Rutilus rutilus) that come down from the lake or even the breeding antics of 3 spined Stickleback (Gasterosteus aculeatus) amongst the flints on the stream bed. 

Of course most streams have what you might call their 'signature species' and Holbrook is no exception. So last night observing by torchlight I was not surprised to see the usual creatures.

The first thing you notice is that the surface of the water seems to be moving, not with the current but with a never ending dance of Water Crickets (Velia caprai). At the moment they are present in great numbers after a very successful first brood of young. Hundreds and hundreds were swirling round and round either running across the surface film or skating as if jet propelled, searching for small, drowning prey. But last night there were also a couple of Whirligig Beetles (probably Gyrinus substriatus although some Hairy Whirligigs, Orectochilus villosus, have been seen in the village streams this week) and this caused a strange behaviour I have never seen before from the water crickets. 

Every few seconds a water cricket would go up to one of the whirligigs and touch it, causing the beetle to swim away only to be met by another cricket. It seemed that the water crickets were 'mobbing' or intimidating the whirligig beetles. By next morning the whirligigs had gone, outnumbered a few hundred to one and fed up with the situation no doubt.

Down at the bottom of the stream I watched a very large Horse Leech (Haemopis sanguisuga) snaking it's way along the mud until it bumped into one of the many Water Scorpion (Nepa cinerea) patrolling the bottom. Both backed away and moved to one side, bumped heads again and this time managed to go in opposite directions. Neither predates the other so I suppose this was the equivalent of many a pedestrian encounter in Ipswich.

Both leech and scorpion have had a constant presence in my stream since we moved in, in 1984, as has the water cricket. It's rather nice to have a breeding population of animals on your land and in your care. Certainly these three 'signature' species have increased in numbers over the years and seem to have responded well to the changes I have made to the stream. 

From time to time I will be noting any further interesting observations I make on my section of the stream, here on the Blog. I hope it may encourage others with ponds or streams to note what they see.