Jono Forgham spots a ruddy darter dragonfly on nature walk along the River Stort and Navigation in Bishop's Stortford

Nature Notes columnist Jono Forgham covers your fortnightly look at nature around Bishop's Stortford in the Indie...

A glance at the weather forecast for my latest Nature Notes wander meant it looked like I had little option but to set out for a walk along the River Stort and Navigation on the Monday, as Tuesday and Wednesday looked to be very wet indeed. As it transpired, very little rain on the Tuesday. This would have been a preferable day as the Monday was hot and very muggy. I certainly knew I had covered more than seven miles by the time I returned to the car at Bat Willow Hurst Country Park.

The car park for this habitat is just before the A120 bridge on the road to Manuden. Once parked, I set off to check the two balancing pools here, usually a great spot for a good selection of dragonflies and damselflies. The grass here was burnt brown, apart from the waterside vegetation that was benefiting from its proximity to the water. The purple loosestrife was in full flower and attracting bee species. A plant I was to encounter all the way to nearly Twyford Locks, south of the town centre.

Common blue damselflies quartered the water surface, many in tandem whilst others were ovipositing (egg laying). This is achieved by the male holding the thorax of the female with claspers that are at the end of his abdomen. He lowers her to the surface whereupon she deposits several eggs before moving to another site. This habit has two benefits. Firstly, if the eggs are found by a predator then not all are eaten and, secondly, she is only at one point for a few seconds and so is unlikely to attract the attention of an underwater predator such as fish or dragonfly nymphs.

Also present were migrant hawker, common darter and an emperor dragonfly, none of which landed for a photo, so I crossed Michael's Road and entered the Red, White and Blue Meadow, with its splendid longhorn cattle grazing.

A common darter roosted on the barbed wire fence just before I reached Cannons Mill Lane and moved on to Grange Paddocks. Very little present here. Four carrion crows lined up as a back four across the football pitch, so I continued towards the weir. This is to be removed sometime before the spring so I thought it would be good to document the state of the river here and then revisit next August to see what changes have taken place.

Between Grange Paddocks and the weir the river is full of heavy vegetation, so much so the water is barely visible. Reeds, sedges, willowherbs and the aforementioned loosestrife predominate. This must have an adverse impact upon the flow of the river, causing it to slow down and consequently drop the silt it carries from further upstream. This silt covers the gravel bed, the natural base for a chalk stream, which means that fish eggs as well as invertebrates cannot survive in the mud. With the removal of the weir, the flow should speed up and maybe wash away some of the heavy vegetation whilst also scouring the bed to reveal the gravel. Be good to see if this is the case. I appreciate this site has been a favoured paddling area for generations, but a quick look at the plans for the river show there are new access points to be put in to compensate for this removal.

The temperature was increasing as I wandered through Castle Gardens, too hot now for many birds to come out from the shade of hedgerows and the canopy. Wood pigeons and magpies were present along with numerous moorhens on the water, especially on the Navigation between the Registry Office road bridge and the offices of Tees.

Several juvenile black-headed gulls and recently-hatched moorhen chicks were noted as well as a flotilla of mallards. Just before the Millennium Bridge, a party of house sparrows were enjoying the dried grasses on the towpath, the seeds all ready for consuming, and consequently the birds were relatively approachable. A goldfinch ripped hairy seeds from a plant on the far bank whilst a blackbird looked forlornly at the baked lawn outside a flat, unable to probe for worms.

Here, also, a good stand of purple loosestrife had attracted five bee species, so I changed camera lenses and tried for a few macro shots. All nectaring here were the red-tailed bumblebee, white-tailed bumblebee, buff-tailed bumblebee, common carder bee and the western honeybee. The flowers were literally buzzing.

Nearby, a constant flurry of Vespula vulgaris, the common wasp, entering their nest hole under a lump of concrete. I crossed the road and picked up the path heading towards South Mill Locks and Rushy Mead Nature Reserve. Some good clearance of the banks here where plants can push through now the willows have been coppiced. A small white butterfly alighted to nectar and a little further on, the similar large white.

By the boardwalk bridge, over the overflow weir, shoals of roach were enjoying the temperature of the surface water and, a little further out, a large carp cruised along, identifiable by its long dorsal fin.

By now I was a sticky mess and took time to sit in the shade of a well-placed bench under a spreading willow. Mallards dabbled, coots argued and several brown hawker dragonflies zipped by, males most probably, patrolling their territory. Three appeared at once and an aerial dogfight ensued to sort out air supremacy. The two interlopers were chased off and the successful male returned to patrolling.

I had a quick check for butterflies in Rushy Mead before hitting on a new plan. Instead of continuing to Twyford Locks at Pig Lane I would retrace my steps for refreshment at 'Spoons as I had now run out of water. Seemed a sensible idea, so off I went. A wonderful stand of teasels broke the skyline and I noticed several blue-tailed damselflies resting on the leaves of comfrey, which appeared to be flowering for the second time this year.

A moorhen was feeding a day-old chick by the Millennium Bridge, but much else was the same as I had recorded previously. I arrived at Station Road and left the towpath. The pint of cool beer outside the pub was most welcome, as were sandwiches from Dorringtons which I enjoyed in Castle Gardens. Here, a nuthatch called and a green woodpecker yaffled.

I headed back along the towpath, noting a pollarded willow near the weir. A professional job and one that will permit more sunlight into the river and also encourage bankside vegetation to flourish whilst it regrows its boughs.

I arrived back at Bat Willow Hurst Country Park and rechecked the balancing pools. A ruddy darter dragonfly was new for the walk as it rested on, yet again, purple loosestrife. Very similar to the common darter, the ruddy species shows all black legs (the common darter has yellow stripes on black legs) and is usually a more scarlet colour. I checked the larger of the two pools here, but just a pair of mallards. Earlier in the year a pair of little grebes had successfully raised two chicks, but they have now fledged and left. Linnets fluttered over, already in their winter parties. Groups numbered up to 12. Plenty of seeds and teasels here to keep them fed throughout the forthcoming autumn and winter.

I checked the field on the other side of the A120 bridge, but only managed to successfully set off a camera alarm placed to protect some builders' equipment as there seemed to be an inspection of the concrete. A computerised voice informed me my image had been forwarded to a third party. The camera was set pointing on to a public footpath, so the third party must enjoy seeing photos of walkers and dog owners!

Home for a drink, note making, photo processing and a cold shower. It had been a good walk although the stuffiness of the air meant not too much was to be seen, particularly on the ornithological front.